mgs_extended_mission_001213 WASHINGTON -- NASA has given a thumbs-up for an extension of the
Mars Global Surveyors (MGS) mission to study the Red Planet until April 2002. Doing so enables scientists to zoom in on prospective touchdown zones for future robotic landers. MGS is to end a nominal assignment of mapping the planet from orbit for one Martian year on February 1, 2001.
Mars takes 687 Earth days to travel around the Sun, making a Martian year almost two Earth years long. Cost of putting the MGS on an extended mission is $16.2 million.
Launched in November 1996, MGS has been dutifully swinging round and round the fourth planet from the Sun since September 1997.
After MGS arrived in Mars' orbit, however, a balky solar panel slowed down the process of aerobraking the spacecraft into the desired orbit for carrying out its prime science-taking tasks.
Also, problems with a dish-shaped high-gain communication antenna early in the MGS mission reduced the full flow of imagery and science data relayed back to Earth.
Data gaps
"The extended mission allows us to fill in the gaps and complete the global inventory of Mars," said
Jim Garvin, Mars exploration program scientist at NASA Headquarters. "MGS will be able to look across seasonal boundaries, where we have repeat seasonal coverage, to look for changes," he told SPACE.com.Bruce Jakosky, an astrobiologist at the University of Colorado in Boulder, said MGS' emphasis will be placed on making measurements to support future missions, such as likely landing sites.
"I think its clear from the science results announced this year that MGS is having a tremendous positive impact on our understanding of Mars. So keeping the spacecraft active and getting more scientists involved in analyzing data is imperative," Jakosky said.
Paul Hertz, program executive for MGS at NASA Headquarters, said that the Mars probe received high marks for its productivity, with a go-ahead given to lengthen its mission from February 2001 to April 2002.
"During the prime mission of MGS, about 1 percent of the surface of Mars was mapped at high-resolution by the camera. We want to take high-resolution pictures of a whole lot of places. So the science we expect to gain from the extended mission is obviously of high value," Hertz said.
Upsetting the Gods of Mars
Garvin said that the MGS is a healthy spacecraft and will be targeted "more aggressively" starting in February. One top look-see is focusing in on
is that it continues to provoke quarrels among planetary scientists decades after the Viking Mars missions in 1976. "There are 25 years of Viking-inspired legacies by some of the gods of Mars research," Garvin said. "The minute you change a paradigm and move things to new time epochs, there is resistance. Thats what we want, once these guys fall prey to the MGS drug, if you will," he said.
Laser looking
Not only will follow-on photos of Mars surface features be possible thanks to the MGS mission extension.
MGS carries a laser altimeter that can detect elevation variations in the polar caps. The caps are altered by seasonal changes.
Garvin said that the MGS laser may discern the amount of water, specifically at the northern perennial cap of Mars, which is composed mainly of water ice. "To get that mass balance of water at the north pole of Mars would be unbelievable," he said.
A high priority for MGS is cranking out high-resolution photos of landing sites, Garvin said, not only for the 2003 twin rover missions, but the long-range mobile laboratory in 2007.
A new landing site steering committee has recently been put together. Future MGS up-close imagery can help this group select Mars spots that offer high science yet are also safe to land in, Garvin said.
Close-up inspection
MGS pictures unveiled earlier this month suggest layers of sedimentary rock indicative of numerous lakes and shallow seas that may have once dotted Mars.
"Whats new about these images is that for the first time they show really good evidence of ancient water-lain sediments in many places on the planet," said Steve Squyres, planetary scientist at Cornell University in Ithaca, New York.
"Water-lain sediments are great at preserving a record of past geologic conditions, and they are also among the best places to go if youre looking for evidence of ancient life," Squyres said.
Squyres is principal investigator for the Athena payload to be hauled by the 2003 rovers. He said that sedimentary materials are ideal for close-up inspection by Athenas instruments.
"These materials are at latitudes where we can land, and tend to cover pretty broad areas," Squyres said.
"I expect the Mars geology community is going to be looking at those areas very hard in the months ahead. Im hopeful that well find some places like this where we can land and do some good science," Squyres said.
As for the importance to the scientific community of extending the MGS mission, Squyres is to the point.
"More data!," he said.
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