Latest / Daniel and Kelly’s Extraordinary Universe / Space Debris (featuring Dr. Jonathan McDowell)

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Space Debris (featuring Dr. Jonathan McDowell) · Daniel and Kelly’s Extraordinary Universe

• 0:05
  Speaker 1: In nineteen sixty two, the United States detonated a one
• 0:09
  Speaker 1: point four megaton hydrogen bomb four hundred kilometers above the
• 0:13
  Speaker 1: surface of the Earth. This was part of a project
• 0:15
  Speaker 1: called Operation fish Bowl. Not Surprisingly, it created a huge
• 0:20
  Speaker 1: explosion which lit up the sky and disrupted radio transmissions.
• 0:24
  Speaker 1: It also knocked out street lights in Hawaii, which may
• 0:27
  Speaker 1: have worried partygoers who, according to Smithsonian magazine, were gathering
• 0:32
  Speaker 1: on hotel rooftops for h bomb explosion viewing parties. It
• 0:36
  Speaker 1: also messed up six different satellites, whour belonged to Americans,
• 0:40
  Speaker 1: one was Russian, and it also messed up the very
• 0:43
  Speaker 1: first British satellite. The Soviet Union was conducting similar tests
• 0:47
  Speaker 1: of nuclear weapons in space at the same time. This
• 0:50
  Speaker 1: didn't bode well for the future of satellites in space.
• 0:54
  Speaker 1: This amazing new technology of satellites held a lot of promise,
• 0:58
  Speaker 1: but who would want to invest in it? If the
• 1:00
  Speaker 1: United States and the Soviet Union kept making satellites inoperable
• 1:03
  Speaker 1: with nuclear weapons tests in space, well lucky for all
• 1:07
  Speaker 1: of us. In nineteen sixty three, both nations agreed to
• 1:10
  Speaker 1: stop screwing up space for the rest of us and
• 1:13
  Speaker 1: signed the Partial Nuclear Test Ban Treaty, which banned the
• 1:16
  Speaker 1: test of nuclear weapons in some places, including space. In
• 1:20
  Speaker 1: this year, you also get a UN resolution saying weapons
• 1:23
  Speaker 1: of mass destruction can't be orbited in space. And you
• 1:26
  Speaker 1: get a United Nations Outer Space Treaty which comes into
• 1:29
  Speaker 1: force in nineteen sixty seven, which reiterated all of these
• 1:32
  Speaker 1: points for other nations as well.
• 1:34
  Speaker 2: New Now satellites are safe, right, well, probably well, space
• 1:41
  Speaker 2: is really vast. We've put a lot of stuff in
• 1:44
  Speaker 2: orbit around Earth, and the pace at which we're sending
• 1:47
  Speaker 2: stuff up is ever increasing as the cost of sending
• 1:50
  Speaker 2: that stuff up drops.
• 1:51
  Speaker 1: Could it get too crowded up there? Could some of
• 1:54
  Speaker 1: the space litter we've left behind smash into the stuff
• 1:56
  Speaker 1: we're still trying to use. I'd be really bummed out
• 1:59
  Speaker 1: if I couldn't watch cat videos using my Starlink satellite
• 2:02
  Speaker 1: provided internet. To answer some of these questions about the
• 2:06
  Speaker 1: risks of stuff bumping into each other in space, we're
• 2:09
  Speaker 1: interviewing doctor Jonathan McDowell, who has been tracking objects sent
• 2:13
  Speaker 1: to space since nineteen sixty one, when the Soviet Union
• 2:16
  Speaker 1: sent up Sputnick, the first ever satellite in space. Welcome
• 2:21
  Speaker 1: to Daniel and Kelly's Extraordinary Universe.
• 2:37
  Speaker 3: Hi, I'm Daniel. I'm a particle physicist, and I feel
• 2:40
  Speaker 3: like my house is constantly filling up with junk.
• 2:43
  Speaker 1: I'm Kelly Winer Smith. I'm a parasitologist and I have
• 2:47
  Speaker 1: felt that way since I married Zach. And the rate
• 2:51
  Speaker 1: at which the junk has been increasing has exponentiated since
• 2:54
  Speaker 1: we had children. So we might have a Kessler syndrome
• 2:57
  Speaker 1: situation happening in our house in the near future.
• 3:00
  Speaker 3: That's only if your children collide with each other and
• 3:02
  Speaker 3: make more children or something.
• 3:05
  Speaker 1: The biologist in me is not okay with that metaphor.
• 3:09
  Speaker 3: No, that was bad. So which of you is the
• 3:11
  Speaker 3: cleaner upper or are you both contributing to the junk?
• 3:14
  Speaker 1: I am the cleaner upper. I am also the less
• 3:17
  Speaker 1: bringer stuffer into the houser. I don't like to buy
• 3:21
  Speaker 1: a lot of new stuff, but that's not my husband's
• 3:23
  Speaker 1: attitude about stuff. What about in your family.
• 3:27
  Speaker 3: I'm the thrower away. I'm the person constantly carding out
• 3:31
  Speaker 3: bags of junk in the house, whereas my wife and
• 3:35
  Speaker 3: daughter like going thrift store shopping and so they're bringing
• 3:38
  Speaker 3: stuff in, and then I'm like taking trips to the
• 3:40
  Speaker 3: thrift store. When I take a trip to the thrift store,
• 3:42
  Speaker 3: for example, it's a negative impact on our house, and
• 3:47
  Speaker 3: they have the opposite effects. So we have like a
• 3:49
  Speaker 3: thrift circuit going.
• 3:50
  Speaker 4: Man.
• 3:51
  Speaker 1: So I've gotten myself in trouble for being the person
• 3:53
  Speaker 1: who throws stuff out in the house because my daughter
• 3:55
  Speaker 1: will not let go of things, and Zach doesn't want
• 3:57
  Speaker 1: to let go of things either, and I got in
• 3:59
  Speaker 1: trouble once. I was like, well, if I just throw
• 4:01
  Speaker 1: it out, they won't notice. But then they notice, And
• 4:03
  Speaker 1: so for a while I moved everything to a storage unit.
• 4:07
  Speaker 1: You might be noticing it's a whole thing, Yes, the
• 4:10
  Speaker 1: whole thing.
• 4:10
  Speaker 3: I see. See, you've moved to the multi stage throwout techniques.
• 4:13
  Speaker 3: I'm gonna put it over here, and then when nobody notices,
• 4:15
  Speaker 3: I'll move it over there, and then eventually I get
• 4:17
  Speaker 3: to throw it away.
• 4:18
  Speaker 1: And that's why I have a whole farm. I've got
• 4:21
  Speaker 1: lots of spots to squirrel their junk away. Oh and
• 4:24
  Speaker 1: I just remembered that Zach has been listening to the podcast,
• 4:27
  Speaker 1: which is so nice of him. Don't check the tenant house.
• 4:33
  Speaker 3: Well. The danger of moving on to a farm in
• 4:35
  Speaker 3: a big house is the more space you have, the
• 4:37
  Speaker 3: more junk you get. I feel like we have a
• 4:39
  Speaker 3: constant density of junk, and if we lived in a
• 4:41
  Speaker 3: smaller space, we would have less stuff.
• 4:44
  Speaker 1: The belief has been that because we have all of
• 4:46
  Speaker 1: this space, we can get more stuff. But I don't
• 4:49
  Speaker 1: want the junk outside. I don't want more stuff. I
• 4:51
  Speaker 1: don't want more stuff.
• 4:53
  Speaker 3: Yeah. Space is more valuable than almost any stuff. Whenever
• 4:56
  Speaker 3: we throw something away, I'm like, Ah, look at all
• 4:58
  Speaker 3: that empty space. It's wonderful.
• 5:00
  Speaker 2: Yes, right, isn't it nice?
• 5:01
  Speaker 1: So when when you come home with like a bag
• 5:03
  Speaker 1: in your hand and to just be able to like
• 5:05
  Speaker 1: put it on the counter because there's clear space on
• 5:07
  Speaker 1: the counter and not like have to elbow cups out
• 5:09
  Speaker 1: of the way.
• 5:10
  Speaker 3: Ah, agree with you? All right?
• 5:15
  Speaker 1: All right, team clean over here.
• 5:17
  Speaker 3: And if we were in charge of the atmosphere around Earth,
• 5:19
  Speaker 3: maybe you and I we keep it pretty clean.
• 5:21
  Speaker 1: Yeah, But the people that we keep interacting with would
• 5:23
  Speaker 1: be like, well, there's a lot of space, so we're
• 5:25
  Speaker 1: just gonna move it somewhere else, you know, And then
• 5:27
  Speaker 1: the graveyard orbit would get all crowded. And I don't know,
• 5:30
  Speaker 1: I'm a pessimist, Daniel.
• 5:32
  Speaker 3: Yeah, Zach and Katrina would fill the universe with junk.
• 5:38
  Speaker 1: There's there's room. Don't worry. Buy more books, buy more books. Well,
• 5:42
  Speaker 1: we don't have to keep them. We're not going to
• 5:43
  Speaker 1: read them again. No, I can't let go of a book.
• 5:45
  Speaker 1: Books gotta stay forever.
• 5:47
  Speaker 3: Zach, you can keep all your books in orbit near Pluto.
• 5:50
  Speaker 3: M I love you, And today on the podcast, we're
• 5:55
  Speaker 3: going to be talking about junk and space junk with
• 5:57
  Speaker 3: somebody who has spent their whole career thinking and tracking
• 6:00
  Speaker 3: bits of garbage in space.
• 6:02
  Speaker 1: I have loved interacting with Jonathan McDowell on Twitter. When
• 6:06
  Speaker 1: we were writing A City on Mars. He was my
• 6:07
  Speaker 1: go to person where I was like the needles from
• 6:10
  Speaker 1: Project west Ford, are they still in space? Jonathan, the
• 6:13
  Speaker 1: glove that got lost during the EVA number five hundred
• 6:15
  Speaker 1: and forty three, is that still in space? He knows
• 6:18
  Speaker 1: the answer to all of these questions. He is the guy.
