Space station maneuvers to avoid debris
By Jeff Foust
WASHINGTON — The International Space Station maneuvered to avoid a potential collision with a piece of space debris Sept. 22, an incident the head of NASA used to advocate for more funding for the agency directed to handle space traffic management.
NASA announced on the afternoon of Sept. 22 that it was working with U.S. Space Command to track an unidentified piece of debris expected to pass within a few kilometers of the station at 6:21 p.m. Eastern that day. Controllers fired the thrusters on a Progress spacecraft docked to the station for two and a half minutes about an hour before that closest approach to keep the station clear of the debris.
The object, projected to come within 1.39 kilometers of the station, passed without incident. While the station’s three-person crew was not in danger, NASA said that they did board their Soyuz spacecraft docked to the station for a time “out of an abundance of caution” until the threat passed.
NASA did not identify the debris in statements about the close approach. Later, space analyst Jonathan McDowell said it was debris from an upper stage of a Japanese H-2A rocket that launched the Ibuki-2, or GOSAT-2, Earth science satellite in October 2018. That upper stage, left in an orbit more than 100 kilometers above the ISS, broke up in February 2019. More than 70 objects from that stage are currently being tracked.
The debris object that ISS avoided is now available on SpaceTrack as 2018-084CQ, 46477, from the breakup of Japan's H-2A F40 rocket stage. At 2221:07 UTC it passed within a few km of ISS at a relative velocity of 14 6 km/s, 422 km over the Pitcairn Is in the S Pacific pic.twitter.com/2T3yFQoFMT
— Jonathan McDowell (@planet4589) September 22, 2020
Many in the space safety community have warned that upper stages can be a leading contributor to the growth of space debris, given their sizes and because many are deposited in similar orbits, increasing the risk of collisions with one another. Upper stages can break apart on their own because of residual propellant that bursts tanks or batteries that explode.
NASA Administrator Jim Bridenstine, in a tweet after the debris avoidance maneuver, expressed some frustration. “The @Space_Station has maneuvered 3 times in 2020 to avoid debris. In the last 2 weeks, there have been 3 high concern potential conjunctions. Debris is getting worse!” he wrote.
According to an August newsletter by NASA’s Orbital Debris Program Office, the ISS previously maneuvered to avoid debris on April 19 and July 3. The first maneuver was to avoid debris from Fengyun-1C, a Chinese weather satellite destroyed in a 2007 anti-satellite weapons test. The second maneuver was caused by debris from a Soviet-era upper stage motor, launched in 1987 and which broke apart in 2003. The report noted that the motor suffered a design flaw that has resulted in more than 50 such breakups to date.
Before this latest close approach, the ISS had maneuvered 27 times to avoid debris dating back to 1999, the year after the launch of the station’s first two modules. Before 2020, the most recent maneuvers were in 2015, when four took place, although in 2017 a potential close approach to the station by the Global Precipitation Measurement satellite prompted a maneuver by the satellite, rather than the station.
NASA currently works closely with the Defense Department on monitoring potential collisions of debris with the ISS and other agency spacecraft. That cooperation was highlighted at a Sept. 22 event where Bridenstine and Gen. John “Jay” Raymond, chief of space operations of the U.S. Space Force, announced the signing of a new memorandum outlining cooperation between the agency and the service.
“We partner in space situational awareness. We have NASA representatives on our operations floor,” Raymond said at the Mitchell Institute event. “One of the thousands and thousands of objects that we track, and the most critical object that we track, is the International Space Station, making sure that we can keep that asset safe and protect the astronauts that call that home.”
Space Policy Directive 3, signed by President Donald Trump in June 2018, called for the Commerce Department, through its Office of Space Commerce, to take on civil space traffic management responsibilities currently handled by the Defense Department. That effort, though, has been slowed by a lack of funding.
Bridenstine, in his tweet, advocated for the funding that Commerce requested for that work. “Time for Congress to provide @CommerceGov with the $15 mil requested by @POTUS for the Office of Space Commerce,” he wrote.
The Commerce Department requested $15 million for the Office of Space Commerce in its fiscal year 2021 budget proposal, with the bulk of the funding going to space traffic management work. A spending bill passed by the House in July, though, rejected that request because it was still awaiting the final report requested by a fiscal year 2020 spending bill to examine which agency was best suited for civil space traffic management.
That report, published by the National Academy of Public Administration (NAPA) Aug. 20, concluded that the Commerce Department was the best agency for civil space traffic management compared to NASA, the Defense Department and the FAA’s Office of Commercial Space Transportation. Commerce Department officials said at the time that they hoped the report would convince Congress to fund their budget request for the Office of Space Commerce.
“We continue to see serious risk of harm to the astronauts aboard the International Space Station, billions of dollars invested in current space capabilities and the growth of space commerce,” Kevin O’Connell, director of the Office of Space Commerce, said of space debris during a Sept. 16 session of the AMOS space surveillance conference held online.
In his remarks, O’Connell highlighted current and planned cooperation with other agencies, including NASA and the Defense Department, on space traffic management. He also emphasized the need for funding for his office to take on that work. “Resources are absolutely key to making the kind of progress we need to make right now,” he said. “We have said that, [Commerce] Secretary [Wilbur] Ross has said that, and we’re pleased that NAPA highlighted this as well in their report.”
September 23, 2020 at 05:19PM
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