Graham Warwick/WASHINGTON DC
Flaws in NASA's "faster, better, cheaper" approach overloaded programme management at the Jet Propulsion Laboratory (JPL), and contributed directly to the failures of the Mars Climate Orbiter and Mars Polar Lander, says the report by the Mars programme independent assessment team (MPIAT).
The US space agency has cancelled a planned Mars 2001 lander mission while it acts on the report's findings. One recommendation has been implemented, with the appointment of an overall Mars programme director at NASA. The report supports Mars exploration and says the faster, better, cheaper approach, properly applied, should be continued.
As expected, investigation of the Polar Lander failure concluded that the most probable cause was "spurious signals" generated when the landing legs deployed. The software was not designed to eliminate such signals, the report says; the signals were not detected during testing because the touchdown sensors were incorrectly wired; and tests were not repeated with them correctly wired.
"The underlying cause was inadequate software design and test," the report says. Two Deep Space 2 microprobes carried by the lander probably failed because they were "not adequately tested and not ready for launch". The combined Climate Orbiter and Polar Lander mission was underfunded by about 30% from the outset, the report says. "The result was inadequate preparation and excessive risk," it adds.
Led by former Lockheed Martin executive Tom Young, the MPIAT scrutinised successful and unsuccessful "faster, better, cheaper" missions to find common characteristics. Successful missions studied were the Mars Gobal Surveyor and Pathfinder, both launched in 1996, and 1998's Deep Space 1 technology demonstration.
The Global Surveyor and Pathfinder had experienced programme managers, adequate margins and acceptable risks, the report says. The Climate Orbiter and Polar Lander had inexperienced programme managers, inadequate margins and excessive risks. Deep Space 1's inexperienced programme manager was augmented by senior JPL management and its inadequate margins were alleviated by descoping the mission and delaying the launch.
Faster, better, cheaper has increased the flight projects under way at JPL from one to four a year to 10-15, says the MPIAT. This means more missions have inexperienced managers. "The current JPL organisation is not adequate to manage the Mars programme successfully," the report says. NASA says it will work with the California Institute of Technology to "institute effective change" at JPL.
Source: Flight International
