SpaceShipTwo, Virgin Galactic’s commercial rocket-plane, logged its 54^th test flight Tuesday at Mojave Air and Space Port, the Bakersfield Californian reports.  This most recent run follows the 10^th anniversary of SpaceShipOne’s historical flight into suborbital space, which was celebrated this past weekend in Mojave.

The methods behind commercial spaceflight vary greatly from those followed by NASA. For one, SpaceShipTwo uses a carrier aircraft, WhiteKightTwo, to reach initial altitudes of over 50,000 feet.

WhiteKnightTwo, christened VMS (Virgin Mobile Spacecraft) Eve in honor of Sir Richard Branson’s mother, is no ordinary cargo plane. The launching aircraft uses a twin-fuselage design with two sets of dihedral wings forming a giant flying “W” made of all carbon composite.

SpaceShipTwo, using similar carbon composite construction, detaches from the center of SMS Eve carrying two pilots and six passengers. The aircraft uses a hybrid rocket motor to reach space, which unlike traditional rocket engines, can be shut off at any point by the pilots allowing the aircraft to safely return to the runway.

Despite the technological progress achieved via these two aircraft, many problems still hinder the first commercial spaceflight. Recent rumors suggest that the company is still having issues with the rocket engine, which Tuesday’s test flight by design did not involve.

“The delay in SpaceShipTwo has not been the development of either of the vehicles. But the rocket motor has just been problematic from the get-go,” said former pilot of SpaceShipOne Brian Binnie, who set a record for commercial flight in 2004 for traveling to suborbital space at an altitude of 112km. Binnie told Popular Mechanics in their Oct.6 issue that the fuel and fuel tank remain an issue.

Flights on the aircraft can be reserved for $250,000 although Sir Branson stated Saturday that he is no longer making predictions as to when the first flight will take place.