Space-Based Attack Weapons

A Compilation of Rumor and Fact, Updated 2/23/2008

Weapons for the 25th Century || Unmanned Space Vehicles || U.S. Anti-Satellite Systems

During the Reagan years, you would had to have been asleep not to hear about the "Star Wars Defense". The U.S. President, using his talent to motivate and instigate, set U.S. aerospace and science communities on a track to build a new set of weapons for use in space. The goal, to build a "shield" of protection over the U.S. and perhaps later our allies, was not intended to build the energy barrier harkened to by his speech, but more a technology of anti-ballistic missile systems that would have high percentage of kill upon incoming warheads.

In fact, the Star Wars initiative (actually called the Strategic Defense Initiative) recognized four clear opportunities for interception of incoming threats to the U.S.

Boost Phase - missiles launched are easily detected, and if somehow you could train a weapon on them at this phase, the missile is quite vulnerable and easy to track being slow moving and surrounded by the light and heat of its high powered rocket motors.
Coast Phase - at the top of the ballistic arc, the missile or perhaps one or more remaining elements of a multi-stage rocket with the warhead, are vulnerable as they pass through the void of space. Most cases the "bird" is unable to maneuver much in this phase, and unless things change, little is done to avoid any attacking space unit.
Re-entry Phase - after coasting through space, the warhead (and perhaps accompanying maneuvering systems or decoys) are now brought back through the atmosphere for terminal maneuver onto the target. In the case of MIRVs (Multiple Intermediate Re-Entry Vehicles) it is best to catch an inbound warhead before it splits up into its multiple units so you only have to track and destroy one unit instead of two or more.
Delivery Phase - Once the warhead and maneuver units have re-entered, and perhaps split (MIRVs) there is an opportunity to catch the device high enough before it can be damaging. This works well except for the effects of EMP (Electro-Magnetic Pulse), which may be effective even at the highest altitude. Delivery phase interception also carries the danger of polluting the atmosphere with possible nuclear contaminants, since interception is likely to explode a fully armed weapon (and perhaps the interceptor itself is nuclear in nature). For this reason, delivery phase interception is highly risky for nuclear weapons.

SDI called for weapons systems to address the phases individually, however, by using a multi-tiered approach to missile defense, the statistical probability that an intercept would take place successfully would be heightened. By throwing lots of weapons and technology at the problem, the initiative hoped to virtually eliminate or so lessen the threat of ballistic missile attack, so as to eliminate the need for the ever-increasing arm race created by the older MAD (Mutual Assured Destruction) and its massive retaliation component.

Controversial at best, the SDI program did not result in an in-penetrable shield against ballistic missile weapons, and as the Cold War ground to ignominious and somewhat unexpected halt, the nuclear necessity seemed to wane.

However, as third world nations have begun to deploy ballistic missile capability with conventional or weapons of mass destruction other than nuclear (chemical or biological weapons can be nearly as dangerous as nuclear weapons and far easier to build), military theorists are quick to point out the threat has not diminished, rather has increased dramatically.

Did SDI die on the vine? Not really, as this 2001 budget request from the Director of the Ballistic Missile Defense Office shows. The military usually never forgets lessons learned in weapons development and especially so in development of new and pioneering technology. In this case, the BMDO has focused on things it learned it CAN do and continues to develop new technology for things it THINKS it can do.

What follows is speculation with added notes to perhaps point to particular programs and research that may indicate continued space based weapons research and perhaps test deployments:

