Examination of Shuttle Challenger Disaster - Case Study Example

Name Course Tutor Date NASA Disaster Introduction NASA’s space Shuttle is the US’s government’s present manned launch vehicle. The Space Shuttle Orbiter is usually winged and it’s launched vertically with about five to seven astronauts though eight astronauts have launched. After completing the launching mission, it can autonomously move out of orbit through its Orbital Maneuvering System and then re-enter the earth (Robbins 32-34). Shuttle’s mission Carrying huge payloads to a range of orbits Offering crew rotation for the International Space Station, and carrying out service missions The orbiter recovers satellites as well as other payloads from orbit and finally returning them to Earth Returning of big payloads from the ISS to Earth. Examples of Shuttles N/B: The orbits currently in use are shown in green. (Alastair 177-185). In this paper, the main focus will be examination of Shuttle Challenger disaster, its history and the reasons that caused the loss of this space Shuttle with seven astronauts on board. Disaster occurrence findings The Challenger Shuttle had been built to withstand a force thrice the force of gravity with another 1.5 safety factor built in. in particular, the cabin crew was a very strong sector of the shuttle since its design and construction had been reinforced with aluminum just like other shuttles (Vaughan 97-123). During the disintegration of the Challenger Shuttle, the cabin crew separated in one portion and gradually dropped into a ballistic arc. NASA projected the separation forces to be around 12 to 20 (G) for a very short time whereby within two seconds the forces of the cabin had fallen to below 4G and in 10 seconds, the cabin crew was in free fall. It has been estimated that these forces were not adequate to lead into a fall. in any case, the was a likelihood of some astronauts being alive and shortly conscious after the disintegration since three of the four Personal Egress Air Packs on the flight deck were found to having been activated. There were remains of air supply that had not been used approximately dependable with the expected using up over the 2 minute 45 second post-breakup arc. The cabin crew hit the ocean floor at approximately 207 mph (333 km/h); leading to an instant deceleration of over 200 G, far ahead of the structural limits of the crew section or crew survivability points (Jenkins 76). History The Space Challenger disaster took place on 28th January 1986. This disaster occurred because Shuttle Challenger disintegrated after 73 seconds after taking off caused the deaths of the seven crew members. The space craft broke apart over the Atlantic Ocean in United States at 11.39 a.m. EST (16:39 UTC). The breaking of the whole vehicle started after an O-ring seal in its right side of the solid rocket booster (SRB) failed after the vehicle took off. The failure of the O-ring led to the damage in the SRB joint it covered and thus permitting pressurized hot gas from inside of the solid rocket motor to get to the outside and invade upon the neighboring SRB attachment hardware and exterior fuel tank (Godwin 123-132). Consequently, this resulted into disconnection of the right-hand SRB's aft attachment and the structural breakdown of the external tank. As a result, aerodynamic forces swiftly disintegrated the orbiter. The crew cubicle and many other vehicle wreckages were finally recovered from the ocean floor after a long-lasting search and recovery process. Although the precise timing of the death of the crew is unidentified, numerous crew members are known to have survived the first breakup of the spacecraft. Nevertheless, the shuttle had no escape system and thus the crew did not survive the impact of the crew section on the ocean surface. The Challenger disaster led into in a 32-month interruption in the shuttle program. Shuttle Challenger was to be launched on January 22nd but there were delays because of bad weather conditions to 25th. It was again set to be launched on 27th but was rescheduled to 28th because of the faults with exterior access hatch. Initially, one of the micros with indicators used to confirm that the hatch was safely locked was faulty. Then, an exposed bolt inhibited the closeout crew from taking away closing fixture from the orbiter’s hatch. When the fixture was eventually sawn off, crosswinds at the Shuttle Landing Facility went beyond the limits for a Return to Launch Site abort. The crew had to wait for the wind to go down until the launch window eventually