SpaceX's Starlink satellites had to avoid debris from a Russian missile test, according to Elon Musk on Tuesday.
On November 15, Russia had used anti-satellite missile to tear down one of its own satellites, causing thousands of debris particles to spill out into Earth's orbit at roughly the speed of a bullet.
The new space junk endanger anything and everything in Earth's orbit, which include Starlink, a network of approximately 1,700 SpaceX internet satellites. "We had to shift some Starlink satellite orbits to reduce probability of collision," said Elon Musk on a Twitter post. "Not great, but not terrible either." he added. The same line appears in the HBO drama Chernobyl, which depicts the Soviet Union's 1986 nuclear plant disaster. When working at a nuclear power plant, a worker says, "Not great, but not terrible," despite the fact that the conditions at the plant are disastrous. Smaller debris could easily disable a satellite because it can travel at speeds of up to 17,500 miles per hour. For that case, the satellite would soon lose altitude until it fell through the Earth's atmosphere, where it would burn up due to friction. "If [a satellite] gets hit by one of the bigger pieces of debris... it could completely destroy the satellite into thousands of more pieces," astronomer Jonathan McDowell, who tracks satellites and debris objects, told Insider after the missile test. "You could see debris hitting the satellites, causing more debris that then hits more satellites." According to the US State Department, the Russian missile test produced more than 1,500 pieces of debris large enough to even be tracked from the ground. However, none of the large objects have yet been identified or tracked. It could take months to complete. "Russia's dangerous and irresponsible behavior jeopardizes the long-term sustainability of outer space,” the US State Department said at the time. To prevent from unnecessary space debris, SpaceX has outfitted each Starlink satellite with an autonomous collision avoidance system that keeps its vessels away from other spacecraft and known fragments of orbital debris. If the propulsion system on board fails, the same satellites will inevitably fall and combust in the Earth's atmosphere within one to five years. However, this strategy is sometimes critiqued by the company's competitors because it can bring in new uncertainty and risk. According to Hugh Lewis, head of the Astronautics Research Group at the University of Southampton and Europe's leading space debris expert, the automatic orbital adjustments change the predicted trajectory, making collision forecasts more complex. "Starlink doesn't publicize all the maneuvers that they're making, but it is believed that they are making a lot of small corrections and adjustments all the time," Lewis said at the time. "But that causes problems for everybody else because no one knows where the satellite is going to be and what it is going to do in the next few days." As a result of the Russian ASAT test, it appears that Starlink will perform many more automated maneuvers, causing even more unpredictability for many others. Russia, on the other hand, claims that the generated debris poses no threat to any space activity. Other countries, according to the Kremlin, have also conducted anti-satellite missile tests. According to experts, operators flying satellites in the area affected will need to undertake twice as many space debris evasion to maintain their satellites' safety. Many space sustainability experts believe that the Starlink constellation itself is a threat to other operators. The satellites presently in orbit represent only a fraction of what SpaceX hopes to achieve in the future. The first formation of the constellation is expected to include 12,000 satellites, with the company already seeking approval to launch an additional 30,000. That is far more than the number of satellites launched in the more than 60 years since Sputnik, the first satellite ever launched.