Aspiring suborbital fliers can prepare themselves for g forces and weightlessness with the NASTAR Center's simulation-based training programme

It could be backstage on opening night. Costumed in blue suits, members of a small group are pacing back and forth, exhaling through pursed lips like actors preparing for a monologue. But this is no stage play. These are civilians who are about to take a flight in the National Aerospace Training and Research (NASTAR) Center's Phoenix Space Training Simulator (STS) 400, the core component of a suborbital spaceflight training course offered to future passengers of Virgin Galactic's SpaceShipTwo. The STS-400 is a 25', 12-ton dual-gimbal centrifuge: one of only two in the world which realistically and simultaneously creates g forces in three different bodily axes. Its riders are practicing a manoeuvre called "positive pressure breathing", which protects their lungs during the g force experienced in the simulator and, ultimately, on the ride to outer space and back.

Participants in the NASTAR Center's two-day spring 2011 training hail from Europe and all four corners of the USA. They want things that pull on the imagination like nothing else: the weightlessness of outer space, an extraordinary view of our home planet and the thrill of being among a new generation of human explorers.

Thought the tickets have been retailing at a cool $200,000, Virgin Galactic's Commercial Director Stephen Attenborough has said it was easy to cultivate a market for them.

Joshua Bush, a Pennsylvania-based Virgin Galactic accredited space agent, has noticed that many of the people drawn to this opportunity are baby boomers. Contrary to younger generations who see space missions as routine events, the baby boomers witnessed the Space Race of the 1950s and '60s. They watched in awe as Neil Armstrong stepped onto the moon. Now they want to make the experience of outer space a reality for themselves.

 Suborbital Scientist training

 Copyright: The NASTAR Center

"It's a unique community," Attenborough says, touting the diversity of Virgin Galactic ticket holders. They come from all fields, including business, science and the arts, and they represent some 45 countries, with about 50% of buyers from the USA and 15% from the UK. The ages of those booked range from teenage riders to individuals in their eighties - while you must be 18 or older to ride, there is no upper age limit. Many of them are "early adopters" with an interest in aviation. Many are entrepreneurs eager to grasp the frontier of the 21st century.

Brienna Henwood, NASTAR Center's director of space training and research, explains that their suborbital spaceflight training course generally attracts four different types of people. Some curious members of the public, while they are not committed to a future spaceflight, want to try the next best thing. Other participants are scientists preparing for research conducted in space, and some are educators who want to share a firsthand experience of the training, and the promise of civilian spaceflight, with their students. Finally, many trainees are tourists bound for outer space, like the ones gathered now in the lounge, practising their breathing.

Those who ride the STS-400 up to its suborbital training maximum of about 6 g's must first obtain a third-class student pilot certificate, for which the medical exam ensures the circulatory, neurological, and cardio-pulmonary health needed to withstand the g forces. Older citizens may get a pleasant surprise: with more rigid blood vessels than younger trainees, their g tolerance can be slightly higher.

"Flights" in the STS-400 are preceded by a series of classroom lectures, including "Intro to Acceleration", a whirlwind course in the physics of flight, and "Motion Physiology", an introduction to the physical effects of spaceflight. As they take notes, students rise and fall almost imperceptibly in their seats. They are silently tensing their thighs and buttocks, part of the anti-g straining manoeuvre (AGSM) they have just learned. At high g's, the AGSM can keep blood in the brain twice as effectively as a g suit.

On the way to the simulator's large chamber, trainees pass a gallery of astronauts and cosmonauts, perhaps quailing a little before the likes of John Glenn, Alan Shepard and Yuri Gagarin. In the 21st century, the word "astronaut", formerly reserved for the most highly trained professionals, is part of a whole new world for civilians with the means to grasp it.

In the NASTAR Center's Observation Lounge, trainees can watch the centrifuge through a large window, as well as see a live video feed of its rider. Meanwhile, Henwood iterates the importance of the correct timing of breaths in the AGSM: "If you're going to need it, you're going to want to do it right." Failing to begin the manoeuvre before the onset of the g's can result in loss of consciousness.

"You'll tell me when to breathe?" the first flier of the course says over the intercom to Greg Kennedy, NASTAR Center's director of educational services and the monitor of participants' in-flight safety.

"Yes," Kennedy says. "Are you ready for your flight?"

