' Space disasters have occurred for the most diverse
reasons and on different scales, both in the Soviet Union and the United States.
In all the cases I am familiar with the common factor is that those who were
truly to blame for the disaster remained alive and faced no censure
Washington--Not since 1986, with the Challenger accident and concurrent failures of Titan, Atlas, and Delta II rockets, has the U.S. confronted a stand down of a large portion of its booster fleet. While the shuttle has been made more reliable, since last summer six launches of expendable boosters have failed. President Clinton asked Secretary of Defense William Cohen to fathom out "root causes behind the recent failures and take corrective action." His final report is due around Thanksgiving.
Here's a run down of this losing streak:
August 19, 1998: wiring damage causes a solid rocket booster on a Lockheed Martin Titan IV to explode, destroying a classified communications satellite.
August 26, 1998: a first-stage guidance design flaw causes an unprogrammed maneuver, over-stressing a Boeing Delta III on its maiden flight with loss of a commercial Galaxy communications satellite.
April 9, 1999: incomplete stage separation on a Boeing Inertial Upper Stage places a missile-warning satellite launched by a Titan IV into an unuseable orbit.
April 27, 1999: a nose cone fails to separate from a small Lockheed Martin Athena booster, and its commercial Earth-imaging satellite payload plunges back into the atmosphere.
April 30, 1999: a black hat trick for Titan IV missions when improper software in a Centaur upper stage places a Milstar communications satellite in a useless, lower-than-geosynchronous orbit.
May 4, 1999: early shut down of a Delta III upper stage, using an advanced version of the Centaur engine, leaves an Orion communications satellite stranded in a low orbit.
Root causes. While seemingly unrelated, experts are looking for common trends. Causes mentioned include: more reliance on computer modeling rather than full, all-up booster testing; over-emphasis on lowering booster costs, perhaps prompting short cuts; and fewer middle-age, more experienced aerospace engineers, leading to a loss in industry "corporate memory."
One of these seasoned veterans of the Rocket Mafia told Design News that, "fewer launches today on each booster make it harder to keep workforce morale and skills up. The failures are random. It doesn't seem to be a design problem, but quality control and human error--just not doing things right--and should be traced.
My Note: Experience counts! Even if you are the wrong side of fifty.
The challenger disaster could have been avoided if the advice of one of the engineers responsible for the solid boosters had been listened to.
He predicted failure of the booster segment ring 'O' ring seals at low temperature launch. The rest is history....
USSR Tyuratam, Nedelin R-16 Disaster On October 26, 1960 Between the official 74 and the actual figure which is now estimated to be closer to 200 soldiers and technicians died after an explosion at the inaugural R16 launch site. When the second stage of the rocket was accidently ignited 30 mins before the planned launch.
This was a hastily arranged prototype rocket launch undertaken with numerous known problems unresolved
1986 Shuttle 'Challenger' accident.
Channel 4 Challenger: Countdown to disaster
The tragedy was the result of a faulty O-ring seal used to seal between the solid booster segment rings. During very low temperature launch conditions. This had been predicted by some of the older engineers at Morton Thiokol, responsible for the construction of the solid rocket booster. Who tried to prevent the launch of the shuttle at low temperatures. There warning was ignored both by there own company and NASA management teams.
After launch on an exceptionally cold morning the seals failed 73 seconds after lift-off and allowed the white-hot exhaust gases from Challenger's huge launch rockets to penetrate its booster rocket mountings – and ultimately to ignite the main fuel tank.
Control ' We have no down link'.
1996 Ariane501 launch failure analysis.
Dec 2002 Initial test flight of the heavy lift Ariane 5 ECA
Vulcan 2 nozzle failed at altitude due to low atmospheric pressure outside the nozzle causing the bell shaped expansion nozzle to deform. The resulting reduced thrust and localised heat transfer problems triggered the abortion of the inaugural flight.
Inadequate development testing was identified as one of the principle causes for this flight failure.
Improved cooling and stiffening of the nozzle that was then proved during numerous static engine test fiirings resolved the problem.
Loss of Shuttle 'Colombia' and its seven crew o February 1st 2003 during re-entry.
Channel 4 History of Space failures
Apollo11 The Untold Story BBC Documentary.
A history of our failures.
One of the keys to becoming a good engineer or research scientist if being able to analyse all the multiple causal parameters that contribute to a system failure.
As an investigator you need to be capable of staying independent and impartial.
A cool clear open minded approach is essential.
Remember there is no good time for the truth. It take courage and professional integrity.
Death of a Blackbird
Low temperature failure at -7C. Combined with high number of launches fatiging the bonded joint line between bottle and fin.
Note the milky coloured wax like appearance of the adhesive.
When you notice that the adhesive is changing in colour replace the adhesive and and if the bottle appears to be damaged replace the bottle
|Here the fine tie cord linking the coiffe with the base plate
was too short and restricted the freedom of the nose cone to seperate
properly from the base-plate.
Here a raised platform is added to the baseplate to prevent the packed parachute from interfering with the pressure equlisation between interior and exterior of the rocket.
Initially we had problems with the nose cone being forced down over the main diameter of the rocket body due to high launch acceleration loads.
We seemed to encounter problems that other people never had!
So we introduced the pressure equalising hard shoulder shock plate
that was just marginally larger than the base of the nose cone.
Up to 8bar the early type of nose cone worked well.
Then all of a sudden it started to fail. Why?
Four failures in a row. Analysis of why these flights failed led to the success of the fifth using a modified coiffe ring. To stiffen the base of the nose cone under higher pressure launch loading.
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©John Gwynn and sons2003
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