NASA has selected six companies to work on designs for deep space habitat modules that could be used by astronauts living and working near the moon as technology is developed for eventual flights to Mars, the agency announced Tuesday.

The top secret intelligence-gathering payload for the U.S. government set for launch Tuesday on top of a Delta 4-Heavy rocket is likely the next in a line of sensitive eavesdropping satellites designed to intercept radio signals and other communications traffic from adversaries around the world.

A new addition to China’s Beidou navigation network launched Monday on top of a Long March 3C rocket, which injected the satellite into an orbit more than 13,000 miles above Earth several hours later.