Technology	Program	Comments
Anti-Satellite Missile	F-15 Strike Eagle with Phoenix Missile carrying umbrella style weapon (see below)	Supposedly some missiles in inventory, some crews undergo training on a periodic basis, although the system is said to be in caretaker status.
Rail gun	"Brilliant Pebbles" - SDI	Supposedly, the idea is to track inbound warheads in the coast phase (in space) and shoot high velocity projectiles (ball bearings work just fine at supersonic speeds possible) using an electromagnetic accelerator. Tracking and aiming were said to be the downfall of this program, however, as these areas improve, it might be possible to pull the weapon system off the shelf?
Umbrella	- SDI?	Another theoretical device was designed to launch a probe in the path of an inbound warhead, and at the last few feet, deploy a huge net of material intended to make up for errors in guidance, impacting the warhead with resulting severe and catastrophic results.
Kinetic Kill (On Orbit Interceptor)	- SDI? Space Based Interceptor?	Akin to ball bearings and the rail gun but using small missiles similar to anti-tank weapons deployed by major armies today. The high velocity missile might have a radar guidance system, a multi-mach boost engine and be fired from a space based launch platform which has the initial tracking and target illumination systems on board, or this launch platform might pass on telemetry from other tracking and illumination systems to the small but potent attacking missiles.
Space Based Lasers and Mirrors	- SDI?	Ahh, this is more like Star Wars types weaponry, a high power chemical laser mounted in a space platform shoots beams of high energy which overheat the thin and vulnerable skin of the warhead or maneuver vehicle causing bursting of pressure vessels or damaging re-entry heat shields. In some cases the beam is sent direct or reflected via precisely positioned mirrors onto the target. Power requirements for this type of device probably require spacing a large nuclear reactor, and therefore may not be practical. This weapon might be more appropriate for ground based, re-entry or delivery phase interception.
Laser armed aircraft (In Atmosphere)	ABL (Airborne Laser)	Carried on a (substantially modified) Boeing 747, this weapon system has moved from development into deployment. The high energy chemical laser is supported by a small power tracking and director laser which pinpoints the target and maneuvers the aiming lens for the "killer laser". The idea is to place several aircraft in the region of conflict and take out ballistic or tactical missiles in flight, either during boost phase or in re-entry/delivery phase.
Ground Based Lasers	THEL (Tactical High Energy Laser) MIRACL (Mid-Infrared Advanced Chemical Laser)	More Star Wars systems, demonstrated recently with today's technology -- Attack lasers aimed at inbound missiles from a ground station, attacking just after re-entry and in delivery phase to damage severely the incoming weapon, perhaps exploding it harmlessly at altitude. This is a more tactical weapon, and therefore used to defend key targets rather than a nationwide system. THEL is a joint U.S. and Israel program to attack inbound tactical missiles, defending a battlefield or key targets (i.e. as in SCUD attacks during the Gulf War). The program successfully demonstrated feasability and according to the Director of BMDO is now in further development. Details are sketchy as this program now moves into the black project arena for development that leads to deployment. MIRACL is actual demonstration system, and is the first laser system to actually destroy an inbound missile warhead actually within the nose cone of the attacking missile. MIRACL is a research system which will lead to better tracking and illumination as well as fine tune the high power laser attack beams to be used in deployed systems.
Ground Based Interceptor	National Missile Defense	Lt. Gen Kadish, Director of BDMO's speech before the Senate Armed Services Committee, Strategic Forces Subcommittee, Monday, February 28, 2000 - "Space-based sensors make the initial detection and report a threat launch. DSP, and eventually SBIRS-High, will alert the entire system of a potential ballistic missile attack, cue the radars to erect "search fences" to detect the incoming missile, and start evaluation of engagement options at battle-management centers. When the threat missile crosses into the range of ground-based early warning radars, these radars confirm target missile flight and tracking information. Upon data confirmation, the BM/C3 center cues the X-Band Radar and directs the launch of a ground-based interceptor. The ground-based X-band radar provides high-resolution target tracking data to the interceptor in flight through an In-Flight Interceptor Communications System. This data will be used by the interceptor to maneuver close enough to the target missile for the on-board kill vehicle sensor to discriminate the warheads from decoys and debris. Sensors on the kill vehicle provide final, precise course corrections to enable the kill vehicle to destroy the target. Multiple interceptors launched at each incoming reentry vehicle, either in salvo or in waves (a "shoot-look-shoot" scenario), are expected to increase dramatically the probability of a successful intercept."
Upper Tier Tactical Missile Defense (TMD)	THAADS (Tactical High Altitude Area Defense System) Ballistic Missile Defense Office Defense Issues Article	In development based upon the Patriot system, but uses a better ground station for identifying, tracking, and directing defending missiles at inbound tactical or strategic missiles. The THAAD system, unlike Patriot which uses a fragmenting warhead, uses a "hit-to-kill" warhead which intends to destroy the incoming warhead at high altitude so as to diminish or eliminate adverse effects of the warhead's destruction (chemical, biological, and perhaps nuclear).
Navy's Tactical Anti-Missile	LEAP (Light Exoatmospheric Projectile) - A Navy Theater Wide (NTW) system	This Navy Theater-Wide Ballistic Missile Defense (TBMD) system missile is designed to attack incoming warheads outside the Earth's atmosphere prior to (or possibly during) re-entry. This is known as an "upper-tier" system. The system is designed to attack medium to long range ballistic missiles and will be equipped on U.S. AEGIS cruisers which can then be pre-positioned near (and within intercept range) of Tactical Ballistic Missile sites.
Manned Space Attack Vehicle	SCREMAR (Space Control with a REusable Military AiRcraft)	Air Force 2025 whitepaper - a TAV/orbiter capable of carrying a 3,000 pound payload to a low-earth orbit. According to the Air Force whitepaper, the SCREMAR could be modified "by fitting the SCREMAR TAV/orbiter with a weapons system capable of destroying satellites at varied ranges, perhaps a laser or other beam weapon. Also, the SCREMAR TAV/orbiter could simply "capture" the enemy's satellite, take it out of orbit, and bring it back to earth."

Further Reading:

Boost Phase, Directed Energy Program, U.S. Ballistic Missile Defense Office / Missile Defense Agency

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