Early Spaceship Designs

“I always had the space bug, keep in mind,” Rutan said. “When did I jump in and do it myself? It came in a time when I thought I could do it. And it wasn’t with SpaceShipOne at first. I was going to do a capsule, and launch it from an airplane that did a steep climb and a parachute recovery.” He began sketching out ideas in 1993.

“I was going to build something to fly out of the atmosphere. I’m not saying the things that I originally laid out were easy. They weren’t easy, but they weren’t really innovative. They were pretty straightforward. It didn’t require anything that was new or patentable or breakthrough in nature.”

His first ideas focused on a single-person rocket carried as an external store by a mothership. The carrier aircraft would pull up and then shoot it off like a missile.

“Around 1995 or so, we were designing and starting to build an aircraft called Proteus,” said Doug Shane, the vice president of business development and the first engineer that Rutan hired at Scaled Composites. An award-winning test pilot himself, Shane also became director of flight operations, which is a position he has held at Scaled Composites since 1989. Figure 1.5 shows Shane in Mission Control with Rutan at his side.

Proteus was a utility aircraft designed to fly at high altitudes above

60,0 feet (18,290 meters), but one of its design requirements was to launch a single-person suborbital rocket. Proteus would perform a zoom maneuver at 27,000 feet (8,230 meters), pulling up to 40 degrees to assist the rocket’s trajectory. Figure 1.6 shows the original launch concept with the rocket attached by an offset mounting, and figure 1.7 shows its separation from Proteus.

When Rutan got word of the formation of the X Prize, well before it was called the Ansari X Prize, he decided to change the design from a single-person capsule to a three-person capsule, which was a condition set forth by the X Prize. Figure 1.8 shows the rocket during ascent and the capsule and booster parachuting down after reentry.

The most important part of the design of the spacecraft was the feather, the little protuberances pointed upward away from the blunt end of the capsule. Acting and looking like the “feathers” of a

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Fig. 1.3. Burt Rutan began his pioneering work with composites on the VariEze, the second air­plane he designed and built. In 1975, the VariEze took him three and a half months to construct, whereas his first airplane, the VariViggen, took more than four and a half years. Mojave Aerospace Ventures LLC, photo­graph by Scaled Composites

к________ ) badminton shuttlecock, the design would accomplish two very important things. First, the high drag would decelerate the capsule very quickly, which would tremendously reduce the thermal loading and the dangers of heat buildup during reentry. And second, it would act to self-right and stabilize the capsule, orienting the capsule’s blunt side down no matter what the attitude during initial reentry. Rutan would call this his “carefree” reentry. This allowed the spacecraft to reenter at a near-vertical trajectory. The Space Shuttle, in comparison, had to precisely control its attitude during reentry, too shallow and it would skip off the atmosphere, too steep and it would experience catastrophic heating.

The capsule would then float down over the water. “I wanted to pick it out while it was still under the chute with a helicopter,” Rutan said.

The method was very similar to the way that film canisters ejected from the very first spy satellites were recovered during Project Corona, the joint effort between the Central Intelligence Agency (CIA) and U. S. Air Force. A film canister would parachute down, and an aircraft with a large catch would swoop by and snag it out of the sky.

“My baseline at first was that if it went into the water it was an unexpected failure or emergency. I wanted to grab them and helicopter them back to the launch site,” Rutan said.

Something about a parachute and helicopter blades make it seem like a bit of an odd combination, though, even for Rutan. “When you work with parachute recovery,” Rutan mused, “you take certain generic risks that you just can’t get around. And I thought I could do it. I think it was a much bigger decision that led me to develop something that could survive a steep reentry and land on a runway and not have to be controlled in attitude during reentry.

“That concept, that design, that approach was much more significant.”

So, the ideas of a capsule and a parachute were scrapped. But air launch was still on the table. Scaled Composites would also stick with

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Fig. 1.4. Scaled Composites built complete aircraft as well as components for many vehicles. Just a few of these are Pegasus,

Starship, Triumph, ATTT, ARES, and Pond Racer. Provided courtesy of Scaled Composites

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using the name “feather” even though the final design looked more like a pair of broken wings.

“If you can buy some time in the event of a propulsion problem instead of being this high off the ground when the motor quits or does something funny,” said Shane while sticking his hand out to his side about four feet off the ground, “if you are at 50,000 feet [15,240 meters], you really have a lot more time to deal with it. It gives you an awful lot more options.”

Early models, like those shown in figure 1.9 and figure 1.10, used a high-drag speed brake and large deflecting elevons as the feather mecha­nism for reentry. And Rutan’s team demonstrated several models where the feather worked subsonically. But when it came to supersonic speeds, like those encountered during reentry, they didn’t trim supersonically. In other words, they were uncontrollable. If the center of gravity (CG) was moved back, they would fly okay, but then they became unstable at sub­sonic speeds. A computerized fly-by-wire flight control system might have made them flyable, but the cost was too high and the reliability too low.

This was an enormous setback. Only two manned, winged vehi­cles had made it to space, the X-15 and the Space Shuttle. Both had fatal accidents during reentry. An X-15 had a flight-control failure in 1967, and the Space Shuttle Columbia had a failure of its thermal protection system in 2003. It was necessary to solve this problem before any more forward progress could be made.

“Finally, maybe it was some spicy food he ate late at night or some other kind of epiphany,” Shane said about Rutan. “He suddenly realized that maybe the thing to do would be to pivot part of the wing and the tails on a hinge on the body and provide that high-drag configuration. And that ended up satisfying all the subsonic and supersonic aerody­namic challenges. That was actually a pretty clever concept, and that’s what we went forward with.”

Figure 1.11 shows the new spacecraft design with the feather deployed for “carefree” reentry.