LEO Growth Raising Sustainability Concerns for Space and Earth

The low earth orbit (LEO) satellite boom is aping the consumer electronics model of cheap and standardized, meaning the industry must focus more on rapid replacements that are also environmentally sustainable, said Aaron Boley, University of British Columbia Outer Space Institute co-director, speaking at an IEEE event Thursday on LEO and sustainability. Darren McKnight, LeoLabs senior technical fellow, said the proliferation of spent rocket bodies left in orbit is an increasing concern. Among regulatory agencies, the FCC has "set a good example" in trying to tackle orbital debris, McKnight said. The commission has said it would refresh its space debris mitigation docket (see 2405020048).

Boley said the possible environmental costs of space activity need additional attention. Addressing this would require regulatory as well as tech approaches, he added. While significant focus is on orbital debris, other space sustainability concerns such as emissions from launches also need attention, he argued. The chance of a casualty event from an object reentering the earth's atmosphere without fully burning up is growing, and a rules regime for controlled reentry of massive objects might be needed, he said. "We can't just abandon rocket bodies in orbit."

Soot is a big component of emissions from some rocket fuels, and it has a major climate impact, Boley said. He said mega constellations of tens of thousands of satellites will mean tons of vaporized aluminum and lithium added to the atmosphere daily. Theoretically, those metals could change the reflectivity properties of the atmosphere, he said.

McKnight said the 840 km orbital attitude is becoming "the bad neighborhood ... you don't want to wander into" because of orbital debris, which includes multiple school bus-sized Russian rocket bodies, some defunct U.S. satellites, and materials left from Chinese anti-satellite testing. "It's an unfortunate, ironic collaboration" by the major space-faring nations, he said. The major near collisions in space in the past two and a half years can't be blamed on the debris of one particular space actor but are due to multiple nations' activities, he said.

Arguably a slow-motion disaster is already underway in some orbits, said Stefan Scharring, German Aerospace Center researcher. He said the growing number of launch payloads and debris objects is putting big pressure on space traffic management, he said.

Big constellations Starlink and OneWeb are good at sharing space body data such as trajectories with other operators, but lots of smaller operators aren't nearly as forthcoming, LeoLabs' McKnight said. The U.K. Space Agency, European Space Agency and especially the Japan Aerospace Exploration Agency have invested in orbital debris removal development and demonstrations, he said. NASA has lagged, though its space sustainability strategy released last month made up some lost ground as it discusses removal, he added.