The importance of Plan B (and Plan C, and Plan D…)by Jeff Foust
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| “All these little pieces, separately, were all okay, but when we put them all together at the end of the study, I had a couple of sleepless nights, thinking, ‘This just doesn’t feel quite right,’” Benson said. |
Benson, speaking Friday at the ISDC, said the study turned up one major issue: the blunt shape of the Dream Chaser’s lifting body profile meant that it generated a lot of drag during its vertical ascent, requiring the use of a separate external booster to get the vehicle into space. Also, engineers found it wasn’t possible to have the vehicle land back at the launch site without subjecting those on board to as many as 7 Gs. A profile that had more acceptable g forces, he said, required them to land over 150 kilometers from the launch site, which was undesirable from an operational standpoint.
“All these little pieces, separately, were all okay, but when we put them all together at the end of the study, I had a couple of sleepless nights, thinking, ‘This just doesn’t feel quite right,’” Benson said. That feeling is the same for any businessman who encounters a “bunch of red flags” while executing their business plan, he said. “You have to stop and reevaluate where you’re going.”
For Benson Space, that meant putting the Dream Chaser design aside and starting from a clean-sheet approach to find an alternative that did meet their requirements. The new design, he said, had its origins in a conversation with Hoot Gibson, a former astronaut who is Benson Space’s chief test pilot. “During the third teleconference after we decided to take a clean look at the vehicle design, Hoot said something like, ‘Well, gee, guys, why don’t we try something that’s shaped like a bullet?’”
That led Benson’s engineers to examine a number of vehicle designs, including the X-1, X-2, and X-15 rocketplanes as well as the T-38 jet used for decades as trainers for astronauts. The resulting design, which Benson revealed on Friday, does superficially resemble some of those vehicles, but with a forward cabin studded with portholes like SpaceShipOne. This vehicle (Benson said they are also calling it Dream Chaser for now while working on a new name) will take off vertically, powered by six hybrid motors virtually identical to the ones SpaceDev built for SpaceShipOne, and reach a peak altitude of about 105 kilometers before gliding back for a runway landing. The vehicle will carry six people, including one pilot. Benson, however, hinted that there are a lot of technical details about their new design the company is keeping under wraps for now: “There’s a lot we’re not showing or saying.”
The redesign did set Benson Space back a couple of months, but Benson believes that the change in vehicles will pay off in the long run. “This is going to be even simpler to fabricate, less expensive, and faster,” he said. “So we think we’re going to make up at least two months with this simpler, more elegant design.” Benson added that he believed he could still beat his major competitors, Rocketplane and Virgin Galactic, by putting his new vehicle into commercial service by 2009, provided he is able to raise a round of financing in the next couple of months. Along those lines, he said he was in talks with five key investors, any one of whom could provide the full amount he’s seeking—a value he didn’t disclose, although last year he said he needed about $50 million for vehicle development.
The new, simpler design also means that Benson Space will be able to outsource some of the fabrication work to any number of companies, rather than have SpaceDev handle all of the work itself. SpaceDev, though, will still be responsible for fabricating the motors, which Benson claimed would alone be enough to account for $400 million in business over the next seven years. “As to who’s going to fabricate the vehicle, that’s still up for grabs,” he said.
Shifting propellants
Benson Space is hardly the first company to change its technical approach. Speaking right after Benson at the conference was John Carmack, founder of Armadillo Aerospace. He and his venture have gone through a wide variety of design changes since Carmack, still best known in most quarters as a video game developer, got interested in spaceflight and rocketry in the late 1990s thanks to what he called a “random chain of events” that ranged from reading Robert Heinlein novels to reading posts on the technology news site Slashdot about RLV development.
Carmack said that when he finally decided to dive into launch vehicle development, he wanted to leverage the technological strengths that had been built up over the last 40 to 50 years, and also make vehicle development more like software development. “A lot of people joke about that, about blue screens of death and crashing and so on, but when you step back and take a look at it, I’ll take the progress the computer industry has made over the progress the aerospace industry has made any day of the week.”
| Carmack: “When you step back and take a look at it, I’ll take the progress the computer industry has made over the progress the aerospace industry has made any day of the week.” |
That meant a more iterative approach, often called “build a little, test a little.” And that, in turn, has meant that Armadillo has had to change its technical approach more than once. Carmack originally started working with high concentration hydrogen peroxide, a propellant that he believed would allow him to start building and testing vehicles quickly. Armadillo started pursuing the X Prize during this process, and developed a design for a peroxide-powered vehicle that was “extremely simple” and “could have possibly made it, but in hindsight a lot of things would have had to go right.”
