Virgin Orbit is closer than ever to its goal of launching orbital satellites from a platform carried aboard a modified 747 aircraft. The company flew a successful cryogenic captive carry test of its LauncherOne rocket, carried by the Cosmic Girl carrier aircraft. This test marks the first time that the LauncherOne flew aboard the aircraft fully fueled with RP-1, though it used liquid nitrogen instead of liquid oxygen as an additional safety precaution.

This is an important test because it simulates the real thermal conditions the rocket would undergo during the actual demo launch, since all prior flights have just used water in place of fuel. That’s good for simulating carry weight, but water is much warmer than rocket fuel, which means it isn’t an accurate representation of actual mission conditions.

Virgin Orbit’s test flight in this case went just as planned, which is good news for its forthcoming full launch demo mission. This flight included a “complete, end-to-end launch rehearsal” that includes all ground operations, mission control, communications, launch range assets and the full flight path of the carrier aircraft.

In a blog post about its preparations for this flight, Virgin describes the changes its made as a result of COVID-19, which include re-written procedures for mission control operations, use o personal protective equipment, additional sterilization and having up to 90 percent of its employee base working remotely.

Next up is that crucial first demonstration launch, which will be the inaugural flight of the system as it’s designed to work in operation, including all components – with the LauncherOne separation and orbital delivery included. That’s still set to take place sometime this year, and with this test not complete, it shouldn’t be all that long before Virgin Orbit takes that step.