ESA Deploys Mars Express Radar Antennas

PARIS-- The three-pronged radar instrument aboard Europe's Mars Express satellitehas been fully deployed and put through initial tests and is expected to startoperations in July following a 10-day commissioning period, the European SpaceAgency (ESA) announced June 22.

Theradar, featuring two 20-meter and one 7-meter boom antennas, is designed tostudy Mars' atmosphere and to look up to 5 kilometers beneath its surface forwater. Its deployment had not been completed until now because of concerns thatthe antennas would snap back toward the satellite's body while they were beingunfolded, damaging the satellite or its other instruments.

MarsExpress, launched in June 2003, arrived in Mars orbit in December 2003.

Withdeployment and initial checkout completed, the Mars Advanced Radar forSubsurface and Ionosphere Sounding, or Marsis,instrument will undergo detailed tests of its observing power.

StartingJuly 4, it should be ready for operations. An initial subsurface examination isexpected to be possible for about two weeks.

Afterthat, the Mars Express satellite's orbit will carry it out of optimal range forthis work, and Marsis will be used for atmosphericsounding.

Thesatellite's orbit is expected to take it closer to the planet's surfacestarting in November. Subsurface soundings can be made when Mars Express is nomore than 800 kilometers from the martiansurface. The satellite's orbit varies between 260 and 11,000 kilometers inaltitude.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at:

Charles Q. Choi
Contributing Writer

Charles Q. Choi is a contributing writer for and Live Science. He covers all things human origins and astronomy as well as physics, animals and general science topics. Charles has a Master of Arts degree from the University of Missouri-Columbia, School of Journalism and a Bachelor of Arts degree from the University of South Florida. Charles has visited every continent on Earth, drinking rancid yak butter tea in Lhasa, snorkeling with sea lions in the Galapagos and even climbing an iceberg in Antarctica. Visit him at