Reviewers see red over recent Mars programs

September 27, 2002 at 1:04 pm

NASA’s most recent missions to Mars failed because they were underfunded, managed by inexperienced people, and insufficiently tested.

Artist’s view of Mars Polar Lander, which NASA lost. NASA

That was the scathing message of a report recently delivered to the space agency and made public this week. The mantra of “faster, better, cheaper” promoted by NASA Administrator Dan Goldin in the early 1990s remains worthy, A. Thomas Young, former executive vice president of Lockheed Martin in Bethesda, Md., told reporters at a March 28 briefing in Washington, D.C. But too much emphasis on the “cheaper” has jeopardized the Mars exploration program, says the report, echoing several other recent studies.

Young chaired a NASA-appointed panel that investigated the Mars program after the loss last year of the $125 million Mars Climate Orbiter, the $165 million Mars Polar Lander, and a $29.6 million pair of microprobes that had piggybacked on the lander. The panel notes that the orbiter and the lander, collectively known as Mars ’98, cost about the same as the successful 1997 Mars Pathfinder mission yet were intended to gather about three times as much data.

“This clearly indicates the significant lack of sufficient budget for Mars ’98. It was underfunded by at least 30 percent,” the panel finds. Young and his team note that because the lander couldn’t communicate with Earth during its descent and landing—a major flaw—they can’t be certain why the spacecraft vanished.

The reviewers say, however, that the most probable cause was spurious signals generated by one or more of the three legs that the lander unfolded during its descent. The signals would have falsely indicated that the craft had landed, causing the lander’s braking engines to shut down prematurely and the craft to crash (SN: 3/4/00, p. 159: Available to subscribers at No signal from Mars Polar Lander.). In four recent simulations, engineers detected such signals, Young said. Prelaunch testing revealed no such signals only because the sensors had been incorrectly wired—and the trial wasn’t repeated after technicians fixed the wiring.

“While the most probable direct cause of the failure is premature engine shutdown, it is important to note that the underlying cause is inadequate software design and systems test,” the report says. The panel uses equally blunt language in assessing the demise of the Mars Climate Orbiter, a loss that NASA had already traced to an embarrassing error. The force exerted by the craft’s thrusters, calculated in English units, had never been converted into the metric system, as engineers had assumed (SN: 10/9/99, p. 229).

Young’s panel reports that the navigation team was understaffed, did not understand the spacecraft, and was inadequately trained.” It notes that navigation errors observed during the craft’s 10-month cruise from Earth to Mars weren’t thoroughly investigated.

Buoyed by Pathfinder’s success, NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., which manages the Mars missions, tried to do too much with too little, Young notes. “In hind sight, we asked them to do the impossible,” says Edward J. Weiler, NASA’s associate administrator for space science in Washington, D.C.

“It’s a very balanced report that also doesn’t pull punches,” says Ray A. Williamson, a space-policy analyst at George Washington University in Washington, D.C. “If I were the NASA administrator . . . I’d be pretty embarrassed by it and would do whatever was needed” to improve.

Weiler says the agency will cancel a 2001 Mars lander mission but go ahead with plans next year for launching a spacecraft to orbit Mars. NASA no longer has a target date for retrieving samples from the Red Planet, he says.

“I’m not telling them to bring back a rock from Mars by 2008,” Weiler says. He notes that NASA headquarters will reserve funds for cases in which a developing project runs into trouble. Furthermore, he ordered an agency-wide review of Mars missions and wants Young’s panel to evaluate it this summer.

The Young report came just days after another embarrassing episode. On March 21, JPL engineers severely damaged a $75 million spacecraft designed to study solar flares.

During a vibration test, engineers accidentally subjected the High Energy Solar Spectroscopic Imager to 10 times the acceleration it would experience at launch. The shaking tore solar panels off the craft, which the agency had scheduled for a July launch. The vehicle may not be ready to fly until January.