• 6:21
  Speaker 1: We're excited to have him on the show today, So
• 6:23
  Speaker 1: let's jump right in. On today's show, we have doctor
• 6:31
  Speaker 1: Jonathan McDowell. He's an astrophysicist at the Harvard Smithsonian Center
• 6:36
  Speaker 1: for Astrophysics in Cambridge, Massachusetts. He's also the editor of
• 6:39
  Speaker 1: Jonathan's Space Report, a free internet newsletter founded in nineteen
• 6:44
  Speaker 1: eighty nine which provides technical details of satellite launches. His
• 6:48
  Speaker 1: website provides the most comprehensive historical list of satellite launch information,
• 6:52
  Speaker 1: starting with Sputnik. And he's a fellow of the Royal
• 6:55
  Speaker 1: Astronomical Society, an American Astronomical Society fellow, and he has
• 6:59
  Speaker 1: an astro named after him forty five eighty nine McDowell.
• 7:02
  Speaker 1: So he's now officially the second person on the show
• 7:05
  Speaker 1: who has an asteroid named after him. Martin Elvis beat
• 7:08
  Speaker 1: you by a few months there.
• 7:09
  Speaker 4: My old boss. Yes, he was your old boss. He's
• 7:13
  Speaker 4: the one who conned me into crossing the pond and
• 7:16
  Speaker 4: coming to work at Harvard instead of staying in England,
• 7:20
  Speaker 4: which I'm now sort of regretting. Yes, no, Martin, I
• 7:24
  Speaker 4: go back away.
• 7:25
  Speaker 1: Ah, wonderful. Well, he's absolutely lovely. And he talked to
• 7:27
  Speaker 1: us about asteroids. We're talking to you about stuff that's
• 7:31
  Speaker 1: floating around in space. So we had a listener who
• 7:33
  Speaker 1: asked a question, and we're going to play the question
• 7:35
  Speaker 1: a little bit later. But that got us interested in
• 7:37
  Speaker 1: space debris. So I think for starters let's just talk
• 7:40
  Speaker 1: about what kind of stuff we have up there, debris
• 7:43
  Speaker 1: or otherwise that's orbiting the Earth right now.
• 7:45
  Speaker 4: So there are about twenty five thousand objects that the
• 7:50
  Speaker 4: Space Force radars are tracking every day.
• 7:52
  Speaker 1: It's a lot.
• 7:53
  Speaker 3: Twenty five thousand. Wow, that's an incredible number.
• 7:57
  Speaker 4: That's just the ones big enough to see. Right. They
• 7:59
  Speaker 4: go from the four hundred and fifty ton International Space
• 8:02
  Speaker 4: Station down to little shards of debris that are only
• 8:07
  Speaker 4: about five or ten centimeters across to aally bit about
• 8:10
  Speaker 4: where they come from. But below that, between like say
• 8:15
  Speaker 4: one centimeter and ten centimeters, we think there might be
• 8:18
  Speaker 4: as many as a million pieces of debris that we
• 8:20
  Speaker 4: don't even know about because they're too small for the
• 8:22
  Speaker 4: radars to see. So now space is big, but everything
• 8:27
  Speaker 4: in space, because of Kepler's laws, is traveling like seventeen
• 8:30
  Speaker 4: thousand miles an hour. And so you know, it's pretty
• 8:34
  Speaker 4: crazy up there. And we have now ten thousand working satellites.
• 8:40
  Speaker 4: Just five years ago it was only one thousand. Now
• 8:42
  Speaker 4: it's gone up to ten thousand. Is that all starlink,
• 8:46
  Speaker 4: well about half of them a starlin Ghia. And so
• 8:48
  Speaker 4: there's Internet relay, there's Internet of things relay, there's ship
• 8:53
  Speaker 4: and the airplane tracking. There's weather satellites, there's SPIC satellites,
• 8:57
  Speaker 4: resource monitoring satellites, those intelligence which is like intercepting communications
• 9:03
  Speaker 4: and radio signals for the military, and of course a
• 9:06
  Speaker 4: few science satellites. People often think that space is like, oh,
• 9:09
  Speaker 4: that's science, but science is a pretty small fraction of
• 9:13
  Speaker 4: what's going on and what can happen is every time
• 9:16
  Speaker 4: you launch a satellite, you use a rocket to do it,
• 9:20
  Speaker 4: and to put it in orbit. The upper rocket stage
• 9:22
  Speaker 4: has to get into orbit along with the satellite. So
• 9:25
  Speaker 4: now you've launched your satellite, but you've also made a
• 9:28
  Speaker 4: piece of space junk the rocket stage. And nowadays, if
• 9:31
  Speaker 4: you're like prudent, you have a restartable engine. You can
• 9:34
  Speaker 4: bring the rocket stage down in the ocean afterwards. But
• 9:36
  Speaker 4: we didn't used to even bother to do that. So
• 9:38
  Speaker 4: if you look in the catalog of there's now over
• 9:42
  Speaker 4: sixty thousand objects in the Space Object catalog, including all
• 9:46
  Speaker 4: the re entered ones. The second entry in the catalog
• 9:49
  Speaker 4: is Sputnik, Russia's first satellite, but the first entry satellite
• 9:54
  Speaker 4: number one is actually the rocket stage that puts Putnik
• 9:58
  Speaker 4: in orbit and so the very first entry in the
• 10:02
  Speaker 4: catalog is a piece of space jump.
• 10:04
  Speaker 1: Oh that's interesting and depressing.
• 10:07
  Speaker 4: Yeah, what's worse if you leave a little extra fuel
• 10:10
  Speaker 4: in the tank of your rocket stage, which you can
• 10:13
  Speaker 4: tend to do because you don't want to arrive at
• 10:15
  Speaker 4: your destination running on empty rocket stages? Have you know
• 10:18
  Speaker 4: fuel and oxidizer that combine to burn to make the flame,
• 10:23
  Speaker 4: but they're in separate tanks, separated by often like a
• 10:26
  Speaker 4: rubber gasket or something like that, which over years can erode.
• 10:30
  Speaker 4: The two can get together and depending on your mix
• 10:32
  Speaker 4: of propellant, ten years after you abandon your rocket stage
• 10:36
  Speaker 4: in Earth orbit, the fuel and oxidizer can have a
• 10:39
  Speaker 4: party and suddenly you don't have a rocket stage. You
• 10:41
  Speaker 4: have three hundred pieces of space to breathe.
• 10:43
  Speaker 1: Oh my god. So you're saying they explode?
• 10:45
  Speaker 4: That will be the technical term, yes, whereas the space
• 10:49
  Speaker 4: guys like to say an RUD a rapid unplanned disassembly.
• 10:56
  Speaker 4: We have all kinds of euphemisms right for the bad
• 10:58
  Speaker 4: things that can go wrong in sp It's another one
• 11:00
  Speaker 4: of my favorites. Say is you know ICIBM into continent
• 11:03
  Speaker 4: balistic missile, But do you know IOBM, which is in
• 11:07
  Speaker 4: ocean by mistake.
• 11:08
  Speaker 3: Oh no, So what's the sort of natural context, Like
• 11:15
  Speaker 3: we are creating these little bits of space junk, But
• 11:17
  Speaker 3: was the near Earth atmosphere sort of empty before that?
• 11:21
  Speaker 3: Or are there are like a lot of natural things
• 11:22
  Speaker 3: floating out there.
• 11:23
  Speaker 4: So within the orbit of the Moon, we do have
• 11:26
  Speaker 4: like meteors coming in on escape trajectories. Right, they're not
• 11:30
  Speaker 4: orbiting the Earth. They have escape colostoy respect to the Earth.
• 11:33
  Speaker 4: They're going much much faster than satellites, and so they
• 11:36
  Speaker 4: come in, they burn up, they're gone. They don't hang
• 11:39
  Speaker 4: out in Earth orbit. The only piece of natural space
• 11:43
  Speaker 4: junk we have orbiting the Earth is the Moon.
• 11:47
  Speaker 3: You can't call the moon junk.
• 11:49
  Speaker 4: Come on, you know, it's a big love huston. You know.
• 11:55
  Speaker 4: We added to that with Spootnak and we've added ever since.
• 11:58
  Speaker 4: Again not just rocket stages blowing up, but also satellite's
• 12:02
  Speaker 4: hitting each other. So in two thousand and nine and
• 12:06
  Speaker 4: an Iridium communication satellite hit an old Soviet dead communication
• 12:10
  Speaker 4: satellite at about twenty thousand miles an hour in orbit.
• 12:14
  Speaker 4: And to give you an idea of the kinetic energy
• 12:16
  Speaker 4: involved in that, right, I mean it's like some number
• 12:19
  Speaker 4: of gigajuls. And now you don't have a feel for that.
• 12:22
  Speaker 4: So I calculated in terms of my unit of how
• 12:26
  Speaker 4: hard something hurts is. Imagine being hit by a one
• 12:30
  Speaker 4: ton truck. You can kind of sense how much that
• 12:33
  Speaker 4: would hurt. The energy involved in one of these orbital
• 12:37
  Speaker 4: collisions is about fifty thousand times that.
• 12:41
  Speaker 1: Wow, wow, oh my gosh.
• 12:43
  Speaker 4: And so what happens is a hypersonic shockwave goes through
• 12:46
  Speaker 4: both spacecraft, reducing them to shrapnel. The clouds of shrapnel
• 12:51
  Speaker 4: passed through each other largely unchanged, and you end up
• 12:53
  Speaker 4: with them in the original orbit, but many many little
• 12:57
  Speaker 4: pieces instead of one big one. So we don't like that.
