The first communications satellite was launched in 1960, and hundreds have followed. Some satellites scheduled for launch as early as this month, though, are going where no comsat has gone before. One will relay messages from the far side of the Moon, while two others will follow another spacecraft to Mars.
The Moon satellite will be launched by China. The country plans to land a probe on the far side of the Moon at the end of the year. Since that part of the Moon is always out of sight, the craft will need some way to relay its findings to Earth.
So China is first launching a communications satellite. It’ll orbit a point in space where the gravity of Earth and the Moon are in balance. That’ll allow it to see both Earth and the lunar farside.
The Mars satellites are known as cubesats. They’ll be launched with InSight, the next Mars lander; more about it tomorrow. The small satellites will relay data from InSight as it lands on Mars.
Several other spacecraft have served as comsats for previous Mars landers. But relaying signals was a secondary mission for those craft — they were conducting their own scientific observations. The cubesats will be the first sent to Mars just to communicate with a lander. They could help pave the way for other small Mars craft in the decades ahead.
And the Moon is almost due south at first light tomorrow. The bright planet Saturn is close to its lower left, with Mars a good bit farther along the same line.
Script by Damond Benningfield