run out leading to another scrub. The temperatures for January 28th were abnormally cold almost 31 °F (−1 °C), the least temperature allowed for launch (Kerzner 321-325). Because of the low temperature a considerable quantity of ice developed on the fixed service structure that was positioned next to the shuttle. There was an infrared camera at the back field joint of the right SRB and the temperature was found to be at 8 °F (−13 °C). This was due to super cooled air propelling on the joint from the liquid oxygen tank expel. This temperature was far below the devised requirements for the O rings. Although Ice Team removed the ice, engineers at Rockwell International expressed some concerns regarding the state of temperatures. The engineers feared that over the launch, the Shuttle Challenger ice could be shaken loose and hit the shuttle's thermal fortification tiles, probably because of the aspiration stimulated by the jet of exhaust gas from the SRBs. However after the final inspection, whereby the ice was melting, the Challenger was eventually cleared to launch at 11.38a.m. EST. Liftoff and initial ascent Challenger lifting off Gray smoke escaping from the right side SRB (253 kB, ogg/Theora format) Plume As the shuttle advanced Max Q, it crashed through the most powerful wind shear that has ever been experienced in the space shuttle program. At T+58.78, a camera captured a plume near the aft joint strut on the right side of SRB. Without the knowledge of those who were on the challenger, hot gas had started to pour out through a developing hole in one of the right hand SRB’s attach. The force of the wind shear splintered the temporary oxide seal that had occurred through the damaged O rings, eradicating the final barrier to flame sealing through the joint. The wind shear is the one that prevented the fortuitous oxide seal from holding through booster burnout. In just a second, the plume turned out to be well defined and powerful. Internal pressure within the right side of SRB started reducing due to the swiftly broadening hole in the joint that had failed. As a result, at T=60.238, there was visual indication of flame getting through the joint and encroaching on the external tank (Ben 234-251). Plume on right SRB At T+64.660, the shape of the plume abruptly changed illustrating that a leak had started in the liquid hydrogen tank, situated within the aft section of the external tank. The nozzles of the key engines rotated under computer control to balance the unstable thrust generated by the booster burn out through. The Pressure within the shuttle’s exterior liquid tank started to decrease at T+66.764 illustrating the impact of the leak. At this juncture, the state looked normal to the astronauts as well as the flight controllers. At T+68, at this stage the situation still seemed normal both to the astronauts and to flight controllers. At T+68, the CAPCOM Richard Covey notified the crew that they were "go at throttle up", and Commander established the call. This response was the final communiqué from Challenger on the air-to-ground loop. Technical faults The right SRB disjointed from the left strut joining it to the external tank. The telemetry information indicated an unexpected agile acceleration to the right at T+72.525 which could have been felt by the crew. The ultimate statement recorder by the crew cabin recorder came merely half a second after this acceleration when the pilot said “Uh oh”. The pilot could have been responding to onboard signals of the key engine performance or to the decreasing pressures in the external fuel tank. At T+73.124, the back dome of the liquid hydrogen tank stopped working generating a propulsive force which pressed the hydrogen tank into the liquid oxygen tank in the frontward component of the ET. All at once, the right SRB revolved around the onward attach strut and hit the intertank structure. The disintegration of the Challenger Shuttle started at +73.162 seconds and at an attitude of 14.6 kilometers. With the external tank breaking apart and with the semi detached right SRB taking part to its thrust on an anomalous vector, Challenger swerved from its accurate attitude with respect to the local air flow and was right away broken apart by anomalous aerodynamic forces leading to a load factor of unto 20 g while the designed limit of the Challenger was 5 g (Kerzner 56). The two SRBs which have the ability to endure larger aerodynamic loads disjointed from ET and continued in uncontrolled powered flight for approximately another 37 seconds. The SRB casings of