New Mars

With the recent announcement of Project Constellation as part of President Bush’s new space initiative, now is a good time to examine past attempts at building a successor to the Space Shuttle, so that we may maintain a fresh perspective. Written by James Burk of the Project Constellation weblog.

With the recent announcement of Project Constellation as part of President Bush’s new space initiative, now is a good time to examine past attempts at building a successor to the Space Shuttle, so that we may maintain a fresh perspective.

On January 14th, 2004, U.S. President George W. Bush gave an historic speech at NASA Headquarters in Washington, DC. “Today I announce a new plan to explore space and extend a human presence across our solar system. We will begin the effort quickly, using existing programs and personnel. We’ll make steady progress — one mission, one voyage, one landing at a time.”

Bush announced that the first goal will be to return the Space Shuttle to flight safely, and consistent with the recommendations of the Columbia Accident Investigation Board. Once construction of the International Space Station (ISS) is complete, the Space Shuttle will be retired by 2010 to make way for a new spacecraft, the construction of which will transform America into a truly spacefaring nation.

“Our second goal,” Bush went on, “is to develop and test a new spacecraft, the Crew Exploration Vehicle, by 2008, and to conduct the first manned mission no later than 2014. The Crew Exploration Vehicle will be capable of ferrying astronauts and scientists to the Space Station after the shuttle is retired. But the main purpose of this spacecraft will be to carry astronauts beyond our orbit to other worlds. This will be the first spacecraft of its kind since the Apollo Command Module. ”

The program to build the CEV, now christened “Project Constellation” is more than about developing a single new vehicle. NASA will work in parallel on concepts which will launch the new manned spacecraft not only to earth orbit, but also to lunar orbit, to help conduct lunar landings, to build extended duration habitats, and to venture forth on interplanetary destinations beyond (read: Humans to Mars.)

Thus, the new Crew Exploration Vehicle (CEV) represents the most significant new research into manned spacecraft since the mid-1960s. It will inherit the legacy and most likely the shape of the Apollo Command Module, and it will benefit from almost 40 years of technological advances.

While this is the first new attempt by the U.S. to create a lunar spacecraft since Apollo, and arguably the most bold and visionary, it is not the first attempt to build a shuttle replacement. In fact, the road to building the CEV is littered with the debris of past failures.

The National Aerospace Plane

In the mid-1980s, as the Space Shuttle program was just getting underway, President Reagan announced a program that would serve as both a shuttle replacement and a replacement for the SR-71, then the preeminent spyplane. The National Aerospace Plane (NASP) would be the world’s first Single Stage to Orbit (SSTO) vehicle. Reagan called it “a new Orient Express that could, by the end of the next decade, take off from Dulles Airport and accelerate up to twenty-five times the speed of sound, attaining low earth orbit or flying to Tokyo within two hours…”

The project required breakthroughs in six different “enabling” technologies, including discoveries in advanced heat-resisting materials and the creation of a “scramjet”, a system designed to compress air into a combustion chamber at hypersonic speeds. As this and later attempts would demonstrate, relying on breakthrough technologies to be developed as part of a planned development cycle can meet with disaster.

The proposed National Aerospace Plane had some black-budget roots in an earlier DARPA program called “Copper Canyon” which operated successfully from 1982-85, and seemed to show that a hypersonic plane could reach the speed of Mach 25 required to attain orbit with a scramjet engine. However, this was later proven a fallacy and the top speed of NASP would be limited to around Mach 17, requiring a rocket engine to be added in order to bring NASP up to orbital velocity.

The NASP program was never formally cancelled, but its research faded into the recesses of NASA & Air Force research programs after more and more technical roadblocks were encountered, and billions more were spent. To this date, the scramjet system has never been fully demonstrated, but NASA’s Hyper-X program is still working hard on the problem and some success could even come this year.

The Rise and Fall of the X-33

In the mid-1990s, NASA still had not decided on a replacement for the Space Shuttle, and a competitive process was begun to award an aerospace company with the contract to build the X-33, which would be a suborbital test vehicle designed to pioneer the needed technologies and pave the way for a later orbital version. Again, the fallacy of requiring technological breakthroughs was part and parcel of the effort.

Early on in the competitive process, it was clear that there were two design choices which to some were quite stark: the winning X-33 design would either encompass an attempt to create a winged, horizontal-landing spaceplane, much like the National Aerospace Plane, or an attempt to do something more revolutionary; a small project run by the Ballistic Missile Defense Organization in the Pentagon that had recently shown the capability to take off and land in a vertical position. Called the “Delta Clipper” or DC-X, it also boasted a small ground crew, rapid turn-around, and was designed for “airplane like” serviceability. Many observers of the program felt intuitively that these were important capabilities for a future SSTO vehicle. Of those who had followed the test flights webcast onto the burgeoning Internet during the mid-1990s, many hoped that this revolutionary project would be named the shuttle replacement that everybody was waiting for.

