By Sam Sargent
The last ten years have seen a dynamic shift in the size and capability of spacecraft. We have experienced a shift from massive GEO communication satellites, once only supported by government missions or major corporations, to the commercial CubeSat model that have been tested and launched into LEO in droves. Spacecraft are now reaching a happy medium, one filled with smallsats designed to conduct custom missions in LEO, GEO, and Cislunar. Driven by a market now supported by multiple monthly launches and high capacity available at a lower per kilogram rate, spacecraft designs have optimized and supported new and exciting missions in an increasingly diverse array of orbits.
While the LEO market has driven the infrastructure development of over a hundred 3.7m S/X antennas, it is only recently that ground antenna diversity and redundancy have become critical to the success of missions in both GEO and Cislunar orbits. Requiring more options for mid-latitude support during LEOP and orbit-raising, operators are now selecting a broader antenna network by utilizing mid-sized tracking antennas and graduating to larger parabolic antennas to support regular TT&C activity.
GEO and Cislunar missions now require the support of spacecraft designed to provide drift operations, maintenance, and refueling when a spacecraft has either lost propulsion or is inoperable due to technical issues. GEO spacecraft, normally in a stationary orbit and licensed at select sites with large stationary antennas, are now drifting outside their operational range. Contracting smallsat operators who specialize in reestablishing connections is paramount to maintaining, at times, multimillion-dollar assets.
A new ground station strategy is being implemented to support these smallsat projects, utilizing tracking antennas of varying sizes scaling with the operator’s link budget to support real-time connectivity over longer distances. Critical maneuvers especially require redundant real-time support and are recommended to have at least two tracking antennas available during any operational activity.
Custom services provide specialized missions for one customer in a unique orbit or multiple localized spacecraft with similar use cases. Providers of custom services intend to design a global fleet of supporting spacecraft to provide services as often as possible. A change of location demands higher reliability in pointing, tracking, and as-needed pass scheduling, requiring a diverse ground station network different than anything that has been traditionally available on the market.
While GEO projects have successfully held the attention by staying in orbit and operational for years, Cislunar projects are returning to the spotlight. With NASA planning a lunar gateway to support on-surface lunar infrastructure and a fourth country now successfully on the moon, more Cislunar projects are being launched than ever before. Smallsats are once again on the cutting edge. The ground Segment must rise to meet the challenges that these new smallsat Cislunar missions require. Ground segment support is only growing in demand for larger tracking antennas with far better data rates.