Shuttle SRB Pilot Line Parachute This (3' diameter) ribbon parachute is deployed once the free-falling Solid Rocket Booster (SRB) reaches an altitude of about 3 miles. The nose cap is jettisoned and the SRB pilot parachute pops open, pulling out the drogue parachute, which stabilizes and slows down the SRB's descent to the ocean. (The SRB's are then retrieved from the Atlantic Ocean by special recovery vessels and returned for refurbishment and eventual reuse on future Shuttle flights.) The parachute bears the following identification numbers: "Part #: 4250-1, Serial #: SS45746, Date of Mfr: Jan 1986". A seldom seen piece of equipment.