National Missile Defense
v1.1.0 By Greg Goebel
(Winter 2001)
Despite the fact that national missile defense has always been a major technical challenge, the current Bush II Administration is strongly pushing the concept, with plans to deploy a limited NMD screen in the near future. This chapter discusses the current status of the NMD effort.Military officials working on TMD were nervous about the push for NMD, since it muddied the waters for TMD efforts. However, the potential threat of ICBMs in the hands of smaller powers gave NMD advocates in the US Congress and the military a lever to push for fielding a pilot NMD system. BMDO initiated a NMD investigation program, with Boeing as the prime system contractor. The core of the NMD system was to be a Raytheon HTK interceptor, designated the "Exoatmospheric Kill Vehicle (EKV)", designed to attack missiles at altitudes of hundreds of kilometers. Space-based intercept is trickier in some ways than atmospheric intercept, since balloon decoys and chaff remain effective until the RV enters the atmosphere.
The EKV includes a 256-by-256 pixel mercury cadmium-telluride infrared imaging array, and a hydrazine-thruster space maneuvering system. The EKV is launched from the ground by a multistage booster to hit targets in space. Research is underway to develop improved infrared arrays and a complementary laser radar that may be used in an improved NMD EKV or other missile defense systems.
The NMD system also involves an early-warning satellite network, linked to a new X-band radar and upgraded existing national early-warning radars. The current "Defense Support Program (DSP)" early-warning satellite network will be used at first, but the NMD system is expected to eventually make use of the next-generation "Space Based Infrared System (SBIRS)" satellite constellation.
The new X-band "Ground Based Radar (GBR)" will be able to provide details of targets to improve accuracy. The existing Ballistic Missile Early Warning System (BMEWS), with sites in Alaska, the UK, and Greenland, and Pave Paws national early warning radars would be improved to the "Upgraded Early Warning Radar (UEWR)" standard. All the elements will be integrated through a "Battlefield Management Command, Control, & Communications (BMC^3)" system.
An initial NMD test was conducted in October 1999 from Kwajalein Atoll in the Pacific, and was a success. The NMD test involved the launch of a surplus three-stage Minuteman II missile modified by Lockheed Martin, carrying decoys and a dummy warhead. The target flew high into space on a trajectory taking it 7,000 kilometers (4,350 miles) downrange, southwest over the Pacific. Less than half an hour after launch of the target vehicle, the EKV interceptor was launched from Kwajalein on another modified Minuteman II.
A second test shot, integrating the X-band NMD radar system, was conducted on 18 January 2000. The test was a failure. Although the EKV's electro-optic sensor array was able to guide the vehicle towards the target, a coolant leak disabled the terminal guidance IR seeker system. The target and EKV passed each other at an altitude of about 230 kilometers (140 miles).
A third test shot took place on 8 July 2000, and failed when the EKV failed to separate from its booster. Although this failure was discouraging, the fourth test, essentially a replay of the third and performed on 14 July 2001, was a success. A fifth test, similar to the third and fourth but using an Orbital Sciences target vehicle, was conducted on 3 December 2001, and was a success. The sixth test, conducted on 15 March 2002, and the seventh, conducted on 14 October 2002, both used a Minuteman target, and were both successful.
Of course, many challenges remain, particularly discrimination against decoys. Program officials say that the EKV seeker system has performed well in tests to see if it can pick out warheads from decoys. There were rumors that senior Bush Administration officials had been considering a nuclear-armed NMD to deal with the decoy issue, but NMD program officials downplayed the idea, and for the moment a nuclear-armed NMD remains a rumor.
The Minuteman booster used to launch the EKV in these tests is just a stopgap. The production "Ground Based Interceptor (GBI)" is envisioned as having three stages, not including the EKV, with the stages derived from commercial solid-fuel rockets. The GBI would be launched from a silo.
Boeing was working on the GBI, but development problems led to an 18-month slip in schedule. Boeing is now working along two tracks, with Lockheed Martin and Orbital Sciences Corporation (OSC) developing competing GBIs. The OSC GBI performed its first flight in February 1993, followed by a second test in August. These launches did not include a kill vehicle, with the first shot carrying a kill vehicle expected in 2004. As of late 2003, Lockheed Martin had not flown its GBI. However, current thinking envisions fielding GBIs from both companies, since they have somewhat different performance characteristics.
