NASA Pinpoints Causes for Climate Satellite Crash

NASA has found four potential causes for the loss of a $273 million climate satellite that crashed into the ocean just after its launch earlier this year, the space agency said Friday in a new report.

The advanced Orbiting Carbon Observatory satellite, built to study atmospheric Earth?s carbon dioxide levels, launched spaceward on Feb. 24 aboard a Taurus XL rocket from California?s Vandenberg Air Force Base, but it failed to reach orbit. Instead, it fell back to Earth and crashed into the ocean waters near Antarctica.

The spacecraft was NASA's first satellite built exclusively to map carbon dioxide levels on Earth and understand how humanity's contribution of the greenhouse gas is affecting global climate change.

Japan's recently launched "Ibuki" climate-studying spacecraft, as well as other satellites already in orbit, may be able to compensate for the lack of OCO.

The Mishap Investigation Board led by Rick Obenschain, deputy director at NASA's Goddard Space Flight Center in Greenbelt, Md., verified that the Taurus launch vehicle fairing failed to separate upon command. The fairing is a clamshell structure that encapsulates the satellite as it travels through the atmosphere. The failure to shed the fairing mass prevented the satellite from reaching its planned orbit and resulted in its destruction.

The board identified four potential causes that could have resulted in the fairing not separating:

• A failure of the frangible joint subsystem. A frangible joint is an explosive device that provides instantaneous separation of flight vehicle structures while maintaining confinement of explosive debris.
• A failure in the electrical subsystem that prevented sufficient electrical current to initiate the required ordnance devices.
• A failure in the pneumatic system, which supplies pressure to thrusters which separate the fairing.
• A cord snagged on a frangible joint side rail nut plate.

The panel also provided recommendations to prevent any future problems associated with the four hardware components that could have caused the OCO accident.

Since its 1994 debut, the Taurus rocket has flown six successful missions out of eight launches to orbit 12 satellites. The last Taurus launch reached space successfully in 2004. The one failure before Tuesday's contingency occurred in September 2001.

The six-member board began its investigation in early March. The panel conducted hardware testing; performed and reviewed engineering analysis and simulation data; reviewed telemetry data; collected and secured more than 2,000 documents; and conducted 78 interviews of critical personnel associated with the mission.

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