A Look Inside Virgin Galactic's Flight Training

The flight simulations break the G forces into components so that passengers understand how each type feels physically, and can better deal with the physiological effects. G forces in the x direction push hard against the chest, which can make it difficult to breathe. Passengers are trained to compress their lips like they’re playing a trumpet, and to take slow breaths, to maintain a positive pressure in their lungs.

G forces in the z direction are more dangerous because they can prevent blood from reaching the brain (the brain can only survive without blood for a few seconds). In class, passengers learn to tighten their muscles to direct blood to their chest area, pushing their legs hard against the cockpit’s foot rails and pulling up against the handrails in order to prevent too much blood from getting sidetracked away from the brain. If this isn’t successful, they risk G-induced loss of consciousness (GLOC), which can leave passengers disoriented and extremely uncomfortable.

The STS-400 simulations gives passengers a taste of Gx and Gz forces alone, first at 50 percent of the force felt on SpaceShipTwo, then at 100 percent. And then the STS combines them together, just like in real flight, so passengers can test out their G force survival skills. The simulator doesn’t, however, give them the sought-after zero gravity sensation—they only experience 0.4G over a period of a few seconds.

Safety First

Safety is top concern for Virgin Galactic: da Silva and other trainees also underwent vigorous medical testing, including a heart stress test and a physical. No one with even the slightest heart condition is allowed to fly, as cardiac arrest is highly likely in candidates with heart problems. Virgin estimates that 80 percent of the population will be healthy enough to fly.

The company is also taking great care with the safety of its designs. As their Web site notes, it “does not regard itself as being in a race” to be the first suborbital tourist flight. And while some reports have suggested a 2009 launch date, the company does not have a scheduled deadline for departure. Waiting until the technology is perfect is probably a good thing: just last year, three Scaled Composites engineers were killed while testing of components of SpaceShipTwo’s rocket motor. Passenger deaths would likely shut down the fledgling space tourism industry.

Da Silva says, however, that he isn’t thinking too much of the safety aspect. “What I care about in this journey is being weightless above the earth, looking down on my home planet where all of human history has occurred, everyone I know and everyone I have ever read about lives or lived. The awesomeness will be overwhelming,” he said.

But, even if his name is drawn first, he may have to wait a bit longer: “I have a deal with my benefactor that if I get a ticket first, Alan is going up in that spot.”

WhiteKnightTwo was named one of PopSci's top 100 innovations of the year. Read more about it and all of our Best of What's New picks at popsci.com/bown2008.