Two recent hypersonic test flights involved a capability developed by Northrop Grumman that enables high-speed systems to navigate and maneuver without GPS. These tests aimed to validate the inertial measurement unit (IMU) technology onboard Stratolaunch’s Talon-A glide vehicle during its initial flights in December and March.

According to Northrop Grumman, the IMU technology marks an industry first for hypersonic aircraft, which can reach speeds of Mach 5 or higher. Jonathan Green, Northrop’s chief technology officer for emerging capabilities, expressed satisfaction with the IMU’s performance during the flight tests, noting that it met all operational goals and demonstrated durability throughout the testing phases.

The Pentagon announced these flights recently, highlighting them as the first successful reusable hypersonic vehicle flights since the X-15 program concluded in 1968. The U.S. has significantly increased its investment in hypersonic technologies, reflecting a renewed urgency to explore test opportunities critical to hypersonic development projects.

The IMU, part of Northrop’s Advanced Hypersonic Technology, is designed to navigate without GPS, which may be compromised by weather conditions, challenging terrains, or enemy interference. It employs advanced sensors to track the vehicle’s movement and calculate its path, which was successfully validated according to Josei Chang, Northrop’s senior director of advanced technologies.

While Northrop has previously developed IMUs for space applications, this specific model is smaller and more resilient, intended for rugged environments associated with hypersonic flight. Green noted that the company’s work builds upon its heritage in space-based inertial navigation systems.

These hypersonic flights mark a significant advancement for the IMU, which is still under research and development. Northrop is collaborating with the Army Combat Capabilities Development Command Aviation and Missile Systems Center on further development, though details on formal partnerships or contracts have not been disclosed.

Northrop plans additional testing of the IMU on a sounding rocket within the current quarter and is preparing for a test at Holloman Air Force Base in Utah later this year to examine the system’s performance under high gravitational forces. The company is also monitoring Talon-A’s testing schedule but has not confirmed if the IMU will participate in the next slated flight this spring or summer.

Green emphasized the critical role of the partnership with Stratolaunch in facilitating the testing of this innovative system, underscoring the importance of having adequate resources for such tests.

Courtney Albon, a reporter for C4ISRNET, specializes in space and emerging technologies, covering the U.S. military landscape since 2012 with a focus on the Air Force and Space Force.