http://ana-logues.blogspot.com/2007/04/nasa-on-friday-thirteenth.html
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On 13-Apr-07, at 9:38 AM, Alan Sondheim wrote:
---------- Forwarded message ----------
Date: Fri, 13 Apr 2007 08:52:34 -0700
From: NASA Jet Propulsion Laboratory <[EMAIL PROTECTED]>
To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
Subject: Report Reveals Likely Causes of Mars Spacecraft Loss
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov
Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
NEWS RELEASE: 2007-040 April
13, 2007
Report Reveals Likely Causes of Mars Spacecraft Loss
WASHINGTON - After studying Mars four times as long as originally
planned, NASA's Mars
Global Surveyor orbiter appears to have succumbed to battery failure
caused by a complex sequence
of events involving the onboard computer memory and ground commands.
The causes were released today in a preliminary report by an internal
review board. The board was
formed to look more in-depth into why NASA's Mars Global Surveyor went
silent in November
2006 and recommend any processes or procedures that could increase
safety for other spacecraft.
Mars Global Surveyor last communicated with Earth on Nov. 2, 2006.
Within 11 hours, depleted
batteries likely left the spacecraft unable to control its orientation.
"The loss of the spacecraft was the result of a series of events
linked to a computer error made five
months before the likely battery failure," said board Chairperson
Dolly Perkins, deputy director-
technical of NASA Goddard Space Flight Center, Greenbelt, Md.
On Nov. 2, after the spacecraft was ordered to perform a routine
adjustment of its solar panels, the
spacecraft reported a series of alarms, but indicated that it had
stabilized. That was its final
transmission. Subsequently, the spacecraft reoriented to an angle that
exposed one of two batteries
carried on the spacecraft to direct sunlight. This caused the battery
to overheat and ultimately led to
the depletion of both batteries. Incorrect antenna pointing prevented
the orbiter from telling
controllers its status, and its programmed safety response did not
include making sure the spacecraft
orientation was thermally safe.
The board also concluded that the Mars Global Surveyor team followed
existing procedures, but that
procedures were insufficient to catch the errors that occurred. The
board is finalizing
recommendations to apply to other missions, such as conducting more
thorough reviews of all non-
routine changes to stored data before they are uploaded and to
evaluate spacecraft contingency
modes for risks of overheating.
"We are making an end-to-end review of all our missions to be sure
that we apply the lessons learned
from Mars Global Surveyor to all our ongoing missions," said Fuk Li,
Mars Exploration Program
manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
Mars Global Surveyor, launched in 1996, operated longer at Mars than
any other spacecraft in
history, and for more than four times as long as the prime mission
originally planned. The spacecraft
returned detailed information that has overhauled understanding about
Mars. Major findings include
dramatic evidence that water still flows in short bursts down hillside
gullies, and identification of
deposits of water-related minerals leading to selection of a Mars
rover landing site.
The Jet Propulsion Laboratory, Pasadena, Calif., manages Mars Global
Surveyor for NASA's
Science Mission Directorate, Washington. Lockheed Martin Space
Systems, Denver, developed and
operates the spacecraft.
Information about the Mars Global Surveyor mission, including the
preliminary report from the
process review board and a list of some important discoveries by the
mission, is available on the
Internet at:
http://www.nasa.gov/mission_pages/mgs
P!^VP
