Prompt Global Strike

The Answer for Today’s Wars, or a Hypersonic Mistake?

By Robert F. Dorr - May 19, 2010

The X-37B Orbital Test Vehicle in the encapsulation cell at the Astrotech facility in April 2010, in Titusville, Fla. The Air Force officials launched the X-37B April 22, 2010, at Cape Canaveral Air Station, Fla. The X-37B is the U.S.’s newest and most advanced unmanned re-entry spacecraft. Courtesy photo via U.S. Air Force

Is it a substitute for a new bomber? Is it a bold new weapon of war? Or is it a costly, dangerous experiment that might increase the likelihood of a nuclear conflict?

When the Obama administration asked Congress for $240 million in fiscal year 2011 to continue the Air Force’s Prompt Global Strike (PGS) program, observers in Washington were saying all of those things.

PGS uses an intercontinental ballistic missile (ICBM) to boost an unmanned spaceplane into the upper atmosphere. Once aloft, the spaceplane will power itself, or glide, to a target halfway around the world and will either release ordnance on the target or dive into it. Funding for the program was justified by delaying another item on the Air Force “wants” list, a next-generation bomber (NGB). Because it may become the first conventional warload to be boosted aloft by an ICBM-like vehicle, critics are asking whether PGS will lower the threshold for nuclear war. Other critics warn that this is a break with a long-held taboo on weapons in space that all spacefaring nations have so far observed.

Apparently in support of PGS, the Air Force launched an Atlas V rocket from Cape Canaveral April 22 carrying X-37B Orbital Test Vehicle 1, a 29-foot, 11,000-pound unmanned space shuttle that can remain in orbit for months and land via remote control.

Also on April 22 – probably not by coincidence – the Defense Advanced Projects Agency launched a Minotaur IV booster from Vandenberg Air Force Base, Calif., carrying DARPA’s Hypersonic Test Vehicle Two, or HTV-2, glide vehicle. The test was only partly successful.

Speaking of the Atlas/X-37B combo, Gary Payton, deputy undersecretary for Air Force space programs, told reporters, “I don’t know how this could be called weaponization of space. It’s just an updated version of the space shuttle type of activities in space.” Others say an LGM-30G Minuteman III ICBM body could eventually replace the Atlas V and be combined with an X-37B or other vehicle to become an operational Prompt Globe Strike system.

Because PGS is sub-orbital, it may not violate international agreements or longstanding tradition against putting warheads into orbit. Still, previous administrations led by both parties have resisted using a ballistic missile-style rocket booster to launch conventional weapons because of the hairtrigger, “launch on warning” alert status of American and Russian nuclear ICBM forces. In 2006, then-Russian President Vladimir Putin told President George W. Bush that he opposed a PGS-type weapon because Russia would not know if a newly launched missile carried a conventional or a nuclear warhead. Still, Defense Secretary Robert Gates told ABC’s “This Week” that the Obama administration has “embraced” a conventional weapon that uses a rocket booster.

The appeal of “prompt global strike” was spelled out by David E. Sanger and Thom Shanker in an April 23 New York Times article. The new weapon, they wrote, “is designed to carry out tasks like picking off Osama bin Laden in a cave, if the right cave can be found; taking out a North Korean missile while it is being rolled to the launch pad; or destroying an Iranian nuclear site” – all without the United States being forced to resort to nuclear weapons. The idea, however, is not purely Obama’s. President Bush pondered these weapons as a possible replacement for nuclear warheads carried on submarines.

The United States will soon have a slower-response version of the same capability using the B-2 Spirit stealth bomber and the Air Force’s Massive Ordnance Penetrator (MOP), a 30,000-pound bunker-busting bomb scheduled to join the B-2’s arsenal after a flight-test program is concluded later this year. Development of the MOP is widely understood to be a direct response to Iran’s nuclear development program, which includes extensive underground construction.

At least some elements of the PGS program are in the Pentagon’s “black” budget and may include vehicles that have not been revealed in public. A senior source said that a part of the program is located at the Air Force’s Groom Lake, Nev., facility.

Given the potentially extra-atmospheric cost of a “prompt global strike” system, does the nation really want to give up a next-generation bomber to get it? The United States must decide whether it can field a PGS capability without violating at least the spirit and possibly the letter of existing arms treaties, including a pact signed by Obama and Russian President Dmitri A. Medvedev in Prague on April 8.