• 13:00
  Speaker 4: That's bad. It can cause it. Ultimately, if you have
• 13:02
  Speaker 4: enough of those, you can get a chain reaction called
• 13:04
  Speaker 4: the Kestler syndrome that could make space unusable. And then,
• 13:08
  Speaker 4: you know, some people think it's fun to fire a
• 13:11
  Speaker 4: missile at one of their own satellites and blow it
• 13:14
  Speaker 4: up just to show how powerful they are anti satellite weapons,
• 13:18
  Speaker 4: and that causes yet there's more debris due to that.
• 13:21
  Speaker 4: There's been a move in recent years to go, you know, guys,
• 13:25
  Speaker 4: that's probably not a good idea.
• 13:27
  Speaker 1: Yeah, let's stick into that a little bit more so.
• 13:29
  Speaker 1: I know that the Soviet Union, the United States, India, China, right,
• 13:33
  Speaker 1: they've all blown their own satellites up in space, is
• 13:36
  Speaker 1: that right?
• 13:37
  Speaker 4: That is correct? Fortunately, so far they've only been tests
• 13:40
  Speaker 4: on their own satellites and not attacking somebody else's.
• 13:43
  Speaker 1: So for our audience who's maybe not familiar with this,
• 13:46
  Speaker 1: why are countries blowing up their own satellites.
• 13:48
  Speaker 4: Right, it's to prove that they could blow up your
• 13:50
  Speaker 4: satellites if they want it. And so the idea, you know,
• 13:53
  Speaker 4: what people may not appreciate is so much of our
• 13:56
  Speaker 4: lives today actually invisibly depends in space technology. I mean
• 14:01
  Speaker 4: the most obvious case, of course is GPS. I actually
• 14:05
  Speaker 4: know how to read a map, but the younger generation
• 14:07
  Speaker 4: are going to be really hosed if GPS ever goes down.
• 14:10
  Speaker 4: They're not going to be able to get home. And
• 14:11
  Speaker 4: that was originally a military system to target CRUISMUSS and
• 14:15
  Speaker 4: so that's in a war, taking out the GPS satellites
• 14:19
  Speaker 4: would be something that an attacker might want to do. Similarly,
• 14:23
  Speaker 4: military allund space communications. There are missile warning satellites that
• 14:28
  Speaker 4: spot when a missile is launched, and that's you know,
• 14:31
  Speaker 4: how you get that warning. And there are these sort
• 14:34
  Speaker 4: of very spic satellites, right, and so the military, even
• 14:37
  Speaker 4: more than normal people, are so very invested in space.
• 14:41
  Speaker 4: Their systems are integrated with space systems, and so in
• 14:45
  Speaker 4: a war, those space systems are obvious targets. And so
• 14:50
  Speaker 4: the idea of anti satellite weapons has been around for
• 14:52
  Speaker 4: a long time. The first attempt that I'm aware of
• 14:55
  Speaker 4: was in nineteen fifty nine when they fired a test
• 14:58
  Speaker 4: missile against the Explorer six satellite and missed it. But
• 15:03
  Speaker 4: it's not a new idea, that's what I'm saying. So
• 15:06
  Speaker 4: all of these things, you know, very early. The fifties
• 15:08
  Speaker 4: were a crazy time, man, They tried all kinds of
• 15:11
  Speaker 4: stuff very early.
• 15:12
  Speaker 3: And so every time we blow up a satellite, you
• 15:15
  Speaker 3: go from one object in space to like a million
• 15:18
  Speaker 3: objects in space. Do we then track all of those
• 15:20
  Speaker 3: individual components?
• 15:22
  Speaker 4: Yeah, well, the ones above ten centimeters we track. And
• 15:24
  Speaker 4: so sometimes people talk about shooting down a satellite, but
• 15:27
  Speaker 4: I hate that phrase because you don't actually shoot it down.
• 15:30
  Speaker 4: You add energy, you especially in the pieces, but those
• 15:33
  Speaker 4: pieces still have orbital velocity and they stay in limit.
• 15:36
  Speaker 4: And so if you have a satellite that's say in
• 15:38
  Speaker 4: a five hundred kilometer circular orbit. The pieces are in
• 15:42
  Speaker 4: elliptical orbits that are one end is five hundred and
• 15:45
  Speaker 4: then the other end might be lower, or it might
• 15:47
  Speaker 4: be higher, as much as one thousand kilometers or two
• 15:49
  Speaker 4: thousand kilometers coming down to the ones that go down
• 15:53
  Speaker 4: where you know we'll re enter quickly. The ones that
• 15:55
  Speaker 4: go up will stay up for a long time. And
• 15:57
  Speaker 4: so the worst one was a China Ease anti satellite
• 16:01
  Speaker 4: test in two thousand and seven, and that created three
• 16:04
  Speaker 4: thousand pieces of tracked debris. And so in my catalog
• 16:07
  Speaker 4: that I have on my website is each one of
• 16:09
  Speaker 4: those three thousand pieces has a catalog number from the
• 16:13
  Speaker 4: Space Force, It has orbital parameters that are updated every day.
• 16:17
  Speaker 4: It's quite a tusk keeping track of these things.
• 16:20
  Speaker 3: So there's some random chunk of a satellite that has
• 16:22
  Speaker 3: like a name and a place in your database, and
• 16:24
  Speaker 3: you're tracking and it's just like a hunk of metal
• 16:27
  Speaker 3: floating through.
• 16:27
  Speaker 4: Space that's exactly right. And you know, every now and again,
• 16:31
  Speaker 4: for example, the International Space Station has to dodge one
• 16:35
  Speaker 4: of these things. So the Space Force tressing goes, oh hey, guys,
• 16:39
  Speaker 4: about twenty four hours from now, this chunk of metal
• 16:42
  Speaker 4: is going to go within a few hundred meters of
• 16:44
  Speaker 4: the space station.
• 16:45
  Speaker 3: Wait before we get to the ISS, how do we
• 16:47
  Speaker 3: track all these things? Like who is tracking this random
• 16:49
  Speaker 3: chunk of Chinese satellite? How do we monitor these things?
• 16:52
  Speaker 4: So mostly it's the US Space Force route. For low
• 16:55
  Speaker 4: orbit satellites, they use radars, so you bounce radar radio
• 17:01
  Speaker 4: energy off the satellite and the echo gives you its
• 17:04
  Speaker 4: position and velocity. But it's a problem because if you
• 17:07
  Speaker 4: have like say one hundred new pieces that you're tracking,
• 17:10
  Speaker 4: so you see them come over, Okay, you get measurements
• 17:12
  Speaker 4: of one hundred pieces. An hour and a half later,
• 17:15
  Speaker 4: they've orbited the Earth. You look again, you've got another
• 17:18
  Speaker 4: one hundred pieces. But matching up which one goes with
• 17:21
  Speaker 4: which one is very non trivial. Yeah, and so it
• 17:24
  Speaker 4: takes a long time to catalog the debris, and that's
• 17:28
  Speaker 4: a period you're not getting warnings from those new objects.
• 17:31
  Speaker 4: So that's why new debris is very bad. Radars are
• 17:35
  Speaker 4: great up to about one thousand kilometers. A few thousand kilometers,
• 17:38
  Speaker 4: they're a one over art of the fourth law. If
• 17:41
  Speaker 4: the thing is ten times further away, it's ten thousand
• 17:44
  Speaker 4: times weaker reflected single. So for high orbit satellites, radars
• 17:49
  Speaker 4: really aren't the way to go, and we've been using
• 17:51
  Speaker 4: regular optical telescopes to observe the objects. And now we're
• 17:55
  Speaker 4: actually starting to deploy satellites in high orbit whose job
• 17:59
  Speaker 4: is to catalog all the other satellites and keep track
• 18:02
  Speaker 4: of them.
• 18:03
  Speaker 3: Why is it one over out of the fourth? Is
• 18:04
  Speaker 3: it because you get one of our r squared from
• 18:06
  Speaker 3: your signal and then one of o are squared from
• 18:08
  Speaker 3: the bounce.
• 18:09
  Speaker 4: Exactly right, it's one of our squared each way.
• 18:12
  Speaker 3: Wow, I see. So that's difficult. It seems to be
• 18:14
  Speaker 3: like a really hard problem, even if you know where
• 18:17
  Speaker 3: everything is, even if there's nothing new, because radar is
• 18:19
  Speaker 3: just giving you locations, right, it doesn't measure velocities.
• 18:22
  Speaker 4: Yes, there's a dopplers, but it's only one component. Oh right, okay, right,
• 18:26
  Speaker 4: you have arrange an arrange rate, and then you only
• 18:30
  Speaker 4: have a very approximate angular position on the sky because
• 18:34
  Speaker 4: the radar is very sharp, and so you need multiple
• 18:37
  Speaker 4: observations to kind of resolve that and do it. So again,
• 18:40
  Speaker 4: this is something they've been doing since the nineteen fifties,
• 18:42
  Speaker 4: and it was kind of manageable back then, and there
• 18:45
  Speaker 4: weren't that many satellites, and now it's getting a really
• 18:48
  Speaker 4: tough problem and you can see them struggling. There was
• 18:52
  Speaker 4: a recent Chinese satellite launch. Eighteen satellites went up about
• 18:56
  Speaker 4: a month ago, and it was only yesterday that Space
• 18:58
  Speaker 4: Farce started issuing orbital for them because it took them
• 19:01
  Speaker 4: that long to sort it out. It's a fascinating problem
• 19:04
  Speaker 4: and really technically challenging, and in the circumstances they do
• 19:07
  Speaker 4: a pretty good job, but it's not really good enough
• 19:11
  Speaker 4: for what we need today.
• 19:12
  Speaker 3: Yeah, it seems like a lot of compute is required.
• 19:14
  Speaker 3: You have to know all these trajectories, predict where they are,
• 19:17
  Speaker 3: get the new data, update the trajectories if they are
• 19:19
  Speaker 3: dev from your prediction. I'm wondering about the security here,
• 19:23
  Speaker 3: Like there must be things in space that are like
• 19:25
  Speaker 3: secret spy satellites. Are those parts of your database? Is
• 19:28
  Speaker 3: the NSA watching you to see if you're tracking that stuff.
