Latest / Space Exploration Stories / The backwards power connector that started the five‑hour countdown

Transcript

The backwards power connector that started the five‑hour countdown · Space Exploration Stories

• 0:00
  Speaker 1: 180 degrees. That is the distance between a successful mission
• 0:08
  Speaker 1: and a satellite slowly dying in the cargo hold of
• 0:11
  Speaker 1: a space shuttle. A single electrical connector, installed half a
• 0:15
  Speaker 1: turn off its correct position, had quietly severed the power
• 0:19
  Speaker 1: link between Endeavour and a one-year-old European science satellite worth
• 0:24
  Speaker 1: more than any single fix anyone had prepared for. The
• 0:27
  Speaker 1: satellite was called Igorica. It had been orbiting Earth for
• 0:31
  Speaker 1: merely 12 months, running experiments on crystal growth, fluid behavior,
• 0:36
  Speaker 1: and the long-term effects of weightlessness on living tissue. In
• 0:41
  Speaker 1: August of 1992, the space shuttle Atlantis had released it
• 0:45
  Speaker 1: into a precise orbit above the planet. It had worked
• 0:49
  Speaker 1: without complaint ever since. Now it was in the payload
• 0:52
  Speaker 1: bay of Endeavour, and its batteries were draining. Not quickly,
• 0:57
  Speaker 1: not dramatically. Slowly, The way a clock runs down in
• 1:01
  Speaker 1: a room nobody checks. The crew of STS-57 had launched
• 1:05
  Speaker 1: from Kennedy Space Center on June 21st, 1993, with a
• 1:09
  Speaker 1: clear mission, retrieve Iuri Sea, bring it home, and conduct
• 1:13
  Speaker 1: a 10-day program of science experiments aboard the shuttle. The
• 1:17
  Speaker 1: retrieval had gone as planned. The Canadarm had reached out,
• 1:20
  Speaker 1: grabbed the satellite, and lowered it into the payload bay.
• 1:23
  Speaker 1: But when the ground teams and crew attempted to route
• 1:26
  Speaker 1: power from the orbiter into ERECA's batteries, Nothing happened. The
• 1:31
  Speaker 1: recharge circuit was dead. And the reason it was dead
• 1:34
  Speaker 1: was not a malfunction of the satellite, not a blown fuse,
• 1:38
  Speaker 1: not a software error. It was a connector. One connector,
• 1:42
  Speaker 1: rotated 180 degrees from where it needed to be. That
• 1:48
  Speaker 1: is where this story begins. To understand what a backwards
• 1:51
  Speaker 1: connector cost this mission, it helps to understand what ERECA
• 1:55
  Speaker 1: was and why its batteries mattered so precisely. The European
• 1:59
  Speaker 1: Retrieval Carrier had been designed and built by the European
• 2:03
  Speaker 1: Space Agency as a platform for long-duration microgravity research. The
• 2:08
  Speaker 1: idea was elegant. Deploy the satellite, let it run autonomously
• 2:13
  Speaker 1: in orbit for months, then retrieve it with a shuttle
• 2:16
  Speaker 1: and bring the experiments back to Earth intact. Atlantis had
• 2:19
  Speaker 1: deployed it during STS-46 in August of 1992. For the
• 2:24
  Speaker 1: ten months that followed, Eureka circled the planet, collecting data
• 2:28
  Speaker 1: on how crystals grow without gravity pulling them apart, how
• 2:31
  Speaker 1: fluids behave in enclosed systems when there is no convection,
• 2:35
  Speaker 1: and how the human spine responds to the absence of
• 2:38
  Speaker 1: compressive load. That last finding would matter far beyond the mission.
• 2:43
  Speaker 1: When Endeavour launched in June of 1993, the plan was straightforward.
• 2:48
  Speaker 1: Mission specialist David Lowe would operate the conodarm to capture Erika.
• 2:53
  Speaker 1: Mission specialist Nancy Curry-Greg would support arm operations from inside
• 2:58
  Speaker 1: the cabin. Once the satellite was secured in the payload bay,
• 3:02
  Speaker 1: the orbiter would recharge its batteries through a dedicated electrical interface,
• 3:06
  Speaker 1: and the science data would remain stable for the journey home.
