Acronym for Fuel And Sensor Tactical (FAST) Packs. Many FAST Packs are built in form factor (conformal) sections to reduce negative effects on variable fighter aerodynamics but some FAST Pack systems are specifically designed for use in space only. Other FAST Packs may be trans-atmospheric and serve different functions (example, YF-19 and YF-21). Virtually all FAST packs are designed with a blow-away capability allowing spent sections to be instantly ejected from the variable fighter either by the pilot or automatically by the onboard computer. While primarily adding fuel and sensor hardware, a large number of FAST packs also provide additional missile or beam weaponry. As time went on, many FAST Pack systems were described using different nomenclature when the acronym no longer accurately detailed the equipment function. Terminology such as Super Packs/Super Parts are often used as well as Boosters/Trans-atmospheric Boosters, or combination of both.