The 2003 Columbia Disaster

Columbia history Milestones – OV102 July 26, 1972Contract Award Nov. 21, 1975Start structural assembly of crew module June 14, 1976Start structural assembly of aft-fuselage March 16, 1977Wings arrive at Palmdale from Grumman Sept. 30, 1977Start of Final Assembly Feb. 10, 1978Completed final assembly Feb. 14, 1978Rollout from Palmdale April Launch Jan 16, th and Last Flight

The Columbia disaster occurred on February 1 It disintegrated over Texas during re-entry. Loss of all seven crew, before concluding its 28th mission. Caused by damage sustained during launch when a piece of foam insulation the size of a small briefcase (loaf of bread) and known as the Left Bipod Foam Ramp broke off the main propellant tank. The damaged area allowed the hot gases to penetrate and destroy the internal wing structure, causing the in-flight break-up. Columbia: 2003 mission STS-107

Columbia Some “foam shedding” had been noticed during the launch However, foam shedding was a common occurrence and so it was discounted. In the aftermath of the Challenger disaster NASA had still not shaken off elements of the mindset that contributed the tragedy. They believed that as it worked, there was nothing to fix. They were wrong.

Thermal Shield Primary heat shield made from reinforced carbon/carbon tiles. Capable of withstanding 1700 o C Secondary shield Fibrous refractory composite insulation (FRCI) tiles, which are flexible and very tough. These combine with interior insulation to protect the crew and vehicle during the atmospheric braking phase of orbital re entry.

Oxygen and hydrogen exist as gases at standard temperature and pressure. Since their density in this state is quite low, the amount of these substances required by the Space Shuttle would take up an enormous volume. The only way to carry sufficient propellant in a reasonable amount of space is to increase the density by cooling and pressurizing them until they become liquids. External Tank Foam Insulation

The liquid oxygen is cryogenically cooled to -300°F (- 184°C) The liquid hydrogen is chilled to -423°F (-253°C). These liquids must be kept at high pressure and very low temperature or they will boil back to a gaseous state. External Tank Foam Insulation

Foam Ramp The Left Bipod Foam Ramp was a one meter cast ramp made entirely out of foam which weighed just under 1kg, dry. Its purpose was to improve the aerodynamic profile of the forward orbiter bipod mount. This entire ramp, which was frozen by contact with the EFT broke away 81.9 seconds after launch. The debris struck the leading edge of the left wing, punching a hole through the carbon/carbon armour.

Warnings Ignored After Columbia safely reached orbit the NASA engineering safety team made three requests to the Department of defence to provide high definition “spy” satellite pictures of the orbiter. The requests were refused as the DOD was busy over the middle east. The engineering team then proposed a space walk to check the wing. NASA management refused on the grounds that the crew schedule was full. Had the damage been discovered the crew had no way of making repairs,. However, Columbia did not have enough fuel to dock with the ISS. Despite rumours, Columbia was beyond help of any kind.

Re Entry February 1 st Columbia made a perfect de-orbit burn and began the aero braking part of its re entry operation. 08:44:09 Columbia hit the upper atmosphere at 7.8 km/s17,500mph. Leading edges quickly heat to 1400 o C. 08:48:39 A sensor on the left wing leading edge spar showed strains higher than those seen on any previous Columbia re-entry. 8:49:32 Columbia executed a pre-planned roll to the right. Speed: Mach 24.5.

Last Moments 8:53:46 Signs of debris being shed were sighted by ground observers. Speed: Mach Altitude: 230,200 feet. 8:54:24 The Maintenance, Mechanical, and Crew Systems Officer notes that four hydraulic sensors in the left wing failed simultaneously. Mission Control discuss the instrument failure. Over the next few minutes ground observers report seeing flashes of light from Columbia, this was debris falling from the orbiter and burning up in the plasma stream.

Destruction 8:59:15 Engineering note that pressure readings had been lost on both left main landing-gear tyres, they tell the crew. A rapid cascade sensor failure followed. The crew response is garbled and before they can repeat the message ground observers report that Columbia has disintegrated.

Survival Unlike the Challenger accident there was never any possibility of survival. The orbiter pitched left as its wing broke up and lost aerodynamic flow. Columbia turned sideways on to the Mach 19.5 air stream. The orbiter was never designed to withstand stress in this orientation and broke up. A human dropped into an airflow of this velocity would disintegrate as quickly as the orbiter.

Now Foam strikes at launch are still a problem for the STS. Strikes occur because of the nature of the lifter, and there is no way to avoid the problem. NASA has investigated many DIY repair methods, but none have a realistic chance of working. As of now, when a shuttle launches there is another ready on short standby.

The Next Step The future appears to lie with truly reusable space vehicle. Research worldwide has been leaning towards hybrid engine space planes such as Skylon and the X 34. These overcome most of the disadvantages inherent in the design of the shuttle. The technology is ready, all it needs is the will and the money.

Flight History The first shuttle, Columbia flew on 12 April Since then there have been 128 launches of which 2 ended catastrophically. This gives the shuttle a failure rate of 1.6%. Which makes it 300 times more dangerous then crossing the road. Columbia and Challenger were both destroyed in accidents, they were also the oldest of the five shuttles on the NASA fleet.

The investigation board recommended: improving photography of launches, using telescopes to photograph shuttles while they are in space adding the ability to repair a shuttle while in orbit. Columbia: 2003 mission STS-107