2016.B.4.5. Emerging techniques for Deep Space CubeSat operations

Author(s)

E. Jay Wyatt (1)
Douglas Abraham (1)
Mark Johnston (1)
Alice Bowman (2)
Benjamin Malphrus (3)

California Institute of Technology Jet Propulsion Laboratory, United States of America
Johns Hopkins University Applied Physics Laboratory, United States of America
Morehead State University, United States of America

Session

B.4

Keywords

communications, operations, scheduling

Abstract

Numerous CubeSat missions in development intend to go beyond Earth orbit and into the realm of deep space. This brings unique challenges to mission operations given light-time delays, low communication rates, and intermittent connectivity. These missions also represent a growing customer base for the few ground tracking assets capable of closing these deep space communication links. To help the mission community contend with the challenges of deep space exploration and help NASA stay in front of new demand for its antennas, new solutions are being devised. This paper describes new techniques and services that have the potential to improve how we explore deep space with small spacecraft. One such technique, called “Opportunistic Multiple Spacecraft per Antenna” (OMSPA), enables a deep space CubeSat that happens to be in the beam of a scheduled Deep Space Network (DSN) customer the chance to use that tracking pass for downlinking telemetry at very low cost. With this technique the telemetry stream is extracted post-pass from a full spectrum recording and may be used any time at least one other spacecraft is within the same ground antenna beam and has a scheduled downlink. If telemetry is not absolutely necessary but the mission would like frequent indication of spacecraft health, the DSN Beacon Tone service can be used to transmit spacecraft state or level of urgency for ground intervention in lieu of a full telemetry pass. The Beacon Tone Service was used successfully on NASA’s New Horizon mission while en route to Pluto. Another technology intended to improve operations is Disruption Tolerant Networking (DTN), which provides more internet-like connectivity with the spacecraft. Single spacecraft can benefit from DTN automated store-and-forward and/or automated retransmission because it reduces human-in-the-loop analysis. DTN can also be enabling to networked mission concepts where sharing of spacecraft resources or other forms of coordination are necessary. To increase capacity of the ground networks, NASA’s Deep Space Network has adopted a strategy of university partnering. The first such partner, Morehead State University, is working with NASA to upgrade its 21m antenna to support the EM-1 CubeSat missions as a “node” of the DSN. Priority-based scheduling techniques are also being developed to more fully automate the DSN resource allocation process in order to reduce operations cost. The techniques described in this paper, taken individually or used in combination, have the potential to enhance individual missions and improve the net science return across many missions.