the Shuttle Challenger were constructed using half inch (12.7mm) thick steel and were greatly stronger than the orbiter and ET. Therefore, the two SRBs survived the disintegration of the space shuttle stack although the right SRB suffered the resulting impact of the joint burn through that had set the damaging of the Shuttle Challenger in motion. As Challenger disintegrated, there was a rupture of the static on the air to ground disk. After it broke apart, there was a cloud of smoke and water vapor which resulted due to hydrogen combustion and pieces of debris falling in the ocean (Ceruzzi 32-36). No explosion The Shuttle Challenger and the external tank din not essentially explode. Alternatively, both swiftly broke apart under tremendous aerodynamic forces because the Shuttle Challenger was to some extent past “Max Q” or maximum aerodynamics pressure. This means that the dynamic pressure had begun to reduce after reaching its maximum. After the external tank broke apart, the fuel and oxidizer which are stored in the external tank were released generating the form of a very big ball. There was a localized burning of the propellant. The visible cloud chiefly consisted of vapor and gases coming from the release of the Shuttle Challenger’s liquid oxygen and liquid hydrogen propellant. Since the liquid hydrogen normally gets stored in cryogenic state, the liquid hydrogen could not have caught fire swiftly enough to cause an explosion in the customary manner of a detonation as opposed to deflagration which is what happened. If a factual explosion had occurred, the whole Shuttle Challenger would have been destroyed immediately killing the crew instantly (Kerzner 67). The more strongly built crew cabin and SRBs survived the disintegration of the launch vehicle; while the SRBs were consequently detonated slightly, the disconnected cabin continued along a ballistic trajectory, and was observed removing the cloud of gases at T+75.237. Twenty-five seconds after the disintegration of the vehicle, which happened at 48,000 feet, the trajectory of the crew cubicle peaked at an altitude of 65,000 feet (Jenkins 45). NASA response After the Challenger disaster, shuttle flights were suspended. NASA opened an overall revamp of the space shuttle’s solid which was being monitored by a self governing supervision group as predetermined by the Rogers Commission. NASA also developed a new office to deal with Safety, Reliability and Quality Assurance administered by a NASA associate official who was to report everything concerning the shuttles to NASA administrators (Feynman 71). Brainstorming Following the information gotten after the Shuttle Challenger disaster, the causes of the disaster could be stipulated to the following: Bad weather conditions Faulty inspection Pushing the schedule Ignorance of notable faults Technical errors Bad monitoring of the shuttle Technical errors Department interior was impatient in getting the results Ignoring alarming inspection results Conclusion The main cause of Challenger’s disaster was mostly human errors as well as bad weather conditions. This is because despite the negative weather forecast, the launching of the Shuttle Challenger went ahead. However, the main cause was human errors. Therefore, in future, human errors and ignorance of small faults should be avoided to hinder any further disasters. Works Cited Feynman, Philips. What Do You Care What Other People Think? Further Adventures of a Curious Character. Austria: Penguin, 2007. Robbins, Jeffrey. The pleasure of finding things out: the best short works of Richard P. Feynman. Sydney: Perseus Books, 2000. Jenkins, Dennis. Space shuttle: the history of the National Space Transportation System : the first 100 missions. Sydney: Midland, 2001. Godwin, Robert. Space shuttle: STS flights 1-5, incl. approach & landing tests: the NASA mission reports. New York: Apogee Books, 2001. Jenkins, Dennis. The history of developing the National Space Transportation System: the beginning through STS-75. Sydney: Perseus Books, 2000. Ben, Evans. Space shuttle Challenger: ten journeys into the unknown. Alabama: Springer, 2007. Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. New Jersey: John Wiley and Sons, 2009. Alastair, Ross. Beyond human error: taxonomies and safety science. New York: CRC Press, 2006. Vaughan, Diane. The Challenger launch decision: risky technology, culture, and deviance at NASA. Chicago: University of Chicago Press, 1996. Ceruzzi, Paul. Beyond the limits: flight enters the computer age. New York: MIT Press, 1989. Read More