Mars Global Surveyor

[Kelvena]

Oh, I agree, I was speaking only of the reception of commands and the completion of tasks. In most other respects, a manned mission would be exponentially more difficult to maintain.

[ROGER]

One of these days , Long into the future , I can see a system of Signal Repeaters like our cell phone towers , spread though out our Solar system. Unless we come up with some way to cheat the speed of light.

[shun]

This satellite was shaken up at launch, and never operated properly. They had to do a set of maneuvers twice each day, just to keep it going- for the panels, and to get the antenna oriented. It managed for years. Except, one last time...

They could have put a radionucleide power back-up, but they had a budget to meet (this unit included lots of recycled parts). Plus, Mars, with a mean orbital distance of 1.5 AU, still recieves plenty of concentrated light for solar panels (unlike Cassini, or Voyager, or Glaileo, which relied on radioisotope thermoelectric generators).

The inner minor-planets or asteroid belt is on the other side of Mars, out to Jupiter. Others are sparse and beyond Neptune. As for signal strength, consider that planet averages

12.5 light minutes travel time. But, sure, all things must be aligned, and working...

My feeling on sending people to Mars is it is a nobel goal, the will not come to fruition.

[Waspie_Dwarf]

They could have put a radionucleide power back-up, but they had a budget to meet

There is also a political issue with using this source of power. There were protests and legal attempts to stop the launches of Galileo, Cassini and New Horizons because of the radiothermal generators (RTGs) that powered these craft. Many people were concerned that a launch mishap would lead to the Plutonium-238, that powers these devices, being released into the environment.

Even NASA's next proposed mission to Jupiter, Juno, will be powered by solar arrays.

[badeskov]

There is also a political issue with using this source of power. There were protests and legal attempts to stop the launches of Galileo, Cassini and New Horizons because of the radiothermal generators (RTGs) that powered these craft. Many people were concerned that a launch mishap would lead to the Plutonium-238, that powers these devices, being released into the environment.

Even NASA's next proposed mission to Jupiter, Juno, will be powered by solar arrays.

There has indeed been a lot of controversy whenever a space craft with RTGs are launched. However, in my point of view that is a battle that has to be taken rather sooner than later. With an increased amount of more and more sophisticated probes being sent towards all corners of the solar system, can we really avoid them in the long run? Are there any alternatives?

Best,

Badeskov

[Waspie_Dwarf]

With an increased amount of more and more sophisticated probes being sent towards all corners of the solar system, can we really avoid them in the long run? Are there any alternatives?

I agree with you that RTGs are necessary for certain missions. My point, however, is that for missions to Mars and the inferior planets solar arrays are the better option.

[badeskov]

I agree with you that RTGs are necessary for certain missions. My point, however, is that for missions to Mars and the inferior planets solar arrays are the better option.

Oh, ok. Admittedly, I don't know myself, but I am very curious about it. Can I ask why solar arrays would be the better option to the inferior planets?

Best,

Badeskov

[Steeler Mania]

And to think NASA wants to sacrifice a rover to go to the bottom of a crater. Those two rovers are still 95% working.. I say no way. They both have out lived their intended mission and why condem one? They still do what they were intended to do. Sorry, just sorry to see another Mars probe die.

Surveyer gave us many exceptional shots and I cannot stand to see another working probe wasted.

[Aztec Warrior]

Were not miracle makers. We simple have to have more power!

[Waspie_Dwarf]

The rover won't be sacrificed, it will continue to explore until it dies a natural death. It will just spend the rest of it's life inside a large crater. The whole point of the rovers is to learn as much as possible and more will be learned inside the crater than outside.

[Steeler Mania]

The rover won't be sacrificed, it will continue to explore until it dies a natural death. It will just spend the rest of it's life inside a large crater. The whole point of the rovers is to learn as much as possible and more will be learned inside the crater than outside.

And what would it learn if it wasn't doomed? What if it found that missing key?

[Waspie_Dwarf]

And what would it learn if it wasn't doomed? What if it found that missing key?

That's silly talk. What if the missing key (what ever that is supposed to be) is in the crater. You could make this argument over ever decission that has been made, what if it had turned left instead of right.

It has done a lot of exploring of the terrain, it hasn't explored inside this crater so the decision makes sense.

[Waspie_Dwarf]

Mars Global Surveyor
Mars Orbiter Camera
Dust-Mantled Olympus Mons Flows
MGS MOC Release No. MOC2-1610, 27 November 2006


Credit: NASA/JPL/Malin Space Science Systems
Click on picture for high resolution image.