* Since one of the objections to NMD is the difficulty of intercepting multiple warheads or warheads protected by decoys, the MDA is also pursuing development of a "miniature kill vehicle (MKV)", about the size of a coffee can, with a weight on the order of 5 kilograms (11 pounds), and fitted with an infrared imaging array. A single interceptor missile would carry a cluster of dozens of MKVs, programming them to attack individual targets before dispersal and then providing them with command updates after dispersal. Lockheed Martin was awarded an initial MKV development contract in early 2004. Initial flight test is expected no earlier than 2007, with fielding no earlier than 2010.
* The NMD tests brought the missile defense issue back into the headlines and onto the first rank of issues for the Clinton Administration and proved a political quagmire. Both hawks and doves were critical of the proposed NMD plans, though for different reasons, and there was no broad-based consensus for deployment.
The Chinese were uniformly critical of TMD as well as NMD, as ballistic missiles are one of the few strong cards China has in projecting force in Asia. The Russians shuffled between fear and derision, and pitched a limited "non-strategic" missile-defense plan of their own to the Europeans, no doubt at least partly to muddy support for NMD. In fact, the Europeans seemed lukewarm on NMD.
The "lame duck" Clinton Administration logically passed the issue on to the incoming Bush Administration, and the whole quarrelsome matter went quiet until the spring of 2001. There had been doubts that the Bush Administration would push for deployment, but at that time President Bush came out strongly for an operational NMD system, lobbying the Europeans and consulting with the Russians on the matter. The response was not highly positive, and indeed the Russians made diplomatic overtures to the Chinese that were seen partly as a counterbalance to US NMD efforts. There was also domestic opposition to what was perceived as a "rush to deployment" of NMD.
Following the terrorist attacks on the US on 11 September 2001, the Bush Administration's top priority became the "war on terror", focusing first on the intervention in Afghanistan in 2001:2002 and then the effort to disarm Iraq. NMD became something of a back-burner issue, though work on the project continued and it remained on the Bush Administration's agenda.
The war in Afghanistan brought the US and Russia closer together, which had the effect of encouraging the US to believe that the ABMT could be abandoned with no real penalty. In early December 2001, President Bush announced that the US would pull out of the treaty in six months. He stated that the ABM Treaty was a "relic" that blocked timely missile defense testing and deployment, which was judged "indispensable" as a defense against terrorists and rogue states.
The decision was criticised by arms-control advocates, but defenders of the Bush Administration replied that the ABM Treaty had never really been an effective security measure in the first place. At the beginning of 2002, BMDO was renamed the "Missile Defense Agency (MDA)" to further emphasize the stature of NMD in the eyes of the Bush Administration, and at the end of the year the administration gave the go-ahead for operational development and deployment. NMD was back on the front burner again, and now it was boiling.
The current plan envisions six NMD silos at Fort Greely, Alaska, and four silos at Vandenberg Air Force Base, California, by the end of 2004. Ten more silos would be added at Fort Greely by the end of 2005. Targeting will be performed by the Cobra Dane phased-array radar in the Aleutians and an early-warning radar at Beale AFB in California. This would give a defense shield against "northeast Asia" (read as "North Korea").
Groundwork for a defense against Middle Eastern nations would also be laid in 2005 with updates of the BMEWS radar sites at Fylingdales in the UK and Thule, Greenland. Both Britain and Denmark (which controls Greenland) have given authorization for the updates.
As discussed earlier, go-ahead has also been given for deployment of the sea-based SM-3 interceptor. Although the Navy was ambiguous about linking SM-3 to NMD, that is now the plan. The Aegis vessels will be linked into the NMD net, with their radars and fire-control systems directing either sea-based SM-3 or ground-based NMD interceptors.
What happens with the current plan remains to be seen. Congressional support is mixed, and the program could either be slowed down or accelerated. Missile defense has always been controversial and promises to stay that way for some time to come.
