SpaceX and its Space Debris

Some time last October, SpaceX had snarled at a report presented to the US Congress by the Federal Aviation Administration (FAA) that warned of falling debris from satellite constellations moving around in low-earth orbit. Now, the company has revealed a decision to junk some around 100 of its Starlink satellites earlier than their retirement dates. 

In a note headlined “Commitment to Space Sustainability”, the company explains that these satellites have been marked for early retirement following the identification of a flaw that could make them a bigger problem later on. “The Starlink team identified a common issue” in the first-generation communication satellites that could “increase the probability of failure.”

Adding to the junk or clearing it up?

Of course, Starlink users have no reasons to worry as services would remain unaffected. However, the explanation given by the company seems half-assed at best. We can only speculate that the failure mentioned in the note refers to loss of control, which happens to be the status of 17 Starlink satellites as on date. 

For a moment let’s hark back to the response from SpaceX to the FAA report. Principal engineer David Goldstein had said the report was based on “deeply flawed analysis” based on assumptions, guesswork and outdated studies. The FAA had noted that 28,000 hazardous fragments from de-orbiting satellites and rockets could survive re-entry each year by 2035, especially if SpaceX’s Starlink expansion continues on track. 

We know for sure that unpowered satellites are considered space debris and could take a few years to burn up since they’re in low orbit, as compared to hundred years when placed in orbits higher from the earth. On its part, SpaceX does seem aware of the challenges and definitely does not want to be party to the space junk issue. 

Controlled deorbits – SpaceX shares the status

With space sustainability in mind, SpaceX has to-date initiated controlled deorbits on 406 satellites out of the nearly 6000 Starlink satellites launched. Of those, 17 are currently non-maneuverable, passively decaying, but well-tracked to help mitigate collision risk with other active satellites. The other 95% of satellites the Starlink team initiated controlled descent for have already deorbited, it says in the note. 

The note says, SpaceX will perform controlled descents of another 100 early version Starlink satellites that are not “maneuverable” but are serving users effectively. The satellites will follow a safe, circular, and controlled lowering operation that should take approximately six months for most of the vehicles, it says while noting that they will follow one by one with no likelihood of any skyshower of sorts. 

What about the FAA report then?

What it does though is raised questions of how SpaceX sought to counter FAA’s report which noted that by 2035, if the expected large constellation growth is realized and debris from Starlink satellites survive reentry, the total number of hazardous fragments surviving reentries each year is expected to reach 28,000, and the casualty expectation, the number of individuals on the ground predicted to be injured or killed by debris surviving the reentries of satellites being disposed from these constellations, would be 0.6 per year, which means that one person on the planet would be expected to be injured or killed every two years. 

“Some debris fragments would also be a hazard to people in aircraft. Projecting 2019 global air traffic to 2035 and assuming that a fragment that would injure or kill a person on the ground also would be capable of fatally damaging an aircraft, the probability of an aircraft downing accident (defined in the Aerospace report as a collision with an aircraft downing object) in 2035 would be 0.0007 per year,” the report had said. 

Now we can only wait to watch whether SpaceX is true to its word about removing space debris or if someone gets accidentally injured or killed due to a fall from above. Let’s hope better sense prevails and human lives do matter more than wealth for one of the world’s richest men.