NASA is planning to launch a group of miniature spacecraft that are set to have a significant impact on ground-space communication and technology. This project is known as the Optical Communications and Sensor Demonstration (OCSD) and includes three satellites to be sent into orbit in the next few months.
These tiny satellites, known as CubeSats, have the standard size of 10 x 10 x 17 centimeters (roughly 4 x 4 x 6.7 inches). With this move, NASA seems to be following a current trend in the private sector of the space industry to develop smaller, lighter instruments, such as the ARKYD from Planetary Resources. The launch cost of satellites and instrumentation depends on the mass of the object that needs to get into orbit, and for this reason NASA is investing in compact technology.
The first launch will investigate how to improve space communication. Most satellites communicate with the ground using microwaves, and the nominal top speed achieved using this technology is 50 megabits per second. For the CubeSats currently in orbit, the figure is closer to 2 megabits per second. Microwaves require emitting and receiving antennas, and they’re relatively energetically intensive. NASA's current alternative is optical laser communication, which could be used for both small satellites and deep space exploration.
Because the laser is fixed in place, beams are directed by pointing the entire CubeSat towards a receiver, in this case a photodiode detector attached to a very standard 30-centimeter (12-inch) telescope. With an expected speed of 200 megabits per second, the laser communication will allow the team to quickly download information regarding science experiments, imaging and data from the satellite sensors.
A second launch is planned for early 2016. Two CubeSats will be launched together to continue the laser communication testing, as well as to perform close proximity operations. The satellites will communicate and interact directly with each other, a capability that has never been demonstrated in space. The ability for these satellites to “bond” and work as a cluster could lead to a momentous shift in approach to space technology.
The success of these “pathfinder” missions, as well as the rise of private enterprises in space launching, could lead to low-cost science missions and rapid innovation in the sector. Miniaturization of technology is an essential development in NASA’s journey to Mars.