********************************* CHAPTER X *********************************
=============================================================================
*******************************  THE ACCIDENT  ******************************


     In an attempt to keep frigid temperatures from causing pipes to freeze 
up before the launch, water was allowed to run slowly through the system 
pipes.  Despite this, large amounts of ice formed below the 240 foot level of 
the service structure and in the water trays below the Shuttle.

     Ice covered much of the launch tower and there was significant concern 
over the potential for damage from falling ice debris during the launch.  
There was concern that large pieces of falling debris could damage the 
vehicle's structure when it was shaken loose at liftoff.  The heat and 
concussion of the blast, as well as the suction of air by the solid rocket 
ignition, caused much consternation over launch timing.  Evidence from 
previous flight data indicated that debris had been sucked into the SRBs 
after ignition but there wasn't data for such extremely icy launch conditions.

     About a half inch of water was found in the clevis joint of the STS-9 
when the pin was removed prior to restacking.  This resulted from less rain 
than was experienced prior to the STS 51-L launch.  Water in the joints turns 
to ice at low temperatures and the joint temperature at launch time for the 
51-L was in the area of 28 degrees plus or minus 5 degrees F.  Failure had 
occurred in O-rings during testing under certain conditions when ice was in 
the joints.  Tests conducted after the accident confirmed that putty sealing 
qualities varied with temperature.  Lower temperatures also delayed sealing 
during the pressure actuation of the O-rings which were less flexible at low 
temperatures.

     Ambient temperature restrictions forbade launch below 31 degrees F and 
this policy had never been violated.  On Monday, January 27th, Thiokol's 
Engineering Vice President, Bob Lund, presented conclusions and 
recommendations that launching should not occur below 53 degrees F.  Thiokol 
engineers considered launch unsafe at lower temperatures because the O-rings 
and putty seals presumably would be stiffer and less elastic at lower 
temperatures.  In January 1985, the 51-C flight suffered extensive erosion.  
There was an 80 degree arc of black grease between the O-rings of the left 
solid rocket booster, and a 110 degree arc of black grease between the 
O-rings on the right solid rocket booster.  The colder temperatures appeared 
to account for the slower sealing of the O-rings which allowed escaping hot 
gasses to damage or destroy the O-rings.  This condition could then 
compromise the secondary seal.  This was the argument presented by Mr. 
Boisjolly on behalf of the Thiokol engineers.

     It was argued by Marshall management that there had been blow-by during
flights with higher launch temperatures, but Boisjolly maintained that the
engineering conclusions were based on more severe damage having occurred 
during lower temperature launches.  The 51-C flight in 1985 had experienced a 
degree and type of O-ring erosion not found on other flights.  Under pressure 
to launch, the attempt to set the lowest safe temperature for launch at 53
degree F was discarded by Marshall, although Thiokol engineers had been 
unanimous in their no-go decision.  Management alleged that there was 
sufficient margin of error in the secondary seal, arguing that the secondary 
seal would compensate for blow-by if the primary seal were to fail.  It had 
been normal operating procedure for teams to prove that they were prepared 
for a launch but, contrary to policy, this time they tried to dissuade 
Thiokol engineers from trying to establish the 53 degree F base.

     Plans for launching from Vandengerg, where morning temperatures were
frequently below 53 degrees F were mentioned.  Had the launch been delayed 
until the ice melted, Casablanca could not have been used as an abort sight 
because it had no lights and Dakar's weather, on the morning of the 28th, was 
not good.  Lacking air breathing engines, the Shuttle had to have an adequate 
emergency landing sight.  Also, the ASTRO Halley's mission would undoubtedly 
be delayed if a launch did not occur on or before January 28th.

     Shirley Green was the agency's Director of Public Affairs.  She was a
political appointee who had been employed by Vice President Bush for seven 
years.  Her current job entailed keeping Larry Speakes and Pat Buchanan 
abreast of NASA's newsworthy activities.  Because she informed Rusty Brashear 
at the White House of the flight's postponement until the day of Reagan's 
State of the Union address, there has been much speculation about whether the 
White House put pressure on NASA to launch so that the president could refer 
to the teacher in space, Christa McAuliffe, in his message.  He had a dismal 
record in education and needed a public relations event to bolster his image.  
During his re-election campaign, he had announced that the first "ordinary" 
citizen to be sent aloft in the Shuttle would be a teacher.

