In Thrust We Trust
To Tim Pickens, rockets are the only way to go.
- By Peter Garrison
- Air & Space magazine, July 2007
(Page 4 of 5)
Rutan, a fanatic for simple systems that use as few parts as possible, was looking for a “bolt-in” propulsion system like the manufactured engines he used on his airplanes. But he was finally won over by Pickens’ arguments for hybrids, even though the choice meant designing an engine from scratch and making a new one for each flight. Rutan was willing to accept those penalties, along with the reduced performance of a hybrid motor, in exchange for tossing out all the tricky plumbing and valves and hassle that liquid oxygen required, not to mention reducing the risk of an explosion like the one he’d seen on the videotape.
According to Rutan, Scaled came up with the concept for SpaceShipOne’s motor and designed, built, and tested its main components, including a massive flange on the tank and motor case from which the motor was cantilevered. Scaled also built the nozzle and the carbon-wound fuel casing. Only a few internal components, including the injector, igniters, and motor controllers, were outsourced, because Scaled had no experience in those areas. Rutan got a couple of small companies, eAc of Miami and SpaceDev of San Diego, to build and test the subsystems. “We did not have full confidence that any small shop could do an adequate job with these components,” he says, so Scaled awarded two contracts, “hoping that at least one would work.” Ultimately, SpaceShipOne included hardware from both SpaceDev and eAc on its historic test flights. (SpaceDev founder Jim Benson tells a different story, and is still arguing with Rutan over who should get credit for the vehicle’s propulsion system.)
Pickens finally went to work for Scaled Composites in 2002, with the title Propulsion Lead Engineer, or, as he likes to put it, Herder of Cats. He remained at the Mojave headquarters for a year before returning to Huntsville and his wife Melanie and their daughter Sarah. “He chose his family over his career,” Rutan says with a slightly disapproving tone. Pickens puts it differently. “A country boy from Huntsville, we just don’t go off and chase too big of dreams. You gotta eat mama’s cooking at night, you know what I mean?”
But Pickens’ year designing the engine for SpaceShipOne at Mojave had been decisive for the project. He was, test pilot Mike Melvill recalls, Rutan’s “golden boy.” And his thinking permeated every detail of the engine. The common bulkhead between oxidizer tank and motor, which had been a basic design feature of the HALO and CATS rockets, became a key element of SpaceShipOne’s design, one that Rutan patented. Without Pickens, Melvill thinks, SpaceShipOne might not have worked.
A year after leaving Scaled, Pickens did something unexpected: Under the aegis of the corporation he had formed with Allison, he entered the X Prize race himself. He called his project Liberator. It was a conventional single-stage, liquid-fuel rocket, about two-thirds the size of the Huntsville-made Redstones that had lofted America’s first satellites into orbit in 1958. “I’m sitting at home with a lot of rocket hardware—engines and tanks and valves and stuff,” recalls Pickens. “I had one 12,000-pound-thrust regeneratively cooled kerosene-LOX [liquid oxygen] engine, and parts for another. And I’m thinking: I could do a mission like this.”
The crew capsule was a tall metal tube in which the occupants sat one above the other. It was not for the claustrophobic, but the X Prize did not stipulate that the passengers be comfortable, nor that anyone but the pilot be on board for the test flights—just that the vehicle had to have enough room to seat three people.
It was very late in the game, but despite having worked at Scaled for a year—or perhaps because he had—Pickens had doubts about Rutan’s vehicle. At the time its key technologies, especially the idea of folding the wings to increase drag during reentry, had not yet been tested at supersonic speed. To Pickens’ knowledge, there had been no wind tunnel work; all of the aerodynamic analysis of the SpaceShipOne design had been done on a desktop computer, and for fun, the early flight simulations were run on X-Plane, a $70 home entertainment program for airplane buffs. “There were performance issues,” Pickens recalls. “We figured SpaceShipOne would probably slide—who knows what can happen, we can’t worry about them, let’s move forward.”
Instead of Rutan’s plan to drop his vehicle from another airplane, “I was banking on a traditional rocketry approach,” says Pickens. “Ocean landing. I’d done ocean launches with the NASA barge program and also the HALO program. We definitely were in the right town with the right talent pool. In my opinion we were certainly one of the two or three most technically competent teams.”
The showstopper turned out to be not technology but money. “Boy,” laughs Pickens, “did I learn a lot about reality. Somebody might want to give you $10,000, but if he’s only got $100,000 to start with he’s gonna annoy you just as much as somebody who had 10 million dollars and gives you a million.”