Space Shuttle Challenger OV-099


Space Shuttle Challenger (NASA Orbiter Vehicle Designation: OV-099) was NASA's second Space Shuttle orbiter to be put into service, Columbia being the first. Its maiden flight was on April 4, 1983, and it completed nine missions before breaking apart 73 seconds after the launch of its tenth mission, STS-51-L on January 28, 1986, resulting in the death of all seven crew members. The accident led to a two-and-a-half year grounding of the shuttle fleet, with missions resuming in 1988 with the launch of Space Shuttle Discovery on STS-26. Challenger itself was replaced by the Space Shuttle Endeavour, which first launched in 1992. Endeavour was constructed from spare parts originally meant for Challenger and the other shuttles in the fleet.

Challenger was named after two previous vessels: HMS Challenger, a British corvette that was the command ship for the Challenger Expedition, a pioneering global marine research expedition undertaken from 1872 through 1876; and the Apollo 17 lunar module Challenger, which landed on the Moon in 1972.[2]
[edit] Construction

Because of the low production of orbiters, the Space Shuttle program decided to build a vehicle as a Structural Test Article, STA-099, that could later be converted to a flight vehicle. In order to prevent damage during structural testing, qualification tests were performed to a factor of safety of 1.2 times the design limit loads. The qualification tests were used to validate computational models, and compliance with the required 1.4 factor of safety was shown by analysis.[3]

NASA planned to refit the prototype orbiter Enterprise (OV-101), used for flight testing, as the second operational orbiter. However, design changes made during construction of the first orbiter, Columbia (OV-102), would have required extensive rework. Because STA-099's qualification testing prevented damage, NASA found that rebuilding STA-099 as OV-099 would be less expensive than refitting Enterprise.

Challenger (and the orbiters built after it) had fewer tiles in its Thermal Protection System than Columbia. Most of the tiles on the payload bay doors, upper wing surface, and rear fuselage surface were replaced with DuPont white nomex felt insulation. This modification allowed Challenger to carry 2,500 lb (1,100 kg) more payload than Columbia. Challenger was also the first orbiter to have a head-up display system for use in the descent phase of a mission.
[edit] Flights and modifications

After its first flight in April 1983, Challenger quickly became the workhorse of NASA's Space Shuttle fleet, flying far more missions per year than Columbia. In 1983 and 1984, Challenger flew on 85% of all Space Shuttle missions. Even when the orbiters Discovery and Atlantis joined the fleet, Challenger remained in heavy use with three missions a year from 1983 to 1985. Challenger, along with Discovery, was modified at Kennedy Space Center to be able to carry the Centaur-G upper stage in its payload bay. Had STS-51-L been successful, Challenger's next mission would have been the deployment of the Ulysses probe with the Centaur to study the polar regions of the Sun.

Challenger's many spaceflight accomplishments included the first American woman, African-American, and Canadian in space; three Spacelab missions; and the first night launch and night landing of a Space Shuttle. Challenger was also the first space shuttle to be destroyed in an accident during a mission. The collected debris of the vessel are currently stored in decommissioned missile silos at Cape Canaveral Air Force Station. From time to time, further pieces of debris from the orbiter wash up on the Florida coast.[4] When this happens, they are collected and transported to the silos for storage. Because of its early loss, Challenger was the only space shuttle that never wore the NASA "meatball" logo.

# Date Designation Launch pad Landing location Notes Mission duration
1 April 4, 1983 STS-6 LC-39A Edwards Air Force Base Deployed TDRS-A.

First spacewalk during a space shuttle mission.
5 days, 00 hours, 23 minutes, 42 seconds
2 June 18, 1983 STS-7 LC-39A Edwards Air Force Base Sally Ride becomes first American woman in space.

Deployed two communications satellites.
6 days, 02 hours, 23 minutes, 59 seconds
3 August 30, 1983 STS-8 LC-39A Edwards Air Force Base Guion Bluford becomes first African-American in space

First shuttle night launch and night landing.
Deployed Insat-1B.
Carried 260,000 envelopes stamped to commemorate the 25th Anniversary of NASA.
6 days, 01 hours, 08 minutes, 43 seconds
4 February 3, 1984 STS-41-B LC-39A Kennedy Space Center First untethered spacewalk.

Deployed two communications satellites, unsuccessfully.
7 days, 23 hours, 15 minutes, 55 seconds
5 April 6, 1984 STS-41-C LC-39A Edwards Air Force Base Solar Maximum Mission service mission. 6 days, 23 hours, 40 minutes, 07 seconds
6 October 5, 1984 STS-41-G LC-39A Kennedy Space Center First mission to carry two women.

Marc Garneau becomes first Canadian in space.
Kathryn D. Sullivan becomes first American woman to make a spacewalk.
Deployed Earth Radiation Budget Satellite.
8 days, 05 hours, 23 minutes, 33 seconds
7 April 29, 1985 STS-51-B LC-39A Edwards Air Force Base Carried Spacelab-3. 7 days, 00 hours, 08 minutes, 46 seconds
8 July 29, 1985 STS-51-F LC-39A Edwards Air Force Base Carried Spacelab-2. 7 days, 22 hours, 45 minutes, 26 seconds
9 October 30, 1985 STS-61-A LC-39A Edwards Air Force Base Carried German Spacelab D-1.

