A very vivid dream I had a few nights ago made me remember that this month marks the 31st anniversary of the Challenger accident. Within 6 days from January 27th through February 1 marks where the United States had all three of our tragedies where astronauts lost their lives. January 27th will mark the 50th anniversary of the Apollo 1 fire (and I will be doing research and article about that tragedy), this one will focus on the Challenger accident, and around the 14th anniversary of the Columbia accident (February 1) I will write an article remembering those 7 crew members. This is talking as an writer, but the dream I had about the crew and a conversation I had on Facebook made me realize that I have to dedicate this article to clear up the main misconception about the tragedy, and that was that the crew was killed instantly. The fact that they survived the breakup of the vehicle, but they were conscious in the seconds, after breakup to realize their fate. I will be as respectful to the crew as I possibly can, but I will give you visual evidence that show that the cabin emerged from the fireball intact and the lives of the crew were also spared from the deflagration.
This tragedy may have happened before some of you were born, just in case some of you don’t know about the incident, I will write a synopsis on what happened. Challenger was launched on the coldest day a shuttle was ever attempted (36 degrees at launch), with temperatures reaching a low of 24 degrees before sunrise, Challenger’s atmospheric conditions were cold and extremely windy aloft. There was a jetstream Challenger would punch through with winds around 100 miles per hour that would play a major role in the destruction of the vehicle. The two solid rocket boosters (the white rockets on the side) are sealed with flexible rubber o-rings. The sub-freezing temperatures made the rubber slower to respond and expand from compressed state to fill gap due to pressure from ignition. At launch that slow response let hot gas by both o-rings and burned through, creating dense black smoke (the second picture), the continued until about 3 seconds after launch when the combustion byproduct of the solid propellant sealed the burn through area. This holds until being jarred loose by the combination of being slammed broadside by the jet stream winds and the increasing thrust of the SRBs after going through maximum dynamic pressure. I’ll describe that set of events below, pulled from the Rogers Commission.
“At 58.788 seconds (into the flight), the first flicker of flame appeared. Barely visible (first 2 pictures), it grew to a large plume and begin to touch and have an affect on the External Tank at about 60 seconds. Flame is pinpointed in the computer drawing between the right booster and the tank, as in the case of the earlier smoke puffs. At far right (arrow), vapor is seen escaping from the apparently breached External Tank.”
The first set of pictures shows the evolution of the breach of the liquid hydrogen tank beginning at 64.660 seconds (1 minute, 04.660 seconds) through the complete failure of the liquid hydrogen tank and just before breach of liquid oxygen tank at 73.124 seconds (1 minute, 13.124 seconds). The second set of pictures (the smaller frames) show the entire breakup event from just before liquid hydrogen tank failure, to impact of right SRB to intertank and lower liquid oxygen tank (last 2 top frames) and complete failure of the tank and vehicle breakup begins at middle frame on bottom. TILE 4 on bottom shows front part of the orbiter (crew compartment) emerging from the flames from the now collapsed external tank (74 seconds). The last tile shows the nose becoming separated from the crew compartment and the spillage of the reaction control system propellants at 74.587 seconds (1 minute: 14.587 seconds). The importance of the last 3 tiles shows the crew compartment emerging intact from the hydrogen/oxygen flames. Note that there was no explosion of the vehicle, but a rapid release and burning of fuel from the External Tank.
The following information will be obtained from the July 28, 1986 letter to then NASA Rear Admiral Richard Truly called “How Crew Died According to NASA Study”. I will leave the link to the letter at end of this article, but I will be quoting directly from this letter”. This will help clear up the misconception about the fate of the seven Challenger astronauts. The images used above, well the first one is self explanatory, but the RCS fuel is originating from the separation of the crew cabin which is at the very top of the cloud, just below the solid rocket boosters. The second picture shows the crew compartment (the small object at the top right hand side just above the second main contrail below the big solid rocket booster trail (so third main trail on the right). If you can click on image and make bigger you can definitely see the crew cabin. Bottom pictures show close up during various points of the cabin’s decent.
“The determination of how the astronauts died or when they died could not be positively determined. The forces in which the crew were exposed during the Orbiter breakup was probably not sufficient enough to cause death or serious injury. The crew possibly, but not certainly, lost consciousness in the seconds following Orbiter breakup due to in-flight loss of crew module pressure.” The breakup wasn’t serious enough to injure the crew, but was enough to separate the orbiter from the forward fuselage, cargo bay, nose cone, and forward reaction control compartment.
“The largest acceleration pulse occurred as the Orbiter forward fuselage separated and was rapidly pushed away from the external tank. It then pitched nose-down and was decelerated rapidly by aerodynamic forces.” The letter goes on to say that “the range of most probably accelerations is from 12 to 20 G’s in the vertical axis” (the crew was pushed down violently into their seats). “These accelerations were quite brief. In two seconds, they were below 4 G’s; in less than 10 seconds, the crew compartment was essentially in free fall.” Risk to crew being seriously injured, according to medical analysis, is low.
The accident happened at an altitude of 48,000 feet and continued upwards to 65,000 feet approximately 25 seconds after breakup (11:39:38 a.m./ MET: 01 minute: 38 seconds). The cabin then descended and struck the ocean surface about 2 minutes, 45 seconds after breakup (11:41:58 a.m./MET: 03 minutes: 58 seconds). The impact had a force on the crew and crew cabin approximately 200 G’s, far in excess of the structural limit of the crew compartment or crew survival levels.
Each crew member’s helmet had an Personal Egress Air Pack (PEAP) that had emergency breathing air (not oxygen). Three of the four PEAPs that were recovered were activated. The one that wasn’t activated was Commander Dick Scobee. Pilot Mike Smith’s was activated, which means Onizuka had to activate Smith’s airpack because the activation was located at the back of the Pilot’s seat. These two PEAP’s were identified by the serial number associated with the Pilot and Commander and the other two could not be identified with any crew member.
The crew compartment or classified “Object D” hit the water 207 seconds after launch about 18 nautical miles east of launch pad 39B. Analysis of the crew cabin wreckage indicates the windows may have survived the breakup and loss of cabin pressure may not have occurred. The crew compartment was at an altitude of 48,000 feet or higher for about a minute, and if cabin depressurized, they would have lost consciousness within seconds, even with the emergency air supply, since it wasn’t oxygen. The cabin hit the water nose down in a steep left bank and hit the water on Commander Scobee’s side. The metal posts of the two forward flight deck seats, were bent sharply to the right by force of impact when the cabin disintegrated. (Harwood, William, The Fate Of Challenger’s Crew)
It is known that the site where the crew cabin wreckage was located was given the name “contact 67”, but the site was erased from all public record, even maps to keep from personal salvage from parts of the crew compartment that was not recovered. It was known that the remains of the crew were not intact, which is not surprising due to the violence of water impact due to the speed. The remains that were identifiable were given to the families for burial and the remains that were not identifiable were buried in a communal grave at Arlington National Cemetery.
Hopefully, this article shed some light on the fate of the crew. I will always remember the brave crew of Challenger and I hope they will never be completely lost to history. I hope this article will give them the respectful reminder of the day they gave their lives for the advancement of education and commercial industry. May they rest in peace.
A footnote: on YouTube, if you want to watch the launch attempt on January 27, 1986, it’s available on YouTube. It was interesting that the launch attempt that day the temperature was around 40-45 degrees. There was heavy frost and ice on the tank that was eventually burned away once the overcast burned away.