Траекториясын өзгерте алатын баллистикалық ракеталардың соғыс бөлігі

Ballistic missile whose warhead capable of changing trajectory

The maneuverable reentry vehicle (abbreviated MARV or MaRV) is a type of warhead for ballistic missiles that is capable of maneuvering and changing its trajectory. There are two general reasons to use MARV. One is to make it more difficult to track the reentry vehicle (RV) and thereby make it more difficult to attack as it approaches its target. This was particularly useful against early anti ballistic missile (ABM) systems which took seconds to calculate an interception course. Making random trajectory changes could render these systems useless. This class of MARV is sometimes known as evading MaRVs. The other is to improve accuracy or track moving targets using terminal guidance systems that can act only during the last stages of the flight. This class is sometimes known as accuracy MaRVs. In this case, it is the short range of the active guidance system that demands the RV be able to maneuver, as is the base in the Pershing II active radar homing system. The same systems may also be used to track moving targets like aircraft carriers, which move far enough between launch and approach that there is no way to predict their location and active terminal guidance must be used.

The development of the Soviet A 35 anti ballistic missile system (ABM) system led to work in the United States to consider ways to defeat it. The tri service Advanced Strategic Missile Systems office was formed to study the problem, and several possibilities were immediately evident. One was the use skip glide reentry to extend the range of the reentry vehicle (RV) while flying at lower altitude, which would make it much more difficult to track at the long distances needed for a successful interception. A similar approach was to use air launched ballistic missiles, which flew much shorter distances and much lower altitudes. Another was to add various decoys and radar countermeasures to make the ABM systems fail to track the RV among the decoys, or in a similar way, to use MIRV systems to increase the number of targets beyond what the ABM system might handle.

Interest in evading MARV grew in the late 1970s as part of the wider debate on nuclear warfighting policy. This led the US Navy to develop a simple MARV for their Trident I SLBM, the Mk. 500, or "Evader". This was a simple modification to the existing RV, which "bent" the nose of the RV slightly to the side. This created aerodynamic lift in a single direction, but the RV's overall direction could be controlled by rolling the RV around its long axis. During the terminal approach, the Mk. 500 would continually roll in different directions to create a random path. and paved the way for the Advanced Hypersonic Weapon program's Alternate Re Entry System in the early 2010s, which was later developed into the Common Hypersonic Glide Body hypersonic glide vehicle.