Virgin Galactic's SpaceShipTwo, a suborbital spaceplane designed for space tourism, crashed during a test flight over the Mojave Desert. One pilot was killed and another seriously injured according to a report from Reuters.

The space tourism company provided live updates of the flight on Twitter. Virgin Galactic tweeted that the engine had achieved ignition and just six minutes later, a second tweet revealed the aircraft had suffered an in-flight anomaly.

Kern County Sheriff's spokesperson Ray Pruitt said the co-pilot was killed in the crash. The primary pilot ejected and survived the incident. He was found near the crash scene and taken to a local hospital for treatment.

The test flight was the 35th time the craft had flown but the first powered flight with a new engine system.

Officials with Virgin Galactic noted earlier this week that if everything went as planned with the first few test flights, commercial service could commence early next year. They've already pre-sold several hundred rides at $200,000 each. The first person scheduled to take a ride to space was none other than Richard Branson, the billionaire entrepreneur and company founder.

The company said they will work closely with relevant authorities to determine what went wrong. As you might expect, SpaceShipTwo is a total loss.

While it's still too early to speculate, the accident will almost certainly push back a project that has already seen multiple setbacks over the years. Branson initially expected the maiden space voyage to take place by early 2011.