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NASA and SpaceX sign agreement on spaceflight safety

WASHINGTON — SpaceX has agreed to maneuver any of its Starlink satellites that come close to the International Space Station or other NASA spacecraft in low Earth orbit as part of an agreement between the agency and the company.

NASA announced March 18 it had signed a Space Act Agreement with SpaceX regarding coordination of operations of the ISS and other NASA spacecraft with SpaceX’s growing fleet of Starlink satellites in low Earth orbit. The agreement, NASA said in a statement, is intended to “formalize both parties’ strong interest in the sharing of information to maintain and improve space safety.”

“With commercial companies launching more and more satellites, it’s critical we increase communications, exchange data, and establish best practices to ensure we all maintain a safe space environment,” Steve Jurczyk, NASA acting administrator, said in the statement.

According to the agreement, SpaceX will use the autonomous collision avoidance feature of its Starlink satellites to move then in the event of any close approaches with NASA spacecraft. That is intended, the agreement states, to avoid a case where both parties maneuvered.

“NASA has agreed to not maneuver in the event of a potential conjunction to ensure the parties do not inadvertently maneuver into one another,” the agreement states. “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 outlines the roles and responsibilities of NASA and SpaceX regarding sharing information on orbital positions and maneuver plans. It requires SpaceX to notify NASA at least a week before each Starlink launch so NASA can determine if that mission poses any collision avoidance issues. SpaceX also agreed to launch Starlink satellites into initial orbits that do not come within five kilometers of the ISS or other NASA spacecraft. SpaceX will also avoid “any notifiable conjunctions” with the ISS in general, which NASA defines as a volume of space 50 by 50 by 4 kilometers, centered on the station.

The announcement didn’t explain the origins of the agreement, which was apparently drafted several months ago. The text of the agreement notes that SpaceX’s Starlink system has “over 600 assets currently in orbit,” a figure it exceeded months ago as it launches new satellites at a frenetic pace. SpaceX currently has 1,260 Starlink satellites in orbit, according to statistics maintained by spaceflight expert Jonathan McDowell.

NASA spokesperson J.D. Harrington told SpaceNews there was not a specific incident, such as a close approach by a Starlink satellite to a NASA spacecraft, that led to the agreement. “The technical teams from NASA and SpaceX have worked together for some time to ensure consistent and timely communications,” Harrington said. “This agreement came about as an offshoot of our work together on human and cargo spaceflight communications.”

SpaceX did not respond to a request for comment about the NASA agreement.

The company has long emphasized its use of automation on Starlink satellites to decide when to perform collision avoidance maneuvers. The company is not alone, though, as other companies planning megaconstellations are adopting similar approaches.

“Every operator I’ve talked to has a tremendous amount of automation in their systems,” said Ted Muelhaupt, principal director of the Aerospace Corporation’s Center for Orbital and Reentry Debris Studies, during a presentation at a March 9 workshop on space traffic management by the LRA Institute. “Effectively, these vehicles are on ‘auto-drive’ and the operators themselves may not know when a vehicle chooses to maneuver.”

While that may increase efficiency, he warned it makes it far more difficult to predict close approaches several days in the future since spacecraft may maneuver in what can seem to be an unpredictable fashion. “When these vehicles are doing autonomous maneuvers, small maneuvers, they are making the assumptions that went into avoiding them in the first place invalid,” he said. “If you put two large constellations near one another, all these get greatly magnified.”

In addition to collaboration on avoiding spacecraft close approaches, the agreement between NASA and SpaceX also covers efforts to reduce the brightness of Starlink satellites, which may interfere with astronomical observations. NASA said it will share “technical expertise and lessons learned to collaborate with SpaceX on developing approaches to monitoring and mitigating photometric brightness” of satellites, while SpaceX said it will share similar insights with NASA “to inform Agency guidance development.”


