Encapsulating service module for emergency descent vehicles

An encapsulating service module for constructing a short, compact descent vehicle, comprising:

• an annular-shaped support structure for attachment around a spacecraft module selected from a variety of modules and used primarily to carry a payload during a descent from orbit, the spacecraft module having an aft end defined by a heat shield that remains attached to the spacecraft module during descent through a planetary atmosphere, and a forward end for coupling to a second spacecraft module;
• one or more propellant tanks mounted to the support structure;
• one or more main and reaction control system (RCS) thrusters mounted to the support structure, wherein the one or more main thrusters are mounted to the support structure to produce thrust in an aft direction, to facilitate separation from the second spacecraft module;
• one or more environmental control and life support system tanks mounted to the support structure;
• and
• one or more avionics and battery units mounted to the support structure;
• wherein the one or more propellant tanks, main and RCS thrusters, environmental control and life support system tanks, and avionics and battery units all provide services to the spacecraft module prior to the beginning of a reentry maneuver, but are separated from the spacecraft module, with the support structure, prior to descent of the spacecraft module through the planetary atmosphere.