• 19:31
  Speaker 4: If they're not, they're not doing their job.
• 19:35
  Speaker 1: You've really acclimated to life in the United States Johnson, Yeah.
• 19:39
  Speaker 4: Right, exactly. The secret satellites are tracked by the Space Force.
• 19:43
  Speaker 4: The US secret satellites, they don't release the orbital data
• 19:47
  Speaker 4: for that publicly. The Russian and Chinese secret satellites they do.
• 19:52
  Speaker 4: The Israeli and French ones they sometimes do sometimes that
• 19:55
  Speaker 4: so our friends they keep the cle one secret. But
• 19:57
  Speaker 4: for people we don't like, we just publish them. Very recently,
• 20:01
  Speaker 4: there was maybe one hundred or so secret US and
• 20:04
  Speaker 4: Allied satellites, and most of them were pretty big. Some
• 20:08
  Speaker 4: of the old big Bird Spy satellites are like ten
• 20:11
  Speaker 4: tons right in low orbit, and so they're as bright
• 20:14
  Speaker 4: as the brightest stars in the sky. And so in
• 20:17
  Speaker 4: order to get their orbits, all you really need are
• 20:20
  Speaker 4: binoculars in the Stopwatch, sometimes not even binoculars.
• 20:24
  Speaker 3: So it's in this category of like officially secret but
• 20:27
  Speaker 3: totally obvious exactly.
• 20:29
  Speaker 4: So, you know, we figure that a bunch of amateurs
• 20:32
  Speaker 4: whose hobby is to fill in the holes and let
• 20:34
  Speaker 4: the orbits of the satellites that aren't meant to be public,
• 20:38
  Speaker 4: and we feel fine about that because we figure that
• 20:40
  Speaker 4: if a bunch of amateur astronomers with binoculars can figure
• 20:44
  Speaker 4: out these orbits, the North Koreans can too, you know.
• 20:48
  Speaker 4: And so I think for a long time, the space
• 20:51
  Speaker 4: force were a bit of denial. The air forces was
• 20:53
  Speaker 4: there were a bit of denial that they would ask us,
• 20:56
  Speaker 4: what sensors are you using to detect our satellites up? Oh,
• 21:02
  Speaker 4: we look up, it's come on overhead. There it is.
• 21:06
  Speaker 4: And so I think now there's more of a realization
• 21:08
  Speaker 4: that actually pretty fruitless trying to keep these orbits secret.
• 21:12
  Speaker 4: And I think in the long run for safety of
• 21:14
  Speaker 4: space operations so that other people know not to bump
• 21:17
  Speaker 4: into them, the era of making the orbit data secret
• 21:21
  Speaker 4: has got to end, I think, and that's an active discussion.
• 21:24
  Speaker 3: Have we ever had a secret satellite blow up or
• 21:27
  Speaker 3: turn into secret space debris?
• 21:29
  Speaker 4: Absolutely, absolutely secret space junk.
• 21:32
  Speaker 3: I never heard of that before.
• 21:33
  Speaker 4: I think the most common case is the upper stage
• 21:35
  Speaker 4: from one of these satellites blew up and created a
• 21:38
  Speaker 4: lot of debris. And so for a long time those
• 21:40
  Speaker 4: orbital data were secret classified. But they kind of wised
• 21:44
  Speaker 4: up eventually and released that. So that's good. There's been
• 21:47
  Speaker 4: some improvements lately in the transparency of the system, which
• 21:50
  Speaker 4: I'm pleased to see that slowly. Know, there was a
• 21:53
  Speaker 4: lot of like Cold War mentality, and now it's sort
• 21:55
  Speaker 4: of even though we may be going to another Cold
• 21:57
  Speaker 4: War or whatever. But see, one of the big things
• 22:00
  Speaker 4: that's changed in the past ten years. As it used
• 22:02
  Speaker 4: to be I would give talks, I would say space
• 22:04
  Speaker 4: is about one third civilian government, one third military, and
• 22:09
  Speaker 4: one third commercial. Those days are gone. Now space is
• 22:15
  Speaker 4: overwhelming the commercial and that means that the incentives at
• 22:19
  Speaker 4: the government level right are to support the commercial industry,
• 22:23
  Speaker 4: and that means more transparency in terms of not having
• 22:26
  Speaker 4: to worry about being hit by secret satellite. There's other
• 22:29
  Speaker 4: transparency issues because companies want to keep their plans secret
• 22:34
  Speaker 4: and things like that for commercial reasons. So that's a
• 22:37
  Speaker 4: whole other issue. So times have really changed the last
• 22:40
  Speaker 4: five to ten years. It's been a dramatic shift towards
• 22:43
  Speaker 4: this new era of commercial space.
• 22:45
  Speaker 3: And what's your interest in it? I mean, you're an astrophysicist.
• 22:48
  Speaker 3: Are you curious about this because you're just curious about
• 22:50
  Speaker 3: anything in space? Or is this like political advocacy where
• 22:53
  Speaker 3: you feel like, hey, space is for everyone and we
• 22:55
  Speaker 3: should all know what's up there.
• 22:57
  Speaker 4: You know, it's changed recently. So yeah, I've had this
• 22:59
  Speaker 4: separate life since I was a kid of wanting to
• 23:02
  Speaker 4: know what was going on in space. And you know,
• 23:04
  Speaker 4: I found this list of the year's satellite launches when
• 23:08
  Speaker 4: I was about twelve, and I very quickly realized after
• 23:12
  Speaker 4: copying it down that it wasn't really that grain of list.
• 23:15
  Speaker 4: They could do better. And so fifty years later I
• 23:18
  Speaker 4: have the best list because I'm obsessive like that, and
• 23:22
  Speaker 4: so that was sort of my original impetus. And I've
• 23:24
  Speaker 4: got more and more dragged into the policy side. And
• 23:27
  Speaker 4: then as space has started to become so busy that
• 23:32
  Speaker 4: we humans are starting to have an impact on the
• 23:36
  Speaker 4: space environment, and part of that is an impact on astronomy.
• 23:42
  Speaker 4: My two lives of astronomer and space pundit have kind
• 23:46
  Speaker 4: of merged and very much now are becoming advocacy and
• 23:50
  Speaker 4: becoming the Cassandra saying, hey, guys, we've got a problem
• 23:55
  Speaker 4: here with the overwhelming effect that we are now having
• 24:00
  Speaker 4: the space environment in a lot of different ways, and
• 24:02
  Speaker 4: the need for new regulation to adapt to the new
• 24:07
  Speaker 4: environment that we're in.
• 24:08
  Speaker 1: Well, let's take a quick break and when we get back,
• 24:10
  Speaker 1: we'll talk about policy and impacts. And we're back. So
• 24:30
  Speaker 1: there's all this junk floating around in space, and I'm
• 24:33
  Speaker 1: under the impression that part of why it's hard to
• 24:35
  Speaker 1: remove the junk from space is because there's policies that
• 24:40
  Speaker 1: make it difficult to take someone else's junk out of
• 24:42
  Speaker 1: space without like getting their permission first. Is that correct?
• 24:46
  Speaker 1: And what's holding us back from removing all of that
• 24:48
  Speaker 1: junk from space?
• 24:49
  Speaker 4: Right? That is hard of it? And so yes, the
• 24:52
  Speaker 4: Outer Space Treaty says that unlike say, stuff abandoned in
• 24:57
  Speaker 4: the ocean, stuff in space you can't abandon it. It's
• 25:01
  Speaker 4: still your problem. And the outer space you didn't have
• 25:03
  Speaker 4: an idea of companies or anything like that. And so
• 25:05
  Speaker 4: if you want to put something in space your like SpaceX,
• 25:07
  Speaker 4: for example, you've got to get a license from your
• 25:10
  Speaker 4: government in this case of the US, and part of
• 25:12
  Speaker 4: that license is then the US as a country takes
• 25:16
  Speaker 4: on the duty of jurisdiction and the control of that satellite.
• 25:21
  Speaker 4: And so that means if there's an old Russian rocket
• 25:25
  Speaker 4: stage orbiting that's been abandoned for thirty years, I can't
• 25:29
  Speaker 4: go up and take it without getting Russian permission because
• 25:33
  Speaker 4: it's still theirs. And so that is seen by the
• 25:38
  Speaker 4: space lawyers, particularly in the US, as a big, big
• 25:42
  Speaker 4: problem that they don't want to they kind of run
• 25:44
  Speaker 4: and hide whenever you bring it up. I do feel
• 25:47
  Speaker 4: this is a solvable problem that no one wants the
• 25:50
  Speaker 4: space junk. One thing I'm encouraged by. So there's a
• 25:53
  Speaker 4: company called Astroscale which is based in Tokyo and in
• 25:57
  Speaker 4: the UK, and they've been recently through satellite around a
• 26:01
  Speaker 4: big old Japanese rocket stage, observing it as sort of
• 26:05
  Speaker 4: a preparatory mission to having the technology to remove it
• 26:08
  Speaker 4: from orbit. And I think companies like that that are
• 26:10
  Speaker 4: sort of have an international basis. If you can do
• 26:13
  Speaker 4: sort of bilateral thing where say a European mission takes
• 26:18
  Speaker 4: out a Japanese piece of space junk with both countries agreement,
• 26:22
  Speaker 4: you can sort of set a tone that you can
• 26:25
  Speaker 4: then grow later to go okay, so we've done this,
• 26:28
  Speaker 4: you see, we're not doing anything that fair. Yes, we're
• 26:30
  Speaker 4: cleaning out the orbit. Hey, Russian guys, can you join
• 26:34
  Speaker 4: us and help us get rid of your junk too?
• 26:37
  Speaker 4: And I think that's the way forward. But you know, obviously,
• 26:40
  Speaker 4: in the world political situation as it is, it's not trivial.
