A United Launch Alliance Atlas 5, 2018 rocket lifted off Jan. 19 carrying the U.S. Air Force's SBIRS GEO Flight 4 satellite. Credit: ULA

WASHINGTON — The fourth satellite of the Space Based Infrared System constellation has been declared fully operational, the Air Force Space and Missile Systems Center announced June 6.

The billion-dollar SBIRS GEO-4, built by Lockheed Martin, launched from Cape Canaveral Air Force Station aboard a United Launch Alliance Atlas 5 411 rocket on January 20, 2018.

“The satellite is healthy and sending data to the Mission Control Station, operated by the 460th Space Wing located at Buckley Air Force Base, Colorado,” the Air Force said in a news release.

At this point, the Air Force Space Command is accepting the SBIRS GEO-4 satellite into the missile warning architecture for real-world operations, said Col Ricky Hunt, senior materiel leader and overhead persistent infrared satellite systems chief.

Four SBIRS GEO infrared surveillance satellites and Highly Elliptical Orbit (HEO) sensors provide worldwide coverage to help detect and track missile launches. The first three SBIRS satellites were launched in 2011, 2013 and 2017.

Lockheed Martin is manufacturing SBIRS 5 and 6, scheduled to be delivered in 2020 and 2021.

The Air Force in 2018 decided to cancel the procurement of SBIRS 7 and 8 satellites and transition to a new program, the Next Generation Overhead Persistent Infrared. The so-called next-gen OPIR satellites are being developed by Lockheed Martin on a faster timeline.

The Air Force Space and Missile Systems Center announced June 6 that Lockheed Martin in March completed a Next Gen OPIR GEO system requirements review for the three space vehicles of the constellation. Separately, two system design reviews were completed in April for the mission payloads with Lockheed Martin’s subcontractors Raytheon and a Northrop Grumman-Ball Aerospace team.

The payload subcontractors are developing competing missile warning sensors.

Next-gen OPIR is one of the Air Force’s largest satellite procurements. The Air Force is requesting $1.4 billion for the program in fiscal year 2020 — $817 million for the development of Lockheed’s three GEO satellites, $107 million for two polar-orbiting satellites to be made by Northrop Grumman, $264 million for ground systems and $205 million for studies of future parts and material obsolescence.

But the program is still $632 million short of what it needs in fiscal year 2019 to stay on schedule, Air Force leaders told Congress in April. They have asked for the money to be reprogrammed into the 2019 budget.

“Subject to funding decisions, the program remains on track to achieve a GEO space vehicle delivery by fiscal year 2025,” the Air Force said in a statement.

Of the $632 million reprogramming request, more than half is for payloads. The other half is to increase spacecraft development personnel to support systems engineering, procurement of long-lead components and the designing and building of bus components, an Air Force spokesman said.

Compared to SBIRS satellites, next-gen OPIR spacecraft have more powerful sensors and other features that make them more resilient for operations in contested environments, said Lt Col. Leroy Brown Jr., deputy chief of SMC’s Space Development Corps’ Next Gen OPIR Division.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...