     "While the Shuttle lifts off, all of America will be reminded of the
     crucial role that teachers and education play in the life of our 
     nation.  I can't think of a better lesson for our children and our 
     country."
     **** Ronald Reagan, August 27, 1984 ****

     The presidential commission, created by Executive Order #12546 which
investigated the Challenger accident, was run by Richard Nixon's former 
Secretary of State, William P. Rogers.  Rogers had been Attorney General 
during the latter part of the Eisenhower presidency and was, at the time of 
the accident, a law partner with the Rogers and Wells law firm in New York.  
Rogers and Wells had represented Lockheed Aircraft who was under contract to 
process the Shuttles at the time of the accident.  As Nixon's Secretary of 
State and close friend, Rogers had been asked by Nixon to order the 
resignations of John Erlichman and Bob Haldeman during the Watergate scandal.  
Rogers refused to do it.  After the Challenger accident, the image of the 
U.S. as the world leader in space travel was on the line and the public 
wanted some answers.

     The commission used three primary sources of data from which it analyzed 
the accident.  These were launch photographs, telemetry and tracking data, as 
well as recovered pieces of the Shuttle wreckage.  The commission explored 
several possible explanations for the accident.  Among these were structural 
failure caused by over heating due to an abnormal trajectory, loss of the 
thermal protection system, a liquid hydrogen leak from the External Tank, and 
a hot gas leak from the Solid Rocket Motor.  The Commission failed to find 
any loss of the thermal protection foam during either the launch or the 
ascent and therefore concluded that it was improbable that a liquid hydrogen 
tank leak had occurred.  It was determined that hot gases had leaked from the 
O-ring failure to the seal the joint, but they could only conjecture as to 
the precise cause of the failure.  The conclusion of the Rogers Commission 
was that Thiokol Management had reversed its no-launch position due to 
urgings from Management at Marshall "in order to accommodate a major 
customer".
     
     A tremendous surge of power is built up before the lift off of the 
Shuttle and it is temporarily held in check with hold down bolts.  This
initial burst of energy bends, twists, and shakes the rockets with vibrations
that roll up and down them at a rate of about three cycles per second until
they are released in a burst of elastic tension.  At this moment the rocket
casings become more elliptical and the point at which this is most pronounced
is at 045-315 degrees on the outside of the right SRB and its mirror image on 
the left SRB.  There are tremendous stresses on the joints, and at the point
where the struts attach the boosters to the external tank this increases 
joint rotation.

     The engines were first throttled up to 100% at lift off and then up to 
104% after clearing the tower.  The Challenger underwent a programmed roll 
maneuver and the engines were throttled back to 94% to help reduce maximum 
aerodynamic load.  The procedure, while the Shuttle is blasting into the 
atmosphere, is for the rockets to ignite, accelerate and then slow down 
before another thrust brings the spacecraft to maximum Q, or the moment of 
greatest stress, which is about the point at which it blew up.  The 
Challenger was 73 seconds into its flights, about 19 miles up and traveling 
over mach 2 at about 1,800 feet per second when the computer screens at 
mission control in Houston, froze with an "S" for static.  This ended the 
24th flight in the Shuttle program.

     The Challenger's starboard booster had suffered a sudden unscheduled 
drop in power 10 seconds before the explosion.  The right hand solid rocket 
motor dropped 30 pounds per square inch, which meant a loss of about 85,000 
pounds of thrust.  The rockets had to stay synchronized in the initial stages 
of flight or the phenomenon referred to as pogo would occur.  Pogo is the 
term which refers to the shaking effect on the entire stack of rocket stages 
when the rockets fail to fire in synch during vertical flight.  At around the 
same time as the pressure drop occurred, the Shuttle had encountered the most 
violent windshear ever experienced by a Shuttle launch.

     The Shuttle continued on a normal trajectory even after a flame from the
Solid Rocket Motor was detected by photographic monitoring at 58 seconds 
after launch.  From information telemetered during flight, there is no 
indications of any abnormal engine conditions occurring in the liquid fuel 
engine prior to a drop in engine fuel tank pressure at 72.56 seconds.  The 
control system automatically opened the fuel flowrate valve when pressure 
dropped in the engine.  A leaner mixture, which resulted from the pressure 
drop, increased the turbine temperatures.  Heating remained within the design 
limits of the tank structural components at 73 seconds and maximum 
aerodynamic heating would normally not be reached until about 90 seconds.

     A white cloud appeared near the side of the external tank at 73.175 
seconds, followed a fraction of a second later by a flash between the orbiter 
and the hydrogen portion of the external tank.  Following this, there was an 
explosion near the nose of the right SRB where it appears to have crashed 
into the external tank.  This occurred as the aft portion of the tail of the 
right SRB was swinging away from its attach point.  Hot gas, at around 5,600
degrees F, is believed to have melted a hole in the half inch steel case of 
the rocket segment and burned a hole in the liquid hydrogen tank.