• 3:10
  Speaker 1: The Canadarm connector was the bridge between the orbiter's power
• 3:13
  Speaker 1: supply and Iareca's battery system. It had one correct orientation.
• 3:18
  Speaker 1: Installed properly, current flowed. Installed 180 degrees off, The circuit
• 3:25
  Speaker 1: was physically incomplete. The power had nowhere to go. What
• 3:29
  Speaker 1: no record from this mission documents is exactly when or
• 3:33
  Speaker 1: how the installation error was identified, or who had placed
• 3:36
  Speaker 1: the connector in that position. No individual or organization has
• 3:40
  Speaker 1: been attributed responsibility in any documentation. What is documented is
• 3:45
  Speaker 1: the consequence. E. S. Sitting in the payload bay of
• 3:49
  Speaker 1: a functioning space shuttle. Could not be recharged. Its batteries
• 3:54
  Speaker 1: continued to lose charge with each passing hour, and the
• 3:57
  Speaker 1: connector problem was not the only problem. When the Canadarm
• 4:01
  Speaker 1: lowered Eureka into the payload bay, the satellite's two antennas
• 4:05
  Speaker 1: failed to latch into their stowed positions. Standard spaceflight rules
• 4:09
  Speaker 1: were unambiguous on this point. Antennas had to be properly
• 4:13
  Speaker 1: secured before a satellite could be considered safely berthed. Eureka
• 4:17
  Speaker 1: was not secured. Its antennas were not latched. Two failures
• 4:23
  Speaker 1: layered on top of each other. Four days into a
• 4:26
  Speaker 1: 10-day mission, the crew and flight controllers now faced a
• 4:30
  Speaker 1: decision that had not been written into any pre-mission checklist.
• 4:34
  Speaker 1: They could not restore the recharge path by rotating the
• 4:36
  Speaker 1: connector from inside the cabin. They could not drive the
• 4:39
  Speaker 1: antenna latches by remote command alone. The rules said the
• 4:43
  Speaker 1: satellite had to be stowed correctly. The rules also said
• 4:47
  Speaker 1: the batteries needed to hold charge. Both conditions were failing simultaneously.
• 4:52
  Speaker 1: and the clock on Eureka's battery life was not waiting
• 4:54
  Speaker 1: for anyone to agree on a solution. The answer that
• 4:57
  Speaker 1: emerged was itself a departure from standard procedure. Flight controllers
• 5:02
  Speaker 1: waived the antenna stowage requirement. They lowered Eureka into the
• 5:06
  Speaker 1: payload bay without the latches engaged, accepting that the satellite
• 5:10
  Speaker 1: was unsecured in order to stop the situation from becoming unrecoverable.
• 5:15
  Speaker 1: It was not a comfortable decision. It was a decision
• 5:18
  Speaker 1: that bought time. Time enough, it turned out, For a
• 5:22
  Speaker 1: spacewalk nobody had originally planned, the morning of June 25, 1993,
• 5:27
  Speaker 1: the crew of Endeavour knew they had roughly five hours
• 5:31
  Speaker 1: and fifty minutes to fix what a single backwards connector
• 5:34
  Speaker 1: had broken. David Lowe suited up. Lowe was the mission
• 5:38
  Speaker 1: specialist assigned to lead the spacewalk. He had trained for contingencies.
• 5:43
  Speaker 1: What he had not trained for was this exact sequence.
• 5:47
  Speaker 1: A satellite with dead antennas sitting unsecured, in the payload
• 5:51
  Speaker 1: bay its batteries drawing down with no recharge path, and
• 5:55
  Speaker 1: a flight rule already waived just to get the vehicle
• 5:58
  Speaker 1: to this moment. The plan devised on the ground was precise,
• 6:02
  Speaker 1: but required three people operating simultaneously across two environments separated
• 6:08
  Speaker 1: by the hull of the shuttle. Inside the cabin, Nancy
• 6:11
  Speaker 1: Currie-Gregg would operate the Canadarm from her controls at the
• 6:15
  Speaker 1: aft station. Outside, Lowe would ride the arm's tip. Standing
• 6:19
  Speaker 1: in a foot restraint, his hands free, his body extended
• 6:23
  Speaker 1: over the open payload bay and on the ground. Flight
• 6:27
  Speaker 1: controllers at Mission Control would monitor telemetry and drive the
• 6:31
  Speaker 1: antenna latches remotely the moment Lowe had the antennas in position.
