v1.1.1 / chapter 3 of 3 / 01 mar 06 / greg goebel / public domain
* 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 deployment of a limited NMD screen now underway. This chapter discusses the current status of the NMD effort.
* As mentioned earlier, work on TMD systems revived interest in a US NMD network. Conservative think-tanks envisioned a range of missile defense scenarios, such as ships carrying loads of ABM interceptors steaming off the coasts of America, able to launch missiles cued by orbiting satellite missile warning and tracking networks, and new ground-based radars.
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. 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 satellites will cue a ground-based radar system, based on a new X-band radar, plus upgrades of existing long-range radar assets. The existing Ballistic Missile Early Warning System (BMEWS), with sites in Alaska, the UK, and Greenland, and Pave Paws national early warning radars are being 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.
Following exercises gave mixed results, with ten more shots performed through 2008, with four failures. However, the system is now regarded as effective, though only against a small number of targets lacking countermeasures. The next phase of testing will improve effectiveness when confronted by decoys. A new "Flexible Target Family (FTF)", with Lockheed-Martin as the prime contractor, will be used in future tests, since the stockpile of "legacy" targets such as the Minuteman has been depleted. The FTF will provide a "mix and match" capability to simulate different classes of threats.
* The Minuteman booster used to launch the EKV in the initial tests was just a stopgap. Development of the production "Ground Based Interceptor (GBI)" originally followed two tracks, one at Boeing that was later handed off to Lockheed Martin, the other at Orbital Sciences. The Orbital GBI performed its first flight in February 2003, followed by a second test in August. These launches did not include a kill vehicle, with the first shot carrying a kill vehicle taking place on 26 January 2004. By that time, the Orbital GBI was seen as the solution, with purchases of the Lockheed Martin GBI curtailed.
Attempts to launch a GBI from a silo on 14 December 2004 and 14 February 2005 were both embarrassing failures, with the missile not even lighting up -- and the targets wasted. The next flight test, on 13 December 2005, was a success, though it was just a systems evaluation, with no target and no attempt at an intercept.
The Orbital GBI is a three-stage solid-fuel missile, derived from the Orbital Pegasus, Taurus, and Minotaur boosters. It is a relatively big weapon, 16.8 meters (55 feet) long, 1.27 meters (4 feet 2 inches) in diameter, with a launch weight of 12.7 tonnes (14 tons). It has an astounding ceiling of 2,000 kilometers (1,250 miles).
The GBI of course carries the Raytheon EKV as its payload. Since one of the objections to NMD is the difficulty of intercepting multiple warheads or warheads protected by decoys, development work is also being conducted on 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. The MKV is expected to be available 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 II Administration, and the whole quarrelsome matter went quiet until the spring of 2001. There had been doubts that the Bush II 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 II Administration's top priority became the "war on terror", focusing first on the intervention in Afghanistan in 2001:2002 and then the invasion of Iraq. NMD became a second-priority issue, though work on the project continued and it remained on the Bush II 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 II 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.
Under the "Ground-Based Midcourse Defense (GMD)" sustem, missiles have been sited, with 20 now in place at Fort Greely, Alaska, and three in place at Vandenberg Air Force Base in California by the end of 2006. The Fort Greely missiles are being supported by the "Sea Based Radar (SBR)", an X-band radar on a floating platform, while the Vandenberg missiles are being supported by a ground-based X-band 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 is also being laid 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. After discussions with eastern European nations, the X-band radar at Kwajalein will be relocated to the Czech Republic by 2011, with ten interceptors sited in Poland by 2013. Rapprochement with the Russians has deteriorated and bearlike growls have been heard from Kremlin brass that siting the missiles in Central Europe was objectionable.
As discussed earlier, the sea-based SM-3 interceptor is now also in service. 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. For the moment, the NMD debate has gone quiet again, but missile defense has always been controversial, and it's not a good bet that it will stay that way forever.
* Boost-phase intercept by a ground, sea, or air-based system is more or less limited to intercept of TMDs, since an ICBM can be launched from well within a country's borders, generally out of reach of such defenses. However, there is no hiding any launch from a space-based BPI system.
