The U.S. Federal Aviation Administration (FAA) has proposed new rules to address the growing threat of orbital debris, which poses a hazard to spacecraft and satellites.
The proposed rules, which were detailed in a notice of proposed rulemaking (NPRM) published this week, would require commercial space launch operators to take responsibility for disposing of the upper stages of their launch vehicles.
Operators would have five options for disposing of the upper stages. The first is controlled re-entry. This would involve guiding the upper stage into Earth’s atmosphere where it would burn up.
The second is uncontrolled atmospheric disposal which will allow the upper stage to naturally decay and re-enter Earth’s atmosphere on its own. While the third is about moving the upper stage to a storage or graveyard orbit. This would move the upper stage to a higher orbit where it is less likely to collide with other objects.
Fourth is retrieving the upper stage within five years. This would involve using a spacecraft or other means to retrieve the upper stage from orbit. Finally, pushing the upper stage into an Earth-escape orbit, which would send the upper stage out of Earth’s orbit completely.
The FAA proposes that operators should be allowed up to 25 years in which the upper stage is removed from orbit using the uncontrolled or natural decay method. The FAA says the proposed rules are necessary because the amount of orbital debris is increasing rapidly. This is due to the increasing number of launches that are taking place, particularly the launch of large constellations of satellites for broadband internet services.
The FAA estimates that there are currently over 23,000 orbital objects 10cm or greater in size, half a million objects between 1 and 10cm, and upwards of 100 million objects larger than 1mm.
The greatest contributor to this swathe of orbital debris is now collisions between large objects such as upper stages. The FAA says the proposed rules are an attempt to limit the threat of such collisions.
The sources for this piece include an article in TheRegister.