Communications satellites continue proliferation into new orbits with expanding services
By Rabindra (Rob) Singh|December 2024
The Communications Systems Technical Committee is working to advance communications systems research and applications.
This year, we noted expansion in the new space domain with the emerging very low-Earth orbit domain and the cislunar and lunar domain, in addition to the always active LEO, MEO and GEO market domains.
VLEO — very low-Earth orbit (400 kilometers or below)
In June, DARPA awarded a contract to Redwire of Florida to be the “prime mission integrator” for the agency’s Otter “air breathing” electric propulsion demonstration. A Redwire SabreSat VLEO spacecraft will be developed into an “orbiting wind tunnel” to test one or more techniques for gathering and ionizing air at VLEO altitudes. This could potentially create “a virtually unlimited supply of propellant” for satellite electric propulsion at these altitudes, DARPA explains. In April, DARPA awarded a $14.9 million Otter contract to Phase Four, an electric propulsion company in California, for its thruster technology.
LEO — low-Earth orbit (400-2000 km):
The most prolific orbital altitude surpassed 8,110 satellites in September, of which 6,350 were from SpaceX’s megaconstellation Starlink, two were from Amazon’s competing constellation, Kuiper, and 634 were from OneWeb. This emerging market has been driving new direct-to-device satellite demonstrations and services, including Apple’s Emergency SOS via Satellite service, provided by Globalstar satellites. In May, AT&T announced an agreement with AST SpaceMobile of Texas, which is creating a space-based broadband cellular network, to provide services to its customers. In September, AST announced that the first five of its BlueBird satellites reached orbit safely. SpaceX in January launched the first of its direct-to-device Starlink satellites and as of early August had commissioned about 100 of them.
MEO — medium-Earth orbit (2,000-36,000 km):
As of June, there were 199 satellites in MEO, the prime location for all global navigation satellite system constellations. In September, the U.S. Space Force announced agreements with four companies to produce design concepts for small satellites to augment today’s GPS constellation under the Resilient GPS initiative. Concepts for these Lite Evolving Augmented Proliferation, or LEAP, satellites will be created by Astranis, Axient, L3Harris and Sierra Space. In the missile defense domain, Boeing subsidiary Millennium Space Systems this year became the sole remaining spacecraft contractor for Space Force’s Epoch 1 program to send missile tracking warning satellites to MEO. Also, this regime is finding growing application for commercial communications and defense monitoring. In April, SES, the Luxembourg-based satellite operator, announced that its O3b mPOWER constellation was operational.
GEO — geosynchronous orbit (36,000 km):
As of June, there were some 552 satellites in GEO. We continue to see a shift from large-scale GEO satellites to smaller and MicroGEO satellites. In March, for example, Astranas, San Francisco maker of MicroGEO satellites, announced that it will provide a satellite to Thaicom, an Asian satellite operator, and one for Orbith, a Latin American internet provider, for service in Argentina. Also in March, Boeing received a contract from the Space Force to build WGS-12, the next Wideband Global Satcom satellite. In June, Airbus Defence and Space announced that it has been contracted by Yahsat of the United Arab Emirates to build the Al Yah 4 and Al Yah 5 satellites.
Cislunar/lunar
The volume of space beyond GEO is of increasing interest to commercial companies as the U.S., and other governments are making plans to explore the moon and open it up to economic activity. In September, Intuitive Machines of Texas received a NASA contract that could be worth up to $4.82 billion to provide lunar relay satellites and other equipment services to the agency.