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SpaceX’s record-setting rideshare mission a challenge for space traffic control

WASHINGTON — U.S. Space Command’s traffic watchers have been working with SpaceX and satellite operators in recent days in preparation for Transporter-1, a rideshare mission scheduled to launch Jan. 23 that could set a new record for the most satellites ever launched in a single flight. 

Space Command crews at Vandenberg Air Force Base, California, will attempt to track as many as 143 commercial and government satellites that Transporter-1 will deploy to a sun-synchronous orbit 500 kilometers above Earth. 

The 18th Space Control Squadron, which monitors satellites and space debris for close approaches, has been coordinating with SpaceX and the satellite owners and operators “to understand the launch plan for Transporter-1 and the satellite deployment sequence so that we can provide optimal spaceflight safety support,” Diana McKissock, a space situational awareness officer at the 18th SPCS, said in a statement to SpaceNews.

Transporter-1 is SpaceX’s first dedicated commercial rideshare on a Falcon 9 rocket. This will be a record-breaking ride with 143 satellites, beating India’s PSLV-C37 launch of 104 satellites in February 2017.

The ability to track so many payloads from a single launch is a concern for satellite watchers. “One of the problems is that we don’t even know for sure what all of the 143 satellites are,” spaceflight analyst and astronomer Jonathan McDowell told SpaceNews. “It’s certainly going to be a challenge to sort them all out,” he said. SpaceX has not released a detailed manifest for this rideshare “which is disappointing,” said McDowell. 

McDowell said there are a couple of experiments on this mission to test RFID tags that will identify satellites. “If those eventually get wide adoption it will make these large cluster launches easier to track.”

Some information has emerged on the satellites flying on Transporter-1. The largest customer on this mission is Planet, with 48 SuperDove satellites hitching a ride to space. There are 10 of SpaceX’s own Starlink internet satellites and 36 very small satellites from Swarm Technologies which is building an internet-of-things service with “SpaceBee” spacecraft the size of a slice of bread. Another payload riding on Transporter-1 is Spaceflight’s SHERPA-FX — a new type of spacecraft that will dispense 18 secondary payloads. 

Smallsat rideshares expected to grow

The competitive pricing and reliability of SpaceX rideshares make them an attractive option for small satellite operators so these bulk launches are expected to become routine. Experts note that consolidating dozens of smallsats from multiple customers on a single flight is efficient but has implications for spaceflight safety that have yet to be sorted out.

A new report by the Aerospace Corp. warns that single  deployments of small payloads — some the size of a shoebox — can create confusion for space traffic controllers. Current space traffic management systems “do not have time to react to the addition of so many new space objects all at once,” the report says. It can take weeks or months to identify objects and some may never be identified at all.

Aerospace Corp. engineer Mark Skinner said the industry should agree on the adoption of standards to make smallsats identifiable. “This needs to become part of the marketplace,” he said on a recent webinar. 

The 18th SPCS “can’t solve this problem,” he said. “They can’t find companies’ cubesats.”

If 100 satellites are launched at once, said Skinner, “you might be left with 25 or so that aren’t identified, at least for the first several months.”

Andrew Abraham, also of Aerospace Corp., said cubesats and nanosatellites “all look the same to a ground radar.” Some companies put ID devices on their satellites using optical tags, blinking lights or GPS trackers. But there are no clear regulations or guidelines even as private companies and governments plan to send thousands more satellites to orbit in the coming years.

The job of the 18th SPCS would be easier if all satellites had ID tags “but they can’t regulate it or require it,” said Abraham. “This is a role for a civilian agency.”

The 18th Space Control Squadron as a public service provides satellites’ positional data and conjunction warnings to satellite operators. It also helps facilitate data exchange between operators. But McKissock noted that spaceflight safety is the responsibility of the launch provider and the satellite operators. 

The Trump administration in 2018 directed the Department of Commerce to provide a basic level of space situational awareness for public and private use based on the space catalog compiled by the Department of Defense. Both agencies are working on a transition plan but it could take Commerce several more years to establish the capabilities it needs to manage space traffic.