In 1996, the historic announcement was made to decide which design would win the X-33 competition. NASA Administrator Dan Golden and Vice President Al Gore gathered reporters at the Jet Propulsion Laboratory in California to decide who would build “America’s revolutionary new reusable launch vehicle” and “why this new vehicle will be commercially efficient and profitable for American industry.”

Lifting up a box that had covered up a model of the winning design, Al Gore announced that the Lockheed Martin’s Skunk Works was the winner with their proposed design dubbed “Venturestar”. At the time, Lockheed had pledged that if NASA awarded them the X-33 program, the aerospace giant would use their own funds to build a series of scaled-up orbital Venturestar vehicles to replace the Space Shuttles, and they would be operated commercially by Lockheed. For NASA, it must have been too good to be true, but unfortunately that’s what it turned out to be.

The Venturestar was designed to be a Single Stage to Orbit (SSTO) vehicle that would take off vertically, making use of an engine called a “linear aerospike”. During the Apollo program, this type of engine was briefly considered as a possibility for the Saturn V, since it could channel its thrust in different ways depending on the air pressure around it, thereby saving fuel during the flight to orbit. The X-33 also ended up using refurbished turbopumps from the Saturn V’s J-2 upper stage engine.

The Venturestar design called for the use of a wingless “lifting body” airframe which would provide good aerodynamics during it launch through the atmosphere, and during the vehicle’s glide back to a horizontal landing. But most challenging of all, the Venturestar would require composite carbon-fiber tanks to hold its hydrogen fuel. The composite tanks were oddly shaped and needed to withstand the dynamic pressures of a launch, while holding liquid hydrogen at sub-zero temperatures.

As a result of the unrealistic goals, the program eventually (and predictably to some observers) hit a technological brick wall; during the testing of the first completed composite tank, a huge crack developed in the tank’s lining and caused it to burst apart in an explosive event. The project then attempted to redesign the vehicle to use lightweight aluminum allows, which required removing the cargo bay, and replacing it with an external cargo pod, which in turn required other changes. It took a couple years, but from the cracking of the tank, the project was doomed.

In early 2001, after the project had spend over $1.3 billion, it was cancelled by the Bush administration which had just come into office. After the cancellation, there were calls for the Air Force to pick up the project so that the time and money spent to date would not be completely wasted, but the service refused to do so and the days of the X-33 were finally over.

The Crew Return Vehicle

While the X-33 program was still underway, the International Space Station began to be built and had begun its permanent habitation. There had almost always been plans in the ISS program for some type of “Crew Return Vehicle”, a lifeboat which would remain permanently attached to the space station in the event that a crew needed to evacuate. It was expected that, at first, the Russian Soyuz would provide this capability. But later on, as construction continued and the capability of the ISS grew from housing three to providing room for seven crewmembers, a larger craft would be needed to bring the crew home in the event of an emergency.

In 1996, NASA formed the X-38 program to develop a new design for a Crew Return Vehicle (CRV) which would fulfill this requirement. A small team at NASA’s Johnson Space Center began work on the vehicle, which, like the X-33, also took the form of a lifting body. Since the CRV would not need to be launched into orbit (it would be delivered to ISS within a Space Shuttle’s cargo bay), it made the project relatively simple, since the only propulsion needed would be for maneuvering and reentry. The first successful unmanned test flight was accomplished in 1998 at Dryden Flight Research Center, the same location that many of the first lifting bodies were tested in the early 1960s.

However, when the ISS was scaled back due to its tremendous cost overruns, the crew of the station was also reduced from the originally planned seven crewmembers down to three. As a result of this, the requirement for a CRV disappeared overnight, since the Russian Soyuz would be able to act as a lifeboat for a three-person crew. While there were no technical problems with the development of the vehicle, the project was nonetheless cancelled in an effort to get the ISS budget under control. It is notable to mention that the CRV, unlike the X-33 and NASP, did not rely on new breakthroughs, but only existing, proven technologies. Many feel that the project should have been allowed to continue, and would have met with success.

The Orbital Space Plane

After the cancellation of the X-33 and Crew Return Vehicle, NASA created the Space Launch Initiative (SLI) which, instead of putting all of its eggs in one basket by focusing on a single design, as was done with the Venturestar, the SLI focused on a range of concepts. The program looked at everything from two-stage reusable vehicles to winged bodies atop existing expendable rockets, to throwback capsule-shaped systems. NASA needed not only a shuttle replacement, but also a vehicle able to transport crewmembers to and from the International Space Station after the Space Shuttle was retired. This was needed because plans at the time called for the Shuttle to fly until 2020.

After much deliberation and review, the program finally settled on the simple concept of a “Crew Transfer Vehicle” that would sit atop an Evolved Expendable Launch Vehicle (EELV) rocket, either a Boeing Delta IV or Lockheed Martin Atlas V. The exact design of the Crew Transfer Vehicle would be determined by industry in a competitive process similar to X-33, but one remarkable thing about the program that differentiated it from the previous attempts was the fact that the initial requirements were able to fit on a single sheet of paper. No breakthrough, pie-in-the-sky technologies would be needed, just old-fashioned engineering and adhering to the program’s simple requirements.