• 26:43
  Speaker 1: And I was talking to someone the other day who
• 26:45
  Speaker 1: was saying that one of the problems with these technologies
• 26:47
  Speaker 1: for clearing out space junk. Is that you can say like, oh,
• 26:50
  Speaker 1: I'm going out there for space junk, and that's why
• 26:51
  Speaker 1: I've got the laser, and that's why I've got this
• 26:53
  Speaker 1: arm so that I can grab your space junk and
• 26:55
  Speaker 1: throw it down so it'll burn up in the atmosphere.
• 26:57
  Speaker 1: But that's all dual use. That laser can be us
• 27:00
  Speaker 1: to destroy someone else's satellite. That grappling arm you can
• 27:03
  Speaker 1: throw someone else. And that is that actually holding anything back?
• 27:06
  Speaker 1: Or are people just willing to accept that when you
• 27:08
  Speaker 1: develop the technology to remove stuff from space, maybe you're
• 27:11
  Speaker 1: also developing some dual use stuff to get used down
• 27:13
  Speaker 1: the road.
• 27:14
  Speaker 4: I think it's an issue that people bring up. I
• 27:17
  Speaker 4: mean personally, I think that's good. I hate the term
• 27:19
  Speaker 4: dual use. It's like everything is dual used. You know,
• 27:21
  Speaker 4: I can stab you with my pen, yeah, I mean yes,
• 27:26
  Speaker 4: of course, any satellite that's maneuverable can be maneuvered to
• 27:30
  Speaker 4: kind of you know, smash into your satellite, right, yeah,
• 27:32
  Speaker 4: and principle, And so I think that's just an excuse
• 27:36
  Speaker 4: for not doing anything, okay, or just an expression of mistrust.
• 27:40
  Speaker 4: You know, that is gettable over in my opinion, but
• 27:44
  Speaker 4: it's going to take a while, so I think, you know,
• 27:45
  Speaker 4: the last ten years, we've seen a bunch of experiments.
• 27:48
  Speaker 4: The British in particular did a fun set of experiments
• 27:50
  Speaker 4: where they sent a harpoon at a target to try
• 27:54
  Speaker 4: and catch it. They threw a net around the satellite
• 27:58
  Speaker 4: to reel it in and catch it. So people are
• 28:00
  Speaker 4: trying crazy stuff, and we're sort of starting to settle
• 28:04
  Speaker 4: on Okay, what are the approaches that will actually work,
• 28:08
  Speaker 4: And I think then the next step is to go
• 28:10
  Speaker 4: and actually do it for real and starting. The first
• 28:12
  Speaker 4: people to do this were actually, surprisingly the Chinese. The
• 28:16
  Speaker 4: Chinese a couple of years ago, they had this navigation
• 28:20
  Speaker 4: satellite in geostationary orbit that had died and was just
• 28:23
  Speaker 4: drifting in the traffic lane, you know, And so they
• 28:27
  Speaker 4: sent up another satellite that went and locked onto it,
• 28:30
  Speaker 4: probably with a robot arm or something, and brought it
• 28:34
  Speaker 4: up three hundred kilometers into what we call the graveyard,
• 28:37
  Speaker 4: a sort of a space junk yard, and released it
• 28:40
  Speaker 4: there and then went back down to go look for
• 28:43
  Speaker 4: other target. And that was the first time that anyone
• 28:45
  Speaker 4: had actually done kind of garbage truck space debris removal
• 28:52
  Speaker 4: for real with a real piece of space debris, and
• 28:55
  Speaker 4: so you know the fact that the US hasn't done
• 28:57
  Speaker 4: that yet is frankly a little bit of better.
• 29:00
  Speaker 1: Yeah, it would be nice for leading the cleanup.
• 29:02
  Speaker 3: I have a sort of naive question as a physicist,
• 29:05
  Speaker 3: like if the natural environment is just the Moon, that
• 29:08
  Speaker 3: suggests that there's some process of clearing the near Earth
• 29:12
  Speaker 3: orbit of bits like that if you had rocks coming in,
• 29:16
  Speaker 3: they would naturally gravitate together or something. What is the
• 29:18
  Speaker 3: sort of timescale for nature to take care of this itself,
• 29:21
  Speaker 3: for it to like form a ring or to pull
• 29:24
  Speaker 3: together into a new moon made of space junk.
• 29:26
  Speaker 4: If you just leave the satellite population as it is, yeah,
• 29:29
  Speaker 4: what happens? And yeah, let's say if the Earth were
• 29:32
  Speaker 4: a perfectly round, you know, point source, and the Moon
• 29:35
  Speaker 4: and the Sun didn't exist, then things were just orbit
• 29:38
  Speaker 4: forever without changing their orbital prepence. The Earth has an atmosphere,
• 29:43
  Speaker 4: and so below about one thousand kilometers there's just enough
• 29:47
  Speaker 4: atmosphere to have a headwind at all glo velocities that
• 29:50
  Speaker 4: will eventually bring stuff back down into the atmosphere, and
• 29:53
  Speaker 4: that timescale is every eleven years. We have the famous
• 29:57
  Speaker 4: solar cycle, the solar maximum that makes the atmosphere more dense,
• 30:02
  Speaker 4: and that basically clears out everything below five hundred kilometers
• 30:06
  Speaker 4: in one or two cycles. So if you blow five
• 30:08
  Speaker 4: or six hundred kilometers, you're going to re enter the
• 30:10
  Speaker 4: Earth's atmosphere within twenty something years. But if you're between
• 30:14
  Speaker 4: like six hundred kilometers and ten thousand kilometers, you're going
• 30:18
  Speaker 4: to stay orbiting for centuries to millennia. There really isn't
• 30:23
  Speaker 4: that much affecting you. The Moon's far enough out that
• 30:27
  Speaker 4: it's not really bothering you. Once you get beyond like
• 30:30
  Speaker 4: one hundred thousand kilometers, now you have to start worrying
• 30:33
  Speaker 4: about the gravity of the Moon and the Sun, and
• 30:36
  Speaker 4: that will squeeze and turn your orbit and it's fun. Actually,
• 30:41
  Speaker 4: there are weird things like the Kosi effect that exoplanet
• 30:44
  Speaker 4: astronomers are really into, but also apply in Earth satellite stuff.
• 30:48
  Speaker 4: There's a lot of parallels in the math.
• 30:50
  Speaker 1: The bail just wants to know what's the Cose effect.
• 30:52
  Speaker 4: So what it is is if you have an elliptical
• 30:54
  Speaker 4: orbit and there's another body like the Moon, tugging on you,
• 30:58
  Speaker 4: what it does is it's wheezes and stretches the orbit,
• 31:02
  Speaker 4: so it becomes more and less elliptrical in a periodic way,
• 31:05
  Speaker 4: and at the same time tilts the orbit relative to
• 31:08
  Speaker 4: the equator. So the satellite I work on, Shander is
• 31:11
  Speaker 4: in an orbit like that, and over a decade or so,
• 31:15
  Speaker 4: it goes from almost equatorial to almost polar and back again.
• 31:19
  Speaker 4: And the low point of the orbit started off with
• 31:22
  Speaker 4: ten thousand kilometers, it goes up to like fifteen thousand,
• 31:24
  Speaker 4: comes down to five thousand, back up again. And if
• 31:27
  Speaker 4: you get the Sun and Moon aligne you could even
• 31:30
  Speaker 4: have the low point go negative, which would be the
• 31:32
  Speaker 4: end of the mission because then you try to orbit
• 31:34
  Speaker 4: through the surface of the Earth. Doesn't work very well.
• 31:37
  Speaker 4: And so that's just one example of all the funky
• 31:40
  Speaker 4: stuff that can happen. The flattening of the Earth can
• 31:43
  Speaker 4: be important.
• 31:44
  Speaker 3: What about the gravitation between the objects? Like I understood
• 31:47
  Speaker 3: that if you have some huge set of debris in
• 31:50
  Speaker 3: orbit around a planet, if it's close below the roach limit,
• 31:53
  Speaker 3: the tidal forces will keep it from coalescing. For listeners
• 31:56
  Speaker 3: who aren't familiar, the Roche limit is how close you
• 31:59
  Speaker 3: can get to a planet before its tidal forces will
• 32:02
  Speaker 3: pull you apart. We have tidal forces from planets because
• 32:05
  Speaker 3: the planet's gravity pulls on the closer bit harder than
• 32:09
  Speaker 3: on the further bit. But if you're far enough away
• 32:11
  Speaker 3: from the planet, your internal structure can still hold you together.
• 32:14
  Speaker 3: But if a moon, for example, gets too close to
• 32:16
  Speaker 3: a planet, those tidal forces will pull it apart, shred it,
• 32:20
  Speaker 3: and turn it into a ring. But if it's far
• 32:22
  Speaker 3: enough away, the self gravity will eventually pull it together
• 32:25
  Speaker 3: into a new moon. Could that happen eventually with all
• 32:27
  Speaker 3: of our space junk?
• 32:28
  Speaker 4: I haven't done that math. I doubt it. I think
• 32:31
  Speaker 4: the total mass isn't enough to get self gravitating. We've
• 32:36
  Speaker 4: launched maybe twenty tons of stuff.
• 32:39
  Speaker 3: That sounds like a lot, but I guess it's not
• 32:41
  Speaker 3: compared to an astronomical object yet.
• 32:42
  Speaker 4: Yeah, not compared to even a fairly small moon. My
• 32:46
  Speaker 4: guess is that that would not happen.
• 32:49
  Speaker 3: Maybe we should use a moon as a unit of
• 32:51
  Speaker 3: measuring how much space junk we put into this otter,
• 32:54
  Speaker 3: because it makes us feel better about it.
• 32:56
  Speaker 4: The International standard Moon. Yeah, okay, I'll take that out
• 32:58
  Speaker 4: a consideration. Daniels.
