GPS military code receives operational acceptance for early use

The Space and Missile Systems Center’s Production Corps achieved a major GPS milestone on Nov. 18 with the approval for Operational Acceptance of GPS Military-Code (M-Code) Early Use (MCEU). MCEU serves as a gap filler for M-code operations before the entire GPS constellation’s operational transition to the Next Generation Operational Control System Block 1.

The encrypted M-code signal enhances anti-jamming and anti-spoofing capabilities for the warfighter. M-code signals are available on all 23 GPS Block IIR-M, IIF and III space vehicles currently on orbit. The successful testing events were completed at the Master Control Station at Schriever Air Force Base, Colorado and Alternate Master Control Stations at Vandenberg Air Force Base, California.

Operational Acceptance followed successful integrated developmental and operational testing of the GPS Operational Control Segment (OCS) upgrade. Operating in a trial period since June 2020, the MCEU upgrade allows the OCS Architecture Evolution Plan to task, upload and monitor M-code within the GPS constellation, as well as support testing and fielding of modernized user equipment. With M-code now declared operational, upcoming Military GPS User Equipment (MGUE) will be able to request early use of the M-code signal-in-space to provide more secure position, navigation and timing (PNT) to warfighters.

“MCEU ushers in a new era of GPS support that will provide operators across the warfighting domain with assured PNT access while further preventing unauthorized use by our adversaries. This is a critical step in remaining the gold standard of PNT systems and promoting a peaceful, secure, stable, and accessible space domain,” said Lt. Jordan Malara, 2nd Space Operations Squadron GPS Warfighter Collaboration Cell assistant flight commander.

M-code designed for security

Military code (M-Code) is a more-secure, harder-to-jam and spoof GPS signal specifically for military forces. Awarded in September 2017, M-Code Early Use (MCEU) is a software upgrade to the OCS AEP, which allows the current ground control system to task, upload and monitor M-Code within the GPS constellation. It will also help Accelerating M-Code’s deployment supports testing and fielding of modernized user equipment in support of the warfighter.

MCEU includes a new software-defined receiver installed globally at all six Space Force Monitoring Sites. The M-code Monitor Station Technology Improvement and Capability (M-MSTIC) uses commercial, off-the-shelf hardware to cost effectively receive and process M-code signals, enabling OCS operators to successfully monitor the M-code signals.

“M-code’s more-secure, harder-to-jam and spoof signals are critical to helping our warfighters complete their missions, especially in contested environments,” said Maria Demaree, vice president and general manager for Lockheed Martin’s Mission Solutions line of business. “This upgrade to the current GPS ground control system, and the launch of more modernized GPS III satellites, is making M-code’s full-fielding a reality.”

With the Dec. 1 Operational Acceptance of GPS III Space Vehicle 04 (GPS III SV04), 23 GPS IIR-M, GPS IIF and GPS III satellites broadcast M-code in the current GPS Constellation.

Ground Control Timeline — OCS AEP

Lockheed Martin has sustained the Space Force’s current GPS ground control system since 2013. The system is known as the GPS Operational Control Segment (OCS) Architecture Evolution Plan (AEP) or “OCS AEP.”

In February 2016, the Air Force contracted Lockheed Martin to develop the GPS III Contingency Operations (COps) software upgrade to the OCS AEP. COps was delivered in May 2019, successfully connected with on-orbit GPS III SV01 in October 2019, and was Operationally Accepted in February 2020. COps enabled the Air Force’s ground control system to command and control both the legacy satellites, as well the more powerful GPS III satellites beginning to launch.

In November 2018, the company completed the AEP 7.5 upgrade — the largest architectural change in the systems history — replacing significant code, hardware and software to improve the system’s cybersecurity capabilities and positioning the Air Force to better operate in contested, degraded and operationally limited environments.

In December 2018, the Air Force awarded Lockheed Martin the GPS Control Segment Sustainment II (GCS II) contract to continue to further modernize and sustain the OCS AEP through 2025.

In the fourth quarter of 2019, Lockheed Martin delivered the Red Dragon Cybersecurity Suite (RDCSS) Phase III upgrade to the OCS AEP, dramatically improving Defensive Cyber Operations (DCO) visibility into GPS network traffic. Other add-ons include user behavior analytics to analyze patterns of traffic and network taps to improve data collections.

Earlier this year — and key to enabling M-Code — Lockheed Martin installed new software-defined M-Code Monitor Station Technology Capability (M-MSTIC) receivers at six Space Force monitoring sites around the world. In Dec. 2019, SMC granted security approval for M-MSTIC.

From his side window, a crew chief relays vital position information back to the CH-47 Chinook pilot as paratroopers hook their pallet of equipment to the underside of the helicopter during sling load and air operations training. (Photo: U.S. Army/Maj. Robert Fellingham)