NASA's chief engineer Friday defended the space agency's "smaller, faster, cheaper" policy for designing space missions, saying that the loss of the $125 million Mars Climate Orbiter was probably unrelated to the accelerated design process of the mission.
Engineers confusing metric and non-metric units incorrectly programmed a part of the orbiter's maneuvering system, sending it gradually off target -- and possibly to its destruction -- over the duration of its nine-month journey.
NASA lost contact with the spacecraft on September 23, and has since theorized that the craft was either destroyed when it burned up after plunging into the Martian atmosphere, or ricocheted into a useless orbit.
The orbiter, which was to study weather and climate on Mars, had been designed as part of a new class of smaller and less expensive space projects meant to decrease the risk of having one mistake throw the space program off course. Missions that took up to seven years to design and implement were done in half the time.
Some have suggested that cost cutbacks and an accelerated development process are to blame for the loss of the orbiter.
"It may be," said John E. Pike, director of the space policy project for the Federation of American Scientists, "that they've gone a little too far in cutting corners. It may be that there are some respects in which 'smaller, faster, cheaper' has been pennywise and pound foolish."
But NASA's chief engineer, Daniel Mulville, said the mistake was likely due to a "breakdown in communications," at an early stage, and that the mistake probably does not signify a systemic problem.
"I would argue that the time we [take to] implement the mission is not the issue," Mulville said. "I'm not sure that that would have made a difference on this."
The decision of what measurement system to use would have occurred at the formation of a mission like the Mars Climate Orbiter, he said, probably around three or four years ago.
NASA's own policy on measurement units, which became effective in January 1996, says that metrics should be the rule.
"Require the use of the metric system for all major flight program new starts unless a waiver is granted," reads the
, which is signed by NASA administrator Dan Goldin.
But the policy allows non-metric systems to be used for existing systems, or if the mission team is granted a waiver.
Mulville, citing an ongoing investigation, declined to discuss the specifics of the Mars Climate Orbiter mission -- including whether any components were certified to operate with non-metrics.
An investigation by an internal review board is expected to conclude by mid-November.
