Drogue parachutes
Apart from using parachutes to slow down prior to landing as used for capsules, spaceplanes use brake chutes as an auxiliary deceleration system, next to or additionally to wheel brakes and/or aerodynamic decelerators. Brake chutes are more commonly used on high-speed military aircraft such as the SR-71, F-4, B-52, F-16 etc. These systems are used when the runway length does not match the landing velocity or breaking capacity of the aircraft. For example, the Norwegian F-35s are equipped with a brake chute to help them slow down on the icy runways.
Land speed record vehicles commonly also use brake chutes to decelerate, such as the Bloodhound LSR for example. The space shuttle and Buran space planes both used brake chutes to decelerate during landing.
Space shuttle
During the first five years of its service, the space shuttle orbiter decelerated on the landing runway using its brakes and aerodynamic decelerators. In 1986, it was decided to include a drag chute to the tail section of the space plane to reduce tire wear, landing gear loads, and add redundancy if the brakes would fail. The drag chute was deployed after the aft landing gear touched the ground and released before standstill.
The task of designing the parachute system was allocated to Irvin Industries. The brake chute of the SR-71 reconnaissance plane was chosen as a baseline because of the similar landing conditions to the shuttle. This variable porosity conical ribbon (VPCR) parachute is extracted from its canister with a smaller, mortar-deployed pilot chute. Several adjustments were made to the SR-71’s drag chute design, for example, the use of Kevlar instead of nylon for the radial ribbons and suspension lines.
The testing program of the parachute included wind tunnel testing, flight tests onboard a B-52 aircraft and a pilot-in-the-loop flight simulator. The wind tunnel tests were required to make sure that the parachute is outside of the space shuttle’s wake and thereby determined the minimum parachute riser length. Some instabilities of the parachute were observed, leading to the removal of several ribbons.
On the first flight with the brake chute, the shuttle experienced a higher-than-expected pitching moment upon deployment of the brake chute, causing the shuttle to skid on the runway. In order to reduce the opening loads, a single-stage reefing system was included.
The space shuttle’s parachute design served as a reference for drogue chutes of future missions such as the Kistler K-1, Orion and starliner capsule drogue chutes for example [5,6].
Buran
The Buran program was an endeavour by the USSR to develop a vehicle with similar capabilities to the US space shuttle. Three split arm cross parachutes were used to slow down the orbiter on the runway. These parachutes were modified versions of existing high-performance fighter jet drag chutes. The Buran spaceplane only flew to space for the first and last time in 1988. [7,8]
Civil aircraft
it is not a very common site to see a parachute behind a civilian aircraft. However there are actually quite some examples. The most famous are the European Sud Caravelle and the Russian TU-104. Other examples include the Tu-124. These are the only two large passenger aircraft that have used such parachutes. Some other smaller aircraft such as the Learjet 25, Learjet 35 and Dassault Falcon 20 have a parachute either for short runways or as a backup parachute.
These parachutes are used when the landing speed is too high for the runway and the aircraft either cannot brake or does not have thrust reversers. These parachutes have to be folded after each flight thus making them quite an operationally heavy system. Most of these business jets only have the parachute installed for situations where the hydraulics would fail and are not to be used in normal operations.
