NASA's 2016 Mars mission called off

A U.S. science satellite slated to launchto Mars in March has been grounded due to a leak in a keyresearch instrument, NASA said on Tuesday, creating uncertainty about the future of a widely anticipated effort to study theinterior of the planet.

The spacecraft, known as InSight, was designed to helpscientists learn more about the formation of rocky planets,including Earth.

The cancellation raises questions about the future of theresearch effort, as it will be another two years before Earthand Mars are favourably aligned for a launch. NASA has not saidif it will have funding for the program, which was capped at$425 million US.

After landing on Mars, the science satellite would haveremained stationary, using three science instruments to detectquakes and other seismic activities. It was also designed tomeasure how much heat is being released from the planet'ssubsurface and monitor Mars' wobble or variations in its orbitas it circles the sun.

A problem with the seismometer triggered cancellation of thelaunch, the agency said in a statement. The instrument, whichwas provided by France's CNES space agency, has a leak in thevacuum container that houses its primary sensors.

CNES repaired a faulty weld on the vacuum tank, butapparently the problem remained, according to NASA.

InSight had arrived last week at Vandenberg Air Force Basein California to begin launch preparations.

InSightmay launch in 2018

NASA managers and French designers of the instrument said Tuesday in a teleconferencethey must now decide whether the leak in the vacuum-sealed connector needs to be repaired, redesigned or the mission scrapped.

"We're close enough to launch but unfortunately we don't have enough time to try to identify the leak, fix it and recover and still make it to the launch pad in March," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate.

The next opportunity to launch theInSightlander is in May 2018 since the best chances of launching missions between Earth and Mars occur for just a few weeks every 26 months.

NASA managers said it could take several months of analysis and discussion before they decide how to proceed. A redesign of the part could make the 2018 opportunity unlikely since it could take up to five years.