As the centrifuge begins to move, one man sits apart from the trainees and staff. Lister Austin is on duty as an emergency medical technician.

"This is a great training facility," Austin praises the NASTAR Center. But he admits that he will not ride the STS-400. "I don't want the experience," he says, blaming his medical background for his reticence: he understands the physical effects of g force all too well, and doesn't like to visualise the compression of his own organs. In a worst-case scenario, high g's can cause a torn aorta, aneurism, ruptured organs, broken bones, or a torn trachea, he explains. Nothing so dire has ever happened during NASTAR Center training, but EMTs and a waiting ambulance are reminders that spaceflight - even when it is simulated - is anything but ordinary.

"Breathe like you're in yoga class," Austin would advise nervous riders. Or - less comfortingly - "pretend you're giving birth". He also elaborates on the value of the AGSM. Not only does it maintain blood flow to the brain, it also stimulates the vagus nerve, helping to keep you conscious and aware.

The first rider finishes the first flight profile, declaring that he feels "perfect".

A NASTAR Center staffer accompanies the student to each turn in the simulator, performing a pre-flight checklist including the five-point harness and its inertia reel, good lumbar support, proper footrest positioning, correct headrest and seat height and communications. The Phoenix's seat is broad and comfortable, and a cool breeze from air vents helps to mitigate claustrophobia in the small gondola. The last item on the checklist is the location of the "emesis bag", in case of motion sickness.

Some go enthusiastically to the Phoenix, and some go with their hands shaking. "Don't hyperventilate," Kennedy says, watching the quick rise and fall of a fearful chest on the monitor. The gondola takes its position and the centrifuge begins to spin - viewing from the lounge, it is as if the centrifuge has made a fist and is swinging for a punch that never comes. As the centrifuge gains speed, the g force increases.

Space Training 

 Copyright: The NASTAR Center

In an initial burst of head-to-toe gz force, your body becomes outrageously heavy, arms pinned down by their own weight. In three-second cycles, each breath and clench of the AGSM keeps the natural panic of the g forces' otherworldly sensations at bay. As the gondola repositions to provide the chest-to-back press of gx forces, it is as if a giant hand pushes inward and upward on your neck and chest. Legs tingle and lungs are shocked by the invisible load. The pursed lips of the Positive Pressure Breathing are challenging to maintain when the g force makes your cheeks feel like cookie dough in a wind tunnel - not to mention your exhilarated grin. Gaining confidence, you can even raise your arms: in the magnified gravity, simply lifting your hands feels like a push-up. When the g's come off, Kennedy suggests that you raise your arms again. For a moment, they feel feather light at normal gravity. "Welcome home, astronauts," the cockpit audio says.

Successful completion of a simulator flight leads naturally to some of the other human issues of civilian spaceflight. One participant skips lunch, worried about motion sickness during the second round of flights, while the rest eat sandwiches. But Kennedy advises that a light meal is fine and probably advisable before the real flight. He also urges the importance of proper hydration to increase g tolerance. However, one trainee points out that they will be boarding a two-hour flight sans lavatory. Kennedy concedes the balancing act.

"Well, I'm not going to drink very much before I get on that flight," the trainee whispers to his companion.

Henwood, along with a few trainees who have been on parabolic flights, also advises on the best snacks to eat in zero gravity. Chocolates are apt to melt - you're better off with hard candy. Just remember: in space, wayward floating candies can lodge anywhere in the cabin. Do not release any candies that you can't finish before you return to Earth's atmosphere.

If there is anything a ride in the Phoenix teaches besides how to cope with g force, it is that for all the sleek and glamorous promotions of the "freedom" of zero gravity, Virgin Galactic fliers' actual time in space will not amount to more than a few minutes. "Be prepared to enjoy it," Henwood says. The euphoria of somersaults in the air will be tempered by the necessity of getting properly fastened back in your seat before you hit the g's of re-entry. As Henwood notes, falling with your normal body weight is bad enough; you don't want to land on a body part at 6 g's.

It's a comprehensive preparation for the realities of spaceflight, from advice on physical conditioning to the manoeuvres that will keep civilian riders safe at g forces exceeding those of a NASA shuttle launch. But is there anything else you can do to maximise your time in space?

"Buy another ticket," says Bush.

Source: Flight International