[lunar-update] Report Reveals Likely Causes of Mars Spacecraft Loss

Fri Apr 13 18:28:58 EDT 2007

Report Reveals Likely Causes of Mars Spacecraft Loss
http://www.nasa.gov/mission_pages/mgs/
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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

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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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http://dsc.discovery.com/news/2007/04/13/surveyor_spa.html?category=space&guid=20070413140000&dcitc=w19-502-ak-0000 
<http://dsc.discovery.com/news/2007/04/13/surveyor_spa.html?category=space&guid=20070413140000&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.

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

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