Virgin Galactic's aerial launcher, WhiteKnightTwo, with a passenger rocket launching from its the midsection. Scroll down for a video of the flight simulation.
Credit: Virgin Galactic
“Be careful what you wish for!” says Wilson da Silva, the Editor-in-Chief of Cosmos, Australia’s biggest-selling science magazine.
In October 2008, he joined other would-be astronauts as they were put through their paces in a massive centrifuge outside Philadelphia, formerly used by NASA's Apollo and Mercury mission astronauts.
His sub-orbital spaceflight is being funded by Dr Alan Finkel, chancellor of Monash University and the scientist and entrepreneur who co-founded Cosmos. As a kid, da Silva dreamed of going into space: then in 2004, Finkel bought a ticket for himself and decided it would be fun to take da Silva along for the ride.
Both ticket-holders for the world’s first sub-orbital tourist flights are getting ready for blast off by testing their grit in one of the world’s most advanced centrifuges, to see if they can withstand the high G forces they’ll experience.
The centrifuge, called the Space Training System 400 (STS-400), is part of the high-tech aviation and space training equipment at the National Aerospace Training and Research (NASTAR) Centre.
NASTAR has been training military pilots for 30 years, and now tourists too, as space travel companies, led by Virgin Galactic, have emerged over the past few years. The STS-400 is one of the few centrifuges in the world that can dynamically position its cabin at almost any angles as it spins up, so that passengers inside experience G forces (or gravitational forces) in multiple directions.
Feeling the big Gs
“It’s like being shot straight out of a cannon and then ricocheting upwards at massive speeds,” da Silva says. “The display inside the cabin looks real, your senses tell you it’s real, and there’s no way to really restrain your composure.
“While I knew I was inside a centrifuge, my brain and body were screaming – ‘You’re blasting off! You’re in space! You’re re-entering! Aaargh’,” he says of the two days of simulated space launches and re-entries he experienced. “It’s amazing how realistic it all felt.”
Sometime in 2009, da Silva, Finkel and their fellow passengers will be strapped into a rocket riding in the underbelly of Virgin Galactic’s SpaceShipTwo and be taken 17 km above the Earth's surface.
There, the rocket will be dropped, the motor will ignite and they’ll fly at three times the speed of sound straight up into the darkening black of space. They'll experience the same physiological impact as a professional astronaut.
Blast off is the most harrowing, and re-entry the most uncomfortable, da Silva says. Upon launch, passengers experience an immediate 3.5 Gs, while the re-entry packs a whopping 6 Gs - the equivalent of 3.5 and 6 times the individual’s body weight, respectively.
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What a ride! A four-minute clip of da Silva's flight simulation inside the spinning centrifuge (Courtesy of the NASTAR Centre).
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Both the flight and the centrifuge simulation create G forces in two directions: against the chest (Gx) and from the top of the head downwards (Gz). These significant pressures can make a passenger feel like they have up to six people piled on top of them – for an 80 kg person, that’s the equivalent of an orchestral grand piano.
Some fairground rides allow you to experience 3Gs for fraction of a second; a launch on Virgin Galactic’s spaceliner service requires you to grit your teeth for 15 long seconds and not pass out, vomit or do any of the other things known to afflict first-timers. Screaming, however, is often unplanned but sometimes mandatory.
Even with previous training to prepare you, the sensation can be shocking. Da Silva says he previously did a test flight in 2007 during a visit to SpaceShipTwo’s manufacturer, Scaled Composites in California's Mojave Desert, where an ex-fighter pilot took him up in regular plane and, from a high altitude, corkscrewed straight down at high speeds to simulate 3 Gs.
But, even the G forces from this wild ride were no match for the Gs in the STS-400, as you can see for yourself in a video of da Silva inside the centrifuge (above), undergoing a complete spaceflight simulation routine: blast-off, coast and re-entry.