• 33:02
  Speaker 1: All right, so when you were describing Chandra's orbit, it's
• 33:04
  Speaker 1: becoming even more clear to me how hard it must
• 33:06
  Speaker 1: be to track all of these objects because they're all
• 33:08
  Speaker 1: doing their own sort of things while they're out there.
• 33:10
  Speaker 1: So we've got all of this junk that's sort of
• 33:11
  Speaker 1: hard to track, do you It sort of touched on
• 33:14
  Speaker 1: the Kessler syndrome. Let's dive into that a little bit more.
• 33:17
  Speaker 4: So.
• 33:17
  Speaker 1: Space is huge. How big of a risk is it
• 33:19
  Speaker 1: that we're going to start getting these feedbacks where everything
• 33:21
  Speaker 1: runs into each other. Let's talk about that.
• 33:24
  Speaker 4: So space is huge, but lower orbit isn't that huge, right,
• 33:29
  Speaker 4: So if we focus on the busiest part of space
• 33:31
  Speaker 4: right now from the human point of view, which is
• 33:34
  Speaker 4: all the satellites between the bottom of the US atmosphere
• 33:37
  Speaker 4: and about two thousand kilometers, there's a lot of stuff there.
• 33:41
  Speaker 4: The average distance between any two objects it's about one
• 33:46
  Speaker 4: hundred kilometers, but you're going at twenty five thousand kilometers
• 33:50
  Speaker 4: an hour. So the analogy I always use is, you know,
• 33:53
  Speaker 4: if you're driving on the highway, we're always reminded the
• 33:56
  Speaker 4: faster you go, the further you have to the distance
• 34:00
  Speaker 4: from the car in front of you. Right, So when
• 34:04
  Speaker 4: you're traveling at twenty five thousand kilometers an hour. You
• 34:07
  Speaker 4: don't have a lot of dotch time in one hundred kilometers, right,
• 34:11
  Speaker 4: And so we do get collisions, and we're seeing them.
• 34:14
  Speaker 4: We're seeing small collisions that are maybe not destroying a
• 34:16
  Speaker 4: satellite entirely, but kind of breaking stuff off it. And
• 34:20
  Speaker 4: the trouble is that the collision rate goes as the
• 34:23
  Speaker 4: square of the number of satellites. So if you have
• 34:25
  Speaker 4: ten times as many satellites, you have one hundred times
• 34:28
  Speaker 4: as many collisions. So right now, the collision rate is
• 34:32
  Speaker 4: not that bad. Even so if you stop launching everything today,
• 34:37
  Speaker 4: the collision rate is high enough that eventually, on timescales
• 34:40
  Speaker 4: of a century, you would start to get this runaway
• 34:43
  Speaker 4: chain reaction.
• 34:44
  Speaker 3: What's the collision rate like now, how many collisions do
• 34:47
  Speaker 3: we see per day or per year?
• 34:48
  Speaker 4: I think we see two or three small ones per year, Okay,
• 34:51
  Speaker 4: maybe one big one a decade of order. And so
• 34:55
  Speaker 4: that is amplified by what we call breakup events. There's
• 35:01
  Speaker 4: not one satellite dumping another, but when the rocket stage
• 35:04
  Speaker 4: blows up, for example, and things like that, and we
• 35:07
  Speaker 4: have several of those a year, adding hundreds of objects
• 35:11
  Speaker 4: to the catalog each year from that kind of source
• 35:14
  Speaker 4: the number of debriogis is increasing. It's not like in
• 35:18
  Speaker 4: the movie Gravity, right, where everything goes to hell in
• 35:21
  Speaker 4: about half an hour. Right, this is something that plays
• 35:24
  Speaker 4: out as with most environmental things. Right, you slowly drown
• 35:28
  Speaker 4: in your own waste. Right, every year, it's a little
• 35:32
  Speaker 4: bit worse and a little worse.
• 35:35
  Speaker 3: But it accelerates.
• 35:36
  Speaker 4: Right.
• 35:36
  Speaker 3: You were saying that the collision rate depends on the
• 35:38
  Speaker 3: number of objects squared. So every time you have an
• 35:40
  Speaker 3: object that breaks into two, you've increased the number, which
• 35:43
  Speaker 3: you know increases the rate of collisions. And that's the
• 35:45
  Speaker 3: feedback loop.
• 35:46
  Speaker 1: Right, That's exactly correct, yes, And is this all going
• 35:50
  Speaker 1: to be exacerbated even more by additional constellations of satellite?
• 35:54
  Speaker 1: So SpaceX has their Starlink, but I think China is
• 35:58
  Speaker 1: planning something similar.
• 36:00
  Speaker 4: I has made the first two launches of its Kianfan
• 36:03
  Speaker 4: thousand sales satellites. And you know, people have seen the
• 36:07
  Speaker 4: success of Starlink in providing communications in Ukraine, and so
• 36:12
  Speaker 4: all the militaries in all the countries want their own.
• 36:16
  Speaker 4: We must have control over it ourselves, Starling constellation. And
• 36:21
  Speaker 4: so I think in addition to the commercial interests, there's
• 36:24
  Speaker 4: military interests, and so yeah, we're going to see more
• 36:27
  Speaker 4: and more of these constellations come along. Amazon have started
• 36:30
  Speaker 4: deploying theirs. There's a company called e Space that wants
• 36:34
  Speaker 4: to launch hundreds of thousands of satellites. So this is
• 36:38
  Speaker 4: really happening. You know. What SpaceX will tell you is
• 36:41
  Speaker 4: they have this Wizzo algorithm that will fix it in software.
• 36:45
  Speaker 4: Basically that the satellites have these argone electric thrusters. They
• 36:50
  Speaker 4: accelerate argon atoms with electric potential from solar panels to
• 36:55
  Speaker 4: provide low thrust but very many miles per gallon rocket
• 36:59
  Speaker 4: engine that can do slow dodges, not fast dodges. And
• 37:04
  Speaker 4: so they're always calculating. You know, they're doing thousands and
• 37:08
  Speaker 4: thousands of small maneuvers to avoid each other and other
• 37:13
  Speaker 4: people's satellites, and they're like, we got this, you know,
• 37:18
  Speaker 4: we know how to do this. I think their math
• 37:21
  Speaker 4: works out if you assume that the you know, errors
• 37:24
  Speaker 4: are always Bell curve and you know, but that's not reality.
• 37:30
  Speaker 4: The reality is that, as we say in the trade,
• 37:33
  Speaker 4: errors are non Gaussian. They're not like random that someone
• 37:36
  Speaker 4: screws up and something goes very wrong and it only
• 37:40
  Speaker 4: takes two people and two different constellations to screw up
• 37:43
  Speaker 4: in the right way, as it were, for your algorithms
• 37:47
  Speaker 4: to just totally fail and you have a collision. And
• 37:50
  Speaker 4: so we've been lucky so far. But I think if
• 37:54
  Speaker 4: you up the number of satellites by another factor of
• 37:56
  Speaker 4: ten or so, the chances are that we're going to
• 37:59
  Speaker 4: start seeing collisions. Space has been quite careful. They're actually
• 38:03
  Speaker 4: retiring now about three hundred of their satellites that have
• 38:08
  Speaker 4: components that they feel a dodgy and might cause a failure,
• 38:11
  Speaker 4: and so they're bringing them down under control while they're
• 38:13
  Speaker 4: still working and incinerating them in the atmosphere, which is
• 38:17
  Speaker 4: a whole other environmental problem that's just emerging because you know,
• 38:20
  Speaker 4: messing with the chemistry the upper atmosphere, what could possibly
• 38:23
  Speaker 4: go wrong?
• 38:23
  Speaker 1: That's worth trying for us so far.
• 38:25
  Speaker 4: Yeah, right, But putting that aside for a second, you know,
• 38:29
  Speaker 4: they're trying to be what they feel is responsible bringing
• 38:31
  Speaker 4: these satellites down, but not all companies maybe are going
• 38:34
  Speaker 4: to do that. And for example, of the first batch
• 38:37
  Speaker 4: of can Fan satellites, seventeen of the eighteen have started
• 38:41
  Speaker 4: raising the orbits. One of them looks like it may
• 38:44
  Speaker 4: have failed in SIH and Tolmerle, which will leave it
• 38:47
  Speaker 4: up there for a century. If you're launching ten thousand
• 38:50
  Speaker 4: satellites and you have a one percent failure rate, say
• 38:54
  Speaker 4: that's one hundred failed satellites added to the mix. And
• 38:58
  Speaker 4: you know, so it doesn't take too any of those
• 39:00
  Speaker 4: to kind of exacerbate the problems.
• 39:03
  Speaker 3: But these companies must be incentivized to solve this problem,
• 39:05
  Speaker 3: right They don't want to invest billions in their network
• 39:08
  Speaker 3: and then have them all be destroyed. They must be
• 39:10
  Speaker 3: clear out about it.
• 39:11
  Speaker 4: If anything will save us, that's it. It's the bottom line,
• 39:15
  Speaker 4: and it's the used environment story that they will do
• 39:18
  Speaker 4: not enough about the problem until it starts getting bad
• 39:22
  Speaker 4: enough that they actually see economic losses due to the problem,
• 39:26
  Speaker 4: and then they will scramble to self regulate and do
• 39:30
  Speaker 4: something that will improve it.
• 39:32
  Speaker 1: And on that positive note, let's take a break and
• 39:35
  Speaker 1: when we come back, we'll talk about implications for astronomy. Okay,
• 39:54
  Speaker 1: so you mentioned a little bit earlier in the show
• 39:56
  Speaker 1: that all of the starlink satellites, for example, are making
• 40:00
  Speaker 1: astronomy difficult. What is the magnitude of this problem right
• 40:04
  Speaker 1: right now?
