Nylon, Dacron, Steel,
An Apollo Command Module Main Parachute assembly manufactured by Northup Corporation Ventura Division under subcontract to North American Rockwell, primary contractor for development and integration of the Apollo Command Service Module (CSM) under NASA contract NAS9-150. This parachute flew on-board CSM 117 for 59 days, 11 hours in support of Skylab 3 (Second Manned Mission - SLM-2 which included crew members - Astronauts Alan Bean, Jack Lousma and Owen Garriott) and as one of three Main parachutes provided deceleration of the Command Module during reentry to ensure safe descent velocity suitable for water landing. The design flew on all Apollo CSM spacecraft as part of the CM Earth Landing System, which assured safe landing for two primary landing modes: landing after a completed mission; and landings by means of the launch escape system (LES) from the time the Apollo crew is in the spacecraft prior to take-off to approximately 300,000 feet after second stage booster ignition. The flown artifact in this collection includes a fully intact, uncut Main 83.5 foot main canopy, 7.2 foot Pilot parachute, Deployment / Retention pack and all riser, suspension lines.
This artifact was originally transferred from the Johnson Space Flight Center in 1975 at the conclusion of the Apollo program to the National Air and Space Museum (NASM). NASM determined the parachute was in excess of their requirements and designated it for destruction (along with several others). The owner of a private institution, Mr. Cole Palen of Rhinebeck Aerodrome in upstate New York was offered this parachute (and one other unflown example) in lew of destruction. Just prior to his death in December 1993, the parachute was bequeathed to an employee of the Aerodrome, Mr. Chris Rogine. After a subsequent legal challenge by the Aerodrome, Mr Rogine was determined to be the lawful owner and placed this Apollo Main Parachute up for sale at which point it was acquired into my collection.
The Main Parachute Deployment pack which housed the hard packed parachute under highly compressed form to a density of .0245 lb/cubic inch (packed under vacuum using specially developed Parachute Packing presses) were installed beneath the Apex Cover in the forward compartment of the Command Module. It was restrained during flight with daisy chain retainers on three sides. The retention system connected directly to the deployment bag without intermittent flaps. The Deployment pack incorporates several layers of Dacron felt for heat protection.
The Pilot parachute is a 7.2 foot diameter , 12 gore Ringslot design permanently attached to the Main parachute deployment bag through a steel riser cable (both the Pilot and Main parachute deployment bag remain permanently attached to the apex of the main parachute). The main parachute suspension line is 600 pound nylon cord, 130.4 feet in length and canopy construction is of 1.1 oz per square yard Ripstop nylon. Constructed porosity is 22 percent with a drag area of 24.4 feet squared. A Dacron cover protects a 346.1 inch length fabric riser interconnecting the Pilot parachute suspension line with the 111 inch steel riser. The chute is retained within a mortar tube assembly until deployment and is installed with a sabot placed between the packed chute and the mortar charge to support safe ejection.
The Main parachute is a 83.5 foot diameter conical Ringsail design actively reefed in two stages. Calculated total porosity is 12 percent. The first stage is actively reefed to 8.4 percent diameter (yielding 285 foot squared drag area) and utilizes redundant reefing lines with two 6.0 second pyrotechnically activated reefing line cutters on each line. The second stage is actively reefed to 24.8 percent diameter (yielding 1080 foot squared drag area) and utilizes two 10.0 second reefing line cutters on a single reefing line. When fully disreefed, the Main parachute Drag area is 4200 foot squared). The canopy consists of twelve rings of sails (hence its nomenclature Ring-Sail parachute) with each ring divided into 68 gores and is manufactured with 1.6 oz per yard ripstop nylon (at the crown) and 1.1 oz per yard ripstop nylon (lower gores) The canopy terminates in 68 suspension lines, 1443.9 inches in length which are attached by six 42 inch long steel connector links to six individual legs of a 15.5 inch fabric riser. The six legs of the fabric riser converge into a single leg which connects to the end of a 6 strand 9/32 cres steel cable riser (the steel cable riser, rated for a design load of 31,000 pounds, is not present on this artifact). The steel cable riser is attached to the Command Module through the parachute attachment and disconnect assembly (informally referred to as the "Flowerpot" because of its appearance). The Main canopy incorporated a two stage reefing system retarded canopy inflation during deployment; this was essential to prevent the destruction of the parachutes and reduce the canopy weight. The reefing system incorporated two reefing lines on the first stage, which each line having its individual set of two pyrotechnically actuated cutters (first stage disfreefing occurred 6 seconds after Main canopy deployment); the second stage had only one reefing line with two cutters pyrotechnically actuated 10 seconds after Main canopy deployment.
Links are fabricated from Inconel 718, Dacron protective booties cover the fabric risers on both the Pilot and Main chutes.
Deployment of the Main parachutes commenced at 11,000 after two 16.5 foot diameter ribbon-type mortar deployed drogues stabilized Command Module attitude and provided initial deceleration. Following detachment of the drogues, the Pilot parachute (one affiliated with each Main chute) was mortar deployed simultaneously at 90 degrees to the CM vertical axis, providing the force necessary to release the Main parachute retention system and extract the Main parachute pack assemblies from the Command Module's upper deck (the parachutes were protected during reentry by a forward heatshield Apex Cover which was jettisoned at 24,000 feet). The deployment sequence was controlled by the fully automatic redundant sequencing system with a manual override mode available as back-up system at the astronauts discretion. As the main parachute packs were pulled away from the command module, the parachutes were extracted from their deployment bags. The Main parachute inflated through the two reefing states to the fully open configuration. Collectively, the three main parachute assemblies decelerated the command module to the final descent velocity of 32 feet per second (two parachute descent rate, i.e. in the event one of the three failed to properly deploy resulted in an off nominal but still very survivable 36 fps descent rate as demonstrated with the flight failure of one Main chute during Apollo 15 splashdown).