Courtesy NASA.
Need proof that space
engineers can overcome
some problems? Check out
this gas cloud captured
by the twice-fixed Hubble
Space Telescope.
Foresight
Does faster and cheaper equal lesser?
Preventing the kind of losses that are plaguing NASA is the job of risk management experts. These fault-obsessed folks try to anticipate what could go wrong -- and devise changes to hardware, software or procedures before launch. It's kind of like the post-mortem investigation now being done on Polar Lander -- before the loss occurs.
After years of lofting spacecraft that cost billions, NASA is now trying to do the job "faster, cheaper and better." But the disappearance of Mars Polar Lander and Climate Orbiter both raised the question of whether the cut-rate missions are hitting the mark.
A variety of space experts told the New York Times that NASA was simply trying to do too much with too little. "We've all seen this," said John Pike of the Federation of American Scientists. "Anybody who has tried to do too much work without enough people immediately recognizes the symptoms. Stuff doesn't get done. Things fail."
Doin' the pre-mortem
For Sojourner, the scientific breadbox that rolled across the Mars landscape in 1997, he started by "looking at a day in the life of the lander. I asked what it is supposed to do, minute by minute." Using a database of failures for the various motors, circuits and other components, he searched for weak links -- components that could bollix the whole mission.
The work focused on the modem Sojourner used to communicate with the lander. "They were spending a lot on software that would make sophisticated, semi-autonomous decisions, but I suggested that they spend a little more on the modem, which was a non-redundant weak link," Frank says.
JPL made changes, Frank says, and the little lander worked 'til the end of its 30-day mission.
Michael Frank, president of Safety Factor Associates, Encinitas, Calif., has done risk assessment for the Cassini and Sojourner spacecraft, says he constructs "fault trees" that try to anticipate every significant malfunction.