Wubbo Ockels becomes the first Dutchman in space
7 days, 00 hours, 44 minutes, 51 seconds
10 January 28, 1986 STS-51-L LC-39B Did not land (Planned to land at Kennedy Space Center). Shuttle disintegrated after launch, killing all seven astronauts on board. Was to have deployed TDRS-B. 0 days, 00 hours, 01 minute, 13 seconds

Challenger was destroyed as it broke up in mid-flight in the second minute of its tenth mission, on January 28, 1986 at 11:38:00 a.m. Eastern Standard Time.[5] The break up was ultimately due to the failure of an O-ring on its right solid-fuel rocket booster (SRB). The O-rings are used to seal the joints between the multiple segments of the SRBs. The failure was due to a variety of factors, including unusually low temperatures prior to liftoff.[6] The failure allowed a plume of flame to leak out of the SRB and impinge on both the external fuel tank (ET) and the SRB aft attachment strut. This caused both structural failure of the ET, and pivoting of the SRB into the orbiter and ET. Damage near the bottom of the ET resulted in the complete loss of the aft dome of the lower tank and a rapid release of hydrogen, creating a forward thrust of about 2.8 million pounds and pushing the tank up into the intertank structure which connects the liquid hydrogen tank and liquid oxygen tank. This was followed by an almost explosive burning of the hydrogen combined with oxygen leaking from the intertank. Challenger's reaction control system then ruptured, resulting in the burning of its hypergolic propellants. The orbiter, traveling at about Mach 1.92, was forced into an attitude that caused it to endure extreme aerodynamic loads, with the resulting stresses causing it to break apart.
All seven crew members died in the disaster. Christa McAuliffe, who was selected to be the first teacher in space, was one of the crew members of this mission.


Ladies and Gentlemen, I'd planned to speak to you tonight to report on the state of the Union, but the events of earlier today have led me to change those plans. Today is a day for mourning and remembering. Nancy and I are pained to the core by the tragedy of the shuttle Challenger. We know we share this pain with all of the people of our country. This is truly a national loss.

Nineteen years ago, almost to the day, we lost three astronauts in a terrible accident on the ground. But, we've never lost an astronaut in flight; we've never had a tragedy like this. And perhaps we've forgotten the courage it took for the crew of the shuttle; but they, the Challenger Seven, were aware of the dangers, but overcame them and did their jobs brilliantly. We mourn seven heroes: Michael Smith, Dick Scobee, Judith Resnik, Ronald McNair, Ellison Onizuka, Gregory Jarvis, and Christa McAuliffe. We mourn their loss as a nation together.

For the families of the seven, we cannot bear, as you do, the full impact of this tragedy. But we feel the loss, and we're thinking about you so very much. Your loved ones were daring and brave, and they had that special grace, that special spirit that says, 'Give me a challenge and I'll meet it with joy.' They had a hunger to explore the universe and discover its truths. They wished to serve, and they did. They served all of us.

We've grown used to wonders in this century. It's hard to dazzle us. But for twenty-five years the United States space program has been doing just that. We've grown used to the idea of space, and perhaps we forget that we've only just begun. We're still pioneers. They, the members of the Challenger crew, were pioneers.

And I want to say something to the schoolchildren of America who were watching the live coverage of the shuttle's takeoff. I know it is hard to understand, but sometimes painful things like this happen. It's all part of the process of exploration and discovery. It's all part of taking a chance and expanding man's horizons. The future doesn't belong to the fainthearted; it belongs to the brave. The Challenger crew was pulling us into the future, and we'll continue to follow them.

I've always had great faith in and respect for our space program, and what happened today does nothing to diminish it. We don't hide our space program. We don't keep secrets and cover things up. We do it all up front and in public. That's the way freedom is, and we wouldn't change it for a minute. We'll continue our quest in space. There will be more shuttle flights and more shuttle crews and, yes, more volunteers, more civilians, more teachers in space. Nothing ends here; our hopes and our journeys continue. I want to add that I wish I could talk to every man and woman who works for NASA or who worked on this mission and tell them: "Your dedication and professionalism have moved and impressed us for decades. And we know of your anguish. We share it."

There's a coincidence today. On this day 390 years ago, the great explorer Sir Francis Drake died aboard ship off the coast of Panama. In his lifetime the great frontiers were the oceans, and a historian later said, 'He lived by the sea, died on it, and was buried in it.' Well, today we can say of the Challenger crew: Their dedication was, like Drake's, complete.

The crew of the space shuttle Challenger honoured us by the manner in which they lived their lives. We will never forget them, nor the last time we saw them, this morning, as they prepared for the journey and waved goodbye and 'slipped the surly bonds of earth' to 'touch the face of God.'

Thank you.

President Ronald Reagan - January 28, 1986

we remember you always