May 02, 2005
The European Space Agency's Mars Express orbiter will soon deploy its radar instrument for the first time. The instrument is designed to look below the surface of Mars for different layers of material, most notably water.
Once the deployment is successful, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (Marsis) instrument will complement the orbiter's study of the planet's atmosphere and surface. The instrument was funded by NASA and the Italian Space Agency and developed by the University of Rome, Italy, in partnership with NASA's Jet Propulsion Laboratory, Pasadena, Calif.
The instrument's co-principal investigator, Dr. Jeffrey Plaut of JPL said, "We look forward to the start of the Marsis experiment, and to becoming full partners in the mission of discovery that is Mars Express. The radar gives us two ways to explore the fate of the water that once flowed on the surface of Mars. We will probe beneath the surface for evidence of frozen or liquid reservoirs, and we will study the outer fringes of Mars' atmosphere, where the planet may have lost its water to space."
The deployment of the three radar booms will take place in three phases, in a window spanning from May 2 to 12. These operations will be initiated and monitored from the European Space Agency's European Space Operations Centre in Darmstadt, Germany. Each boom will be deployed separately, with the two 20- meter-long (66-foot-long) dipole booms to be unfurled first and the 7-meter (23-foot) monopole boom to follow a few days later.
Before each deployment, the spacecraft will be placed in a 'robust' attitude control mode, which will allow it to tumble freely while the boom extends before regaining standard pointing to the Sun and Earth.
The result of each deployment can be assessed only after a series of tests, each taking a few days. After the deployment of the three booms, European Space Agency engineers will start the analysis of the complete behavior of the satellite to be able to confirm the overall success of the operation. The current schedule is subject to change, due to the timing and nature of the complex series of operations.
Once deployment is complete, the Marsis instrument will undergo three weeks of commissioning before the start of actual science investigations. This timing coincides with the spacecraft's orbit reaching a favorable position to examine one of the prime targets for radar observations.
JPL's Richard Horttor, project manager for NASA's roles in the Mars Express mission, said, "The first data from the radar next month will signal the success of an innovative international partnership." Italy provided the instrument's digital processing system and integrated the parts. The University of Iowa, Iowa City, built the transmitter for the instrument, JPL built the receiver and Astro Aerospace, Carpinteria, Calif., built the antenna.
JPL is a division of the California Institute of Technology in Pasadena.
Guy Webster (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Dolores Beasley (202) 358-1753
NASA Headquarters, Washington