Mid-Air Retrieval

Mid-air retrieval (MAR) is a technique for retrieving a payload descending under a parachute using an aircraft so that it can be returned to a designated location without impact damage.In the 60's and 70's, film canisters from reconnaissance satellites were routinely recovered using MAR.

In 1992, HDT demonstrated tandem parafoil MAR of the Mid-Range UAV under contract to Teledyne Ryan Aeronautical and the U.S. Navy. The program was extremely successful and showed substantial advantages over previous non-gliding systems.In 2001, NASA and Lockheed Martin selected HDT to develop a method for retrieving the Genesis sample return capsule prior to ground impact. Advantages of a MAR system for recovery of Genesis compared to a non-gliding descent to ground impact were:

• Lower installed recovery system weight
• Elimination of the pyrotechnic ground release mechanism
• Avoidance of ground impact

System Description

The Genesis recovery system is a single-stage, slider-reefed parafoil, which relies on a mortar-deployed pilot chute. A system of load lines is added to the normal suspension lines for the purpose of MAR hook engagement and captive carriage loads.

The MAR helicopter subsystem consists of a constant tension winch, a single pole that pivots off of the pilot-side landing skid, a hook-and-release mechanism and rigging to guide the retrieval cable out the door of the helicopter.

Historically, MAR systems have used separate main and target parachutes, with the main parachute being cut away when the engagement network in the target parachute is put under tension.The Genesis system used a single main parachute that contains the load network.The main parachute is of a size that is small enough not to interfere with towing the payload back to the landing pad, yet large enough to present a good engagement target.

The parafoil size determines gliding airspeed, which was chosen based on experience for best MAR safety and reliability. The descent rate determines the number of engagement passes possible from intercept altitude to impact and should be minimized.

The Aerospatiale AS 350B Ecureuil helicopter was used on this MAR system based on safety, cost and cabin configuration.