by Douglas Messier
Virgin Orbit completed a cryogenic captive carry flight test with a fueled LauncherOne rocket aboard for the first time, clearing the last hurdle before Richard Branson’s company can conduct the maiden flight of the air-launched booster.
Virgin Orbit’s modified Boeing 747, known as Cosmic Girl, took off from the Mojave Air and Space Port in California at 11:43 a.m. PDT. The aircraft had a LauncherOne filled with RP-1 and liquid nitrogen under its wing.
During the 1 hour 57 minute flight, the jumbo jet flew over the Pacific Ocean where it practiced the maneuvers needed to air launch the booster.
“We’ve successfully completed our pull-up maneuver and simulated drop,” Virgin Orbit tweeted. “Everything has looked good thus far on this capstone launch rehearsal. Cosmic Girl heading back to base.”
LauncherOne is a two-stage booster fueled with RP-1 and liquid oxygen (LOX). In previous flight tests, the booster’s tanks were filled with water, which is much warmer than LOX.
For this cryogenic test, Virgin Orbit substituted liquid nitrogen for the LOX as a safety precaution.
“So, for this end-to-end rehearsal, we’ll have liquid nitrogen — which is very similar in temperature to liquid oxygen, but which would pose less of a risk in case anything were to go wrong despite all of our planning — in our LOX tanks for both stages,” Virgin Orbit wrote in a mission update.
VIrgin Orbit engineers will now review data from the flight before preparing for the maiden launch of the booster. The company has not announced a date for the flight.
LauncherOne is capable of placing payloads weighing 500 kg (1,102 lb) into low Earth orbit and 300 kg (661 lb) into sun synchronous orbit.