Dust-covered lava flows on the lowermost south flank of Olympus Mons are captured in this 3 kilometers (1.9 miles) wide Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) view acquired during northern summer on 12 October 2006. One leveed lava channel just south (below) the center left of of the image disappears into a thick, pitted and cratered dust mantle. Sunlight illuminates the scene from the left/upper left. The image is located near 13.8°N, 134.1°W. North is toward the top/upper right.

Source: Malin Space Science Systems - Mars Global Surveyor

[Waspie_Dwarf]

Panel Will Study Mars Global Surveyor Events

The press release is reproduced below:

Jan. 10, 2007

Dwayne Brown
Headquarters, Washington
202-358-1726

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

RELEASE: 07-03

Panel Will Study Mars Global Surveyor Events

WASHINGTON - NASA has formed an internal review board 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 launched in 1996 on a mission designed to study Mars from orbit for two years. It accomplished many important discoveries during nine years in orbit. On Nov. 2, the spacecraft transmitted information that one of its arrays was not pivoting as commanded. Loss of signal from the orbiter began on the following orbit.

Mars Global Surveyor has 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 Jet Propulsion Laboratory, Pasadena, Calif., manages Mars Global Surveyor for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft.

Information about the mission is available on the Internet at:

http://www.nasa.gov/mission_pages/mgs/index.html

- end -

--------------------------------------------------------------------------------

Source: NASA Press Release 07-04

[Waspie_Dwarf]

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.


Image above: Artist's concept of Mars Global Surveyor.
Image credit: NASA/JPL
+ Larger view

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 *** 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

Related links:
+ Preliminary Report: MGS Loss of Contact (28Kb PDF)

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

Dwayne Brown 202-358-1237/1726
NASA Headquarters, Washington

2007-040

Source: NASA - Missions - MGS

[Waspie_Dwarf]

Fossil Fans in Melas Chasma
Captioned Image Release No. MSSS-2 — 13 April 2007

(A) and ( Mosaic of sub-frames of MGS MOC images R12-00541 and R17-01687

50% size (1.5 MB) -- full size (5.1 MB)

(C ) Sub-frame of MRO CTX image P05_002828_1711_XI_08S076W_070304

25% size (1.6 MB) -- 50% size (6.2 MB)
full size (18.8 MB) -- full size, no annotation (18.8 MB)
Credit: NASA/JPL/Malin Space Science Systems

The geologic history of ancient Mars—and the kinds of environments that existed back then—are revealed through layered sedimentary rocks. Such rocks are created when weathering breaks down older rock, and wind and water transport the rock fragments to a location where they are deposited and subsequently lithified—turned back into rock—by cementation and compaction.

During its 9 year mission at Mars, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) discovered many complex relationships within martian sedimentary rocks. One of the most complicated locations it found occurs along the southern margin of Melas Chasma, one of the large troughs of the Valles Marineris system.

These images show a portion of a topographic depression eroded into layered rocks. Erosion has revealed layers of different ages—the oldest are at the bottom of the depression. Within this depression are two sets of alluvial—that is, water-lain—sedimentary rock units that retain their original shape, indicating how the sediments were deposited long before the material became rock. In these cases, the processes created fans of debris with finger-like protrusions at the ends and sides of the fans. Also preserved are the channels through which water and sediment flowed. In Figures (A) and (, the pictures are identical except that in (A) the fans have been colored to indicate their location. Long after these fans were formed, they were buried and subsequently uncovered by more recent erosion.

Figures (A) and ( are map-projected mosaics of MOC images R12-00541 and R17-01687. They were taken in 2003 and 2004, respectively, during the second MGS mission extension, the third Mars year that MGS was in its nearly-circular, nearly-polar mapping orbit. Figure © shows the context of the images in Figures (A) and ( in the area outlined by a white box. Figure © is a sub-frame of Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) image P05_002828_1711_XI_08S076W_070304, acquired last month on 4 March 2007. Sunlight illuminates all of these scenes from the left. The area of interest is located near 9.9°S, 76.6°W. .

Citation and Credit
Malin, M. C., and K. S. Edgett (2007), Fossil Fans in Melas Chasma, Malin Space Science Systems Captioned Image Release, MSSS-2, http://www.msss.com/msss_images/2007/04/13/.

Source: Malin Space Science Systems