• 6:35
  Speaker 1: Three hands on the same problem, none of them in
• 6:38
  Speaker 1: the same room. At 13.07 UTC, the airlock opened. Lowe
• 6:44
  Speaker 1: moved out into the payload bay. The sun over the
• 6:47
  Speaker 1: Terminator line made the metalwork bright and the shadows absolute.
• 6:52
  Speaker 1: Eureka sat below him. A satellite the size of a
• 6:55
  Speaker 1: small car studded with experiments that had been running for
• 6:58
  Speaker 1: nearly a year in the silence of low Earth orbit.
• 7:02
  Speaker 1: It had traveled more than a hundred million kilometers since
• 7:05
  Speaker 1: Atlantis released it in August of 1992. It had done
• 7:09
  Speaker 1: everything asked of it. Now it needed one thing in return,
• 7:13
  Speaker 1: a physical hand pushing its antennas into their stowed positions
• 7:17
  Speaker 1: so a remote latch command could finish the job. Lowe
• 7:21
  Speaker 1: descended toward it on the arm. Curry Gregg moved the
• 7:23
  Speaker 1: canid arm in short, controlled arcs from inside. She could
• 7:28
  Speaker 1: see Lowe through the overhead windows. She could also see
• 7:31
  Speaker 1: the payload bay displays that told her where the arm
• 7:34
  Speaker 1: was in three-dimensional space. What she could not do was
• 7:38
  Speaker 1: feel what Lowe felt. The slight give of the antenna,
• 7:41
  Speaker 1: the resistance of the mechanism, the physical feedback that told
• 7:44
  Speaker 1: a human hand whether pressure was working or not That
• 7:47
  Speaker 1: information existed only at the end of the arm. Only
• 7:51
  Speaker 1: in Loh's hands. He reached the first antenna. The antenna
• 7:55
  Speaker 1: had to be pressed into its stowed position against the
• 7:57
  Speaker 1: body of Eureka. It was not a violent action. It
• 8:01
  Speaker 1: was a patient one. Loh applied steady, even pressure. The
• 8:06
  Speaker 1: kind of force you use when you know the mechanism
• 8:08
  Speaker 1: needs encouragement, not brute strength. Behind him and below him,
• 8:13
  Speaker 1: the curve of the Earth... scrolled past at roughly 7.7
• 8:17
  Speaker 1: kilometers per second. He did not look at it. He
• 8:20
  Speaker 1: looked at the antenna. The latch engaged. Ground controllers confirmed
• 8:25
  Speaker 1: it on telemetry. One antenna secured. The clock read fewer
• 8:30
  Speaker 1: than five hours remaining. The second antenna was the harder one.
• 8:34
  Speaker 1: The geometry was different. The angle of approach from the
• 8:37
  Speaker 1: conodarm tip placed Lowe's body at a less favorable position
• 8:41
  Speaker 1: relative to the mechanism. Curry Gregg adjusted the arm incrementally
• 8:45
  Speaker 1: from inside, reading the telemetry, watching the window, listening to
• 8:50
  Speaker 1: Lowe's call-outs over the comm loop. Each adjustment was small.
• 8:55
  Speaker 1: Each one changed the mechanical advantage Lowe had against the antenna.
• 8:59
  Speaker 1: Peter Wissoff moved into position to assist. Wissoff was the
• 9:03
  Speaker 1: co-lead on this spacewalk, and his job in this moment
• 9:06
  Speaker 1: was support, not primary contact with the antenna, but close
• 9:11
  Speaker 1: enough to intervene. close enough to provide a second set
• 9:14
  Speaker 1: of eyes on what Lowe's hands were doing. Two astronauts
• 9:18
  Speaker 1: outside the orbiter, one inside on the arm controls, three
• 9:22
  Speaker 1: ground controllers watching the telemetry. The redundancy was human, not mechanical.
• 9:28
  Speaker 1: Lowe pushed. There is something almost unreasonable about this image.
