http://www.aviationnow.com/awin/awin_awst/awin_awst_story.jsp?issueDate=2004-09-27&story=xml/awst_xml/2004/09/27/AW_09_27_2004_p54-58-01.xml

Space Technology

Aviation Week & Space Technology, 09/27/2004, page 54

Craig Covault, Las Vegas

Bigelow's Gamble

The Bigelow Aerospace project to privately develop inflatable Earth-orbit space modules is beginning to integrate diverse U.S. and European technologies into subscale and full-scale inflatable test modules and subsystems at the company's heavily guarded facilities here.

While much public attention is focused on the massive International Space Station (ISS), Bigelow has quietly become a mini-Skunk Works for the NASA Johnson Space Center (JSC).

Ongoing technical assistance to Bigelow from JSC is focused on helping the company spawn development of orbiting commercial inflatable modules by the end of the decade, with the possibility of JSC later using the Bigelow technology for inflatable modules on the Moon or Mars.

Inflatables are attractive because they offer large volume with enormous launch weight savings.

Bigelow Aerospace is also increasing the stakes that low-cost non-government transportation can be available to send astronaut crews to its inflatable space modules in Earth orbit by 2010.

Company founder and millionaire Robert T. Bigelow told Aviation Week & Space Technology that he will announce as early as this week a new $50-million space launch contest called America's Space Prize.

The objective is to spur development of a low-cost commercial manned orbital vehicle capable of launching 5-7 astronauts at a time to Bigelow inflatable modules by the end of the decade.

America's Space Prize will be patterned somewhat after the Ansari X-Prize that will go to the first team to demonstrate back-to-back suborbital flights.

America's Space Prize, however, is to award five times more money than the $10-million X-Prize. And if successful, the winner of America's Prize would have developed something different--the first commercial manned orbital spacecraft--which unlike the X-Prize, could be used for something other than just a spectacular ride.

The new contest also presents challenges far greater than the X-Prize by requiring development of a vehicle that could maneuver to dock at well over 100 mi. altitude and survive a 17,500-mph. reentry.

Bigelow triple-module metallic simulator shows two inflatables docked to central node with a third out of view behind docking interface. Units are used for outfitting studies and an educational program.Credit: WILLIAM G. HARTENSTEIN/AW&ST

America's Prize will be set up so the winner can propose launch on an existing (even non-U.S.) booster, depending upon the entrant's spacecraft configuration.

Inflated Bigelow Genesis one-third scale module bladder and restraint system is tested. Note full-scale bladder in background. Credit: WILLIAM G. HARTENSTEIN/AW&ST

Bigelow is committing $25 million to the prize, and more than one additional proprietary benefactor is in final discussion with Bigelow for the other half. Potential funding partners include NASA, as a follow-up to the prize-related recommendations by the Aldridge Commission on Exploration.

In addition to the $50 million, the America's Prize winner would also be guaranteed first rights on a contract from Bigelow for ongoing orbital servicing missions to its inflatable 45 X 22-ft. "Nautilus" modules--possibly docked together as a small space station (see artist's rendering on p. 58).

With 330 cu. meters of volume, each Nautilus has 2.75 times the volume of individual ISS modules, Bigelow says.

Initial Nautilus unmanned operations are possible by 2008 with the first manned flights to dock with the previously unmanned Nautilus possible by 2010, according to Bigelow. The Nautilus would require a Proton-class booster.

Preceding the first full-scale Nautilus will be two "Genesis" one-third scale inflation test modules to be launched in 2005 and 2006--one on a SpaceX Falcon V and the other on a Russian "Dneper" commercial version of the SS-18 ballistic missile.

Following those missions will be two "Guardian" 45% scale inflatable module flights in 2007 carrying critical life-support system demonstration hardware.

A Dneper will also launch the Guardian flights and could be used for the first Genesis if the SpaceX Falcon V is not ready.

All four of these inflatable test spacecraft will be designed to last for several years in orbit. And Bigelow is offering free rides in them to any corporate or government research payload that would like to take advantage of flying in such a pressurized vehicle.

The first Genesis will be pressurized with nitrogen, but later units will use an oxygen/nitrogen mixture, says Jay Ingham, who runs the Bigelow integration team and also handles mechanical design. He was formerly with Raytheon.

Robert Bigelow says when he started the project in 1998 he decided he could afford to put $500 million of his own funds into the effort by 2015 to achieve launch of full-scale hardware by then.

He says, however, that developments at his North Las Vegas plant and at his nearly two dozen subcontractors have put him as much as five years ahead of schedule, with at least the chance of launching the first 20-25-ton Nautilus for unmanned tests by 2008 and placing a crew on board that first unit as early as 2010.

Inflatables like the Bigelow modules could also form the basis for manned lunar and eventually Martian habitats. Lockheed Martin has just contracted with Bigelow for inflatable module concepts that Lockheed Martin hopes to use in its response to major NASA studies on a return to manned lunar operations.

Interior of three-deck, web-floor, 330-cu.-meter inflatable is much larger than NASA modules. Longitudinal deck layout improves habitability.Credit: WILLIAM G. HARTENSTEIN/AW&ST

Bigelow's work follows NASA's mid-1990s TransHab inflatable technology efforts now shifted to the company (AW&ST July 5, p. 20).

Bigelow has two licensing agreements with NASA. The first is an exclusive license for two patents related to the TransHab. The second is a license for radiation shielding technology that has both exclusive and non-exclusive components, says Mike Gold, Bigelow's general counsel. "By virtue of those agreements we are able to get very valuable ongoing assistance and advice from NASA," Bigelow says. "A lot of key NASA folks are in this plant on a regular basis, and they help us a lot."

