NASA and SpaceX signed a Space Act Agreement in January to coordinate flight safety in orbit between the agency’s space assets and Starlink satellites. “Starlink is a large constellation of spacecraft launched and operated by SpaceX. The goal is to have approximately 1,500 individual spacecraft in an orbit of 550 km by calendar year 2021, with over 600 assets currently in orbit. The Starlink spacecraft are equipped with an autonomous maneuvering capability,” the Space Act Agreement document reads, “Consequently, increased interaction and partnership between NASA and SpaceX is needed to ensure continued safe on-orbit operations and avoidance of conjunctions between agencies satellites and human missions.” Overall, the Starlink constellation will have over 12,000 internet-beaming satellites that will provide service globally.
Under the Space Act Agreement NASA says it will “not maneuver in the event of a potential conjunction to ensure the parties do not inadvertently maneuver into one another,” because it will rely on SpaceX’s Starlink satellites capability to detect and avoid collisions. SpaceX’s Starlink satellites are equipped with krypton-powered ion thrusters that are used to autonomously move to avoid collisions with space debris and other spacecraft. The satellites utilize inputs from the U.S. Department of Defense’s debris tracking system. Navigation sensors, 'Star Trackers,' tell each satellite its attitude as well. “NASA will operate on the basis that the autonomous maneuvering capability of the Starlink satellites will attempt to maneuver to avoid conjunction with NASA assets, and that NASA will maintain its planned trajectory unless otherwise informed by SpaceX,” the Agreement states. SpaceX will provide NASA with ‘at least 8 hours lead-time for emergency trajectory changes.’
The Space Act Agreement document also mentions the “importance of mitigating spacecraft light interference to ground-based and space-based astronomical observations.” Astronomers have previously voiced concerns over the Starlink constellation potentially interfering with their work, SpaceX said it is working with senior astronomers to ensure Starlink satellites do not interfere too much with space research. The first step SpaceX took is make the satellites less bright by adding a deployable visor to cover the sun’s rays from hitting the satellites' most reflective surfaces. The company is still working on engineering ways to decrease the brightness of the satellites. The Agreement states that NASA is sharing “technical expertise and lessons learned to collaborate with SpaceX on developing approaches to monitoring and mitigating photometric brightness.”
NASA and SpaceX signed a Space Act Agreement in January to cooperate on how to avoid collisions with the company's Starlink satellites, with now more than 1,200 in orbit and more to come this year.— Michael Sheetz (@thesheetztweetz) March 18, 2021
Read it here (highlights mine): https://t.co/59OLN4ehko pic.twitter.com/cvQ0aAO6CM
Featured Image Source: SpaceX