With Beta testing of SpaceX’s Starlink Internet Constellation already under way, more invitations will be sent soon, and it appears that the satellite’s operational security is improving. Unlike most satellite-based Internet constellations, Starlink (and Amazon’s upcoming Kerber constellation) orbits in low-Earth orbit (LEO) and thus flies closer to the surface.
The satellite’s first orbital crust (the outer-lying altitude) will reach more than 550 kilometres above the Earth’s surface and consist of 22 satellites on 72 planes. This will be the lowest operating altitude of the satellite because the height of the other planes is higher. Of course, such a low altitude raises concerns about the simultaneous failure of orbital debris and multiple satellites.
Now Jonathan McDowell, a physicist at Harvard University, has released the latest estimate of Starlink’s failure rate on Twitter. Earlier estimates caused a stir in the media, and now researchers believe SpaceX may have improved Starlink’s failure rate. Of The 413 satellites spaceX has launched in its last seven, only one has failed, according to McDowell. This significantly reduces the failure rate compared to the previous batch of 420 satellites launched by the company between November 2019 and June 2020.
According to McDowell, 413 of the 420 satellites are currently in operation, 11 of which are not mobile. This represents a failure rate of about 3 per cent, compared with 0.2 per cent for the latest satellites. In addition, these figures are much smaller than the 13 per cent failure rate of SpaceX’s first (V0.9) satellites, with 46 out of 60 satellites out of orbit and 8 of the remaining 14 satellites not responding to SpaceX’s orders, with a failure rate of 13 per cent.
However, these statistics do have a warning. As McDowell warns, a large proportion of the latest batch of 413 satellites is still in orbit, or has a relatively short time to orbit. The former includes 180 new satellites launched by SpaceX in October, and of course, no more accurate failure rates for the latest batch of satellites will be available until all satellites reach orbit and stay there for some time.
In fact, some satellites exhibit abnormal behavior after launch and before their orbits rise completely. SpaceX makes 120 satellites a month, according to details the company disclosed to the FCC in August. As with high-speed mass production, quality control becomes more difficult as production speeds increase. At the time of the launch of the Internet network’s beta service, SpaceX had submitted a revised request to the FCC to significantly reduce the satellite’s orbital altitude. This improvement will play a key role in the company’s commitment to ultra-low network latency, while also ensuring that failed satellites are released from orbit more quickly.