Northrop Grumman Corporation conducted its first full-scale static test fire of the Sentinel stage-one solid rocket motor at the company’s test facility in Promontory.

This development test will further prove the Sentinel team’s design approach and gain confidence to move to the next stage of testing. The motor fired for the anticipated duration and met performance parameters and objectives within expected ranges.

«This static fire highlights the advances we’ve made in digital engineering and gives us confidence in our ability to translate that into hardware build and test as we continue to make progress on the path to flight testing», said Sarah Willoughby, vice president, Sentinel, Northrop Grumman. «The results allow us to validate and anchor our stage-one motor performance before entering qualification testing and completing system analyses, key to lowering risk as we mature the Sentinel design and advance towards critical design review».

Northrop Grumman also leveraged advanced testing equipment that allowed for increased data collection to better understand motor characteristics.

«Our investments in digital design, test and advanced manufacturing help to ensure we develop this next-generation missile more affordably and with innovation at its core, delivering to the Air Force a safe, secure, reliable and flexible capability», added Willoughby.

The Sentinel intercontinental ballistic missile weapon system is the U.S. Air Force’s program to modernize the land-based leg of the strategic triad, replacing the Minuteman III system that has been in service for more than half a century.

The Sentinel missile features a three-stage booster, with Northrop Grumman producing stages one and two. The booster is a new design, using the latest materials and design technologies to ultimately improve performance, reliability, safety and sustainability.

Northrop Grumman Corporation successfully completed a series of wind tunnel tests of the LGM-35A Sentinel InterContinental Ballistic Missile (ICBM). Using scaled models of the vehicle, stressed under environments from sub to hypersonic speeds, the robust test campaign validated digital modeling and simulations and proved design maturity of the missile.

«This wind tunnel campaign is an opportunity to put our digitally engineered designs to the test, under conditions that mimic a missile launch», said Sarah Willoughby, vice president and program manager, Sentinel, Northrop Grumman. «Predictions from the modeling correlated with the testing results, giving us confidence in our model-based engineering approach. Data from these tests will inform future engineering decisions as we mature the design and continue on a path to deliver this critical capability to the Air Force».

Wind tunnel testing is a key early step in any missile development program because it determines how a vehicle will perform during flight. A team of engineers created seven comprehensive test campaigns, each with a unique set of requirements, to measure how the missile would respond to various atmospheric, load and speed conditions. Tests simulated everything from firing the missile, to stage separation and various flight maneuvers. The team is now updating models to enable full scale predictive environments for the development of Sentinel flight hardware.

«Tests were conducted at industry and government-run facilities across the U.S. in under a year», said Willoughby. «This is an extremely complex effort proving the value of digital engineering in helping us move to the next phase with certainty».

The U.S. Air Force’s Sentinel weapon system is a critical modernization of the current land-based leg of the U.S. nuclear triad, replacing the Minuteman III ICBM system that has been in service for more than 50 years. The program represents advancements in technology with the use of digital engineering, advanced tooling, and a modular, open-architecture approach.