Virgin Orbit, a satellite launch company, is performing a thrust chamber assembly test on the E-1 test stand at the Stennis Space Center. The company partnered with Stennis to conduct a series of recently completed hot fire tests totaling 974,391 seconds.
Credit: NASA / SSC
When Virgin Orbit, a California-based satellite launch company, sought to broaden its horizons, it was natural for the company to think of NASA’s largest rocket engine test site – the Stennis Space Center near Bay St. Louis, Mississippi.
With a well-established and positive reputation, a specialized infrastructure equipped to test high-powered rocket engines, and 55 years of experience in propulsion testing, the Stennis Space Center has offered a unique set of benefits, including benches test drives that can simulate an entire rocket engine, allowing their partners to test single components rather than shipping an entire engine to site.
In November 2020, thanks to a Space Act agreement that allows NASA to partner with organizations, Virgin Orbit entered into a partnership with Stennis to reimburse the center for all testing costs. As a result, they were given the opportunity to use Stennis’ experience and expertise, which allowed them to avoid building their own test facilities while gaining valuable hands-on experience.
The Virgin Orbit test campaign had team members focused on the 75,000-pound thrust chamber (TCA) assembly, which consists of an injector, combustion chamber, and nozzle. The TCA is not a complete engine. Instead, this is where the propellants are mixed, burned, and depleted. The goal is to test different configurations of propellant injectors to determine which configuration will maximize performance and efficiency. Most of the main engine can be simulated with the test stand itself.
“With the excellent support of the NASA SSC team, Virgin Orbit has successfully completed the test campaign and collected invaluable data on key injector parameters and their effect on engine performance,” said Vishal Doshi, senior propulsion design engineer at Virgin Orbit.
These tests took place on test stand E-1, cell 1, set up for the retest in early 2021. The round of hot shots began on March 30 and lasted until the last day of testing, the July 20.
“Commercial projects are happening at a rapid pace, helping us learn new things and giving us the opportunity to help commercialize space,” said Paul Rydeen, NASA project manager at Stennis.
Originally there were 30 scheduled tests involving 10 different injector configurations with a minimum of three tests each. However, the project was later extended to 14 injector configurations and many other tests.
When the Virgin Orbit team got to grips with the testing process, they were able to set a pace that led them to success, allowing them to perform up to four tests per day. Each of these tests would typically last a total of 12.1 seconds. With 87 hot fire tests performed during the test period, the combined test time totaled 974,391 seconds.
“Virgin Orbit has worked with the Stennis test team since late 2020 on a variety of complex engine-related activities,” said Tom Alexiou, Virgin Orbit’s advanced launcher program manager. “Their support for us has been exemplary in all facets of the program. We continue to have an excellent working relationship and look forward to our latest N3.2 engine development test program which will take us through 2022. “
Testing at Stennis directly contributed to the design changes appearing on the Newton 3 engine – a first stage engine that uses Rocket Propellent-1 and liquid oxygen as the propellants. A typical run time for this step is three minutes with a top speed of 8,000 miles per hour. Virgin Orbit uses Newton 3 to propel the LauncherOne rocket, a two-stage orbital air vehicle transported into the upper atmosphere and released over the Pacific Ocean. This rocket holds the title of the first orbital-class liquid-powered rocket to reach space.