Bigelow is pursuing markets for a variety of users including biotech and pharmaceutical company and university research, entertainment applications and government military and civil users. The flight of the NASA-developed bioreactor human tissue growth apparatus, spun off to the private sector, could also be a key medical research market, he says.

He is hoping to earn the trust of those markets by low cost and rapid turnaround, contrary to traditional NASA ISS and space shuttle operations and bureaucracy.

Dark micrometeorite and thermal protection layers cover lower left of Bigelow simulator. Credit: WILLIAM G. HARTENSTEIN/AW&ST

"Part of the challenge is to be technologically proficient with a product that is safe and reliable, user-friendly and economical--otherwise there is no point doing what we are doing," Robert Bigelow says. Although he made his fortune as a general contractor and founder of Budget Suites of America, contrary to media reports he says he is not pursuing "space hotels."

What he is doing, however, is looking at "leasing out" small space stations or habitats made of one or more Nautilus inflatable modules to different research communities or corporations.

To do that Bigelow, with NASA and subcontractor help, is pioneering the development of lightweight but extremely strong and long-lived inflatable "soft goods" to form modules made of proprietary advanced aerospace materials.

The Bigelow team is also developing how to fold and package those soft goods around the module's aluminum core, so once inflated in space, creases and folds and critical seals around windows and hatches do not leak. This is a major challenge on which there is little literature. The company is doing extensive testing to obtain such baseline data.

Other key developments include an external "restraint system," essentially a large bag formed of high-strength interwoven fabric straps to keep the air bladder, of a laminate polymer, at the desired shape once inflated.

Covering the straps will be a five-layer micrometorite shield constructed in part of carbon-fiber composites, but using a less costly design than similar NASA shields. The module will have a total of seven layers with the interior inflated to 10 psi. compared with 14.7 psi. for the ISS and 12 psi. for the 1970s Skylab space station.

More than 50 ballistics tests at the University of Dayton Research Institute and the University of Denver Research Institute were devoted to firing particles of 0.25-58 )[5491]>in. toward the Bigelow shield at velocities from about 1.9-4.3 mi./sec.

"The tests showed we have a shield that performs comparably to NASA's, but at a fraction of the cost," says Brian Aiken, the overall Bigelow program manager. Aiken has extensive experience in satellite design, mostly on military spacecraft at TRW (now Northrop Grumman).

To protect against radiation, the inner walls will be covered with crew-deployed water blankets.

In addition to test and inflatable module technology visible throughout the 120,000 sq. ft. of floor space here, the facilities have large simulators and test articles including:

*Triple module "metallic envelope" station: Three full-scale metallic modules simulating inflatables are joined by a central node for use in visualizing and outfitting attached inflatables. The company will also use it as part of a major Las Vegas area education program for schoolchildren--a Bigelow priority.

*S-1A module: This full-scale metallic simulator (see p. 57) is also used for outfitting tests and will be used for life-support systems tests. A clean room will be added adjacent to it next year.

Rendering has two Bigelow inflatables docked to airlock node with Russian Soyuz/Progress spacecraft at ends. Bigelow is initiating $50-million America's Space Prize for crew servicing.Credit: BIGELOW AEROSPACE

*Two Nautilus full-size inflatable bladders: One is inflated with a simulated airlock (see cover) and one is being outfitted for inflation. There are also two full-scale woven restraint layers for the bladders.

*A 50% scale inflated Nautilus. Used for underwater testing, this inflation test article has a full-scale diameter but half-scale length.

*Genesis one-third scale: Appearing similar to the first subscale flight article (see cover), there are two of these 10 X 8-ft. inflated units.

*A number of 25% inflatables for various test purposes.

Key tests of an advanced Genesis development flight article are about to get underway in Jet Propulsion Laboratory facilities in Pasadena, Calif., by mid-October. The JPL facilities are being used under the latest Space Act agreement with NASA.

The 2,500-lb. test article will be in its 10 X 4-ft. launch configuration for launch load and modal vibration tests. It will also undergo an altitude chamber depressurization test to see how the restraint system straps hold the bladder when gradually exposed to a vacuum as during launch. In flight it will carry enough makeup nitrogen for about three reinflations if necessary, Ingham says.

A successful test will bring the Genesis configuration to the Critical Design Review level, clearing the way for integration of the first flight article.

Genesis will also include windows and an airlock simulator with key seal interfaces. Both the plant here and subcontractors have done extensive tests at the component and inflated envelope level. Both long and short duration tests are being made on all the module's materials, at different temperatures. These include tests to failure done underwater or in special padded facilities to catch flying debris. And some debris has indeed "flown."

"We do not care that much about what a computer model says something is supposed to do," Bigelow said. "We test to the limit. We want to know point-blank what a component actually can do. And we do repeated tests on hardware from the same manufacturers."

Bladder permeability tests at up to four times normal pressure have been done, much of it at two subcontractors. There is little data on how unfolded materials behave for this key parameter, and Bigelow believes it is broadening the database for all future space inflated structures.

Subcontractors make more than 50% of the parts designed by Bigelow engineers, but the plant also makes key components. It has five computerized numeric control machines that can machine parts to within one-ten-thousandth of an inch, says Mike Penosa, the plant manager, with years of engineering experience in the U.S. Navy. The company's welders and machinists average 15-18 years' experience.

Bigelow has coupled a competent team with a pragmatic philosophy. "We are a 100% experimental program, and we have to prepare for failures and not be overly shocked if they happen. We realize all of this is going to be done at significant risk," Bigelow says.

"But we also have an agenda we want to carry out, tied closely to the timing of our flight tests."