LONDON — Building and launching spacecraft sometimes gets so much attention that the ground segment — user terminals, command and control systems and network operations —isn’t always ready even after a satellite is in space.

Leaders in U.S. military space programs said they are prioritizing the ground segment half of their missions to avoid more scenarios where satellites go underutilized because of incomplete ground segment systems.

Deanna Ryals, Air Force Space and Missile Systems Center’s chief partnership officer, said one of the big revelations that came from the Air Force’s Wideband Analysis of Alternatives study this summer was the need to prioritize the ground segment in future missions.

“A lot of the results of that [study] were you have to fix the problems on the ground first,” she said Nov. 7 at the 2018 Global MilSatcom conference here. “The problem is not with the spacecraft, it is on the ground.”

Last year, the U.S. Government Accountability Office flagged major ground segment delays in two military satellite programs: GPS 3 and the Mobile User Objective System. Five years of delays with the GPS 3 ground segment, called OCX, led the Air Force to develop two backup ground systems to ensure GPS continuity and boost resistance to jamming without the Raytheon-led system.

Raytheon said last November that the Air Force accepted the OCX launch and checkout system, and last week said OCX is ready for the first GPS 3 satellite after it launches on a SpaceX Falcon 9 rocket next month.

The five-satellite MUOS constellation, completed in 2016, remains limited in its use because of delays with user terminals.

Ryals said the current approach should be flipped to start with communications waveforms, then progress to modems and other parts of the ground network before getting to the satellite.

“We will get to the space segment when we get the rest of this figured out,” she said.

Kay Sears, vice president and general manager of military space at Lockheed Martin, the prime contractor for MUOS, said MUOS satellites have been in orbit for years now without the right user terminals.

“If we don’t think about it as a system and you don’t build it as a system, then you get it delivered in components that don’t talk to each other,” she said.

Lockheed Martin Space Systems is hiring more software engineers than hardware engineers, she said, driven by a need for expertise with software in satellites and on the ground.

“The ground element is one of those things that takes time and [for] each new generation we can’t have a new ground system,” she said.

Andrea Loper, Air Force Research Laboratory Space Vehicles Directorate acquisition program manager, said the small-satellite experiments her group launches are built on short timelines and don’t have time to build new ground systems for each mission.

“The small-satellite portfolio works a lot with external agencies and meeting their timelines, so creating an independent ground system for each of those experiments is not feasible,” she said. What they’ve done and what [the Air Force Research Laboratory] has historically done is use a common ground system and just keep reusing it and updating it.”

The Air Force Research Laboratory wants its ground segment to support as many missions as possible without the need for new developments with each experimental satellite, she said.