Spaceflight Insider

SpaceShipTwo conducts successful test flight

Photo of VSS Unity during is seventh glide flight on January 11, 2018. Photo Credit: Virgin Galactic

Photo of VSS Unity during is seventh glide flight on January 11, 2018. Photo Credit: Virgin Galactic

Virgin Galactic conducted a successful test flight of the SpaceShipTwo, VSS Unity vehicle on Thursday, Jan. 11. The high-speed glide test marks the seventh for VSS Unity, which reached a top speed of Mach 0.9 during the flight.

At the helm were pilots Mark Stucky and Michael Masucci, who pushed the test article of the spacecraft to the limits of its atmospheric gliding capabilities. The flight comes several months after the previous flight of Unity in August of 2017. In the intervening time, extensive analysis, testing, and some small modifications were made to the vehicle to prepare it to withstand higher loads. Mach 0.9 is approximately the highest speed the vehicle can reach without firing the rocket motor, according to a release on the Virgin Galactic website.

Unity has not yet conducted a powered test flight. In order to simulate the weight and positioning of the rocket motor, water ballast is added to the vehicle. The water is then jettisoned around 22,000 feet (6,705 meters) to allow the vehicle to land under lighter conditions that better simulate the weight of the vehicle after its load of propellant has been spent.

To prepare the VSS Unity for its first powered flight, Thursday’s test also saw the full application of the craft’s thermal protection system (TPS). Like the black and grey tiles on the bottom and leading edges of the space shuttle, the TPS protects Unity from the heat loads generated during atmospheric reentry.

Virgin Galactic has not set a firm date on when to expect the first powered flight of VSS Unity. The last powered test flight of a SpaceShipTwo vehicle was on Oct. 31, 2014, during which the premature release of the craft’s innovative feathering system resulted in a loss of the vehicle and the death of copilot Michael Alsbury.



Paul is currently a graduate student in Space and Planetary Sciences at the University of Akransas in Fayetteville. He grew up in the Kansas City area and developed an interest in space at a young age at the start of the twin Mars Exploration Rover missions in 2003. He began his studies in aerospace engineering before switching over to geology at Wichita State University where he earned a Bachelor of Science in 2013. After working as an environmental geologist for a civil engineering firm, he began his graduate studies in 2016 and is actively working towards a PhD that will focus on the surficial processes of Mars. He also participated in a 2-week simluation at The Mars Society's Mars Desert Research Station in 2014 and remains involved in analogue mission studies today. Paul has been interested in science outreach and communication over the years which in the past included maintaining a personal blog on space exploration from high school through his undergraduate career and in recent years he has given talks at schools and other organizations over the topics of geology and space. He is excited to bring his experience as a geologist and scientist to the Spaceflight Insider team writing primarily on space science topics.

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