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Former astronaut Jim Voss came out of retirement to help lead the underdog effort. (University of Colorado Boulder)

The Other Guys

NASA needs a space taxi. The likely pick is SpaceX—but don’t count out Colorado-based Sierra Nevada.

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The other guys are no slouches. Among the team members is chief systems engineer Stokes McMillan, who forsook retirement to manage Dream Chaser’s pilot training program and run its flight simulator. McMillan cherishes his 32 years at NASA—where he trained crews for the first 25 space shuttle missions—but says of Sierra Nevada, “We are given a lot more freedom here.” Lindsey goes further, claiming: “We have a team of people who are here not for the money, not for the job. They’re here because they believe in what we’re doing.” I ask Lindsey why he came to Sierra Nevada. “I made the jump from NASA because I liked the Dream Chaser design, I loved the team, and I wanted to change the world,” he says.

The Dream Chaser clan is tight-knit, its members collaborating on the fly in a setting that feels more like a nimble cash-strapped startup than a billion-dollar conglomerate. They often work nights and weekends when up against a deadline. In the company’s bay, hand-cranked hydraulic jacks prop Dream Chaser three feet off the floor. A technician is crouched beneath its nose, whistling while hand polishing a section of fuselage with a piece of sandpaper. Inside the spacecraft, on the flight deck, a pair of fuzzy dice hangs from the ceiling. (“They flew on our first flight test and now they are our lucky dice,” says Voss.) Vise grips are clamped to bulkhead dividers where makeshift repairs are under way. At one end of the bay—beneath a floor-to-ceiling American flag—are several red rolling Craftsman tool chests, drawers slung open and ransacked.

The effort exudes garage-inventor enthusiasm. You can tell by looking at Dream Chaser’s flight simulator: McMillan assembled it almost entirely from store-bought components. “It runs on seven off-the-shelf Dell computers you get at Best Buy,” he says. For the cockpit view, “I’ve wrapped around five commercially available 60-inch plasma screens.” At one point, he decided to paint the simulator’s fiberglass shell. “I put out some bids and was getting offers of like $5,000 over three weeks. So, heck, me and a grad student went to a paint store and spent $69 on paint and took a weekend and did it ourselves.”

For Voss, the project differs vastly from his experiences at NASA. “We move a little quicker here,” he says. “The engineering staff is here, our machine shop is here.” Just then, a technician rams an object into a bench grinder, filling the room with an ear-splitting screech and the stench of charred metal. “We make decisions in hours instead of weeks or months,” Voss shouts over the din. He recounts a story told to him by one of his engineers, who had come to Sierra Nevada from NASA’s Orion program, which is developing a crewed spacecraft for missions to the moon and Mars. To approve a single design modification, “he had to go through, I think, about 70 [review] boards and it took almost a year. I can get my management together and in an hour we can make a decision, a programmatic decision, and go on.”

Dream Chaser’s lineage goes back to the very earliest spaceplanes. The concept of a lifting body—an aircraft that generates lift with its fuselage more than with its wings—is often credited to an inventive Austrian aerospace engineer named Eugen Sänger. In the mid-1930s, Sänger conjured up a manned rocket-powered spaceplane with cropped wings and convex belly—features that allow the vehicle to operate both in space, under rocket power, and in the atmosphere, where it behaves like a fixed-wing aircraft.

Sänger, working under Nazi Germany, envisioned a sub-orbital bomber, known as the Silbervogel (“silver bird”), which could zoom through the stratosphere to the edge of space, from where it would drop ordnance (New York City was the intended target), then return and glide unpowered back to Earth. While the Silbervogel never got out of the wind tunnel, it inspired many future lifting bodies, including Boeing’s X-20 Dyna-Soar.

Dream Chaser’s nearest cousin is the HL-20, a craft designed at NASA’s Langley Research Center in Virginia in the early 1990s. (Langley engineers co-opted the design from a photograph of a Soviet spaceplane, revealed later to be the BOR-4.) At least in shape, the HL-20 and the Dream Chaser are nearly identical. (Lindsey says Sierra Nevada “actually brought in a couple of retirees who had worked on the HL-20 [at Langley] to help us.”)

“The only modifications we’ve made are to the wings,” says Voss. “Langley had more of a slab wing—an aerodynamic shape that worked really well in the atmosphere but would probably burn off on reentry.” Slimming the wings enhanced Dream Chaser’s inherent stability, a characteristic that allows it to naturally right itself and restore level flight.

Dream Chaser’s shape—its body providing about 50 percent of total lift—is also supposed to make for smoother reentries and cushier landings than the competing designs. During reentry and at touchdown, it reaches just 1.5 Gs. A capsule, on the other hand, can hit the water at a gut-crushing 10 Gs (or possibly twice that if a navigational glitch forces what’s known as a ballistic reentry). A low-G ride permits Dream Chaser to carry fragile scientific cargo with a greater margin of safety. “If you don’t shake, rattle, and roll as much, you get better science,” says Ed Mango, NASA program manager for Commercial Crew Integrated Capability. Drug companies are interested in growing protein crystals in microgravity, explains Lindsey. “You grow these things very carefully in orbit. If you’re putting 8 Gs on them, or [they are in a capsule that is] slamming into the water or slamming into land, you can damage that payload” if it is not sufficiently buffered.

About Michael Behar

Based in Boulder, Colorado, Michael Behar (michaelbehar.com) writes about aerospace, adventure travel, science, and the environment.

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