Deep Space Network in the CubeSat Era

• Published in: IEEE aerospace and electronic systems magazine 2019-04, Vol.34 (4), p.46-54
• Main Author: Berner, Jeff B.
• Format: Magazinearticle
• Language: English
• Subjects: CubeSat; Deep Space Network; Downlink; Space vehicles; Telemetry; Transponders; Uplink
• ISSN: 0885-8985; 1557-959X
• DOI: 10.1109/MAES.2019.2913266

As the CubeSat era moves from low Earth operations to beyond geostationary orbit into Deep Space, many changes to NASA's Deep Space Network's (DSN's) operating paradigm will be required. The DSN is made up of three communication complexes spaced approximately 120 degrees apart around the world that have a set of high-performance antennas which track (providing uplink and downlink services) spacecraft from geostationary orbit to beyond the edge of the solar system. CubeSats will usually start their missions as secondary payloads in a launch, generally with multiple CubeSats being released from a launch vehicle over a short period of time; this a time period when the majority of the DSN assets (e.g., antennas) will likely be supporting the primary spacecraft that will accompany the CubeSats on the launch vehicle, leaving a limited number of assets for use for the CubeSats. When the CubeSats are initially released, they will all be in the beamwidth of the ground antenna assigned by the DSN to track them. To allow a single antenna to track several CubeSats simultaneously, frequency diversity in the CubeSat downlinks can be employed; however, only one spacecraft at a time will be able to get an uplink. Enhancing the existing techniques that the DSN currently uses daily for Mars missions to provide greater flexibility in the CubeSat era, is one of the changes that the DSN is presently addressing. Additionally, future changes in the CubeSat transponders may allow further enhancement of initial acquisition challenge, as may other changes that could be done in the DSN. As the CubeSats transition to nominal operations, other challenges will need to be addressed, such as minimizing the resource scheduling overhead for the missions and maximizing the CubeSats’ usage of the limited DSN resources. This paper will discuss the challenges in the DSN support for CubeSats and the planned and potential changes to both the DSN and CubeSats to increase the CubeSat data return.