Missile maker Raytheon has unveiled a new scramjet-powered weapon designed to minimize the reaction time of enemy air defenses. The unnamed weapon would travel at speeds in excess of Mach 5, or 3,800 miles an hour, blazing past existing anti-air defenses to destroy high-value targets.
Aviation Week & Space Technology first reported on the unnamed weapon, describing it as a “waverider-like missile design powered by a relatively compact booster stage.” The missile design popped up on the Raytheon website as part of a discussion of hypersonic weapon systems, and its appearance coincided with the start of the Paris Air Show.
There are currently two types of hypersonic propulsion: boost glide and scramjets. Hypersonic boost glide weapons such as the AGM-183 ARRW (“Arrow”) are boosted to near-space by ballistic missiles and then glide to their target at eye-watering speeds. Boost glide weapons are essentially unpowered after separation from the missile and glide to their targets.
The other hypersonic propulsion method, scramjets, power Raytheon’s new weapon concept. The weapon has a small booster stage, a conventional rocket motor designed to accelerate the missile fast enough that the scramjet can take over. Like all air-breathing engines, the scramjet takes onrushing air and forces it into a combustion chamber, expelling the exhaust as thrust.
Unlike turbines and ramjets, scramjets are designed to ingest air moving at supersonic speeds, resulting in a great volume of air pushed through. (“Scramjet” is actually short for “supersonic combustion ramjet.”) More air means more fuel, and at least in this design, more fuel means more speed. As a result, engineers believe scramjets are capable of speeds of up to Mach 24.
The Pentagon, scorched by reports that China and Russia were taking the lead in hypersonic weapons, now has several hypersonic weapons under development, both boost glide- and scramjet-powered. In addition to ARRW, which underwent captive carry tests from a B-52 bomber last week, the U.S. Air Force has the Hypersonic Conventional Strike Weapon (HCSW, or “Hacksaw”) and the Navy has a boost glide weapon program. DARPA is developing two hypersonic weapons, Tactical Boost Glide and a scramjet-powered Hypersonic Air-Breathing Weapon Concept (HAWC, or “Hawk”).
Hypersonic weapons are the new frontier in weapon propulsion, promising extremely high-speed atmospheric flight. This allows the weapons to avoid interception by specialized ballistic missile defenses while proving an extremely tough target for existing air defense missile systems.
A Mach 6 missile would travel at more than a mile a second, or 76 miles an hour. That would give many long-range air defense systems just three minutes or less to detect, track, and shoot down a target. Many existing air defense missiles, designed to shoot aircraft and cruise missiles, are likely unable to intercept hypersonic weapons.
Raytheon’s weapon appears similar to another hypersonic weapon program, the X-51A Waverider, that ran from 2004 to 2013. Defense contractor Lockheed Martin built four X-51As, each of which had a top speed of Mach 6 and a range of 400 miles. The Waverider project was ended seemingly without a follow-up to continue development.
In the mid-2010s, just as U.S. hypersonic research trailed off, reports from Russia and China indicated both countries were stepping up their hypersonic weapon research. Earlier this year, a panel of experts declared Beijing the world leader.
The development timeline for Raytheon’s scramjet missile is unknown, but a separate article on the company’s website, last updated in May, says flight tests on hypersonic weapons are expected in two to four years.
Source: Aviation Week & Space Technology