Report Reveals Likely Causes of Mars Spacecraft Loss

http://www.nasa.gov/mission_pages/mgs/
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snip

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.

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I missed sending this in time for you to listen to the teleconference
but copied the report below.
- LRK -

The Discovery News clip makes a more dramatic heading with "Human Error
Caused Mars Surveyor Loss".

It is easy to get a sun burn while laying on the beach.
It is easy to overheat the shuttle if you can't open the cargo doors.
It is easy to overheat a spacecraft if you don't allow for where the Sun is.

When Pioneer 10 was launched it needed to make attitude adjustments to
point the spin axis in the direction you needed to make a Jupiter
encounter. Normally the big antenna dish would shadow the instrument
compartment if the antenna was pointing towards Earth when far away from
the Sun but in those first maneuvers after leaving earth you had thrust
vector considerations as well as antenna pointing issues, and you did
not want the instrument compartment and batteries getting blistered by
the Sun.

In a Pioneer/Jupiter News Letter issued on March 14, 1972, the title is
"PIONEER 10 DRAWS A BEAD ON JUPITER".
It mentions that on the 6th day of the mission the initial midcourse
maneuver was performed. The objectives of this maneuver were to locate
the encounter 3 radii from the center of Jupiter 14 degree below a
parallel to the ecliptic through the planet's center and time the
arrival within one of the daily 5 hour overlaps of tracking capabilities
of the 64 meter antennas at Goldstone, Calif., and at Canberra, Australia.

During reorientation of the spacecraft to earth alignment after
injection, signal dropouts were experienced in the interference region
between forward and aft (oppositely polarized) spacecraft antennas. This
restricted the alignment to within 45 degrees of earth alignment. Also
equipment compartment temperatures were near the upper design limits, so
it was preferred not to turn the spacecraft backside towards the sun
during the maneuver. They selected the maneuver strategy 48 hours after
launch and was sustained by excellent performance of the propulsion
system and JPL's measurements during calibration maneuvers during the
next 15 hours.

Sounds like fun, huh, where is Earth, where is Jupiter, where is the
Sun, where is my coffee? Oh, Oh, where is Pioneer 10?
Earth - Spacecraft Distance 8,789,2001 km
Spacecraft - Jupiter Distance 817,799,413 km

Even Lunar Prospector going to the Moon had to worry about where was the
Sun to get power to the solar panels and don't get the Sun shining on
the Alpha Particle Spectrometer bottom face as it may have gotten a
wrinkle in its Sunglasses when the trans lunar injection module pushed
itself away with its little nitrogen jets. You also had to worry about
not flying down Earth's shadow from the Sun because it was a full Moon
[Sun behind Earth, shadow looking out towards the Moon].

Want to fly a deep space mission?


Thanks for looking up with me.

Larry Kellogg

Web Site: http://lkellogg.vttoth.com/LarryRussellKellogg/
BlogSpot: http://kelloggserialreports.blogspot.com/
RSS link: http://kelloggserialreports.blogspot.com/atom.xml
Newsletter: https://news.altair.com/mailman/listinfo/lunar-update

==============================================================

April 13, 2007

Dwayne Brown
Headquarters, Washington
202-358-1726

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278

RELEASE: 07-88

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

EDITORS NOTE:

NASA will hold a media teleconference today at 3 p.m. EDT, to discuss
the report.

Reporters should call 1-888-398-6118 and use the pass code "Mars" to
participate in the teleconference. International media should call
1-773-681-5826. Replays of the teleconference will be available by
calling 866-369-3645. International media may call: 203-369-0243.

Audio of the teleconference will stream live at:

http://www.nasa.gov/newsaudio


-end-

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Snip
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http://dsc.discovery.com/news/2007/04/13/surveyor_spa.html?category=space&guid=2
0070413140000&dcitc=w19-502-ak-0000

Human Error Caused Mars Surveyor Loss

Alicai Chang, Associated Press

*April 13, 2007* � Human error triggered a cascade of events that caused
the battery to fail on the Mars Global Surveyor last year, according to
a preliminary report released Friday.

An internal NASA board determined that power loss likely doomed the
spacecraft after a decade of meticulously mapping the Red Planet.

But the problems actually began in 2005 when a routine technical update
to onboard computers caused inconsistencies in the spacecraft's memory.
The board concluded that engineers didn't catch the mistakes because the
existing procedures to do so were inadequate.

Scientists lost contact last November with the $154 million Global
Surveyor. Launched in 1996, it was the oldest of six different active
probes on the Martian surface or circling the planet.

Snip
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WHAT THE MIND CAN CONCEIVE, AND BELIEVE, IT WILL ACHIEVE - LRK

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