AeroCube-7 to Be Highlighted at Small Satellite Conference
The Aerospace Corporation will be well-represented at this year’s Small Satellite Conference, Aug. 5-10 at Utah State University in Logan, UT. The theme of the event is “Small Satellites — Big Data.” One of the presenters, Dr. Richard Welle, senior scientist in the Space Science Applications Laboratory at Aerospace, will speak on how a network of small satellites, like CubeSats, could use lasers to transmit data to ground stations more efficiently than current systems, which use radio-frequency (RF) transmitters.
Satellites can transmit data directly to ground stations, but require a direct line-of-sight, which is available for just minutes per day. In his paper, A CubeSat-Based Optical Communication Network for Low Earth Orbit, which will be presented at the Small Satellite Conference, Welle describes how a constellation of small satellites could receive and transmit data to other satellites within its network, that have immediate access to a ground station. This system could provide extended communication between satellites and ground stations, and be a service to any satellite in low-Earth orbit (LEO).
NASA is currently sponsoring an Aerospace CubeSat — the AeroCube-7. The program, called Optical Communication and Sensor Demonstration (OCSD), consists of two flight units and an engineering model. The engineering model was flown in 2015 to provide risk reduction for the flight units. The flight units were completed in 2016, but a launch pad fire at Cape Canaveral delayed their launch. It has now been rescheduled for this coming October.
Aerospace’s design for the OCSD is a 1.5 unit CubeSat that’s 10x10x15 cm and weighs about 2.3 kg. Each carries a laser hard-mounted to its body. The laser is guided by the satellite’s attitude control system (which stabilizes the satellite and points the laser), rather than the larger and more complicated two-axis gimbal control that larger spacecraft use for laser pointing. These pointing capabilities are critical, Welles says, “because it allows the laser beams to be very narrow, which is required to support very high communication rates.” From the experience with AeroCube-7, and an expectation of increased downlink requirements, there’s “a preference for including laser communication where appropriate on future CubeSat missions being developed by Aerospace,” according to Welle.
In his paper, Welle writes that technological advances have “allowed satellites to shrink significantly in size, disrupting a legacy industry where traditional satellites cost $500 million to $1 billion to build and launch.” There are increasing opportunities, he writes, for companies to launch microsatellites for data collection. Small satellites, used as a network to relay data, could also help companies reduce the need for additional or extended ground stations. “An available LEO network could minimize, or even eliminate, the need for new satellite companies to develop their own ground network,” he writes.
About two dozen Aerospace employees will attend the Small Sat conference, and among them they are scheduled to present 11 papers. Aerospace is also a sponsor, exhibitor, and student paper judge, and will be located at booth 173 throughout the week-long event.