What eventually derailed those plans, though, was the loss of Armadillo’s peroxide supplier. The only other company that sold the type of peroxide Armadillo needed proved to be too difficult to work with, and Carmack instead decided to purse a different technical direction while still trying to achieve the X Prize. That involved the use of “mixed monopropellants”, a combination of lower concentration hydrogen peroxide with alcohol. “But two years down the road Burt [Rutan] went ahead and won the X Prize, so that was no longer a driving force for us, and we still had a couple of technical issues that we never did really get to resolve,” Carmack said.
That, in turn, led to another change in technical approach, this time to the use of liquid oxygen (LOX) and ethanol. “That was a big, fairly traumatic decision for us because we had built up all this great experience flying these monopropellant vehicles,” Carmack said, “and we knew we were going into another level of technical complexity because a typical bipropellant vehicle is about three times as complex as a monopropellant vehicle.”
However, this new technical approach has paid dividends for Armadillo Aerospace. The LOX-ethanol engines Armadillo has developed allowed them to almost win the Northrop Grumman Lunar Lander Challenge last October at the Wirefly X Prize Cup in New Mexico (see “Climbing the steep learning curve to space”, The Space Review, October 23, 2006). Since then Carmack said that they have done over 15 test flights of Pixel, their Lunar Lander Challenge vehicle, nearly all of which have lasted over 90 seconds, including one earlier this month that went 192 seconds. That has given Carmack confidence that they have the right technical approach, and that they will do very well at this year’s Lunar Lander Challenge. “It will take very bad luck for us not to win” this year, he said.
Chasing markets
Rocketplane, Inc., meanwhile, has not only seen a change in technical approaches for its winged suborbital vehicle, it has had to revise its business plan and the markets it pursued many times since the company’s origins as Pioneer Rocketplane in the mid-1990s. Chuck Lauer, one of the founders of the company and today the vice president for business development of Rocketplane Global, described in an ISDC presentation on Sunday how the company had changed approaches in search of viable markets.
Initially, Rocketplane was looking at various growth areas like point-to-point fast package delivery, although the “killer app” at the time was the planned constellations of low Earth orbit communications satellites like Teledesic, which in its early incarnations required as many as a thousand satellites. “This was an obvious market for us,” he said. Through the latter half of the 1990s the company altered the vehicle design, in part as the size and weight of Teledesic’s and others’ satellites grew.
While the Rocketplane design changed to accommodate satellite launch, Lauer sought other markets that could be served by the same vehicle. “I started staking out where we could go with this,” he said. Various concepts he looked at included launching small cargo spacecraft to the ISS, performing microgavity research, and even transporting troops and delivering munitions.
| “There was really no market to address for that kind of satellite launch vehicle,” Lauer said, “and we could either fold up our tents or try something else.” |
A NASA contract for its Bantam program—an effort to develop a low-cost launcher in the late 1990s that was eventually cancelled—gave Rocketplane an infusion of money that allowed it to refine its design just as Motorola took over development of the Teledesic satellite design. “They were essentially using the Iridium bus, so the number of satellites had dropped, the weight had grown, and the orbits had increased, so it was much more challenging to serve the monster Teledesic customer,” Lauer said. That same refined design could also be used to serve space tourism and even point-to-point passenger markets.
Of course, working to meet Teledesic’s requirements became a moot point when Teledesic collapsed without even beginning to deploy its satellite constellation, as part of the broader global telecom downturn that also killed off a number of similar satellite systems and forced the surviving ones into bankruptcy protection. “There was really no market to address for that kind of satellite launch vehicle,” said Lauer, “and we could either fold up our tents or try something else.” That something else led Rocketplane onto its current path, less technically ambitious than their previous designs but one focused on the “last man standing” in the market, space tourism.
Lauer said that flexibility has led then to embrace today what he described as “charter flight opportunities” for certain customers with specific requirements. “We let our customers paint their own message onto the blank paper,” he said. “We’re a transportation company, we’re a service provider, we don’t have to co-brand with everybody who flies in our vehicle. We let the customer basically take over and we’ve found a lot of success in the charter flight business model.”
Not only do some companies have to reinvent their business plan more than once, some people get to reinvent the business plans for more than one space company. In 1999 Jim Benson shifted SpaceDev from a company that was pursuing missions to near Earth asteroids for potential exploitation of their resources to a bit more mainstream space technology company, given the difficulties and long timeframes that would have been required for his original plans to come to fruition. “I had to restructure SpaceDev about two and a half years after I started it,” he said. “Luckily, with Benson Space Company it only took about five months.”