Mars Climate Orbiter Team Finds Likely Cause of Loss

Douglas Isbell

Headquarters, Washington, DC

(Phone: 202/358-1753)

Mary Hardin

Jet Propulsion Laboratory, Pasadena, CA

(Phone: 818/354-5011)

Joan Underwood

Lockheed Martin Astronautics, Denver, CO

(Phone: 303/971-7398)

RELEASE 99-113

A failure to recognize and correct an error in a transfer of
information between the Mars Climate Orbiter spacecraft team in
Colorado and the mission navigation team in California led to the
loss of the spacecraft last week, preliminary findings by NASA’s
Jet Propulsion Laboratory internal peer review indicate.

“People sometimes make errors,” said Dr. Edward Weiler,
NASA’s Associate Administrator for Space Science. “The problem
here was not the error, it was the failure of NASA’s systems
engineering, and the checks and balances in our processes to
detect the error. That’s why we lost the spacecraft.”

The peer review preliminary findings indicate that one team
used English units (e.g., inches, feet and pounds) while the other
used metric units for a key spacecraft operation. This
information was critical to the maneuvers required to place the
spacecraft in the proper Mars orbit.

“Our inability to recognize and correct this simple error
has had major implications,” said Dr. Edward Stone, director of
the Jet Propulsion Laboratory. “We have underway a thorough
investigation to understand this issue.”

Two separate review committees have already been formed to
investigate the loss of Mars Climate Orbiter: an internal JPL peer
group and a special review board of JPL and outside experts. An
independent NASA failure review board will be formed shortly.

“Our clear short-term goal is to maximize the likelihood of a
successful landing of the Mars Polar Lander on December 3,” said
Weiler. “The lessons from these reviews will be applied across the
board in the future.”

Mars Climate Orbiter was one of a series of missions in a
long-term program of Mars exploration managed by the Jet
Propulsion Laboratory for NASA’s Office of Space Science,
Washington, DC. JPL’s industrial partner is Lockheed Martin
Astronautics, Denver, CO. JPL is a division of the California
Institute of Technology, Pasadena, CA.