• 9:33
  Speaker 1: A man in a spacesuit standing on the tip of
• 9:36
  Speaker 1: a robotic arm. manually pressing a satellite antenna into position
• 9:39
  Speaker 1: while the orbiter moves at orbital velocity over the Indian Ocean.
• 9:44
  Speaker 1: The engineering that made the moment possible was decades in
• 9:48
  Speaker 1: the making, and it still required a person to put
• 9:50
  Speaker 1: their hands on a piece of hardware and push. The
• 9:54
  Speaker 1: second antenna resisted, not dramatically, not catastrophe. It resisted the
• 9:59
  Speaker 1: way mechanisms resist when tolerances are tight, and the approach
• 10:03
  Speaker 1: angle is slightly off. Lowe adjusted his grip. Curry Gregg
• 10:07
  Speaker 1: made another small correction with the arm. The second attempt
• 10:11
  Speaker 1: produced more movement. A third attempt, Lowe pressing steadily, Wisoff
• 10:16
  Speaker 1: watching the gap between the antenna and its housing. Brought
• 10:19
  Speaker 1: the antenna to its stowed position. Ground controllers drove the latch.
• 10:24
  Speaker 1: Telemetry confirmed. Secured. Both antennas latched. Eureka now sat properly
• 10:30
  Speaker 1: stowed in the payload bay. For the first time since
• 10:34
  Speaker 1: Endeavour had retrieved it, the waived flight rule had bought
• 10:37
  Speaker 1: the time needed. The EVA had done what the flight
• 10:40
  Speaker 1: rule waiver was designed to allow. The clock showed just
• 10:43
  Speaker 1: over three hours remaining in the spacewalk. What Lowe and
• 10:47
  Speaker 1: Weisshoff did next... was not in the original emergency plan.
• 10:51
  Speaker 1: It was always in the original flight plan. Before the
• 10:54
  Speaker 1: connector error, before the unlatched antennas, before the waived rule
• 10:58
  Speaker 1: and the unplanned spacewalk, STS-57 had a scheduled EVA test objective.
• 11:04
  Speaker 1: The mission carried an experimental agenda for the spacewalk itself.
• 11:08
  Speaker 1: Mass handling tests, mass fine alignment procedures, high torque exercises.
• 11:14
  Speaker 1: These were data collection activities designed to inform future spacewalk procedures.
• 11:19
  Speaker 1: unglamorous work, the kind that fills in the engineering tables
• 11:23
  Speaker 1: that protect the next crew, and the one after that.
• 11:26
  Speaker 1: The antenna crisis had consumed the first half of the spacewalk.
• 11:31
  Speaker 1: With the second half restored, Lowe and Wisoff worked through
• 11:35
  Speaker 1: the test objective as planned. This is the detail that
• 11:38
  Speaker 1: earns the most respect from anyone who has spent time
• 11:41
  Speaker 1: with this mission. The crew had absorbed a hardware failure,
• 11:44
  Speaker 1: a waived flight rule, and an unplanned EVA, And then
• 11:48
  Speaker 1: with antennas secured, Eureka birthed and the immediate crisis resolved.
• 11:54
  Speaker 1: They returned to the original work, not because they had to,
• 11:57
  Speaker 1: because the data mattered. Inside the cabin, the rest of
• 12:01
  Speaker 1: the mission continued in parallel. Janice Voss had been growing
• 12:05
  Speaker 1: crystals in the space HAP module using a floating zone
• 12:09
  Speaker 1: process that only worked in the absence of gravity. Ron
• 12:12
  Speaker 1: Grabe and Brian Duffy had participated in spinal lengthening measurements
• 12:17
  Speaker 1: Their spines had extended between 26 and 51 millimeters since
• 12:21
  Speaker 1: launch of finding that would eventually reach the engineers designing
• 12:25
  Speaker 1: future spacecraft seats and suit interfaces. And Nancy Currie Gregg,
• 12:29
  Speaker 1: hours after she had moved the Canadarm with the precision
• 12:32
  Speaker 1: of a surgeon, would spend part of June 28th with
• 12:35
  Speaker 1: a pressurized water fitting that had come loose in the
• 12:38
  Speaker 1: environmental control system. Her solution involved an absorbent diaper to
• 12:42
  Speaker 1: catch the escaping water in a laptop to reverse a
• 12:45
  Speaker 1: pump cycle. 20 minutes of hands-on work. 90 minutes of
• 12:49
  Speaker 1: ground monitoring afterward. The spacewalk closed at 1857 UTC, five
• 12:55
  Speaker 1: hours and 50 minutes after it opened. Every objective, planned
• 13:00
  Speaker 1: and unplanned, complete. Endeavour landed on July 1st, 1993. Ten
• 13:07
  Speaker 1: days after launch, the orbiter touched down at Kennedy Space
• 13:10
  Speaker 1: Center with Ifer, secured in the payload bay one year.
