NASA to test new laser communication system via two nanosatellites
The American space agency NASA is going to test a laser communication system in low Earth orbit via two launched so-called CubeSats. This should ultimately lead to significantly higher data speeds.
Currently, the Cygnus spacecraft, launched on November 12, which carries the two nanosatellites, among other things, is in the final phase of approaching and docking with the ISS. Once that’s done, the ISS’s NanoRacks CubeSat Deployer will launch the two satellites into low Earth orbit. The satellites have a size of 10 x 10 x 17cm.
The so-called Optical Communications and Sensor Demonstration mission of which the two CubeSats are part is twofold. First of all, the intention is that they will test a new laser system that should provide much higher data rates. The lasers are attached to the satellite housings, requiring the satellites to adjust their orientation in order to target the lasers. This allows the laser system to remain much more compact than comparable systems previously used in space.
The data rate that must be achieved is 200Mbit/s; that’s 100 times more than current CubeSat communications systems, according to NASA. Ultimately, even a speed of 2.5 Gbit/s should be possible via relatively simple upgrades.
Not only the data rate between the satellites and the earth is increased, but also the precision of the laser targeting system. Because the satellites are equipped with small star trackers, the satellites can achieve a higher precision in aiming the laser based on the position of the stars. Accuracy is expected to be increased to 0.05 degrees, which NASA says is 20 times more precise than previously possible with satellites of this size.
Second, the satellites have a special system that is being tested to prevent the satellites from colliding with other space objects or spacecraft. The satellites are equipped with cameras, beacons, sensors and laser rangefinders to measure distance from each other and other objects and craft in space. A new system is used in which water in the form of steam is used for propulsion when an evasive maneuver is required.