• 40:05
  Speaker 4: It's an annoying nuisance. But again, up things by another
• 40:09
  Speaker 4: factor of ten, and it becomes really difficult to do
• 40:12
  Speaker 4: certain kinds of science. And so the problem is this,
• 40:14
  Speaker 4: there are two problems. They're different for lower bit satellites
• 40:17
  Speaker 4: and high orbit satellites. For low orbit satellites they're so
• 40:21
  Speaker 4: low that in the middle of the night they can't
• 40:23
  Speaker 4: see the sun. They shine by your affected light, and
• 40:25
  Speaker 4: so they're dark, and so they're not really a problem
• 40:27
  Speaker 4: for astronomers in the middle of the night. They are. However,
• 40:29
  Speaker 4: if you have enough of them. For example, if this
• 40:32
  Speaker 4: espace company I mentioned really launches like one hundred thousand satellites,
• 40:36
  Speaker 4: you could get to a situation where there are more
• 40:39
  Speaker 4: visible satellites in the sky than visible stars.
• 40:43
  Speaker 3: Oh my god.
• 40:44
  Speaker 4: Especially like just at the limit of visibility, the sky
• 40:48
  Speaker 4: instead of being nice and dark, will be kind of
• 40:50
  Speaker 4: seething in this nauseous way. And then the brighter ones
• 40:54
  Speaker 4: will make it very hard to kind of recognize the
• 40:56
  Speaker 4: constellations because it's going to be so much traffic. It's
• 40:58
  Speaker 4: going to be like in the flight plat hat a know,
• 41:01
  Speaker 4: logan airport or whatever.
• 41:02
  Speaker 3: But why these things bright? I mean, they don't have
• 41:04
  Speaker 3: lights on them, right, are they just reflecting the sun.
• 41:06
  Speaker 4: They reflect sunlight, and they're big. They're big and low
• 41:10
  Speaker 4: and they reflect sunlight. The current Starlink satellites are thirty
• 41:14
  Speaker 4: meter span Oh my god, panels. They're not small. These
• 41:17
  Speaker 4: are not tiny CubeSats. They're one ton ish satellites. So
• 41:21
  Speaker 4: it's it's really a change in the environment for everyone
• 41:25
  Speaker 4: in the world, right, even if you're not a space
• 41:27
  Speaker 4: faring country, but you're like looking up at the sky,
• 41:29
  Speaker 4: you maybe have cultural connections to the sky, and now
• 41:32
  Speaker 4: suddenly you're seeing the sky changing. And one of my
• 41:35
  Speaker 4: colleagues was just out hiking in the wilds of Canada said,
• 41:38
  Speaker 4: you know, they saw like so many satellites now that
• 41:42
  Speaker 4: they would never have seen it a few years ago.
• 41:43
  Speaker 3: Can they do something on the satellites to reduce the reflectivity,
• 41:46
  Speaker 3: like have an anti reflective coating or a sunshade.
• 41:49
  Speaker 4: To SpaceX's credit, they are doing a number of things
• 41:51
  Speaker 4: that have reduced the brightness of the satellite. But then
• 41:54
  Speaker 4: they came up with this new model of satellite where
• 41:56
  Speaker 4: they had these fancy new mitigations, but they were also
• 41:59
  Speaker 4: twice as big, so it kind of canceled out. To
• 42:03
  Speaker 4: their credit, they've done a lot of work, but there's
• 42:05
  Speaker 4: still more that needs to be done. So then the
• 42:07
  Speaker 4: second problem is the high orbit satellites. They are too
• 42:11
  Speaker 4: faint because they're high up, they're too faint to be
• 42:13
  Speaker 4: seen by the average person looking at in the evening
• 42:16
  Speaker 4: of the constellations, but they leave trails on astronomical images,
• 42:21
  Speaker 4: and they're way way brighter than the distant galaxies that
• 42:24
  Speaker 4: we're looking at. And so you take this picture of
• 42:27
  Speaker 4: some you know, distant galaxy and you've got a big
• 42:29
  Speaker 4: streak going across the image, and you know, we're not
• 42:32
  Speaker 4: just trying to take pretty pictures. We're trying to measure
• 42:34
  Speaker 4: brightnesses of stars to like one or two percent accuracy,
• 42:39
  Speaker 4: and so just photoshopping out the trail doesn't entirely solve
• 42:42
  Speaker 4: the problem. And even if that works, if you have
• 42:46
  Speaker 4: one trail every five images, you do what we call
• 42:48
  Speaker 4: medium filtering. Basically you throw away the bad ones and
• 42:51
  Speaker 4: you just have to observe for longer than you otherwise
• 42:53
  Speaker 4: would have. So it's attacks, but it's workable. But then
• 42:57
  Speaker 4: you know, if you up the number right so that
• 42:58
  Speaker 4: it's like streaks on every image going crisscrossing, going every way,
• 43:03
  Speaker 4: that becomes pretty impossible to analyze in an automated way.
• 43:08
  Speaker 4: If you have, like you know, ten thousand images of
• 43:10
  Speaker 4: galaxies and you're trying to analyze them remote with an algorithm,
• 43:14
  Speaker 4: and trying to distinguish between the crisscrossing satellite streaks and
• 43:17
  Speaker 4: actual astronomical phenomena is going to get pretty impossible. You know,
• 43:22
  Speaker 4: there are some science that's going to be affected worse
• 43:24
  Speaker 4: than others. The Magellanic clouds our nearest galaxies are visible
• 43:29
  Speaker 4: high in the southern sky in southern Midsummer. Southern midsummer
• 43:34
  Speaker 4: is the worst for this because that's when the sun
• 43:37
  Speaker 4: isn't that far below the horizon. The satellites get illuminated
• 43:40
  Speaker 4: all night long, and in plausible scenarios five or ten
• 43:44
  Speaker 4: years from now, there are several thousand illuminated satellites all
• 43:49
  Speaker 4: the time in the sky throughout the night in midsummer.
• 43:54
  Speaker 4: We may be able to work around it with new
• 43:56
  Speaker 4: kinds of cameras that can turn their shutters off for
• 44:00
  Speaker 4: brief modes of time while the satellite is passing, triggered
• 44:03
  Speaker 4: maybe by a finer camera that spots the satellite coming over.
• 44:07
  Speaker 4: It's not trivial. That's money, right, that's money that we
• 44:10
  Speaker 4: don't have to re equip the observer trees.
• 44:13
  Speaker 3: So Musk said, quote, I am confident that we will
• 44:16
  Speaker 3: not cause any impact whatsoever in astronomical discoveries zero. How
• 44:21
  Speaker 3: confident are you that that's the case.
• 44:24
  Speaker 4: I am one hundred percent confident that he is wrong
• 44:26
  Speaker 4: about that. Okay, there are subtleties, right, and so for example,
• 44:32
  Speaker 4: there was a report of a flare in a red
• 44:35
  Speaker 4: shift eleven galaxy that was super scientifically exciting until it
• 44:38
  Speaker 4: turned out to be actually a satellite passing through the
• 44:40
  Speaker 4: field of view the telescope at the time. If you've
• 44:43
  Speaker 4: just got like an optical fiber on the sky that
• 44:46
  Speaker 4: you're taking a spectrum, right, you don't have an image
• 44:49
  Speaker 4: of the sky, it's hard to figure out that that
• 44:51
  Speaker 4: was a satellite. So there's all kinds of ways in
• 44:54
  Speaker 4: which this is like a new kind of contamination factor
• 44:58
  Speaker 4: that ranges from mild annoying to oh, we accidentally published
• 45:04
  Speaker 4: a wrong exciting result because there was no way to
• 45:08
  Speaker 4: tell that it was caused by satellite contamination.
• 45:10
  Speaker 3: So if you were a dictator of the Earth and
• 45:12
  Speaker 3: you were in charge of this and everybody had to
• 45:14
  Speaker 3: follow your instructions, what would you do to allow us
• 45:17
  Speaker 3: to have this amazing space technology and worldwide network and
• 45:22
  Speaker 3: also do astronomy.
• 45:23
  Speaker 4: Yeah, that's the challenge. I think we just need a
• 45:26
  Speaker 4: cat on the number of active satellites of a given
• 45:30
  Speaker 4: brightness at a given altitude. You know, we have caps already,
• 45:34
  Speaker 4: Like in geostationary orbit, there's orbital slots that get assigned
• 45:37
  Speaker 4: by the International Telecommunications Union. You can't just launch as
• 45:40
  Speaker 4: many geostationary satellites as you like. I think we're going
• 45:44
  Speaker 4: to have to go to that. In lower th orbit,
• 45:45
  Speaker 4: We're going to have to have some kind of orbital
• 45:47
  Speaker 4: slot thing, and that will then change the design trade
• 45:50
  Speaker 4: so that instead of launching ten thousand small satellites, maybe
• 45:54
  Speaker 4: you launched one thousand bigger satellites and that helps with
• 45:58
  Speaker 4: not bumping into each other as well. So I think
• 46:01
  Speaker 4: it's a matter of finding regulation that will yes, absolutely
• 46:08
  Speaker 4: let the space technology develop, but not in a complete
• 46:14
  Speaker 4: free for all way, and manage the resources that we
• 46:18
  Speaker 4: have in a sustainable way and in a way that
• 46:20
  Speaker 4: doesn't impact the environment and astronomy more than a certain amount.
• 46:25
  Speaker 4: And where I mean absolutely it's going to be worse
• 46:27
  Speaker 4: for us than it used to be. But I do
• 46:30
  Speaker 4: believe there's a happy medium where the astronomers could just
• 46:33
  Speaker 4: about kind of survive and the satellites can still make
• 46:35
  Speaker 4: bunches of money.
• 46:37
  Speaker 1: So let's wrap up the show by asking the two
• 46:39
  Speaker 1: questions that we got from a listener. So Josh sent
• 46:43
  Speaker 1: us two questions.
• 46:44
  Speaker 5: Here we go, Besides the stuff that just orbits the Earth,
• 46:49
  Speaker 5: what happens to all the other stuff? Does it just
• 46:53
  Speaker 5: go off into space, run into planets, moons and stars?
