Spent Shuttle Fuel Tanks Envisioned as Structure for Research Space Park
A consortium of 57 major universities and research institutions has put together a bold plan to build its own space station out of discarded fuel tanks from routine launches of the space shuttle.
Normally, the massive tanks are destroyed as they tumble from near-orbital velocity, plunging through the atmosphere and eventually into the Indian Ocean. The consortium wants to propel the tanks into orbit and use them as building blocks for huge industrial and research parks in space.
Although austere compared to the state-of-the-art space station that NASA wants to build, the facility envisioned by the universities would cost a small fraction of NASA’s station.
The space station planned by NASA is being designed to push technology to the limits through the use of artificial intelligence, high-speed computers and sophisticated hardware.
However, the station proposed by the universities would be much larger than NASA’s--so large, in fact, that space would be so plentiful it could be offered for rent to universities, governments and corporations at bargain-basement prices, according to officials with the project. The proposal is being sponsored by the University Corp. for Atmospheric Research, which includes such prestigious universities as Caltech, Stanford, Harvard, Yale and MIT. The corporation runs the National Center for Atmospheric Research here as well as several other major facilities.
The universities’ space station would be designed to supplement NASA’s station.
“We are not a substitute for the space station,” said Randolph H. Ware, president of External Tanks Corp., a nonprofit company set up by the university consortium to build the station. “We are a warehouse on the edge of an industrial park.”
Tall as a 13-Story Building
The heart of the proposal involves the use of the massive external fuel tanks used during the shuttle launches. The 30-ton tanks, constructed of high-grade aluminum and reinforced to serve as the “strong back” supporting the shuttle and its two solid rocket boosters during ascent, are larger in diameter than a Boeing 747 and as tall as a 13-story building.
Studies by NASA have shown that the tanks could be delivered safely to orbit with only a small sacrifice in the shuttle’s payload, and with no major changes in shuttle operations or equipment.
The tanks cost $30 million to build, and since it would cost at least $80 million to carry an equivalent weight into space, each tank in orbit would be worth a minimum of $110 million. And since they are designed to carry pressurized fuel through the rigors of climbing into space, each tank could be easily converted into a pressurized orbiting capsule which could house crews in a shirt-sleeve environment, according to Ware.
Although there have been other proposals for use of the tanks in the past, this one has caught the attention of NASA executives because of the stature of the universities and the success of their research facility here, possibly the premier center for atmospheric research in the world.
“This is for real,” said David J. Padwa, vice chairman of the company’s board of directors.
Philip Culbertson, NASA’s general manager who chairs the agency’s task force that is looking into the proposal, is optimistic that NASA will commit itself to at least the first phase of the project, which is primarily a feasibility study with some support engineering.
Ware, a space physicist and researcher at the University of Colorado, envisions the tanks as the key ingredients in “an orbiting research park” that would work in concert with NASA’s station, now estimated to cost $16 billion and reportedly in serious trouble with Congress because of its escalating price tag.
The proposal could provide the solution to a problem that has long vexed space officials: How to use a valuable resource, the external tanks, that are now deliberately destroyed.
“It’s crazy to throw them away,” said Padwa, a lawyer and economist who has a long track record of building new companies into successful enterprises.
But, according to Culbertson, nobody until now has come up with a plan for using the tanks that had a good chance of succeeding.
The project is called “Space Phoenix” because the station was “visualized as rising from the charred remains that previously marked the end of their (external tanks) journey to the threshold of space,” the company’s prospectus says.
About eight minutes after launch, the space shuttle goes into a shallow dive and jettisons its external tank so that the tank will break up into a fireball as it tumbles through the atmosphere. That eliminates the tank as a potential hazard that could otherwise descend out of control, endangering populated areas.
Since the tank carries most of the fuel for the shuttle’s three main engines, the orbiter has nearly reached its orbital velocity by the time it drops the tank. It then uses its smaller maneuvering thrusters to climb on to its orbit, usually about 200 miles above Earth.
Only Needs a Nudge
NASA studies have shown that at the point of separation, the tank is within 99% of the speed needed to carry it on into orbit, so it would take only a nudge to push it the rest of the way. The studies show that would force only a slight reduction in the shuttle’s payload, probably no more than 2,000 to 3,000 pounds. The shuttle can carry more than 60,000 pounds of cargo into orbit.
The National Commission on Space, appointed by the President to chart the nation’s course in space exploration for the next 20 years, has bemoaned the present system because it allows a “potentially valuable” resource to go “to waste.”
In its report to the President last year, the commission, chaired by former NASA chief Thomas Paine, said:
“The shuttle fleet’s flight schedule suggests that over a 10-year period about 10,000 tons of that tankage will be brought almost to orbit and then discarded. At standard shuttle rates, it would cost about $35 billion to lift that mass to orbit.”
Twenty-five tanks have already been destroyed, 24 on successful shuttle missions and one in the explosion of the Challenger.
