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Planetary News: Genesis (2006)Genesis Mishap Investigation Board releases Final ReportBy Amir Alexander13 June, 2006 Nearly two years after the Genesis sample return capsule slammed into the Utah desert, NASA released the final report of the Genesis Mishap Investigation Board. As had been previously reported, the Board found that the immediate cause of the accident was the incorrect positioning of the "G-switches" within the spacecraft's sample return capsule. In addition, the Board cited lax review procedures and inadequate emphasis on systems engineering as contributing factors to the mishap. According to the report, NASA's "Faster, Better, Cheaper" approach, which was dominant inthe 1990's, contributed to these deficiencies. On September 8, 2004, after more than three years in space, the Genesis spacecraft swept by Earth and released its sample return capsule. Within the cylindrical container were unique samples from the solar wind that Genesis gathered during more than two years orbiting the Sun at the first Lagrange point (L1). As the capsule swept over the western United States, it was designed to release a drogue parachute to slow it down, and then a giant parafoil when it reached its landing site over the Army's Dugway Proving Grounds in Utah. Helicopters with Hollywood stunt pilots at the helm were poised to pluck the Genesis capsule from the air as it hung beneath the gently floating parafoil. Instead, as the helicopters hovered nearby, the capsule shot by, and crashed into the desert. When the Mishap Investigation Board was formed two days later, it quickly zeroed in on the accident's proximate cause. Gravity switches, better known as "G-switches," installed within the capsule, were supposed to be activated by the G-forces operating on the capsule during it reentry into the Earth's atmosphere. This in turn was to trigger the release of the drogue parachute, which would then release the giant parafoil some seconds later. As the Board quickly found out, however, the "G-switches," were installed in an inverted position, and could not be triggered by the capsule's deceleration. As a result, the drogue parachute and the parafoil were never deployed, and the capsule continued unchecked on its trajectory, slamming into the ground at 200 miles per hour.
Once the immediate cause of the mishap was established, the Board expanded its investigation to include the systemic failures which allowed for the design error to occur, and then go undetected through an extended review process. The Board pointed to a lack of involvement by the Jet Propulsion Laboratory Genesis project management in the design, review, and testing of the spacecraft by Lockheed Martin Space Systems. They also cited inadequate systems engineering processes and a deficient review process, which allowed the design defects to go undetected, and recommended instituting a review of the systems engineering procedures as a necessary milestone in any project development. The Board expressed concern that technical reviews have become "too superficial and perfunctory," and recommended that the process be strengthened. The Board noted that the G-switches that failed were originally designed for the Stardust mission, and were adopted by Genesis as a "heritage technology." Such technologies, having supposedly been tested previously, are often subjected to less scrutiny than systems designed specifically for the mission at hand. This, the Board warns, is a dangerous assumption, and it recommends that heritage designs should undergo the same level of review as other mission systems. In addition, it recommends that items such as the G-switches should be subject to testing during the spacecraft's flight. Finally, the Board is critical of the "Faster, Better, Cheaper" approach to space missions that guided the selection and development of the Genesis mission. The pitfalls of "Faster, Better, Cheaper," they say, were already evident in the failure of two previous missions – the Mars Climate Orbiter and the Mars Polar Lander. The way that JPL chose to implement the approach, according to the Board, substantially reduced their oversight of the technical progress of the project. A closer oversight, they note, could have ensured that the design and construction process would follow previously successful mission practices. When the Genesis sample return capsule slammed into the Earth, it was a serious setback to the science team intent on collecting and studying the solar wind samples. Close to two years later, thanks to hard work and ingenuity, it now appears that nearly all of Genesis' samples will be salvaged, and the mission's science goals ultimately attained – though it will take considerably longer than planned. For the Genesis team, this is undoubtedly a happy outcome, the Board notes. Nevertheless, it should not obscure the seriousness of the accident itself or reduce the importance of its lessons for future missions. |
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