In late 2001 the Pentagon requested funding to resurrect the space-based HTK interceptor concept to perform BPI, reviving the Brilliant Pebbles technology shelved a decade earlier. The scope of the proposal was limited to performing a demonstration of a space-based interceptor, not developing an operational system with any intent to deploy. The proposal for a space-based BPI missile system went nowhere in particular, but work is underway to build a demonstrator for a space-based BPI laser system, the "Space Laser (SL)", previously the "Space Based Laser (SBL)" system.
SL has its roots in the overly ambitious SDI "Zenith Star" project, which was followed by a scaled-down concept named "Star Lite". The Air Force and BMDO had wanted to test a Star Lite armed with a hydrogen fluoride laser in orbit in 2005, but concluded that it would not be truly representative of an operational system and went back to the drawing board.
Boeing, Lockheed Martin, and TRW are now working on the SL, with the current plan to launch a demonstrator, the "Integrated Flight Experiment (IFX)", in 2012, with intercept of a missile a year after launch. Although program officials were originally cautious about pushing the program, after all the dead ends in the past, they are now hoping to push up the launch to 2010.
The IFX will weigh about 18.2 tonnes (40,000 pounds), and will be launched from Cape Canaveral on an Evolved Expendable Launch Vehicle (EELV) into a orbit with an altitude of 425 kilometers (264 miles) at an orbital inclination of 28 degrees. It will be built around a chemical hydrogen-fluoride laser, since such a device generates a beam at wavelengths that have good atmospheric penetration, while the fuels used to drive a COIL don't mix well in zero gravity conditions.
The IFX will have fuel stores for up to ten test shots and three actual intercept attempts. Its laser beam will have a range of several hundred kilometers, though an operational SL would have much longer reach. The IFX will use beam control and tracking technology obtained from the ABL effort. It will not have anything resembling an operational guidance and control system, however, since the IFX is strictly a "proof of concept" system, and targets will be launched on predetermined trajectories.
Cost estimates for the IFX are in the range of $3.5 billion to $4 billion USD. First launch of an operational satellite is not expected until 2018 at earliest. The IFX is being designed with an eye to scaling it up to such an operational satellite. The SLs would have passive sensors, probably infrared imagers, to identify missiles, and a laser radar system to target them precisely. The operational SLs will be no longer than 16.2 meters (53 feet) and weigh no more than 19,700 kilograms (43,400 pounds) so it can be put into orbit with a heavy-lift Evolved Expendable Launch Vehicle.
An operational SL constellation set up as a backup to ground-based defenses would consist of six SLs and 12 orbital relay mirrors in orbits 800 kilometers (500 miles) high. This system would cost up to $80 billion USD. If the defense system were entirely space-based, the constellation would require at least 24 SLs.
An operational SL satellite will have provisions for being refueled in orbit. The US Defense Advanced Research Projects Agency (DARPA) is now working on a project named "Orbital Express" to develop a space tug that can service and maintain spacecraft in orbit, such as spy satellites or laser satellites, by swapping out equipment modules and installing fuel packs. An Orbital Express test flight was conducted in March 2007.
* The debate over missile defense is very convoluted and eye-glazing, with the rhetoric clearly outstripping the facts. I had such trouble sorting my way through all the pros and cons that I finally came to the solution of covering the controversies in the overview section of this document, allowing me to set them in the background in the rest of the text so I could deal with the technical details with minimal distraction.
* Sources include:
The Federation of American Scientists (FAS) website was surveyed for this document as well.
* Revision history:
v1.0 / 01 jun 00 / gvg
v1.1 / 01 jul 00 / gvg / Minor cosmetic update, minor additions.
v1.2 / 09 jul 00 / gvg / Update on NMD test failure.
v1.3 / 01 jan 01 / gvg / New details, broke into two chapters.
v1.0.4 / 01 oct 01 / gvg / Minor update.
v1.0.5 / 01 may 02 / gvg / Minor update.
v1.1.0 / 01 mar 04 / gvg / General update, broke into three chapters.
v1.1.1 / 01 mar 06 / gvg / Minor update.
v1.1.2 / 01 mar 08 / gvg / Minor update.
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