Launch of Vulcan showcases new solid rocket boosters

New solid rocket boosters that Northrop Grumman developed specifically for the Vulcan Centaur were successfully demonstrated during the vehicle’s first launch by United Launch Alliance.

Two GEM 63XL solid rocket boosters, which contributed nearly two-thirds of the vehicle’s total thrust at liftoff, were used in the Jan. 8 launch of Vulcan on the Cert-1 mission. Before they burned out and were removed, the strap-on boosters fired for almost two minutes.

Utilized on ULA’s Atlas 5, the GEM 63XL is an elongated variant of the GEM 63 booster. Despite being almost two meters longer, it has the same diameter as the GEM 63. The largest solid rocket booster ever constructed is the GEM 63XL, which is monolithic or non-segmented.

The benefits of a monolithic motor are numerous. In an interview conducted prior to launch, Bret Baldwin, the program director for Graphite Epoxy Motors at Northrop Grumman Propulsion Systems, stated, “Your thrust-to-mass ratio is certainly better.” “You will have a lighter, more efficient motor because you will have fewer joints.” In comparison to the GEM 63, he claimed that the GEM 63XL provided 20% more thrust for 10% more mass.

According to him, the absence of joints between booster segments enhances both dependability and safety. However, due to their length, transportation presents a challenge. He declared, “To try to transport them is a significant undertaking.” Specifically designed over-the-road transporters were created by Northrop to move the boosters from their production facility in Utah to Cape Canaveral.

Right now, Northrop is concentrating on increasing GEM 63XL production. For what it described as “multiple years of high-rate production,” the company was awarded a contract by ULA in 2022 worth over $2 billion to produce the booster for ULA’s backlog of Vulcan launches. Depending on the needs of the mission, each Vulcan can use up to six of the boosters.

Baldwin stated, “We’re focused significantly on the scaling aspect of this program,” which will take three years to complete. Northrop is spending money on new structures and other infrastructure to support the production of solid motors in general, including the GEM 63XL. “We are really looking forward to having buildings that are big enough and designed for rockets that are this large,” the statement reads.

The company is investigating different ways to enhance the motors as it increases production. As part of an annual cycle of tests, the Solid Motor Annual Rocket Technology Demonstrator, or SMART Demo, program includes the integration of technologies that have been tested. This is a recent initiative from the company, which included the test-firing of a new motor in December.

He did not specify any particular features he hoped to include in the GEM 63XL, but he did say, “We are very open to any lessons learned from the SMART motor program.” “SMART Demo 2 has already been discussed, and its application to these boosters and other propulsion systems is discussed.”