NGSO Boom Raising Collision, Coordination Concerns

Many also see regulatory challenges of keeping up with that increased launch and orbital traffic, said Dynamic Spectrum Alliance President Kalpak Gude. Weeden said there have been some policy discussions about different regulatory requirements for different types of satellites or constellations, such as different provisions covering cubesats that can't maneuver: "There's no real answer at the moment." He said the federal hiring freeze puts regulators already facing backlogs further behind.

The FCC in a statement Friday said it "has been tremendously busy the last few months and the freeze has not pinched us with respect to getting this important work done. Chairman [Ajit] Pai is very proud of the work the FCC staff has done -- including the International Bureau staff who have done a great job keeping up on applications and avoiding a significant backlog." The agency said its earth station backlog "recently reached an all-time low ... of 6 applications."

Operators such as Boeing (see 1606230050), OneWeb and SpaceX (see 1703020036) intend to put up thousands of low and medium earth orbit satellites in coming years, and numerous other NGSO operators are planning similar -- if smaller -- constellations.

Most of the NGSO constellations are going to have onboard maneuvering, said satellite lawyer Jim Dunstan of Mobius Legal Group. He said the Air Force's S-band ground radar space fence system for tracking satellites and orbital debris is expected to become operational next year, allowing improved space situational awareness data at the Joint Space Operations Center (JSpOC). A larger concern is the expected growth of the number of cubesats without any active avoidance capabilities, Dunstan said, saying the FCC is hoping to propose rules this year that would segment orbits, limiting cubesats without maneuvering capabilities to orbits below the International Space Station.

Even within one constellation, NGSO operators are going to want to spread traffic across a zone to manage conjunction issues, Gude said. When a constellation means hundreds or even thousands of satellites, the question becomes how much separation between planes is allowable before the physical geography of space "becomes largely occupied," he said.

Spectrum coordination issues pose similar issues, with regulators increasingly likely to push spectrum sharing, Gude said. "Governments are unlikely to want to give any one party control from an NGSO perspective of all that spectrum," he said, saying the databases in the 3.5 GHz band are demonstrating dynamic sharing is possible. Dunstan said NGSO operators are finding themselves hampered by geostationary operators that already have claimed much of the spectrum, with that issue to be compounded by NGSO mega constellations. "The system is about ready to break," he said.

That few of the proposed constellation ever will get off the ground mitigates some of the worst-case scenarios, said one satellite lawyer. Echoed Gude, "We shouldn't get caught in the parade of horribles discussion ... of tens of thousands of satellites flying all over the place."

In their applications before the FCC, some operators give insights into their plans for avoiding collisions and spectrum congestion. Boeing said its orbit designs would have a minimum close approach of 10 kilometers with other satellites in the constellation. It estimated each of the satellites would have to perform 1.6 collision avoidance maneuvers annually. It said its V-band downlinks would cause less than 0.6 dB of worst-case interference into terrestrial upper microwave flexible use or fixed microwave services in the band, which could easily be handed by the terrestrial systems using power control or adaptive coding and modulation. SpaceX said it would employ dynamic beam forming and phased array antennas both in space and terrestrially, plus optical inter-satellite links, "to allocate broadband resources in real time, so that capacity can be placed where it is most needed and energy can be directed away from areas where it might cause interference to other systems." It pledged to work with JSpOC and other operators on coordination. OneWeb said it would largely avoid any GSO interference because its satellites would be in a low earth near-polar orbit significantly isolated from GSO satellites and earth stations most of the time, and that it would be "gradually tilting its satellites and adjusting beam usage as they approach the equator" to ensure they don't cause GSO interference.

Congress could be looking to roll back federal control over space. "It should be easier, not harder for private sector companies to freely explore space," said House Science, Space and Technology Chairman Lamar Smith, R-Texas, last month at a hearing, according to posted comments. "Instead of presuming that expansive new agency regulatory powers are needed, the conversation is shifting to questions of how to minimize agency regulation or avoid it all together. This is a good sign." Weeden said the White House is revising the interagency National Space Council to look at space policy, and that NGSO-related issues could be high on its agenda. The White House didn't comment.