Thursday, March 13, 2008

SpaceShipTwo (SS2) is a sub orbital spacecraft currently under development by The Spaceship Company (a joint venture between Sir Richard Branson’s Virgin Galactic and Scaled Composites). It forms part of Tier 1b, a two-stage to suborbital-space manned launch system. Virgin Galactic plans to use this for their space tourism venture. The ship in development has been christened VSS Enterprise. The name is an acknowledgement to the USS Enterprise from the Star Trek television series.

SpaceshipTwo and White Knight Two

It is based on SpaceShipOne, developed by Scaled Composites which won the Ansari X-Prize in 2004 for launching a privately-funded reusable manned spacecraft into space twice within two weeks. The SpaceshipTwo is designed to carry six passengers and two pilots to an altitude of approximately 110 km (360,000 ft). This will be 10km higher than the altitude achieved by SpaceShipOne. The officially defined “boundary of space” is 100km. The SpaceshipTwo will reach a speed of approximately 4000 kmph, using a single hybrid rocket motor, which runs on a rubber-based solid fuel and nitrous oxide oxidizer.

Burt Rutan, SpaceshipTwo designerFor returning to earth, the SpaceshipTwo uses a technique called feathered reentry. In this system, the spacecraft itself changes the shape of its wings so as to make it less streamlined. This causes more atmospheric gas particles (which are still present at 100km altitude) than otherwise, to hit the spacecraft, increasing drag. This allows the reentry deceleration to occur at a higher altitude and greatly reduces the forces and heating on the structure. Also, the ship, in the feathered configuration, will align itself automatically such that the pilot has a less-critical flight control task. Burt Rutan describes this as "care-free reentry". This is different from the shuttle which re-enters at speeds in excess of 25000 kmph which necessitates heat shields. At approximately 60,000 feet, SpaceshipTwo’s wings are re-configured into their original position allowing for an unpowered (glide) landing back at the spaceport.

SpaceshipTwo picture

The spacecraft is launched mid-air and is carried to launch altitude aboard its mother-ship, the WhiteKnightTwo(WK2). WK2 is an aircraft with a wingspan similar to a B29 bomber ( around 43m) , powered by 4 Pratt & Whitney turbofan engines. It will carry the SpaceshipTwo to an altitude of 15200 m (50000 ft), from where it is dropped. The spacecraft will then fire its hybrid rocket motor to boost it to space.

The spaceline is expected to start operations in late 2008 or early 2009. 100 tickets were initially made available at a cost of $200000 each. After the first 100, the price will drop to $100000 and after the first year, it will drop to $20000. The flight will last 2 ½ hours. Passengers will experience 5 minutes of weightlessness and will be able to experience it unhindered by any seat-belts. There are also a large number of portholes from which the passengers can observe the curvature of the earth. During the initial boost phase, the passengers will experience accelerations of 3 to 4 Gs and up to 6 Gs (for a very short period) during reentry.

SpaceshipTwo photo

The SpaceShipTwo craft along with its mothership will take off from the Mojave Spaceport in California during testing. Spaceport America (formerly Southwest Regional Spaceport), a $200 million spaceport in New Mexico partly funded by the government will become the permanent launch site when commercial launches begin. Weekly launches are planned.

The craft is currently 60% completed and is expected to be finished in June 2008 with first test flights in July. The Scaled Composites SpaceShipThree is a proposed orbital spaceplane to be developed by Virgin Galactic and Scaled Composites if SpaceShipTwo is successful. Early reports suggest it will be capable of orbital flight, and possibly able to dock with space stations. SS3 would be part of Scaled Composites/Virgin Galactic's Tier Two program of orbital spaceflight.

SpaceshipTwo flight profile image
SpaceshipTwo interior photo with Burt Rutan

SpaceshipTwo under construction picture


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