Requirements:
Lower payload at a rate
that will avoid damage at impact
Deploy reliably at any payload
orientation
Have mission failure modes
(Deploy early if boost phase is aborted)
Adhere to FAA regulations
concerning our launch (deploy below 20,000 ft.)

Description:

The SRP4 2-stage parachute recovery system consists of a 6 ft guide surface drogue and a 33 ft main cross parachute designed to recover a 75-lb to 150-lb sounding rocket payload. The recovery system is deployed from the aft end of 3-ft long payload tube with a 14-in diameter secured to a 4:1 ogive nose cone for a total payload length of 92-in. At approximately 65km on the descent the payload section is separated from the Orion rocket motor using a pyrotechnic device yet to be determined. The payload then tumbles orflat-spins during reentry to gain maximum passive aerodynamic deceleration prior to deploying the parachute recovery system. At 20,000 ft, a barometric pressure switch will send an electrical signal to two Holex 2900-1 pyrotechnic thrusters to break shear pins on the parachute canister to jettison drag plates to extract and deploy the drogue parachute. The drogue parachute will fly for 10 seconds to stabilize and further decelerate the payload prior to deploying the main cross parachute. Drogue deployment will pull pins to mechanically activate the 10-second pyrotechnic charge of the Technical Ordnance pyrotechnic pencil cutters on the drogue staging bridle. After 10 seconds, the pencil cutters will fire to sever thestaging bridle drogue parachute drag to extract and deploy the main cross parachute. The main cross parachute will then be deployed for inflation with or without skirt reefing using another two 750-lb Technical Ordnance pencil cutters. The cross parachute will stabilize the payload for descent from to touch down. Total rocket flight time is approximately 30 minutes from launch to touch down under the main parachute. Time to apogee is approximately 2.5 minutes. Payload free-fall reentry time from apogee to parachute recovery system deployment at 20,000 feet is approximately 4 minutes. Time of payload descent under the main parachute from the deployment altitude of 20,000 ft to touch down is approximately 19 to 23 minutes for a payload weight range of 100- lb to 150-lb. Final payload weight may be lower than 100-lb, this figure was chosen as aconservative estimate. This recovery system was successfully drop tested from an Air Force C-130 in 1997 and qualified as flight worthy hardware for launching on a NASA sounding rocket from Poker Flat Research Range. This parachute recovery system will fly on the Orion 30.047UP mission to recovery the sounding rocket payload with its science mission instruments.