Laser communications, an ever so important factor for the future of space exploration, has seen some important steps forward recently. Two test missions are on the way to provide important information, and a third one is planned for next year. //

Like using a laser pointer to track a moving dime from a mile away, aiming a laser beam over millions of miles requires extremely precise “pointing.” So, the transceiver must be isolated from the spacecraft vibrations, which would otherwise nudge the laser beam off target.

The demonstration also needs to compensate for the time it takes for light to travel from the spacecraft to Earth over vast distances. In the first DSOC test, the near-infrared photons took about 50 seconds to travel from the probe to Earth. Once the probe arrives at the asteroid, the transmission time will be extended to 20 minutes. In that time, both the spacecraft and the planet will have moved, and the uplink and downlink lasers will have to be adjusted accordingly.