Northrop Grumman artist's rendering of a Next-Generation Overhead Persistent Infrared satellite in polar orbit. Credit: Northrop Grumman

ST LOUIS – A U.S. missile-warning satellite completed a major review, keeping the spacecraft on track for launch in 2028.

Northrop Grumman announced May 24 that the Next-Generation Overhead Persistent Infrared (OPIR) polar satellite passed its preliminary design review earlier this month.

Preliminary design review “is the first milestone that demonstrates the maturity of the system to meet the mission,” Alex Fax, Northrop Grumman vice president of Next-Gen OPIR polar program, told SpaceNews. “It’s significant that we got there on time, per an accelerated schedule, so we can get the spacecraft delivered on time.”

Northrop Grumman won a $2.37 billion contract in 2020 to develop two Next-Gen OPIR polar satellites with infrared sensors to detect and track ballistic and hypersonic missiles for the U.S. Space Force Space Systems Command. The spacecraft will travel “in highly elliptical polar orbits, which gives them full-time visibility of the Northern Hemisphere,” Fax said.   

With the preliminary design review completed, Northrop Grumman will begin manufacturing and procuring key spacecraft components ahead of the critical design review scheduled for May 2024.

Northrop Grumman is supplying its Eagle-3 spacecraft and communications payloads for the Next-Gen OPIR polar satellites. Northrop Grumman also is working with Ball Aerospace to develop the infrared payload.

“A key feature of that payload is that it’s effectively the same payload that is being produced for the Next-Gen [OPIR] GEO program,” Fax said.

Five-Satellite Constellation

The Space Force Next-Gen OPIR program includes five satellites: two polar satellites from Northrop Grumman and three geosynchronous satellites being produced by Lockheed Martin under a $4.9 billion contract awarded in 2021.

Northrop Grumman and Raytheon are developing sensor payloads for the Lockheed Martin-built OPIR geosynchronous satellites.

The Northrop Grumman-Ball Aerospace infrared payload already completed preliminary and critical design reviews for the Next-Gen OPIR geosynchronous program.

Given the maturity of the payload, the preliminary design review for Next-Gen OPIR polar was an important milestone “to verify that we’re able to leverage this payload that was designed for both polar and GEO orbits,” said Aaron Dann, Northrop Grumman vice president for strategic force programs.

The Next-Gen OPIR polar satellites are designed to identify the infrared heat signatures of incoming missiles and transmit that information to the ground through a resilient, secure communications system.

“Because we’re in a polar orbit, looking over the Northern Hemisphere, we have continental U.S. in full-time view, which limits our dependency on overseas ground sites,” Fax said.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...