Space Force eyes advanced tech, new orbits for narrowband SATCOM

The Space Force offered a glimpse this week of its vision for the future of narrowband satellite communications, a plan that could include a large number of spacecraft in multiple orbits with advanced capabilities.

Today’s narrowband communication satellites, part of the Mobile User Objective System constellation, provide cellular voice and data capabilities to military forces around the world. Their location in the narrowband frequency range makes them less susceptible to bad weather or tricky terrain and allows for more secure communications.

In a May 29 notice, the Space Force said it wants its future narrowband satellites to be more resilient, cost less to build and maintain, and be fielded on faster timelines. The service hasn’t finalized those plans, but is analyzing its options and plans to complete that work later this year.

“The U.S. military must preserve its asymmetrical advantage given a contested, degraded, and operationally limited space environment,” the service said. “The capabilities provided by narrowband SATCOM are critical to the US military and its allies and they must continue to evolve in order to address expanding needs, benefit from emerging technologies, and to mitigate future threats.”

The service also envisions the proliferated constellation residing in medium Earth orbit, or MEO, below geostationary orbit where the satellites are currently positioned. MEO is located between 1,200 and 22,000 miles above sea level and geostationary orbit is around 22,000 miles.

The Space Force has four MUOS satellites in orbit and one spare, all built by Lockheed Martin. Each spacecraft has two payloads — one that maintains a legacy Ultra High Frequency Network and another that offers a new Wideband Code Division Multiple Access, or WCDMA, capability.

As the service crafts its vision for what capability will follow MUOS, it plans to launch two more satellites to keep the constellation operational through at least 2035. In January, the service awarded Lockheed and Boeing each a $66 million contract to design prototypes of the two spacecraft by July 2025. The Space Force had planned to choose one of the two companies by the end of fiscal 2025 to build the satellites, but that decision has been pushed to FY26.

Those two MUOS satellites, slated to launch in FY31, will provide a bridge to the new narrowband architecture. However, the service said in the notice it may want to take greater steps to transition to the future architecture by launching spacecraft to MEO in the same time frame.

The key, it said, is whether the existing ground terminals designed to link with satellites in GEO can interoperate with MEO spacecraft without the need for major upgrades. The notice seeks feedback from companies on potential modifications.

“Continuation of these services to the current set of user terminals creates an opportunity to increase space segment resiliency on the path to a more capable and resilient architecture,” the service said. “Additionally, if there are software or hardware modifications that user terminals may have to consider in order to be supported from MEO, those should be identified in the response.”

The service also wants to better understand the technical and schedule risks that could impede its plan to launch the transitional system by 2031 and whether companies recommend any demonstrations that could help reduce that risk.

The notice does not discuss the role commercial systems may play in the future narrowband architecture, though Space Force officials have said they are considering how to integrate technology available in the private sector.

In its commercial space strategy released in April, the service highlighted satellite communications more broadly as an area of opportunity for commercial collaboration. The document says the Space Force will prioritize those capabilities that are system-agnostic and can be easily integrated into a diverse architecture.

“The USSF will look to improve resilience through the integration of proliferated commercial networks into hybrid architectures and offset future investments in government owned capabilities,” the service said.