• 13:14
  Speaker 1: And ten months after Atlantis had released it into orbit,
• 13:17
  Speaker 1: the European Space Agency received its satellite back. The science
• 13:22
  Speaker 1: was intact. A year of microgravity research, preserved. That outcome
• 13:27
  Speaker 1: was not guaranteed on June 25th. The backwards connector had
• 13:31
  Speaker 1: started the chain. 180 degrees off correct, it broke the
• 13:36
  Speaker 1: recharge circuit between the orbiter and EREC's batteries the moment
• 13:40
  Speaker 1: the satellite entered the payload bay. The batteries had been
• 13:43
  Speaker 1: draining quietly ever since. When the antennas failed to latch,
• 13:48
  Speaker 1: the crew faced a compounding problem. A satellite, they could
• 13:52
  Speaker 1: not fully power and could not fully secure. The flight
• 13:55
  Speaker 1: rule existed for a reason. Antennas stowed before berthing. That
• 13:59
  Speaker 1: was the procedure. The rule was waived. AUEK was lowered
• 14:04
  Speaker 1: into the payload bay with the antennas loose and the
• 14:07
  Speaker 1: batteries still losing charge. That decision made the spacewalk necessary.
• 14:12
  Speaker 1: David Lowe suited up. Peter Wissoff joined him. At 1307
• 14:17
  Speaker 1: UTC on June 25th, they stepped outside into the void,
• 14:21
  Speaker 1: and the clock started. What followed was not heroic in
• 14:25
  Speaker 1: the theatrical sense. It was precise. Lowe mounted the foot
• 14:29
  Speaker 1: restraint at the tip of the Canadarm. Mansi Currie Gregg,
• 14:32
  Speaker 1: sealed inside the cabin, moved the arm with him attached
• 14:35
  Speaker 1: to its end, positioning him against a satellite the size
• 14:39
  Speaker 1: of a car, In orbit, while both the arm and
• 14:41
  Speaker 1: the satellite had their own mass and momentum, Lowe applied steady,
• 14:46
  Speaker 1: manual pressure to the antennas. Ground controllers drove the latches remotely.
• 14:51
  Speaker 1: The action was divided across three locations. Lowe's hands outside,
• 14:56
  Speaker 1: Curry Gregg's commands inside, flight controllers on the ground, pressing
• 15:01
  Speaker 1: keys in Houston. All three had to work in sequence.
• 15:05
  Speaker 1: None of them could see what the others were doing
• 15:07
  Speaker 1: in real time. They trusted procedure and voice. The latches engaged.
• 15:12
  Speaker 1: Both antennas secured. Five hours and 50 minutes after it opened,
• 15:17
  Speaker 1: the spacewalk closed at 1857 UTC. Every primary objective, the
• 15:23
  Speaker 1: unplanned antenna work, and the pre-planned EVA test objectives, was completed.
• 15:29
  Speaker 1: Lowe and Wizoff ran through mass handling procedures, fine alignment exercises,
• 15:34
  Speaker 1: and high-torque tasks after the antenna crisis was resolved. They
• 15:38
  Speaker 1: finished the job they were always supposed to do, on
• 15:41
  Speaker 1: top of the job they were not expecting. That is
• 15:44
  Speaker 1: the detail that does not appear in the mission headline.
• 15:46
  Speaker 1: The crew absorbed a hardware failure, a waived flight rule,
• 15:50
  Speaker 1: and an unplanned EVA, and then methodically completed the original plan.
