NASA on Tuesday said it has canceled the March 2016 launch of a space probe that was designed to give scientists a deeper look inside Mars.
The space agency said project managers decided to cancel the launch of their Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission after repeated attempts failed to fix a leak in a critical scientific instrument onboard the spacecraft.
"Learning about the interior structure of Mars has been a high priority objective for planetary scientists [for decades]," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate. "We push the boundaries of space technology with our missions to enable science, but space exploration is unforgiving, and the bottom line is that we're not ready to launch in the 2016 window."
It's not clear when the mission will be rescheduled, but it is not expected to launch until 2017 at the earliest.
"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," Grunsfeld added.
NASA first announced the planned InSight mission in August 2012. The probe was to be one of the scientific tools that researchers would use to determine why Mars evolved so differently than Earth.
InSight is made up of a lander that carries a robotic arm, two cameras, and a thermal probe that will dig into the Martian surface to calculate the planet's temperature.
Scientists have high hopes for the probe, expecting it to tell them how Mars is cooling, whether the core of Mars is solid or liquid like Earth's, and why Mars' crust is not divided into tectonic plates that drift like they do on Earth.
The instrument causing the trouble is the Seismic Experiment for Interior Structure (SEIS), a seismometer built by France's Centre National d'Études Spatiales (CNES). The seismometer measures movements in the ground, some as small as the diameter of an atom, according to NASA.
The sensitive instrument requires a vacuum seal around its three main sensors to withstand the harsh conditions of the Mars environment, NASA said.
Scientists thought they had repaired the leak around the seal, but a test on Monday showed that the instrument could not hold its vacuum seal in extreme cold temperatures.
"It's the first time ever that such a sensitive instrument has been built," said Marc Pircher, director of CNES's Toulouse Space Centre. "Our teams will find a solution to fix it, but it won't be solved in time for a launch in 2016."