Virgin Galactic’s second SpaceShipTwo, a reusable suborbital “spaceplane” for flying tourists and other paying customers to the edge of space and back, is coming together in Mojave, Calif. The major build of the spaceship itself, which is being led by The Spaceship Company, a subsidiary of Virgin Galactic, is expected to be complete “soon, within months,” according to Virgin Galactic’s CEO George Whitesides, speaking at the 2015 International Symposium for Personal and Commercial Spaceflight (ISPCS) this week in Las Cruces, N.M.
“We’re now working to integrate all the systems into the vehicle: the plumbing, the electrical, the pneumatics and other systems,” said Whitesides, stressing that Virgin Galactic is working toward internal schedules but not willing to commit publicly to a firm Return-to-Flight (RTF) test date just yet.
“We’re working three shifts now to finish the vehicle. The trick with all these programs is to find the right balance of moving quickly, but also building it right and building it safely.”
SpaceShipTwo is designed to launch mid-air from a mothership, WhiteKnightTwo, carried aloft to 50,000 feet before being released in free-fall and firing its hybrid rocket motor for the ascent to 62 miles (100 km); the internationally recognized boundary of space.
A total of eight passengers, including two pilots, accelerate for 70 seconds to Mach 3.5 before shutting down the engine and coasting to the edge of space. The vehicle’s interior design encourages passengers to unstrap and float around, enjoying the view out of one of its many windows for five minutes of zero-g before strapping back in for the glide to a runway landing.
The first SpaceShipTwo, VSS Enterprise, was lost on its fourth rocket-powered flight test in a fatal accident on Oct. 31, 2014, over the Mojave desert. The spacecraft broke apart 13 seconds into flight as it accelerated through the sound barrier, killing co-pilot Mike Alsbury and injuring pilot Peter Siebold.
On July 28, the National Transportation and Safety Board (NTSB) determined human error as the cause of the crash, blaming a “failure to consider human error and the co-pilot’s early deployment of the feathering mechanism that slows the vehicle during reentry.”
As explained in a previous AmericaSpace report on the NTSB determination, SpaceShipTwo was traveling at 0.8 Mach when Alsbury unlocked the feather system, which was not supposed to happen until 1.4 Mach. This premature deployment of the braking system caused the loads to overcome the feather’s actuators, resulting in loss of control and break-up of the vehicle. Siebold was thrown from the ship while still strapped in his seat, at which point he released himself from the seat to automatically deploy his parachute.
Over 700 people from more than 50 countries around the world have already purchased tickets to fly, at a cost of $250,000 each. Well known clients include Brad Pitt and Angelina Jolie, Ashton Kutcher, Leonardo DiCaprio, Tom Hanks, and even famed theoretical physicist Stephen Hawking.
NASA also awarded Virgin Galactic a three-year long indefinite-delivery, indefinite-quantity contract in September 2014 for integration and flight services to fly a variety of payloads to near-space. However, NASA has not yet revealed any specifics regarding what would fly on SpaceShipTwo.
Of the 700+ tickets sold, only about 3 percent were cancelled following the accident; about 20 people according to the Virgin Galactic.
The company has also switched back to a rubber-based fuel for the second SpaceShipTwo, formally known as hydroxyl-terminated polybutadiene (HTPB). It was the original choice for the vehicle’s hybrid rocket motor to begin with, but was switched to a nylon-based fuel in May 2014. The first flight with the new fuel was to be the last.
The decision to switch is most likely based off better performance as a result of ongoing work with both fuels, rather than anything related to the loss of Enterprise, and Virgin Galactic has been conducting full-duration test fires of SpaceShipTwo’s motor with the new fuel in Mojave.
Back in May SpaceShipTwo reached a major construction milestone when the structure was finally able to stand on its own landing gear instead of sitting on supports, known as “Weight on Wheels.” It has since been mated with its WhiteKnightTwo mothership, and its oxidizer tank will be installed into the fuselage “later in the year,” according to Whitesides. The spacecraft’s avionics and new improved pilot seats will be installed onboard soon as well.
The new SpaceShipTwo has not been given a name yet.
Once the build is complete ground tests will commence, followed by captive-carry and unpowered glide flight tests, before beginning the rocket-powered flight tests above 50,000 feet, slowly flying higher toward 62 miles with each test before qualifying SpaceShipTwo for operational commercial flights with paying customers.
Virgin Galactic still hopes to begin those commercial flights next year, but if history is any indication that is not very likely, seeing how ground tests won’t even start until after the new year. The flight tests, however, won’t be starting from scratch, as it will build on the successes of the first flight test program.