NASA Releases Orbiting Carbon Observatory Accident Summary

July 17, 2009

Katherine Trinidad
Headquarters, Washington
202-358-1100


RELEASE: 09-163

NASA RELEASES ORBITING CARBON OBSERVATORY ACCIDENT SUMMARY

WASHINGTON -- A NASA panel that investigated the unsuccessful Feb. 24
launch of the Orbiting Carbon Observatory, or OCO, has completed its
report.

NASA's OCO satellite to study atmospheric carbon dioxide launched
aboard a Taurus XL rocket from Vandenberg Air Force Base in
California on Feb. 24 at 4:55 a.m. EST, but it failed to reach orbit.


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.

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.

The official report of the board contains information restricted by
U.S. International Traffic in Arms Regulations and company sensitive
proprietary information. As a result, the board has prepared a
summary of its report, which provides an overview of publicly
releasable findings and recommendations regarding the OCO mission
failure. The summary is available at:

http://www.nasa.gov/oco

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