10.03.17

Which company is behind the “deadly falling satellites”?

Posted in Regulatory, SpaceX, Spectrum at 8:15 pm by timfarrar


That’s one question raised by a September 29 letter to the FCC from Senators Cory Booker and Dan Sullivan, expressing concern for the “growing challenge presented by low-Earth orbit (LEO) space debris” and asking Chairman Pai to coordinate with NASA and the FAA to “establish an interagency working group on space debris and to develop a comprehensive domestic policy on space debris mitigation”.

The letter focuses primarily on collisions between satellites and other in-orbit debris, such as the Iridium 33 incident in 2009, but the FCC also has concerns about debris falling to Earth as highlighted in the Dilbert cartoon. SpaceX has now submitted proposals for both a 4425 satellite LEO constellation and a 7518 satellite VLEO (very low Earth orbit) constellation, and when the FCC assessed SpaceX’s proposal, it calculated a worst case “aggregate casualty risk from components that survive atmospheric re-entry as roughly 1 in 4 for the 7,518 satellite deployment described in the application, assuming no replenishment” and a risk of “roughly 1 in 5 for the 4,425 satellite deployment“.

SpaceX’s application indicates that there will be five or six components on each VLEO satellite which would survive re-entry with a kinetic energy of at least 960 Joules (equivalent to a 5lb brick traveling at 65mph) and its response to the FCC’s query, stating that “individual vehicle risks rang[e] from 1:17,400 to 1:31,200″, is not exactly encouraging when there are intended to be 12,000 satellites in the constellation.

Indeed, although Elon apparently has only Non-GAAP “adjusted” hair rather than pointy hair, SpaceX’s proposed mitigation measure was similar to that in the Dilbert cartoon, suggesting that (rather than aiming for cities that have lots of swimming pools) the Commission take into account “the degree to which people would be located within structures that would provide shelter from potential impact”.

With concern now being expressed from Congress as well as within the FCC, it will therefore be interesting to see what happens next, and in particular whether this impacts the approval process, including the two draft orders that were circulated by Chairman Pai last week to “grant U.S. market access to two more NGSO systems in the Ku- and Ka- spectrum bands”. I had assumed these orders would be for SpaceX and Telesat, due to those companies’ intention to launch test satellites later this year, but according to Communications Daily, the orders are in fact to approve Space Norway and Telesat, leaving SpaceX out in the cold.

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