Back
in 2004, when NASA's Genesis return sample capsule tumbled from the sky and
slammed into the Utah desert, scientists quite literally had to pick up the
pieces of the mission.
Delicate
wafers holding precious samples of atoms and ions from puffs of solar wind that
Genesis accumulated while lingering at Lagrange Point 1--an area in space
between Earth and the Sun--were shattered to bits.
Since
the crash landing, researchers have been hard at work pulling science data from
the fragments--but it's a far tougher task than originally planned when the $260
million Genesis mission lifted off in August of 2001.
Soon-to-be
released findings from a study of the Genesis mishap have brought to light
several "lessons learned"--action items that NASA's next sample return mission
team for Stardust are embracing for that capsule's upcoming January 15th
Utah landing.
The
$212 million Stardust mission blasted off in February 1999--more than two years
earlier than the Genesis departure. It is coming home next month after a nearly
seven-year space trek.
Test, test, test, and test
The
lesson learned from Genesis is straightforward, said space engineer Michael
Ryschkewitsch who chaired the Genesis Mishap Investigation Board (MIB) and is
now deputy center director of the NASA Goddard Space Flight Center in Greenbelt, Maryland.
"It's
the 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 were
people that were trying very hard...and sometimes things don't go the way you
want them to," Ryschkewitsch told SPACE.com.
Ryschkewitsch
said that the MIB findings are to appear in two volumes: One, an engineering
autopsy that looks at the causes for the Genesis crash landing itself, the
other volume focused on the ground recovery procedures that took place on the
capsule's plow-down in Utah on September 8, 2004.
NASA's
chief medical officer was not pleased with the initial stages of the ground
recovery actions that took place. An MIB subteam was formed to look into this
matter, as well as the overall training of personnel and steps taken by
post-landing ground teams.
"There
was not enough training by all of the people involved so that everybody had the
same knowledge," Ryschkewitsch said. In the minutes following impact of the
Genesis return sample capsule, he noted, there was a conflict between ground
units regarding what team was in charge and what procedures they were operating
to.
"Then
the people that had been intended to be in charge under the normal operation...took
over...and from that point on everything was okay," Ryschkewitsch added.
But
what's the multi-million dollar answer to the question of why Genesis took the
fall in the first place?
Proximate cause
Back
in October of 2004, the MIB had quickly identified a likely direct cause of the
failure of Genesis' parachute system to open.
The
MIB--analyzing the badly crunched Genesis capsule--said the likely cause was a
design error that involved the orientation of gravity-switch devices. Those
tiny switches sense the deceleration caused by the craft's high-speed entry
into the atmosphere--switches that were then to initiate the timing sequence
that deployed the capsule's drogue parachute, followed by release of a
parafoil, followed by an in-the-air helicopter capture.
That
critical sequence did not happen. The capsule smacked into a pre-determined
landing site at the Utah Test and Training Range (UTTR), a vast and unoccupied
salt flat controlled by the U.S. Army and Air Force.
The
inappropriate positioning of the gravity-switch devices (g-switches)--upside
down--led to the Genesis capsule's less-than-soft touchdown. That wrongly placed
piece of hardware was installed in 1998.
The
g-switch problem has been identified by the Genesis MIB as the "proximate
cause", Ryschkewitsch said. That "most immediate cause" spurred the MIB team to
dig back and trace how that happened and how the problem was not addressed
prior to launch.
Installation error
Lockheed
Martin Space Systems of Denver, Colorado designed, built and operated the
Genesis spacecraft, as well as the Stardust probe now en route to Earth.
While
the fundamental structures between Genesis and Stardust are different,
Ryschkewitsch said a great deal of commonality exists in the avionics within
the 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 other
avenues they are dissimilar.
That
is why lessons learned from Genesis became a heads-up in some ways for those
dealing with the incoming Stardust spacecraft and its prized catch of
interstellar and comet particles.
Ryschkewitsch
said that Genesis had a great deal more motor controllers to handle the opening
of its sample capsule, including the spreading of paddles out into space to
collect solar wind--gear that also tucked inward for the ride home.
In
the case of Genesis--why g-switch orientation was upside down--Ryschkewitsch said
that happened during the process of reconfiguring the electronics from Stardust's
design in order to accommodate all of the extra motor controllers onboard
Genesis.
"Most
of the other functioning pieces of the spacecraft...the timers, deployment
mechanisms...are very similar," Ryschkewitsch said.
In
their investigations, Ryschkewitsch advised that Stardust underwent a "very
specific 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 test
program, he said, with the g-switch installation error going unnoticed.
Full-circle circumspection
In
a kind of full-circle circumspection, the wreckage of the Genesis sample return
capsule underwent engineering scrutiny and testing at the Waterton, Colorado
facility of Lockheed Martin Space Systems, back where both Genesis--and Stardust--were
assembled.
Lockheed
Martin supported the MIB, both in examining the recovered hardware and in assembling
documentation relevant to the development of Genesis.
"We
worked side-by-side with NASA to determine the cause of the Genesis hard
landing, and continually review our processes and procedures, putting measures
in place to avoid problems in the future," explained Buddy Nelson, a spokesman
for Lockheed Martin Space Systems.
"We've
had the opportunity to review preliminary iterations of the MIB report and have
incorporated 'lessons learned' into our preparations for the Stardust return
next month, Nelson told SPACE.com.
"We
are hopeful that the recovered samples captured by Genesis will enable
researchers to achieve most of their scientific objectives," Nelson said.
No lack of information flow
Meanwhile,
Stardust draws closer to Earth.
Spacecraft
blueprints, pre-flight photos, and a re-check of the Stardust g-switch test
have been thoroughly gone over, Ryschkewitsch said. "We were fully satisfied with the
responses to our recommendations...that they had closed them all out. There has
been absolutely no lack of information flow."
Ryschkewitsch
said that the Genesis incident, like other mishaps in space, involves a chain
of events. Processes are set up so that spacecraft designers have multiple
chances to catch errors.
"We
talk about safety nets one behind the other and behind the other," Ryschkewitsch
explained. "There were a number of different things and very specific things
that needed to be improved and tightened up."
In
specific, there's been a beefing up of Stardust contingency plans, in the event
that things unexpected occur during the entry and parachute landing of the
sample capsule. Team training was enhanced, Ryschkewitsch said, "to make sure people
could react as quickly, efficiently, and as safely as possible."
Internal wherewithal
No
doubt, the drama of the Stardust samples coming back to Earth will undoubtedly
be 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 lengthy
space voyage.
Stardust
will undergo a blistering high-speed entry into Earth's atmosphere on January
15th - the fastest human-made object to fireball home as it plunges
into the Utah
Test and Training Range.
"A
great deal of effort has gone into the planning, leading up to the capsule's
release...to make sure it's released in exactly the right place, in the right
direction, and to make sure it comes down on range," Ryschkewitsch said.
"Fundamentally
this is a very, very tough business," Ryschkewitsch concluded. "You've got
many, many things that have to go exactly right."
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