About 3% of Starlinks Have Failed So Farhttps://www.universetoday.com/148514/about-3-of-starlinks-have-failed-so-far/amp/... To date, the SpaceX has launched over 800 satellites and (as of this summer) is producing them at a rate of about 120 a month. There are even plans to have a constellation of 42,000 satellites in orbit before the decade is out.
However, there have been some problems along the way as well. Aside from the usual concerns about light pollution and Radio Frequency Interference (RFI), there is also the rate of failure these satellites have experienced.
Specifically, about 3% of its satellites have proven to be unresponsive and are no longer maneuvering in orbit – which could prove hazardous to other satellites and spacecraft in orbit. In order to prevent collisions in orbit, SpaceX equips its satellites with krypton Hall-effect thrusters (ion engines) to raise their orbit, maneuver in space, and deorbit at the end of their lives. However,
according to two recent notices SpaceX issued to the Federal Communications Commission (FCC) over the summer (mid-May and late-June), several of their satellites have lost manoeuvring capability since they were deployed.Unfortunately, the company did not provide enough information to indicate which of their satellites were affected. For this reason, astrophysicist Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics (CfA) and the Chandra X-ray Center presented his own analysis of the satellites’ orbital behaviour to suggest which satellites have failed.
https://www.planet4589.org/space/stats/megacon/starbad.htmlNaturally, some level of attrition is inevitable and 3% is relatively low as failure rates go.
But every satellite that is incapable of maneuvering (due to problems with its communications or its propulsion system) creates a collision hazard for other satellites and spacecraft.
Their latest launch took place earlier today (Saturday, Oct. 24th), which effectively brought their constellation to 835. Therefore,
A 3% failure rate means that roughly 25 satellites will fail and become part of the growing problem of “space junk.”... “I would say their failure rate is not egregious. It’s not worse than anybody else’s failure rates. The concern is that even a normal failure rate in such a huge constellation is going to end up with a lot of bad space junk.” - McDowell... When one takes into account rates of failure and SpaceX’s long-term plans for a “megaconstellation,” the Kessler syndrome naturally rears its ugly head.Recent filings with the International Telecommunications Union (ITU) show that the company hopes to create a megaconstellation of as many as 42,000 satellites.
In this case, a 3% failure rate works out to 1,260 satellites With a mass of 250 kg (550 lbs) becoming defunct over time. As of February of 2020, according to the ESA’s Space Debris Office (SDO), there are currently 5,500 satellites in orbit of Earth – around 2,300 of which are still operational.
That means that a full Starlink megaconstellation would increase the number of non-functioning satellites in orbit by 40%.The problem of debris and collisions looks even more threatening when you consider the amount of debris in orbit. Beyond non-functioning satellites, the SDO also estimates that there are currently 34 000 objects in orbit measuring more than 10 cm (~4 inches) in diameter, 900 000 objects between 1 cm to 10 cm (0.4 to 4 in), and 128 million objects between 1 mm to 1 cm.