     The SRBs received tremendous jolts when the accident occurred and they
continued to burn as they descended into the Atlantic.  Any harm that 
occurred to the right hand SRB, which showed some initial damage at launch, 
may have been accelerated after such a shock.  That the right hand rocket
motor was damaged at the point where hot gases leaked was to be expected.  
But to counter the slipstream and blow at an angle sufficient to torch the
external tank would require a rather massive breach to have occurred before
the blowup.  There is some indication for this in the debris which was 
recovered from the ocean offshore from Cape Canaveral.  This may, though,
have accelerated after the blowup.  Near the 307 degree position of the aft
field joint, on the recovered portion of the Solid Rocket Booster, there was
extensive burn damage.  Most of the insides of the casings which were 
recovered had some unburned propellant still in tact.  The burn pattern was
star shaped, which is normal in a forward segment of the casing.  The 
recovered casing pieces showed normal hardness, and no cracks were found in
any of the recovered propellant.  Video and photographic evidence showed that
the SRBs remained in tact until the explosion, with the exception of the 
right hand SRB field joint leak.

     It was thought that icicles may have broken a tile during launch.  Also,
before the launch, a derrick on the 39-B launch tower struck one of the three
attach points of the tank on the 12 story tall Challenger driving a bolt an 
inch into the insulation.  No x-rays were made of the underlying metal before 
liftoff.  One theory concerning this incident is that the struts, which 
connect the external tank to the orbiter, are thought to have broken when the 
derrick struck.  Television monitoring gave no indication of debris having 
hit the hydrogen tank at liftoff.

     No subsequent flight data indicated any structural loads had exceeded 80
percent of the Shuttle's design limitations during liftoff or during the 
flight before the explosion.  Sabotage was considered as a possibility, 
partially due to other accidents to missiles which occurred about the same 
time, but no evidence has emerged.

     At the time of the Challenger launch, atmosphere in the region could be
assumed to be highly electrically charged, due to several events then 
occurring.  First, the sun was at a low point in solar activity.  This means 
that the amount of cosmic radiation entering the atmosphere was at a peak.  
The accident occurred near the second day after a full moon, which is when 
lightning storms are at a statistical high, and it occurred in the region of 
the United States that receives the highest number of electrical storms of 
any part of the country.  There was a full moon at 7:35 P.M. EST on the 25th 
of January, 1986.

     The main source of energy that creates lightning by ionizing the 
ionosphere and electrifying the earth's atmosphere, comes from outer space.  
Due to a diminished atmosphere cosmic ray bombardment is more intense during 
lows in sunspot activity, and 1986 was a low point in the solar cycle.  While 
there are frequent observations in the Antarctic of the thinning of the ozone 
layer, there have been few such observations in the Arctic.  In May of 1988, 
at a meeting of the American Geophysical Union, W.F.J. Evans, an atmospheric 
physicist for the Canadian Department of the Environment, described a 1,500 
mile ozone crater which occurred between January and March of 1986 over the 
Arctic region.  This would seem to imply that sunspot activity was at an 
extreme low.

     The time of the Challenger accident coincided with the same lunar/solar
position that had occurred at the time of the Grissom, White and Chaffey 
accident 19 years earlier.  The events were in coincidence with the period of 
lunar/solar repetitions known as the Cycle of Meton.  This suggests that the 
reason for the fire in the Grissom, White and Chaffey capsule, and the 
Challenger accident, may have been the result of environmental electricity.

     Like a condenser, the ionosphere controls the interchange of electricity
between the earth and the atmosphere.  The earth's surface is negatively 
charged and the atmosphere is positively charged.  The atmosphere is a porous 
insulator between the earth and the ionosphere and an average difference of 
about 300,000 volts exists between them.  The potential gradient, or 
difference in electrical potential, which occurs in fair weather, varies in 
direct relation to the earth's proximity to the sun.  It reaches a maximum of 
about 20% above average in January, when the earth is at perihelion, and 
about 20% below average in July, when the earth is at aphelion.  The 
eccentricity of the earth's orbit is 0.017, which comes very close to a 
circle, but this small deviation is sufficient to cause significant 
variations in the amount of solar radiation which is received by the earth.  
It has been observed that the effects of the solar wind are greater when the 
region that is affected is toward the sun, which means that the atmosphere 
has the least amount of protection at about noon.  The Shuttle exploded at 
11:39 and 13 seconds.  Halley's comet was then just behind the sun's corona 
and approaching what would be its greatest elongation.  This would make the 
comet a linear particle accelerator longer than the distance between the 
earth and the sun.  The interactions then taking place between the comet and 
the sun are beyond the scope of this work, but whether the comet diverted 
solar energy, managed to send cosmic radiation back through the sun's coronal 
lense toward the earth's magnetosphere, or created bursts of solar activity, 
there is a significant coincidence in timing.  It would appear to be an 
effect which parallels what occurs during solar conjunctions with the 
Pleiades.  The volcanic and earthquake activity which occurs when the sun 
lies between the earth and the sidereal position of the Pleiades implies that 
the sun is acting as a kind of lense.

