Virgin Galactic’s SpaceShipTwo, dubbed the VSS Unity, took to the skies over Mojave, California this morning to complete the craft’s first ever free-flight test. And preliminary data shows it was a huge success.

Today’s flight marked the fifth overall flight for the VSS Unity, which has the distinction of being the only spacecraft built by the company’s in-house manufacturing team — TheSpaceshipCompany — and the 218th flight for its mothership, the WhiteKnightTwo.

Earlier in the week, the duo joined forces to complete a fourth captive carry test. Following the pair’s second captive-carry test in September, engineers decided that all systems were performing as expected and the crew could move onto free-flight testing. The first two attempts (both in November) were thwarted due to weather and an unexpected anomaly, which prevented the crew from separating the two vehicles.

That was not the case today. Following takeoff, the pilots of both vehicles tested multiple onboard systems, ensuring they were ready (and able) to release the spacecraft. Once they received the green light from the control room, the VSS Unity was set free and coasted down to a gentle landing.

During free-flight (also known as a glide test) testing, the two vehicles take off as a mated pair, with the SpaceShipTwo detaching from the WhiteKnightTwo during flight before gently gliding back to the runway. In-flight testing allows engineers thoroughly study how various systems on board the vehicles perform during flight.

The glide tests are not designed to go into space; however, they are a major step towards Virgin Galactic’s ultimate goal: launching people into space. Before that can happen, the aerospace company must first prove its vehicles are safe to carry human passengers. In order to do so, the company has to complete a lengthy testing process that includes captive-carry, free-flight, and rocket-powered tests.

The road to space.
The road to space. 

Rocket-powered testing was suspended following a tragic accident in 2014, when the first SpaceShipTwo crashed as a result of pilot error. The accident resulted in the death of one pilot, leaving a second injured.

Today’s successful free-flight test, was a crucial step to resuming rocket-powered flights.

Both vehicles are reported to have landed safely, and the team will now begin the tedious process of analyzing all the data collected during the test.

Photos via Virgin Galactic