The Challenger Disaster By Diana Clarke The Orbiter

The Challenger Disaster By Diana Clarke

The Orbiter l l Dimensions: 122’ L x 78’ W x 57’ H Crew size: Up to 8 people Weight: 160, 000 lbs (unfueled) 3 SSME’s - Single engine produces 375, 000 lbs of thrust - 104% thrust (sea level / vacuum): 393, 800 lbf / 488, 800 lbf

The External Liquid Fuel Tank (EFT) l l Fuels the 3 SSME’s Carries liquid hydrogen and liquid oxygen Attached to the bottom of the orbiter Capacity - top portion: 143, 000 gallons of liquid oxygen - bottom portion: 385, 000 gallons of liquid hydrogen

The Solid Rocket Boosters (SRB) l l l Attached to the EFT Most powerful boosters ever built Provide 80% (approx 3. 3 million lbs) of thrust at launch Burn time: 2 minutes Jettisoned after fuel exhaust

Challenger Accomplishments 1 st seven and eight member crews in orbit l 1 st EVA (cargo bay) l 1 st to carry a female astronaut l 1 st night launch and landing l 1 st untethered manwalk from an orbiter l 1 st capture, repair & redeploy of non functioning satellites l 2 nd orbiter to fly in space l

The Crew Francis Scobee (Commander) Michael J. Smith (Pilot) Ronald Mc. Nair (Mission Specialist) Judith A. Resnick (Mission Specialist) Gregory B. Jarvis (Payload Specialist) Sharon Christa Mc. Auliffe (Payload Specialist) Ellison Onizuka (Mission Specialist)

STS – 25 Mission Flight Plan 6 days, 34 minutes l Objectives - Technology - Science - Public education l

Launch Delays l l Original launch date January 22, 1986 Changed to January 23 rd and 24 th - due to previous mission l Reset to January 25 th - bad weather at TAL l Postponed one more day to January 26 th - lift off time not met l Reset to January 27 th - hatch problems/weather concerns l Rescheduled to January 28, 1986 at 9: 38 am

Pre-Launch Concerns 01/28/86 l l l 1: 30 am - Ice formation noted 7: 00 am - Icicles found hanging at launch site 8: 30 am - Crew enters shuttle - 2 hour delay (fire detection system failure) l 9: 00 am – Mission management team meets one last time

The Tragedy l 11: 38 Lift-off (T=0) T+. 678 Puff of smoke T+. 836 and 2. 50 Puffs of smoke darken T+3. 375 Last Puff of smoke is seen T+58. 788 Plume noted T+59. 262 Well-defined plume T+60. 00 Telemetry pressure differential noted

The Tragedy T+64. 660 Flame breaches EFT T+72. 20 Lower strut attaching SRB to EFT severed T+72. 525 Sudden acceleration to the right T+73. 00 Smith, “Uh oh…” T+73. 124 Beginning of structural failure T+73. 162 Vehicle break-up begins

The Tragedy T+79. 00 Smoke and flame captured by TV tracking camera http: //spaceflightnow. com/challenger/video/launch_qt. html

Roger’s Commission l Presidential Commission - Sally Ride, Neil Armstrong, Chuck Yeager and others l Investigation - Cause of failure l Findings - O-Rings - Weather - Ineffective communication l Recommendations - Redesign O-rings - Escape system - Better communication

“All of a sudden, space isn’t friendly. All of a sudden, it’s a place where people can die…Many more people are going to die. But we can’t explore space if the requirement is that there be no casualties; we can’t do anything if the requirement is that there be no casualties” – Isaac Asimov