• 46:58
  Speaker 5: And parenthetically thinking that if they do hit planets and moons,
• 47:02
  Speaker 5: they just sit there forever, and if they hit stars,
• 47:06
  Speaker 5: I'm assuming they melt away.
• 47:08
  Speaker 4: Right Well, even if they hit a planet, you know,
• 47:10
  Speaker 4: the typical planet hitting speed is going to be more
• 47:13
  Speaker 4: than enough to pulbarize you. We have, in addition to
• 47:16
  Speaker 4: the twenty five something thousand objects currently in orbit, the
• 47:20
  Speaker 4: sixty thousand objects that have been in orbit since Futnik,
• 47:24
  Speaker 4: there's about one to two thousand objects that we have
• 47:28
  Speaker 4: sent beyond Earth orbit, either to the Moon or into
• 47:32
  Speaker 4: orbit around the Sun. And they're poorly documented. I've been
• 47:35
  Speaker 4: trying to make a catalog of them, figure out where
• 47:38
  Speaker 4: they all are. Most of them will just orbit the
• 47:40
  Speaker 4: Sun forever, I say, forever. After a million years, there
• 47:43
  Speaker 4: are various effects that will cause them, probably the spiral
• 47:46
  Speaker 4: into the Sun or to hit a planet. But you
• 47:48
  Speaker 4: know we're talking million year timescales. These things are going
• 47:51
  Speaker 4: to be out there for a while, unless you know,
• 47:53
  Speaker 4: the Smithsonian goes and clangs them or something.
• 47:56
  Speaker 1: With their gigantic budget.
• 47:58
  Speaker 4: Yeah. Well, you know, a thousand years from hopefully it
• 48:00
  Speaker 4: will have ejective or one hundred thousand years from now.
• 48:04
  Speaker 4: We do have stuff in orbit around Mars. We have
• 48:06
  Speaker 4: stuff in orbit around Jupiter, and we have stuff on
• 48:09
  Speaker 4: the surface of the planets.
• 48:11
  Speaker 3: Stuff you mean on purpose or space junk or both.
• 48:13
  Speaker 4: Well, both, right, So we try not to have the
• 48:17
  Speaker 4: space junk hit Mars because and so what we do
• 48:21
  Speaker 4: is when we send stuff out in the direction of Mars,
• 48:24
  Speaker 4: we actually sterilize the probe, sort of bake it so
• 48:27
  Speaker 4: that there's hopefully no bacteria on it, so that we
• 48:29
  Speaker 4: won't contaminate the search for Martian life with bugs from Florida.
• 48:35
  Speaker 4: And then when we launch it, we actually deliberately aim
• 48:38
  Speaker 4: it away from Mars a little bit. We deliberately miss
• 48:41
  Speaker 4: a bit separate from the rocket stage. So now the
• 48:44
  Speaker 4: rocket stage is in an orbit that doesn't go close
• 48:46
  Speaker 4: to Mars, and then we make a course correction to
• 48:50
  Speaker 4: put the probe on course from Mars, and so that
• 48:53
  Speaker 4: way we avoid having the big sort of space junk
• 48:56
  Speaker 4: pieces that we launch an orbit around the Sun hit
• 48:59
  Speaker 4: Mars at least on the first time round. You can't
• 49:02
  Speaker 4: sort of predict far enough in advance to guarantee it'll
• 49:04
  Speaker 4: never hit, but hopefully the buzz will be done by then.
• 49:08
  Speaker 4: So that is, you know, this whole issue of you know,
• 49:09
  Speaker 4: protecting the environment of the other planets is certainly something
• 49:13
  Speaker 4: that people give a lot of thought to, but there is, Yeah,
• 49:15
  Speaker 4: there's a bunch of junk orbiting the Sun. One of
• 49:18
  Speaker 4: the things that I've been involved in is movement to
• 49:21
  Speaker 4: try and regulate this better and at least get people
• 49:25
  Speaker 4: to say what orbit they put their junk in so
• 49:27
  Speaker 4: that we can find it later. Occasionally we've accidentally catalog
• 49:30
  Speaker 4: space junk. Is, oh, we discovered an asteroid, and then well,
• 49:35
  Speaker 4: never mind that asteroid is on an asteroid, it's a
• 49:37
  Speaker 4: rocket stage. We would like you please, if you launch
• 49:40
  Speaker 4: something in the orbit around the Sun, give us the
• 49:43
  Speaker 4: orbital elements so that we can you know, disambiguate it
• 49:47
  Speaker 4: from asteroids. There's an asteroid mining company that's explicitly said
• 49:50
  Speaker 4: it wants to launch this survey probe next year and
• 49:53
  Speaker 4: they're not going to tell us which asteroid is going
• 49:55
  Speaker 4: to because that's proprietary information. Right. I think that's just
• 49:58
  Speaker 4: not okay. If you're flying a light plane in the US,
• 50:02
  Speaker 4: you have to file a flight plan. You should have
• 50:03
  Speaker 4: a file a flight plan. If you go to the asteroids,
• 50:06
  Speaker 4: that's public interest information. And so the American Astronomical Society
• 50:10
  Speaker 4: has issued a statement saying that we think that interplanetary
• 50:14
  Speaker 4: orbits like we're like those solar systems are area and
• 50:17
  Speaker 4: if you're going to be in it, we think you
• 50:18
  Speaker 4: should publish your orbital data and not keep it secret.
• 50:22
  Speaker 4: So we'll see if we can make that stick. But
• 50:25
  Speaker 4: that's going to be an area of discussion in the
• 50:29
  Speaker 4: years to come as more and more activity. You know,
• 50:31
  Speaker 4: it used to be that the deep space arena was
• 50:35
  Speaker 4: just NASA, JPL and the Soviets, right, and now it's
• 50:40
  Speaker 4: all kinds of developing countries. The UAE has a Mars orbiter,
• 50:44
  Speaker 4: India has a Moon Landers and private companies like SpaceX
• 50:50
  Speaker 4: are launching stuff to the Moon and Mars and so
• 50:53
  Speaker 4: we really need to do a better job of keeping
• 50:55
  Speaker 4: track of what's out there.
• 50:57
  Speaker 1: Yeah, And speaking of keeping track of what's out there,
• 50:59
  Speaker 1: Josh is the second question is right on point there.
• 51:02
  Speaker 5: This is probably more speculative and harder to answer. But
• 51:05
  Speaker 5: in the event of the existence of advanced extraterrestrial beings,
• 51:11
  Speaker 5: what might they into it about us? If or when
• 51:14
  Speaker 5: they do find the random fastener or rocket booster or
• 51:19
  Speaker 5: humanoid poop? Would they be curious? Would they be bored?
• 51:25
  Speaker 5: Would they be disappointed? We were so wasteful with the
• 51:28
  Speaker 5: stuff we ejected into the space trash can.
• 51:33
  Speaker 4: Yeah, I think they're out of you is going to
• 51:36
  Speaker 4: be well, what those guys went extinct?
• 51:43
  Speaker 1: Well, I'm hoping our clean up methods really get much
• 51:46
  Speaker 1: better in the coming decades.
• 51:47
  Speaker 4: Yep, you and me both.
• 51:48
  Speaker 1: Yeah, fingers crossed.
• 51:50
  Speaker 3: Have we had elements of space junk that we think
• 51:52
  Speaker 3: have gone interstellar, that have left the Solar System? You know,
• 51:56
  Speaker 3: basically the inverse version of Abilobe's omuamua.
• 51:59
  Speaker 4: Yep. Absolutely. There are a couple of pieces of the
• 52:03
  Speaker 4: New Horizons probe, one of the rocket stages, and a
• 52:07
  Speaker 4: couple of there are things called d spin weights that
• 52:10
  Speaker 4: are like you have a spinning rocket stage, you want
• 52:13
  Speaker 4: to slow it down, you unspool two weights on a wire,
• 52:17
  Speaker 4: kind of like a yo yo kind of thing, and
• 52:20
  Speaker 4: then they float off and take the angle the momentum
• 52:22
  Speaker 4: with them. And so that's like another class of space jungle.
• 52:25
  Speaker 4: That's like little pieces of space chapment. Just okay, they're
• 52:28
  Speaker 4: on their way out the Solar system, all right.
• 52:30
  Speaker 1: So to wrap up, are you feeling optimistic about the future?
• 52:33
  Speaker 1: Are we going to get those caps on satellites? What
• 52:36
  Speaker 1: do you think.
• 52:36
  Speaker 3: Before we go extinct?
• 52:38
  Speaker 1: Yeah?
• 52:38
  Speaker 4: I don't know, Kelly. I think that there is you know,
• 52:42
  Speaker 4: even in the companies, right, I don't want to paint
• 52:44
  Speaker 4: them as unfeeling corporate. You know, money is a little thing.
• 52:47
  Speaker 4: They do care about space, and so I think there
• 52:50
  Speaker 4: is interest in being responsible space citizens, and that, you know,
• 52:54
  Speaker 4: gets balanced against all the pressures that are pushing them
• 52:57
  Speaker 4: to be careless. And so I think it could go
• 53:00
  Speaker 4: either way. It's the usual environmental thing. It will get
• 53:03
  Speaker 4: bad enough that something will have to be done, and
• 53:06
  Speaker 4: then there'll be a scramble to try and fix in.
• 53:09
  Speaker 1: I think that's a very realistic take on things, all right.
• 53:11
  Speaker 1: Thank you so much for being here. Today, Jonathan, we
• 53:13
  Speaker 1: had a lot.
• 53:14
  Speaker 4: Of fun hide Vice. Thank you for having me, good
• 53:16
  Speaker 4: luck tracking everything.
• 53:17
  Speaker 3: Thank you and listeners. If your planning to launch anything
• 53:21
  Speaker 3: in order to please please let Jonathan know.
• 53:31
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