The Space Reviewin association with SpaceNews

The Air Force continues to pursue programs like the Space Maneuver Vehicle as part of efforts to get into space quickly and cheaply, and to project military force around the globe. (credit: US Air Force)

Missile defense, RLVs, and the future of American spacepower

<< page 1: the high cost of space access

A short history of the RLV

Back in the mid 1980s, many of the supporters of missile defense realized this and began to look for ways to escape this dilemma. One of the driving factors was the so-called Nitze criterion. This laid out the principle that for any missile defense system to be cost effective each increment of defense had to cost less than each increment of offense. The arguments over this quickly degenerated into a debate over how to properly estimate the cost of Soviet military systems. (One Russian writer suggested that the US measure the cost of the Red Army’s tanks in pairs of blue jeans per vehicle.)

General Graham realized that the best way to confront this was to drastically cut the costs of putting the missile defense sensors and weapons into orbit. In February 1989 Graham, along with Jerry Pournelle, the science fiction writer, and Max Hunter, a legendary rocket engineer, met in the White House with Vice President Dan Quayle. They proposed that the US build an experimental single stage to orbit (SSTO) RLV technology demonstrator that would lead to airliner-like operations: the whole thing would go up, the whole thing would come back and it could be given a quick inspection, refueled and flown again.

If successful, such a vehicle could be flown far more often than the Shuttle. A future version could even be flown several times a week. Every professional study, notably the recent Futron ASCENT study, shows that cost of access to orbit is related to flight rate. A fleet of RLVs flying thousands of missions a year could reduce the cost of getting to LEO to as little as $300 a pound, which would mean that a human being weighing 180 lbs. with a 120 lbs. baggage allowance could be flown into space for $90,000. More to the point, it would cost about the same to send a Brilliant Pebble missile interceptor.

Quayle was convinced. In turn, he sold the rest of the administration on the potential of such an effort. Instead of handing it to NASA, which was obsessed with the Shuttle, the project was instead handed to what was then called the Strategic Defense Initiative Organization (SDIO).

In those days, SDIO was still full of imaginative thinkers who were ready to pursue radical new ideas and were also merciless about dropping projects that failed to meet their initial promise. After a nasty political and bureaucratic struggle in which the Vice President played a critical part, money for a precursor SSTO project was included in the defense budget. When McDonnell Douglas won the contract, the vehicle became known as the DC-X. While it would never reach orbit, it would demonstrate a “build a little, test a little” approach to launch vehicle development. It would also show what could be done if all the usual expensive rules for large aerospace programs are thrown out the window. The management of the program was assumed by Pete Conrad, the former astronaut, Air Force Col. (now General) Pete Worden and Maj. Jess Sponable.

The DC-X rolled out of the hangar where it had been built, in Huntington Beach, California, in April 1993. To the small segment of the American public that followed such things, it was a momentous event. In spite of all the many bureaucratic efforts to kill it, and the utter indifference of the new Clinton administration, a new space age was conceived.

On August 18, 1993, the vehicle flew for the first time, at White Sands, New Mexico. This was the first time in history that a rocket had landed vertically with the engine still running, just like in the old science fiction movies. Proving vertical landing was an important part of that program. More important was proving that a launch system could be run by a couple of technicians out of a trailer. As long as each launch is regarded as a “campaign” needing thousands of highly-paid experts to check and recheck every element of the vehicle, any serious reduction in the cost of getting into space is impossible. The DC-X and its successors have proven that, given current materials and propulsion, the SSTO dream is impossible, but a two stage to orbit (TSTO) system is within the state of the art.

Current military RLV work

The Air Force has published a concept call for transformational delivery vehicles, both to replace the Minuteman III ICBMs and to accomplish the Prompt Global Strike and Operationally Responsive Spacelift missions. While it is hard to imagine an RLV replacing ICBMs as America’s land based nuclear deterrent, the latter job, also called FALCON, for Force Application and Launch from the Continental United States, would be within the capabilities of such a vehicle. Being able to hit any target on earth within 90 minutes or less without having to fly through any other nations’ airspace is something America is going to need to be able to do.

Indeed, the DoD had been working on a Military Space Plane concept in the early 1990s, but it was canceled by Bill Clinton in 1997, when he used the line-item veto for the first and last time. The idea has never really died and today Boeing is working on the X-37, which could be part of such a system as well as a technology demonstrator for NASA’s Orbital Space Plane (OSP). This spaceplane shares many of the requirements of the Air Force’s ongoing Space Maneuver Vehicle studies.

The Defense Advanced Research Projects Agency (DARPA) is currently working on the RASCAL project. This would be an aircraft capable of at least Mach 3 that would zoom up to 200,000 feet, where it would release a smaller rocket that would propel its payload into space. The goal is to produce a vehicle that can put a 130-kg payload into orbit for operating costs of about $750,000 dollars per mission. By a happy coincidence, this is about the weight of an evolved version of a Brilliant Pebble.

Assuming 100% cost overruns, the marginal cost of building and deploying a single evolved version of the Brilliant Pebble would be 6 million dollars. A constellation of 2000 of these would cost 12 billion dollars to build and deploy—about the same as a single aircraft carrier and its aircraft. RASCAL, or something similar, might also fulfill the Pentagon’s need for Prompt Global Strike.

Today, neither the DoD nor NASA has any clear idea of how to fix America’s access to space problem. There are a number of promising alternatives. Without high level attention, America’s space warriors will continue to depend on glorified versions of von Braun’s V-2 on the 60th anniversary of the attack on London. We can—and should—do better.