The Genesis Mishap
An object lesson on human competence in dealing with complex systems.
The inversion might not have occurred if the direction of the acceleration vector had been written in SRC avionics coordinates, or if a coordinate system figure had been included with the acceleration vector noted.1
Chapter 1: Departure
On August 8, 2001, the fifth American space probe of the new millennium launched from Complex 17 at Cape Canaveral, Florida. Ushered beyond the atmosphere and to escape velocity by the time-tested Delta-II/Star 48B rocket/motor tag-team, the ambitiously named Genesis glided off into the depths of space.
Her path toward the Sun described that of a machine which is slowly crawling toward the center of a rotating disc, which bears on its outer rim the Earth. But when this particular machine had traveled 1% of the way toward the center, 3 months and 1.5 million kilometers away from Earth, she did something strange. She veered upward from the disc that previously seemed to hold her in place, and curved into orbit around the invisible, moving point in space below her. No sooner did she rise up from the disc, than did the curves of space begin to arc her back down, and then below the disc, and then back up toward it, in perfect equilibrium. She maintained this seemingly impossible movement without the aid of her thrusters, beyond those brief flashes which steadied her balance. There she was, like a wizard rolling around the Sun on the edge of a quarter, mocking the very laws of the universe on behalf of all humanity.
It was now November. While the beings who created her were caught in the throes of sudden, unforeseen destruction, Genesis, in the silence of space, was engaged in transformation. On the mysterious object crowning her central bus, gears rotated, and hinges turned. Devices of measurement, unveiled by stirring lids, blinked into the brilliant light. Genesis worked with patience, so that no instrument would be harmed by haste. Within a few days, the hard, ugly object on her central bus had hinged open two protective upper lids, revealing glorious golden undersides, and unveiling a nest of spirally pivoting arrays of equal splendor. The result seemed deliberately ebullient: circular dish overlapping circular dish; honeycombs of gem-like hexagons; like a masterfully-designed watch somehow taking itself apart under the astonished eye of the Sun. Her wonders thus fully displayed, Genesis began to absorb the residues of coronal plasma streaming toward her on the solar wind - which at this outpost, away from the Earth’s corrupting magnetosphere, were in their pure form.
Incredibly, she was not alone. Deftly teasing the edges of the same same invisible, centrifugal gradient that surrounds the moving point where the gravitational distortion of Earth and the Sun are in balance, were SOHO, and ACE. These two had arrived, respectively, six and four years earlier. Both steadfastly gazed toward the solar giant as she did, bathing in its ions. Yet she was not like them. With her incredible unveiling chrysalis, her physical absorption of the pollen of the Sun, she was something greater - more alive. They were merely machines. They did spectrometer readings in their ion receptors, and reported the values back to Earth as cold, numerical transmissions. They took pictures. “Soho.” “Ace.” Even their names were dreary and business-like. Still, it was more comfortable not to be alone, and who could have expected company at so strange an outpost as this? There was even a story, shared by the older machines, that another craft had visited this place, decades before them; that it had spent four years watching the Sun in L1 Halo Orbit, just like them, until it escaped, to touch the tails of comets. But what is one to make of such preposterous tales?
Two years passed, out there in the silent wind. As Genesis neared the end of her fifth orbit, so too did near the time for her departure. She made ready, re-folding and re-nesting the clockwork away of golden lids and dishes in the object crowning her central bus, as slowly as she had opened it. For anything to go awry here would spoil all of her work - the inner and outer lids must close and latch completely, so that her carefully stolen samples within would survive their coming journey. At last she finished her packing, again without a single mistake. She bid farewell to her fellow spies, delicately eased herself back onto the invisible disc which had brought her to this magic place, and began her return. This would be the most intricate part of her voyage yet.
Back on Earth, nearly three years had passed from the date of launch, when word came that Genesis was on her way. Incredibly, the beings who created her had not destroyed themselves in the interval. Now preparations were being conducted for her arrival. Two helicopter crews, and a team of mission programmers, were tirelessly rehearsing the delivery of the Sample Return Capsule which she would send from outside Earth. It was another strange sight. The two crews - each consisting of three men - practiced making coordinated, staggered attempts to intercept a parcel descending with a parachute from midair, with a hook hanging out from their open fuselage door.
This is how they would receive the SRC. So important was it to avoid a partial opening of the lids protecting the samples, that merely allowing it to land with the built-in, automatically deploying main parachute would risk disaster. The intercept was crucial. The helicopters would try to catch the fast-descending SRC with their hook, and if they missed, rapidly dish altitude to attempt again. The first possible attempt starting at 2500 meters elevation, the mission programmers and the helicopter crews expected to have enough time to make five passes. It was a feat appropriate for a Hollywood movie stunt - and in fact it was Hollywood stunt-flyers who the Genesis mission programmers had hired.
Above the Utah Test and Training Range where the crews trained and where the SRC’s real arrival would take place, once one of the helicopters successfully hooked onto the parachute, the hook would reel out to 100 feet, allowing the crew to safely and gently return their prize to the recovery platform, and lower it to the ground. Intercepting a package from space with a helicopter would be a first for mankind. The crew that succeeded would have a place in history.