Asked why NASA did not incorporate the tanks into the design of its own station, NASA’s Culbertson said: “We don’t have any real need for that kind of volume.” He added that the tanks are so massive that they could cause problems in controlling the kind of station NASA wants to build.
The primary concern at NASA is to make sure that delivering the tanks to orbit would pose no risk to the astronauts, and ensuring that once there, the tanks would not endanger people on the ground by crashing to Earth.
The tanks could be controlled in orbit, and even moved around so that they could be clustered together, by small maneuvering rockets that could be attached to the bottom of each tank before liftoff, Ware said. Other options include the installation of maneuvering systems by space-walking astronauts after reaching orbit.
Ware and his colleagues want NASA to commit itself to giving the tanks “on orbit” to the control of their organization.
“The easiest thing to do right now is just to park them” in orbit until they can be put to use, Padwa said.
“Just like a squirrel would save a nut for winter,” Ware added.
The initial plan calls for linking two tanks together, in what looks like an orbiting catamaran, so that both tanks could be served by an “auxiliary support element” consisting of solar panels, a maneuvering system, and crew quarters. Space aboard the station would be leased to anyone who wants it at a cost of about $1 per cubic foot, roughly twice that of a room in a good New York City hotel, Ware said.
Proposals for Use
Other tanks could be added later. The proposals for their use range from melting the aluminum for other uses by concentrating solar heat; to the construction of huge industrial parks where satellites could be serviced and materials manufactured free of the distorting effects of gravity; and to housing scientific instruments, including telescopes. The unmanned “space tug,” now being developed by TRW, could be used to retrieve instruments and satellites from space for servicing.
Another imaginative proposal, advanced earlier by Hughes Aircraft Co., called for linking several tanks together in a configuration that looks somewhat like a giant wagon wheel, with the tanks serving as spokes. The wheel could be given a slight spin so that crews in the tanks could work and live in artificial gravity equivalent to the Earth’s. A pod at the center of the wheel would remain stationary, using a technique already employed aboard more than 100 orbiting satellites, thus providing a zero gravity laboratory at the heart of the wheel.
Thus astronauts could work in their zero gravity laboratory at the center of their station, but go “home” to sleep and relax in conditions more like those on Earth.
What appeals to men like Ware is the sheer size of the tanks. Each tank has a volume of 70,000 cubic feet, seven times that of the shuttle’s cargo bay. Measuring 27.5 feet in diameter and more than 154 feet tall, the entire flight of the Wright brothers could have been carried out inside a single tank. The strong aluminum siding is protected by an inch-thick coating of insulation, which was designed to keep the super-cooled fuel from warming up, but it would also serve to insulate the orbiting tanks from the varying temperatures of space.
Each tank has a 36-foot manhole that could be unbolted in orbit for access.
The various proposals for their use are to be discussed at a symposium at the University of Colorado, tentatively set for the first week of August.
But working in space is never cheap, even if the tanks are turned over to the company free of charge, already in orbit. So the company has embarked on a campaign to sell 10% of its stock to those willing to invest in what it calls a “high-risk” venture.
The initial goal is to raise $550,000 for the feasibility study, but billions of dollars could be required down the road.
Project officials have been a little surprised by the kind of support they have received.
“NASA surprised us by embracing it immediately,” Ware said.
But financial support has not been forthcoming from the huge aerospace companies that would be expected to make the most use of the space station.
“The corporate sector is saying this is so far out we may look stupid,” Padwa said.
Space Buff Backup
But that does not pose any serious problem in raising the money for the feasibility study because “there are so many space buffs we could easily get the whole amount from small investors,” he said. “But that’s the desperate route.”
Support from the aerospace giants would guarantee a long-term commitment, Padwa said. He expects that support to grow once NASA formally endorses it, but others suggest the high-risk nature of the project, with no assurances from the federal government of profits at the end of the line, may be too bold for companies that are used to lucrative federal contracts.
There has been, however, ample support from some industries that see the project as a great avenue for publicity.
At least one hotel chain, for instance, already has approached the company in hopes of advertising itself as the hotel that will be the first to offer rooms in space.
THE SPACE PHOENIX PROJECT The huge external tank that supplies fuel to the space shuttle’s main engines during ascent would become the key component of a massive orbiting space facility proposed by a consortium of 57 research institutions. Workmen are dwarfed inside the huge tanks used to carry fuel for the space shuttle’s main engines. The tanks are larger around than a Boeing 747 and taller than a 13-story building. About two minutes after the launch of the space shuttle, the solid rocket boosters are ejected and fall to Earth. The main tank remains attached. Under current launch procedures, when the shuttle climbs to about 68 miles above the Earth, it dips slightly as it separates from the tank. The space Phoenix project would have the tanks, equipped with their own maneuvering systems, continue into orbit with the shuttle. Once there, such tanks would be turned into huge warehouses and laboratories in space. Following present practice, the main fuel tank is sent plugging into the atmosphere. The tank virtually disintegrates during the descent. External Tank Length = 154 ft.