Last week NASA announced that they had signed a Joint Spaceflight Safety Agreement with Space Exploration Technologies Corporation (SpaceX) to help regulate low-Earth orbit traffic patterns and enhance the safety of NASA spacecraft as they attempt to launch through the constellation of 1,320 SpaceX Starlink satellites in non-geostationary orbit.
And it is “high” time, too. Early this morning (Wednesday, March 24, 2021), B1060-6, the latest SpaceX Starlink Falcon 9 rocket, thundered skywards from Cape Canaveral. Each Falcon 9 can send up to 60 satellites into low-Earth orbit. SpaceX already controls over one-third of all active satellites. Today marked the 23rd successful Starlink deployment, bringing SpaceX incrementally closer to its stated goal of more than 12,000 satellites capable of beaming high-speed broadband internet connectivity to virtually every crevice and corner if the Earth. That figure might be on the low side. SpaceX CEO Elon Musk has suggested that the numbers could eventually exceed 40,000.
Starlink satellites weigh in at around 500 pounds and are equipped with global navigation systems. When released from the Falcon 9 second stage into a 170-mile preliminary transfer orbit, they use onboard krypton Hall ion propulsion thrusters to boost themselves higher into operating orbits of around 340 miles. The relatively low orbital altitude (over 60 times closer to Earth than traditional satellites) ensures low-latency, high-speed broadband internet service. It also squeezes the constellation of Starlink satellites into a compact shell of whirling metal between 300 and 400 miles above our planet. Not impenetrable — but still.
The Hall thrusters that allow the Starlink sats to maneuver into orbit also allows them to avoid incoming NASA spacecraft — either autonomously or by ground control commands.
Under the NASA–SpaceX Safety Agreement, SpaceX “has the conn” when it comes to clearing a path for endangered NASA spacecraft. In addition to providing for “prompt and proactive exchange of information” to ensure “all parties are fully aware of the exact location of spacecraft and debris in orbit,” the agreement outlines protocols to prevent collisions.
To ensure that “the missions of NASA science satellites and other assets can operate uninterrupted from a collision avoidance perspective,” NASA agrees not to maneuver its assets when threatened with a “potential conjunction” (a close approach between two objects in space, usually at extremely high speed) “unless otherwise informed by SpaceX,” to ensure that “the parties do not inadvertently maneuver into one another.”
Of course, it’s not just SpaceX, although they pretty much own “ultra-low Earth orbit.” There are dozens of communications conglomerates interested in creating or expanding their own constellations of satellites and observation platforms, and SpaceX isn’t the only outfit offering rideshare launch services. From established giants like Arianespace, Northrop Grumman, and the United Launch Alliance to relatively new contenders like Rocket Lab, Relativity Space, Vector Launch, Virgin Orbit, and Firefly Aerospace, there’s a lot of competition out there, and there’s more in the wings. All are jostling for position and partnerships in the shadow of national space agencies like NASA, the European Space Agency (ESA), Roscosmos, and China’s space agency.
Just this past Monday, a Roscosmos Soyuz 2.1a/Fregat rocket launched its first dedicated commercial rideshare mission, delivering multiple orbital payloads, including a half-ton South Korean observation satellite, multiple Japanese commercial microsatellites, multiple Italian CubeSats, and PocketQubes, and payloads from Argentina, Brazil, Canada, Germany, Holland, Hungary, Saudi Arabia, Slovakia, Spain, Thailand, and the United Arab Emirates.
That same day, Rocket Lab launched its 19th Electron rocket (and 100th satellite) from its Mahia Peninsula launch site in New Zealand. The Electron rocket (named appropriately “They Go Up So Fast”) deployed satellites for commercial, military, and university customers, as well as a Rocket Lab Photon pathfinder satellite (Pathstone), designed as a technology testbed for future missions to the Moon.
There’s a lot of stuff up there.
Under the NASA–SpaceX agreement, NASA basically blasts off and expects SpaceX to hustle their Starlink “assets” out of the way, which they seem perfectly capable of and willing to do. Envision a SpaceX Space Traffic Control command center, stuffed with oversized screens tracking the paths of hundreds of satellites and dozens of launches, plotting flight paths, computing trajectories, and initiating emergency avoidance protocols. Cool.
But the agreement is between NASA and SpaceX, and there really is a lot of stuff up there.
Last December, in collaboration with U.S. Space Command, NASA published the “Spacecraft Conjunction Assessment and Collision Avoidance Best Practices Handbook” to improve global awareness of space activity and to share lessons learned regarding close approach coordination and mitigation.
The agreement and the handbook are tailored to address satellite constellations of 100 or more assets, but by extrapolation they both embrace space debris, probes, and interplanetary missions.
Envision an international/global Space Traffic Control command center stuffed with oversized screens tracking the paths of hundreds of satellites, space stations, spacecraft, launches, and re-entries, plotting flight paths, computing trajectories, and initiating emergency avoidance protocols. Even cooler.