Little Bits of History


Posted in History by patriciahysell on January 28, 2012

Challenger explosion

January 28, 1986: At 11:38:00.010 the space shuttle Challenger hits T=0 or liftoff. Later review showed a puff of black smoke issued from the right SRB (Solid Rocket Booster) at T+0.678. The last smoke puff was seen at T+2.733. The smoke dissipated by T+3.375. At T+28 the engines throttled back to limit velocity in the dense lower atmosphere. At T+35.379 they throttled back further to 65%. At T+51.860, after passing through Mach 1 speed, the engines throttled back up. All was going as planned. The shuttle passed Max Q, the period of maximum aerodynamic pressure. Just as it passed through, it encountered the greatest wind shear experienced to date.

At T+58.788 a tracking camera spotted a plume on the right SRB. At T+60.238 flame was visible near the plume. At T+64.660 the plume’s shape changed indicating a liquid hydrogen leak. At T+68 both astronauts and ground control were preparing to “throttle up” and all were unaware of any problem. At T+72.284 the right SRB pulled away from the strut. At T+72.525 the shuttle accelerated to the right at an angle and force unprecedented and unsupported by the engineering of the craft. At T+73.124 the aft dome of the liquid hydrogen tank failed. At T+73.162 the shuttle disintegrated.

The crew consisted of Michael J. Smith (pilot), Dick Scobee (commander), Ronald McNair, Ellison Onizuka, Gregory Jarvis, Judith Resnik, and winner of the Teacher in Space, Christa McAuliffe. By the time of the launch, space shots were common. With the addition of the civilian teacher as one of the crew, many jaded Americans once again tuned in to watch the launch, televised extensively. Within an hour, 85% of Americans knew the Challenger and all her passengers were gone.

President Reagan formed a special group, the Rogers Commission, to investigate the disaster. All further launches were put on hold and it was 32 months before Americans once again flew to outer space. The Commission’s findings pointed to a faulty O-ring. The flaw was first found in 1977 but was not properly addressed. NASA also failed to heed the warnings of engineers concerning launches on cold days. Both factors led to the catastrophe.

Sometimes, when we reach for the stars, we fall short. But we must pick ourselves up again and press on despite the pain. – Ronald Reagan

I took this stuff that I got out of your seal and I put it in ice water, and I discovered that when you put some pressure on it for a while and then undo it, it does not stretch back. It stays the same dimension. In other words, for a few seconds at least and more seconds than that, there is no resilience in this particular material when it is at a temperature of 32 degrees. – Richard Feynman

The Committee feels … the fundamental problem was poor technical decision-making over a period of several years by top NASA and contractor personnel, who failed to act decisively to solve the increasingly serious anomalies in the Solid Rocket Booster joints. – U.S. House Committee on Science and Technology

I touch the future. I teach. – Christa McAuliffe

Also on this day:

Beautiful Snow – In 1887, the largest snowflake on record was found.
Serendipitous Find – In 1754, Horace Walpole coined a new word.
Lighting the Night – In 1807, the first street was lit by gas light.

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