Worries over ‘dead’ satellites
July 10, 2019
On May 24th a SpaceX rocket launched 60 tightly packed Starlink satellites into one dispenser launching them as if a string of pearls into Low Earth orbit. Three of the sixty subsequently failed, and now there are anxieties that the failure rate might be typical for future mega-constellations.
The Elon Musk-backed project calls for an eventual 12,000 satellites to be launched and in the process create a global space-based internet system. The overall target is to create three separate orbital systems with an initial plan to loft 1584 satellites at 550 kms high, and thereafter 2800 satellites at 1150 kms and finally about 7500 satellites in V-band at 340 kms.
Musk’s team have always planned to “mass produce” its satellites, and to thus keep costs down and the speed of production up. It is a scheme that has worked well for his fleet of SpaceX Falcon rockets, and bringing client fees down from a typical $63 million per launch to nearer $50 million for a ‘pre-flown’ rocket.
But a 5 per cent failure rate on the May batch is a worry. Other plans from rival operators (in particular OneWeb and Amazon) will place tens of thousands of satellites into orbit. A 5 per cent failure rate could be potentially catastrophic to the constellations themselves, as well as other users of space.
Musk’s team said these initial 3 filed satellites would de-orbit passively and safely burn up in the atmosphere. Additionally, two further satellites would be deliberately de-orbited in order to prove the on-board control systems. Typically, the design of the satellites allows for a 5-year life in orbit but the prospects of having hundreds of ‘dead’ satellites in orbit.
One industry expert, Matt Desch, CEO of Iridium (with 75 satellites in orbit) has called these dead satellites “rocks” in the sky, and argues that we may end up in creating a space environment that simply isn’t sustainable. Iridium has had its own problems, both with dead or dying satellites, as well as satellites lasting 3 times longer than intended. 30 per cent of its initial batch of 95 satellites were dead, and still in orbit.
It is a worry.