NPR 8621.1A, NASA Procedural Requirements for Mishap Reporting, Investigating, and Recordkeeping, defines a proximate cause as “The event(s) that occurred, including any condition(s) that existed immediately before the undesired outcome, directly resulted in its occurrence and, if eliminated or modified, would have prevented the undesired outcome.” It is also known as the direct cause.2
Chapter 2: Arrival
Genesis was only hours away from Earth, awaiting final word from the humans below. Ever the model of patience, she had chosen a path home that first placed her beyond Earth and then looped back, adding two months to her return: This way, her final approach trajectory could be tuned for any delays in the days and hours just before her historic cargo’s scheduled delivery. She had been preheating the batteries within the SRC since the day prior, and adjusting her spin and trajectory as needed; but before she could do anything else, she must receive the Enable signal from her creators. When the final Enable/NoGo window opened, the command arrived without hesitation. The humans on the ground were as ready for delivery as she was.
Bravely she lowered herself into the gravity well of Earth, eight hours away from the SRC’s pending reentry. Well before that moment arrived, the braces fixing the SRC to her central bus would release, after which she would never be in contact with it again. She would use her thrusters to roll herself back out from the gravity well; the SRC would continue rolling deeper within it. True to its name, the Sample Return Capsule was not a spacecraft. It had no thrusters or gyroscopes to change position after release: The SRC would literally be riding the curve of space on a four hour ballistic course, a giant spinning bullet thrown sixty thousand kilometers at a rotating target on the surface of the Earth where two helicopters waited to catch it with hooks.
Further peril would still await the stranded SRC upon contact with the atmosphere. It would need to detect the beginning of reentry - experienced as a brutal deceleration reading over 25 g’s - with at least one of its two pairs of Aerodyne 7200-6-000 g-sensor switches; then, when the g-sensor plungers released contact with their switches at the moment deceleration dropped below 3 g’s, blast open the mortar in the center of its top lid, releasing the critical primary drogue chute upon which all subsequent steps depended. At the correct moment - determined by the timer and air-pressure regulated circuit within the activated Avionics Unit - the unit would send a blast command to the three frangible bolts securing the crown of the SRC’s top lid. The drogue chute would then rapidly pull the Deployable Aft Conical Section upward, opening the larger, main parachute behind it; lastly, the Avionics Unit would send a command up to sever the cables to the drogue with another set of charges.
There would only be one shot at the pyro sequence. There was no room for error - which is why the SRC contained two equal-purpose Avionics Units, as a redundancy against the failure of either; why every component of both Avionics Units had been inspected multiple times before launch; and why a g-sensor centrifuge test was mandated as part of the inspection process. Finally, even if everything went right, the first possible helicopter pass would take only place when the SRC was a mere 2500 meters above the surface - a four minute window. But that final, crucial stage - the helicopter recovery - still depended on Genesis, and the accuracy of her throw.
-5:55 to Entry: Release Sequence Start. Genesis powered on the SRC Avionics Units, one at a time. Moments later - at -5:24 to Entry - she released the giant hinge she had used to open and close the SRC’s outer lid at L1 Halo Orbit, and severed the cables connecting the capsule to her - this was the point of no return. The batteries powering the Avionics Units would now self-drain within hours; a last-minute diversion was out of the question. -5:07 to Entry: She increased her rate of spin to 10 rpm. -4:23 to Entry: 22 minutes away from release, Genesis increased her rate of spin again; a dizzying 15 rpm. When the braces released, the SRC would carry forward with this stabilizing spin for its last four hours in space, then drill into Earth’s atmosphere with its heat shield. Who knows what import this moment would have, to the humans who had created her? The pure, perfect samples of solar wind she had so miraculously collected could advance human knowledge by years, even decades; they could be the difference between future apocalypse, and salvation. -4:01: The moment was here. Her tens of thousands of patient, precise movements all culminating to this final rushing test, Genesis executed the SRC release. It was done. Her aim was flawless.
The SRC failed to deploy its drogue chute because all four g-sensors had been installed upside-down. A miscommunication had allowed for the cancelling of the centrifuge tests during construction. The capsule crashed into the Earth like a common piece of space junk, bursting into parts and contaminating the samples inside with dust and ruptured battery juice. The extensively trained helicopter crews took their paychecks, and went home.
(Continued in Afterward.)
GENESIS Mishap Investigation Board Report, p. 32. Cover illustration: Aerodyne 7200-6-000 3-g acceleration switch, as used in the Genesis Sample Return Capsule. Switch contact facing down.
ibid, p. 23. SRC Release Sequence timetable from p. B-10-12.
Notes:
Using the pedantic end- and start- dates for millennia, Genesis was the third American space probe. Besides being in accordance with the “incorrect” lay understanding, I thought fifth was a better match in tone with “space probe.”
“There was even a story…” is a reference to the ISEE-3 (“International Sun-Earth Explorer-3”), renamed ICE (“International Cometary Explorer”) in 1982.
As the SRC is released upside-down, it presumably drops its stabilizing spin upon encountering atmospheric resistance and flips around to lead with its center of gravity, the heat shield; the atmosphere therefor remains thoroughly “undrilled.” The description of the SRC Avionics Unit logical design is a bit simplified. The actual placement of the drogue chute cable-cut charges, additionally, was unclear.
It is probable that the helicopter crews actually received their paychecks some time after they returned home.
wow! great story!