The space agency planned to launch a new Mars lander called InSight in March from Vandenberg Air Force Base in California.
, short for Interior Exploration using Seismic Investigations Geodesy and Heat Transport, was expected to arrive at Mars in September to take measurements of the red planet's interior and its atmosphere and to take color images.
Instead, it's being sent back to its maker -- Lockheed Martin -- in Denver, Colorado.
The faulty instrument is a very sensitive seismometer designed to measure movements in the Martian soil as small as the diameter of an atom, NASA said in a statement
. The device is provided by France's Centre National d'Études Spatiales (CNES).
NASA says the instrument requires a vacuum seal around its three main sensors to protect it from harsh conditions on Mars. During testing on Monday in extreme cold temperatures the instrument failed to hold a vacuum, the agency said.
"The vacuum issue is the only thing that was standing between us and launch," Bruce Banerdt, InSight's principal investigator at the Jet Propulsion Laboratory, told CNN.
"We do not believe that this is a fundamentally difficult problem, given enough time to systematically investigate and resolve it," he said. "The French space agency estimates that a handful of months should suffice, although we will probably take a little longer to make sure there aren't any further subtle problems hiding in the wings."
Even if the leak is fixed in a few months, InSight can't be launched anytime soon. The 2016 launch window closes March 30, NASA said.
"Everything else about the mission is ready to go, and we are already starting to work toward the possibility of continuing on to Mars at the next orbital opportunity in 2018," Banerdt said.
Banerdt says both he and his team are naturally saddened by the setback.
"Although I have personally been working toward making these measurements on Mars for 25 years, the actual InSight Mission Project has only been underway since about 2009," he said. "The whole project team has been giving it everything they've got for many months to try to make this launch opportunity, so we are understandably disappointed."