Rocket-Balloon Combo—First Private Spaceship?

Sam Burbank
National Geographic On Assignment
December 16, 2003
If all goes according to plan, the world's first independent manned space rocket will lift off from Kindersley Field, Saskatchewan, before the end of next year.

The mission sponsor is the da Vinci Project, the largest high-tech volunteer effort in Canadian history. About 200 volunteers are working on the project, headquartered in Toronto, with contributions from engineers in Montreal, Regina, Vancouver, and St. Petersburg, Russia.

"After we finish this, we're going to build the next pyramid, we have so many people working on this project," said Toronto-based Brian Feeney, da Vinci Project leader and a former designer of aerospace life-support systems for Avstar Aerospace.

The da Vinci project has been in the works for seven years, with funding in kind and cash from a multitude of corporate sponsors. The volunteers include air traffic controllers, graduate students, college professors, aerospace and thermodynamics engineers, and computer programmers—every specialty necessary to build a complete space-launch infrastructure from scratch.

The da Vinci inspiration is the X-Prize competition, announced in 1996 by entrepreneur Peter Diamandis, chairman and CEO of the Zero Gravity Corporation, who is based in Santa Monica, California. The purpose of the X-Prize is to jumpstart commercial space tourism by encouraging private groups to develop new spacecraft.

The X-Prize promises U.S. $10 million to the first group to build and launch a privately designed craft to the cusp of space—62.5 miles (100 kilometers) altitude—with three people aboard. But once is not enough, the rocket must then be flown again to the same height within two weeks.

Rockets and Balloons

The da Vinci Project engineers have a radical idea for getting into space: a rocket and balloon combination.

It's time to take a new look at how to escape the pull of Earth, said Feeney.

Conventional rockets typically start with a large first stage that pushes the rest of the rocket through the Earth's thick atmosphere. When the first stage is empty, it's ejected and the second stage ignites.

The first stage is nothing but dead weight, Feeney said. His team has replaced the first stage with a gigantic reusable helium balloon.

Feeney himself plans to pilot the Wild Fire. In the da Vinci dream scenario, the balloon, with the manned Wild Fire dangling hundreds of feet below, slowly rises to 15 miles (24 kilometers)—a quarter of the way to space, where the air pressure is one thirty-fifth that of sea level.

That's when Feeney hits the switch. In an instant, he and his drifting crew are thrown back into their seats as the rocket engines fire and the ship blasts to four times the speed of sound till it reaches 34 miles (55 kilometers). Then the engines shut off, and the momentum allows the craft to coast to 71 miles (115 kilometers)—the top of the trajectory—before it slows to a halt and begins its free fall to Earth.

After a slow two-hour ascent under the balloon, the rocket portion of the trip lasts just a brisk 30 minutes—about seven minutes from the point the engines fire until the parachutes kick in on the return trip. From there it is a 20-minute parachute ride to the ground.

Winning the X-Prize?

The advantage in launching from this altitude is that the rocket doesn't suffer the same aerodynamic stress as during a ground launch. Rockets have been successfully launched from aircraft before. "A balloon is even easier because there isn't much movement," Feeney said.

"The X-Prize is basically an altitude prize," said Mark Lewis, professor of aerospace engineering at the University of Maryland in College Park, who specializes in advanced launch vehicles, "with the balloon and rocket combination the da Vinci team could certainly win the X-Prize."

But winning with this combination would be more of a demonstration, said Lewis, because this is not something that would likely evolve into a reusable launch vehicle. "It is not the obvious solution if you want to go commercial."

"There are some very clever designs and technology entered in the competition, and there are some very capable and credible teams," said Lewis.

The da Vinci team's first move was to build a prototype. But the material for the ribs of the aeroshell was expensive and hard to handle. Then the design changed. Now, with a better design, but considerably less cash, the Canadians are embracing a local product they had previously overlooked: wood.

The da Vinci engineers use the wood for the streamlined aeroshell that sits on a metal frame that in turn cradles the engine. Wood is not so far-fetched: oak has been used for heat shields of spacecrafts.

It once took an army of engineers with slide rules to build a space rocket. Now, with powerful computers on every desktop, a warehouse of enthusiasts can move into what was once a government monopoly. The da Vinci project, and the 23 others teams spawned by the X-Prize, embark in the spirit of the Wright Brothers. They launched a new era of flight by taking wing in an untried craft that also used wood.

National Geographic On Assignment, 7 p.m. ET/8 p.m. PT in the United States, is available only on the National Geographic Channel. Click here to learn more about it.

Got a high-speed connection? Watch National Geographic On Assignment in streaming video.

© 1996-2008 National Geographic Society. All rights reserved.