Backin 2004, when NASA's Genesis return sample capsule tumbled from the sky andslammed into the Utah desert, scientists quite literally had to pick up thepieces of the mission.
Delicatewafers holding precious samples of atoms and ions from puffs of solar wind thatGenesis accumulated while lingering at Lagrange Point 1--an area in spacebetween Earth and the Sun--were shattered to bits.
Sincethe crash landing, researchers have been hard at work pulling science data fromthe fragments--but it's a far tougher task than originally planned when the $260million Genesis mission lifted off in August of 2001.
Soon-to-bereleased findings from a study of the Genesis mishap have brought to lightseveral "lessons learned"--action items that NASA's next sample return missionteam for Stardust are embracing for that capsule's upcoming January 15thUtah landing.
The$212 million Stardust mission blasted off in February 1999--more than two yearsearlier than the Genesis departure. It is coming home next month after a nearlyseven-year space trek.
Test, test, test, and test
Thelesson learned from Genesis is straightforward, said space engineer MichaelRyschkewitsch who chaired the Genesis Mishap Investigation Board (MIB) and isnow deputy center director of the NASA Goddard Space Flight Center in Greenbelt, Maryland.
"It'sthe same motto that we've all had for years and years and years. Test, test,test, and test...this business is very hard and you can never be too careful.That's not to say that anybody in the process was not careful. There werepeople that were trying very hard...and sometimes things don't go the way youwant them to," Ryschkewitsch told SPACE.com.
Ryschkewitschsaid that the MIB findings are to appear in two volumes: One, an engineeringautopsy that looks at the causes for the Genesis crash landing itself, theother volume focused on the ground recovery procedures that took place on thecapsule's plow-down in Utah on September 8, 2004.
NASA'schief medical officer was not pleased with the initial stages of the groundrecovery actions that took place. An MIB subteam was formed to look into thismatter, as well as the overall training of personnel and steps taken bypost-landing ground teams.
"Therewas not enough training by all of the people involved so that everybody had thesame knowledge," Ryschkewitsch said. In the minutes following impact of theGenesis return sample capsule, he noted, there was a conflict between groundunits regarding what team was in charge and what procedures they were operatingto.
"Thenthe people that had been intended to be in charge under the normal operation...tookover...and from that point on everything was okay," Ryschkewitsch added.
Butwhat's the multi-million dollar answer to the question of why Genesis took thefall in the first place?
Proximate cause
Backin October of 2004, the MIB had quickly identified a likely direct cause of thefailure of Genesis' parachute system to open.
TheMIB--analyzing the badly crunched Genesis capsule--said the likely cause was adesign error that involved the orientation of gravity-switch devices. Thosetiny switches sense the deceleration caused by the craft's high-speed entryinto the atmosphere--switches that were then to initiate the timing sequencethat deployed the capsule's drogue parachute, followed by release of aparafoil, followed by an in-the-air helicopter capture.
Thatcritical sequence did not happen. The capsule smacked into a pre-determinedlanding site at the Utah Test and Training Range (UTTR), a vast and unoccupiedsalt flat controlled by the U.S. Army and Air Force.
Theinappropriate positioning of the gravity-switch devices (g-switches)--upsidedown--led to the Genesis capsule's less-than-soft touchdown. That wrongly placedpiece of hardware was installed in 1998.
Theg-switch problem has been identified by the Genesis MIB as the "proximatecause", Ryschkewitsch said. That "most immediate cause" spurred the MIB team todig back and trace how that happened and how the problem was not addressedprior to launch.
Installation error
LockheedMartin Space Systems of Denver, Colorado designed, built and operated theGenesis spacecraft, as well as the Stardust probe now en route to Earth.
Whilethe fundamental structures between Genesis and Stardust are different,Ryschkewitsch said a great deal of commonality exists in the avionics withinthe two systems, as well as procedural handling of the entry capsule. Therefore,in some ways, Genesis is a technological look-alike of Stardust, but in otheravenues they are dissimilar.
Thatis why lessons learned from Genesis became a heads-up in some ways for thosedealing with the incoming Stardust spacecraft and its prized catch ofinterstellar and comet particles.
Ryschkewitschsaid that Genesis had a great deal more motor controllers to handle the openingof its sample capsule, including the spreading of paddles out into space tocollect solar wind--gear that also tucked inward for the ride home.
Inthe case of Genesis--why g-switch orientation was upside down--Ryschkewitsch saidthat happened during the process of reconfiguring the electronics from Stardust'sdesign in order to accommodate all of the extra motor controllers onboardGenesis.
"Mostof the other functioning pieces of the spacecraft...the timers, deploymentmechanisms...are very similar," Ryschkewitsch said.
Intheir investigations, Ryschkewitsch advised that Stardust underwent a "veryspecific test" to check g-switch function. That test was not done on Genesis,due to a more complex setup of hardware, making it also a more complicated testprogram, he said, with the g-switch installation error going unnoticed.
Full-circle circumspection
Ina kind of full-circle circumspection, the wreckage of the Genesis sample returncapsule underwent engineering scrutiny and testing at the Waterton, Coloradofacility of Lockheed Martin Space Systems, back where both Genesis--and Stardust--wereassembled.
LockheedMartin supported the MIB, both in examining the recovered hardware and in assemblingdocumentation relevant to the development of Genesis.
"Weworked side-by-side with NASA to determine the cause of the Genesis hardlanding, and continually review our processes and procedures, putting measuresin place to avoid problems in the future," explained Buddy Nelson, a spokesmanfor Lockheed Martin Space Systems.
"We'vehad the opportunity to review preliminary iterations of the MIB report and haveincorporated 'lessons learned' into our preparations for the Stardust returnnext month, Nelson told SPACE.com.
"Weare hopeful that the recovered samples captured by Genesis will enableresearchers to achieve most of their scientific objectives," Nelson said.
No lack of information flow
Meanwhile,Stardust draws closer to Earth.
Spacecraftblueprints, pre-flight photos, and a re-check of the Stardust g-switch testhave been thoroughly gone over, Ryschkewitsch said. "We were fully satisfied with theresponses to our recommendations...that they had closed them all out. There hasbeen absolutely no lack of information flow."
Ryschkewitschsaid that the Genesis incident, like other mishaps in space, involves a chainof events. Processes are set up so that spacecraft designers have multiplechances to catch errors.
"Wetalk about safety nets one behind the other and behind the other," Ryschkewitschexplained. "There were a number of different things and very specific thingsthat needed to be improved and tightened up."
Inspecific, there's been a beefing up of Stardust contingency plans, in the eventthat things unexpected occur during the entry and parachute landing of thesample capsule. Team training was enhanced, Ryschkewitsch said, "to make sure peoplecould react as quickly, efficiently, and as safely as possible."
Internal wherewithal
Nodoubt, the drama of the Stardust samples coming back to Earth will undoubtedlybe a nail-bitter. The capsule carries no transmitter or receiver. Like Genesis,it is on its own internal wherewithal to perform as designed after a lengthyspace voyage.
Stardustwill undergo a blistering high-speed entry into Earth's atmosphere on January15th - the fastest human-made object to fireball home as it plungesinto the UtahTest and Training Range.
"Agreat deal of effort has gone into the planning, leading up to the capsule'srelease...to make sure it's released in exactly the right place, in the rightdirection, and to make sure it comes down on range," Ryschkewitsch said.
"Fundamentallythis is a very, very tough business," Ryschkewitsch concluded. "You've gotmany, many things that have to go exactly right."
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