SpaceX’s plan to deploy thousands of satellites worries NASA

Elon Musk’s satellite internet access program has raised concerns among one of SpaceX’s biggest customers — the National Aeronautics and Space Administration (Nasa) — that it could cause traffic jams and possible collisions hundreds of kilometers above the Earth.

SpaceX is stepping up its deployment of satellites to power Starlink, the high-speed internet service it offers worldwide. In January, the company applied to the Federal Communications Commission (FCC) for permission to use a particular configuration allowing it to send 30,000 additional satellites. These represent the bulk of the fleet of 42,000 satellites that SpaceX hopes to deploy in total on behalf of Starlink.

In early February, NASA wrote to the FCC that if launched, these 30,000 satellites would significantly multiply the number of monitored objects in space — by a factor of more than five in some low orbits.

“An increase of this magnitude in these restricted altitude bands carries an intrinsic risk of debris-generating collisions”, explains the space agency in its missive. NASA is also concerned about the interactions of the automated maneuvering systems used by the Starlink satellites with those of other satellite networks with comparable capabilities, given the absence of rules governing this type of situation.

Positioning satellites relatively close to Earth helps deliver faster internet service with fewer lags, analysts say

The space agency depends on SpaceX to ship its astronauts to the International Space Station and pays that company for other missions. NASA does not oppose its plans in its comment to the FCC. “Space traffic coordination is a key area of ​​concern for NASA,” she said.

SpaceX did not respond to our requests for comment.

The potential threat of crowding more near-Earth orbits is a growing concern for space companies and agencies. Collisions that generate debris could make these orbits more dangerous for astronauts and other spacecraft. In addition, other issues could arise, according to researchers and executives.

SpaceX isn’t the only company considering launching constellations, as these groups of satellites are called, into low Earth orbit. Positioning satellites relatively close to the Earth helps deliver faster internet service with fewer lags, analysts say.

Boeing, a unit of Amazon and other companies have also said they want to launch new satellites to provide broadband services from near-Earth orbits, according to filings with the FCC. Chinese reports sent to the International Telecommunication Union (ITU), a UN agency, mention plans to send more than 7,800 satellites, while companies that capture images or data on earth send they too have satellites in orbit.

At the moment, the researchers claim that the largest constellations are those of Starlink. In a recent tweet, Musk announced that SpaceX’s 1,741 Starlink devices were either active or heading to operational orbits.

Space Exploration Technologies, the full name of the Hawthorne, Calif.-based company, previously said it was investing heavily in more capable satellites and taking a cautious approach to protecting the lower levels of Earth’s orbit.

There is no single global regulator responsible for making decisions about orbital congestion or the possible limitation of the number of satellites. The UN ITU simply takes care of the coordination for the frequencies used by the operators. Government agencies in different countries, including the FCC in the United States, set the rules for satellites operating within their jurisdictions.

In 2020, the FCC updated its orbital debris mitigation rules for the first time in more than fifteen years. Its president, Jessica Rosenworcel, indicated on this occasion that the agency must do more to address the problem of the risk of collisions and the creation of debris.

In December, Chinese diplomats claimed that their space station had to perform evasive maneuvers twice to avoid collisions with two different Starlink satellites, according to a letter to the United Nations Office for Outer Space Affairs. Last month, American diplomats replied that a military branch dedicated to space had not considered that there was a significant risk of collision between the Chinese space station and the Starlink satellites, and as such had not not alerted China.

SpaceX has announced that it has taken other measures to avoid leaving debris in orbit; including the deployment of satellites at relatively low altitudes, which allows them to re-enter the atmosphere and disintegrate there.

Space companies and agencies are already grappling with space junk such as decommissioned satellites and abandoned rocket bodies in the lower levels of Earth’s orbit

Earlier this month, the company announced that preliminary analysis showed atmospheric drag created by a storm was preventing some Starlink satellites from moving to planned orbits. Last week, up to 40 satellites were expected to disintegrate upon re-entering the atmosphere or had already done so, according to SpaceX.

“De-orbited satellites pose absolutely no risk of collision with other satellites and are designed to destroy themselves upon re-entering the atmosphere, which means no orbital debris is created and no piece of satellite touches the ground,” SpaceX explained.

Space companies and agencies are already grappling with space junk such as decommissioned satellites and abandoned rocket bodies in the lower levels of Earth’s orbit. This debris can reenter the atmosphere over time, at higher or lower speeds depending on their altitude, the researchers say.

In documents filed with the FCC, SpaceX says that between November 2020 and November 2021, its satellites, which are equipped with automated collision avoidance systems, performed more than 5,500 maneuvers, or about 15 a day. Most were related to debris or satellites that could not be moved.

The company also reported to the FCC that its satellites veer when the probability of collision is greater than one in 100,000. This figure compares with what SpaceX says is the industry standard in this case; i.e. a collision probability of one in 10,000.

Comspoc estimated that the 42,000 satellites SpaceX says it wants to deploy could be involved in 52 collisions and 1.8 million maneuvers over ten years based on the current number of monitored objects. SpaceX did not respond to our request for comment on this.

There is room for large constellations of satellites as long as space is intelligently managed, according to Jim Cooper, head of space problem identification at Comspoc. The basic rules, such as the management of rights of way, are not yet very clear.

“These kinds of indications don’t really exist yet,” concludes Mr. Cooper.

(Translated from the original English version by Bérengère Viennot)

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