The Crew Transfer Vehicle was later dubbed the “Orbital Space Plane” and plans for a second-level set of requirements soon got underway. Most observers thought that NASA was finally on the right track to replacing the shuttle with a viable new design, although some derided the lack of private sector input into the decision-making process.

However, as the behind-the-scenes discussions on a new exploration initiative for NASA were conducted by the Bush Administration, it was eventually realized that the OSP program would need to be realigned to fulfill the new vision. One early warning of this was the cancellation of a Request For Proposal to industry contractors in November 2003. As Bush gave his speech calling for NASA to return to the Moon and someday travel to Mars, he announced that NASA would develop a Crew Exploration Vehicle to accomplish all of these efforts.

CEV: Not Just An “Orbital” Space Plane Anymore…

The effort to develop the Orbital Space Plane will not be wasted, and it should be noted that the project was only in its initial phases when it was morphed into the new Crew Exploration Vehicle (CEV). Perhaps most importantly, the same thinking that led NASA to keep the OSP requirements simple are still at work on the initial CEV requirements.

While it is still early in the development of the CEV, some of the concepts that may be adopted have already started to emerge. Overall, a modular design is being touted in order for new capabilities to be added and to allow future launch vehicles designs to be easily swapped out. Versions of the CEV for earth orbit, lunar orbit and beyond are all being planned and considered.

One thing that is clear from the outset is that a capsule-shaped design is being favored. Other wing-shaped designs have not been ruled out yet, but many observers of the project, including the very astronauts that will ride the vehicle, are strongly in favor of the capsule shape due to its proven flightworthiness during the Mercury, Gemini, and Apollo programs.

Aside from the crew module itself, other modules are being designed to enable extended stays in space. Included in a series of graphic mockups released by Boeing is an inflatable habitat module, which many have already compared to a past NASA effort to develop an inflatable habitat for ISS, and as part of an interplanetary vehicle for future voyages to Mars.

Transhab, or “Transit Habitat”, was a $3 million technology development program funded by NASA that was cancelled, once detractors in Congress realized its applicability to future manned Mars hardware. At the time of its cancellation, a moratorium was in place at NASA to prevent any research not specifically tied to the Shuttle or ISS programs. If no other advances are made by the current Space exploration initiative, the single greatest thing it has done, in the opinion of many, is to shatter that moratorium and allow research on human exploration beyond earth orbit to be conducted by NASA.

A Presidential commission will make recommendations on the implementation of the President’s new vision for space exploration and what the exact requirements of the CEV will be. The first report of the commission is expected in around four months. The commission is headed by former Joint Strike Fighter program director Pete Aldridge, who was selected due to his experience with managing that large technology-development project. Aldridge also trained to be a payload specialist on the first west-coast Space Shuttle mission, which was cancelled following the Challenger disaster. He later served as Secretary of the Air Force, President of McDonnell Douglas (now part of Boeing), and recently retired as Under Secretary of Defense for Acquisition, Technology and Logistics. However, he has been recently criticized by Sen. John McCain due to his position on the board of directors for Lockheed Martin, which McCain feels is a potential conflict of interest. In the past, McCain also criticized Aldridge for his involvement in the Boeing refueling tanker decision, which has been plagued by scandals surrounding the contacts between employees of Boeing and Pentagon officials.

The requirements and supervision of construction for Project Constellation hardware will be the job of NASA’s new Exploration Systems office (NASA Code T). It was created the day after Bush’s announcement and is headed by Craig E. Steidle, a retired Navy Admiral. Steidle was formerly the Vice Commander, Naval Air Systems Command which is responsible for research, development, and procurement of new naval aeronautical systems. Under his watch, NAVAIR transformed the way it did business during a time when its budgets were decreasing. Steidle streamlined the command, improving processes for communication, responding to problems, and bringing commercial methodologies into use. He also commanded the Navy’s largest production, research, and development effort, the F/A-18 Program.

Over this summer more details will emerge on the form and function of the CEV, and more granular timelines will be decided. Whether the first test flight of the CEV will occur in 2008 remains to be seen. But all in all, this is a most exciting time for observers of the space program and those who dream of humans again walking on the Moon and, someday within the lifetimes of most reading this, humans walking on the surface of the Red Planet.

Related Articles

X-30 National Aerospace Plane (NASP)

X-30 (Astronautix.com)

DC-X Pages (NASA History Office)

X-33: Single Stage To Orbit

X-38 Crew Return Vehicle

Interview with Steidle (PDF)

X-33 Announcement

NASA Developing Crew-Return Vehicle

NASA’s Orbital Space Plane Project Delayed

An Interview with RAdm. Craig E. Steidle, Vice Commander, NAVAIRSYSCOM (PDF)

Overview of NASA’s FY 2005 Budget

Filed under: Articles on February 5th, 2004