TES News

May 1994, Volume 3, No. 2

Thermal Emission Spectrometer Project Mars Global Surveyor Space Flight Facility Department of Geology, Arizona State University Box 871404, Tempe, Arizona 85287-1404, U.S.A.

To Mars in '96:

U.S. Prepares Two New Spacecraft

November 3, 1996- a Delta II rocket lifts from its pad at the Florida Kennedy Space Center. Several hundred students from Phoenix-area schools are gathered to watch the event on televisions in the Moeur Building at Arizona State University (ASU). They cheer. Mars Global Surveyor and a new Thermal Emission Spectrometer (TES) are on their way to the Red Planet.

As they begin to file out of the building, the visitors are reminded to return a month later for a second Delta launch. An ASU student in her junior year remarks that on December 5th they will see the launch of Pathfinder- the first U.S. Mars lander to be sent since before she was born.

Pathfinding and the Global Survey

On February 7, 1994, NASA proposed the Mars Surveyor exploration program, designed to send a lander and an orbiter to Mars during every launch opportunity in the next decade (1996, 1998, 2001, 2003). The first of these spacecraft, Pathfinder, had already received Congressional approval and funding in October 1993. The second spacecraft was proposed in President Clinton's FY 1995 budget request.

Named Mars Global Surveyor, this spacecraft is a small orbiter which carries only a fraction of the instruments originally flown on the lost Mars Observer. Mars Global Surveyor's instruments include a camera, laser altimeter, the TES, a magnetometer, and radio science experiments. Two other Mars Observer instruments, the Gamma Ray Spectrometer and Pressure Modulator Infrared Radiometer are expected to fly on a second small orbiter to be launched in 1998. At the time of this writing, there are no pictures of the 1996 orbiter available- the final builder and spacecraft design have not been chosen by NASA.

Mars Global Surveyor will launch in November 1996 and reach Mars orbit in September 1997. It will take about four months to circularize the orbit, then it will begin intensive mapping in January 1998. The mapping mission is expected to continue for an entire Martian year- 687 Earth days.

Pathfinder is scheduled for launch between December 5, 1996 and January 3, 1997. Its landing date is fixed: July 4, 1997. Pathfinder is on a faster trajectory than Mars Global Surveyor, and it is expected to complete its primary mission in 30 days. Pathfinder's main objective is to test a new landing system, which includes inflatable airbags- bigger versions of the type found in modern automobiles. It carries science instruments designed to investigate the properties of rocks and soil in the vicinity of the lander, and is equipped with a 6-wheeled rover 65 cm long by 45 cm wide by 32 cm high. The rover will allow scientists to examine rocks that would normally be out of reach of a fixed lander like the Vikings of 1976. Like Mars Observer and Mars Global Surveyor, Pathfinder has a unique Arizona Connection- its camera, IMP (Imager for Mars Pathfinder), is directed by a team under Dr. Peter Smith at the University of Arizona in Tucson.

Giant Sand Dunes of Kaiser Crater, Mars. This Viking 2 image obtained in the late 1970's shows dark dunes spaced about 1 km apart. The Mars Global Surveyor TES will be able to determine their composition in the late 1990's.

TES Play - By - Play

After the November 1996 launch, the Thermal Emission Spectrometer (TES) will be controlled from the Mars Global Surveyor Space Flight Facility at ASU. The TES story began ten years ago, when Dr. Philip R. Christensen of ASU and a team of scientists proposed an instrument for Mars Observer that would map the mineral composition of the Martian surface. Following the loss of Mars Observer in August 1993, the future of TES became very uncertain. Several hurdles toward a reflight of TES were cleared in early 1994. The first step was the inclusion of a Mars orbiter in the FY 1995 budget request to Congress. The second step was NASA's decision to include TES on this orbiter. The ASU TES personnel received word that TES was being recommended for the new mission on February 11, 1994. Final approval was made public during the last week of March 1994. On March 1st, the team was informed of the new name, Mars Global Surveyor. By the middle of March, the ASU TES team had changed all of the signs at the ASU facility to reflect the new mission.

The next hurdle for the new orbiter and TES: the U.S. Congress. Fiscal Year 1995 begins on October 1, 1994. It may not be known until October 1994 whether Mars Global Surveyor has been approved.

Meanwhile, preparations are moving forward because Mars Global Surveyor's launch is less than 1,000 days away. The new TES will once again be built by the Hughes Santa Barbara Research Center (SBRC) in Goleta, California. The chief SBRC engineer for the project, Steve Silverman, has formed a team of 5 full-time engineers to begin building TES. Greg Mehall, TES Systems Engineer at ASU, packaged up the full-scale TES prototype that had been on display for the past year at ASU and delivered it back to SBRC on April 7, 1994. Engineers at SBRC have begun to purchase some of the electrical components for the new TES. For the next 12 months, electronic parts will be purchased and tested for longevity and reliability. Final assembly of the new TES will begin in April 1995. TES is expected to be delivered to NASA for integration with Mars Global Surveyor in February 1996.

Educational Opportunities

The ASU Mars K-12 Education Program provides an opportunity for students and educators in Arizona to experience their own "piece" of the space program. Teachers may arrange student visits to the TES facility by contacting the ASU Undergraduate Admissions Office at (602) 965-2622. The facility can also be "visited" by computer over the Internet using the "Mosaic" program. Our URL is: http://marsed.asu.edu

Mars/Space Teacher Workshops at ASU


Soil from Mars

Red soil from Mars (Texas, that is!). Mars Mission International is a project in the Houston, Texas, area designed to teach students about human space exploration, in particular the concepts needed to send people to Mars. The soil samples are part of a fund raising effort. If you are working in your classroom on Mars mission scenarios and would like some real soil samples collected May 1993, in Mars, Texas, write to: Mars Mission International, 14534 Oak Chase Drive, Houston, TX 77062. The soil samples are red like Mars-- but can you determine whether they are a good analog for real Mars soil?

Name the Pathfinder Rover!

Pathfinder's microrover needs a name, and The Planetary Society is offering a chance for you to name it. Choose the name of a heroine from mythology, fiction, or history (not living). How would she explore Mars?

Classroom Activity

The Mars science community has been asked to help NASA pick a landing site for Pathfinder. The initial meeting to discuss landing sites was held in Houston, Texas, on April 18 and 19, 1994. The actual landing site will likely be chosen within the next 5 months. As an excercise in mission planning, consider in the classroom where you might land

Pathfinder if you had the opportunity to do so. NASA gave the Mars scientists the following constraints:

Where would you land Pathfinder and why? Where did the Viking landers go, and why? How do the Viking lander sites compare with your proposed Pathfinder site? How were the Viking landing sites chosen? What were the Vikings searching for? Is Pathfinder equipped to look for evidence of life on Mars?

Once you have chosen the latitude and longitude of your Pathfinder landing site, find out what occurs on Earth at that same latitude and longitude. If you landed at that location on Earth, what would you find? How much or how little would you learn about Earth by landing there?

Pathfinder reference material:  
"Mars Environmental Survey Pathfinder and 
Network- 1993," Available from the 
NASA Jet Propulsion Laboratory, 
Teacher Resource Center, Mail Stop CS-530, 
Pasadena, CA  91103.

Topographic Map of Mars, Map Number I-2179
1:25,000,000 scale, (c) 1991
U.S. Geological Survey, Map Distribution
Box 25286, Denver, CO  80225.

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Text and Typesetting by:
K. S. Edgett
Original Text: April 14, 1994
Hypertext: April 24, 1994