• 15:56
  Speaker 1: Because the data mattered, and they had the time, the
• 15:59
  Speaker 1: connector that started everything, the one rotated 180 degrees from
• 16:03
  Speaker 1: its correct position, was never publicly attributed to a specific
• 16:07
  Speaker 1: person or organization. No name, no organization, and no date
• 16:12
  Speaker 1: of discovery appear anywhere in the record. What the record
• 16:15
  Speaker 1: says is that it was installed wrong, that the crew
• 16:18
  Speaker 1: found the consequence of it in orbit, and that they
• 16:21
  Speaker 1: solved it. That is where the documented account ends. There
• 16:24
  Speaker 1: is a question this mission plants that the record never
• 16:27
  Speaker 1: fully answers. A single connector, half a turn-off. That is
• 16:32
  Speaker 1: what it costs to nearly lose a year of European
• 16:35
  Speaker 1: science data. Not a catastrophic systems failure. Not a design
• 16:40
  Speaker 1: flaw discovered in testing. One component installed backwards that slipped
• 16:44
  Speaker 1: through every pre-launch check and every pre-retrieval review until the
• 16:49
  Speaker 1: moment Irica's batteries started draining in Endeavor's payload bay. No,
• 16:54
  Speaker 1: one was ever charged. No organization was ever named in
• 16:58
  Speaker 1: the transcript as responsible. The connector's origin remains undocumented in
• 17:03
  Speaker 1: the public record. What the mission left behind is more concrete.
• 17:08
  Speaker 1: The spinal lengthening data, 26 to 51 millimeters of extension
• 17:12
  Speaker 1: measured in Ron Grabe, Brian Duffy, and Janice Voss, entered
• 17:16
  Speaker 1: the engineering literature and eventually reached the teams designing future
• 17:21
  Speaker 1: spacecraft seats and pressure suit interfaces. The human body, it
• 17:25
  Speaker 1: turned out, needed more room than the original measurements assumed.
• 17:29
  Speaker 1: The discomfort that future crews did not feel was purchased here.
• 17:33
  Speaker 1: Janus Voss's floating zone crystals, grown in the Space Ape
• 17:37
  Speaker 1: module in conditions unavailable on Earth, came home with the satellite.
• 17:42
  Speaker 1: The fluid transfer work that Brian Duffy and Peter Wissoff
• 17:45
  Speaker 1: ran in space, HAP, moving liquid without bubbles in microgravity,
• 17:51
  Speaker 1: fed into research on orbital refueling systems that engineers are
• 17:55
  Speaker 1: still working toward decades later. Nancy Curry Gregg's diaper and
• 17:59
  Speaker 1: laptop repair on June 28, is the quieter legacy. A
• 18:04
  Speaker 1: pressurized water fitting came loose in the environmental control system.
• 18:08
  Speaker 1: She improvised a solution with the materials available, reversed a
• 18:12
  Speaker 1: pump cycle remotely via laptop, and then waited 90 minutes
• 18:15
  Speaker 1: while the ground monitored the system. It held. That kind
• 18:19
  Speaker 1: of repair, unscripted, unglamorous, successful, is what keeps a mission
• 18:24
  Speaker 1: alive past the headline event. The mission patch shows five
• 18:28
  Speaker 1: stars and a robotic arm. Irakay appears at the center,
• 18:33
  Speaker 1: trailed by three yellow contrails. The crew designed it that way.
• 18:38
  Speaker 1: At the start of the story, Eureka was sitting in
• 18:40
  Speaker 1: a payload bay with its batteries draining and its antennas unsecured.
• 18:45
  Speaker 1: The consequence of one connector rotated half a turn in
• 18:48
  Speaker 1: the wrong direction. By the end, it was home. The
• 18:52
  Speaker 1: science was intact. The crew was safe, and the half
• 18:56
  Speaker 1: turn that nearly broke everything became a footnote to a
• 18:59
  Speaker 1: mission that completed Every objective it set out to achieve.
• 19:03
  Speaker 1: The connector was wrong. The connector rotated half a turn
• 19:07
  Speaker 1: in the wrong direction. The battery strained in orbit. The
• 19:10
  Speaker 1: antennas sat unsecured. Nancy Curie Gregg improvised a repair with
• 19:15
  Speaker 1: a diaper and a laptop. A pressurized water fitting came loose,
• 19:18
  Speaker 1: and then held. Ereka came home, and the science was intact.
• 19:23
  Speaker 1: This show is made by Obomidi.