A NASA mission [nasa.gov] previously scheduled to launch a robotic lander towards Mars in March may face up to a two year delay [bbc.com] due to a fault in a seismometer provided by the French space agency [wikipedia.org]:
The InSight spacecraft was scheduled to take off between 4-30 March and land on the Red Planet six months later to examine Mars' geology in depth.
Nasa said it had decided to call off the launch because the agency was unable to fix a leak affecting the seismometer, which required a vacuum seal to cope with harsh conditions on Mars. The instrument is designed to measure ground movements.
"A decision on a path forward will be made in the coming months, but one thing is clear: Nasa remains fully committed to the scientific discovery and exploration of Mars," Nasa's John Grunsfeld was quoted as saying by the AFP news agency. The next time the earth and Mars are favourably aligned for a launch will be in 2018.