Richard Branson’s space tourism company, Virgin Galactic wants to get humans to space before SpaceX. The firm announced Wednesday that it will attempt to test fly its SpaceShipTwo, aka VSS Unity, its suborbital spaceplane on Thursday. This trial intends to reach “space altitude” for the first time in the company’s history, which it hopes will pave the way for commercial space travel.

Weather permitting and assuming ground preparations go off without a hitch, the VSS Unity could be airborne as early as Thursday morning, Virgin Galactic stated in a press release. Two pilots will helm the spaceplane, and getting it into the atmosphere will require firing the plane’s rocket motors for longer than ever, long enough to get roughly 30 to 50 miles above the surface. This is technically considered space and the pilots should experience a period of micro-gravity as the VSS Unity reaches the highest altitude of its flight. These ambitious goals will be backed up by stringent safety measures.

VSS Unity firing its rocket motor during its third test flight. Virgin Galactic

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“[Crew safety] is brought sharply into focus by the fact that SpaceShipTwo is crewed by two pilots,” stated the press release. “This means that circumstances may require the team to cancel or change plans either before take-off or in-flight in order to bring our pilots and the spaceship home safely.”

This would be the VSS Unity’s fourth test flight in its existence and it’ll be by far its riskiest. Previous tests were conducted on the ground or at much lower altitudes, so this could be a make it or break it moment for Virgin Galactic’s space tourism dreams. The company has been incrementally trying to make a comeback since the crash of the previous VSS Enterprise killed one of the two pilots aboard and severely injured the other.

Branson made it clear in an interview with CNN Business that he’s weighing the crew’s safety more heavily than the status that would come with beating SpaceX to crewed spaceflight. Thursday’s test flight has the potential to be a monumental milestone for Virgin Galactic, both in the field of space tourism but also toward being able to compete with SpaceX for contracts to bring NASA technology into space.

If all goes according to plan, we’ll be one step close to being able to reserve a seat aboard the VSS Unity for a couple-hour space flight.