     The altitude at which the Challenger blew up is the altitude to which 
the cosmic radiation usually penetrates and forms the densest layer of 
charged particles.  At about this height, the troposphere meets the 
stratosphere.  It is from this altitude that the temperature of the upper 
atmosphere begins to rise from radiation induced activity.  Above around 11 
miles up in the atmosphere, cosmic rays collide with neutral particles of air 
and produce ions that conduct electricity.  The earth is shielded from this 
deadly radiation by the atmosphere and the further up one goes the more 
electricity the atmosphere conducts.  This is a highly charged region in the 
afternoon.  In Florida, the ozone density tends to increase from about 9-1/2 
miles above the ground and tends to decrease again at about 20 miles up under 
normal conditions.  Normally the greatest density of ozone would occur just 
above the tropopause at about 12 to 18 miles high.  Radar data indicates that 
the Challenger broke up at about 104,000 feet, which is 19.7miles. 
(_Challenger:  The Final Voyage_ , page 31.)

     When an aircraft travels through the atmosphere, it collects a charge by 
a process of electrostatic induction and atmospheric friction.  When 
sufficient voltage difference occurs between the metal aircraft and the 
atmosphere for ion collisions to cause particles of air to be luminous, brush 
discharge or corona often occurs.  This is popularly called St. Elmo's fire.  
The region in which the aircraft is traveling as well as its speed and size 
determine the amount of charge which is built up.  The dynamics of the 
Shuttle design are such that a large charge would be built up on its 
structure because of its large size and great speed.  This is what did in 
fact occur at 45 seconds into the flight when three bright flashes appeared
downstream of the Challenger's right wing.

     St. Ermo or St. Erasmus was the patron saint of Mediterranean sailors.  
St. Elmo's fire, which appears as slow electrical discharges, is evidence of 
a strong difference of electrical potential between the atmosphere and the 
glowing object, and often indicates a rapid buildup of electrostatic force 
which precedes lightning strikes.  An aircraft which travels through 
particles of moisture or dust in the air becomes charged from friction.  A 
charge can also be induced when an aircraft flies near a heavily charged 
region such as a thunder cloud.  The larger the aircraft width and the 
greater its speed the greater the charge that can build up.  If an aircraft 
has a fuel leak this can ignite the vapors.  There should still have been 
tiny particulate dust and water vapors in the region from the eruption of the 
Columbian Nevado Del Ruiz volcano which would be highly charged and this 
could also have been a factor contributing to the cold weather.  This 
atmospheric dust would have been at the top of the troposphere where the
anviltops of thunder clouds occur and this dust would have spent some time 
being exposed to the cosmic radiation of the low sunspot period.

     Lightning has been known to strike the earth when no clouds were in 
sight.  Electrification of regions around and within clouds in the upper 
atmosphere largely results from cosmic radiation from interstellar space, our 
sun and other regions of the cosmos.  Ionizing radiation also comes from the 
soil and from plants as well as from the ocean's surface.  The result is some 
1,800 to 4,000 electrical storms which occur on the average at any given time 
on the planet and lightning strikes the earth more than 100 times per second.  
It is, therefore, suggestive that the initial ignition of the solid fuel 
propellant in the SRBs occurs electrically.

     The earth continually loses electrons into the atmosphere.  There is
electricity in the air even in fair weather and all air contains some 
moisture which is a gaseous and invisible vapor on clear days.  When there 
are no clouds, however, there is usually an absence of atmospheric lightning 
discharge under normal conditions.  Heat thunderstorms are a common 
phenomenon over Florida in the afternoons when electrons generally flow back 
to the earth which has been losing them from its negatively charged surface.  
Small artificial thunderstorms may arise from such things as forest fires or 
from the ejection of a volcano when conditions of the atmosphere are right.  
The hot vapors which trailed the shuttle were similar in composition to the 
effluence of a volcanic eruption.  A normal shuttle launch leaves about 5,000 
pounds of nitrogen oxides, 8,000 pounds of chlorine, 77,000 pounds of 
hydrogen chloride, and over 100,000 pounds of aluminum oxide in its vapor 
trail.  The cloud column disperses slowly and the by-products of the main 
engine fuels, hydrogen and oxygen, create water vapor in the form of steam.  
This trail had reached the ionospheric layer when the Shuttle exploded.




=============================================================================
     end of chapter