Statistics don’t count for anything,” declared Will Willoughby, the National Aeronautics and Space Administration’s former head of reliability and safety during the Apollo moon landing program. “They have no place in engineering anywhere.” Now director of reliability management and quality assurance for the U.S. Navy, Washington, D.C., he still holds that risk is minimized not by statistical test programs, but by “attention taken in design, where it belongs.” His design-­oriented view prevailed in NASA in the 1970s, when the space shuttle was designed and built by many of the engineers who had worked on the Apollo program. NASA documents show that the airline vision also applied to risk. For example, in the 1969 NASA Space Shuttle Task Group Report, the authors wrote: “It is desirable that the vehicle configuration provide for crew/passenger safety in a manner and to the degree as provided in present day commercial jet aircraft.” Statistically an airliner is the least risky form of transportation, which implies high reliability. And in the early 1970s, when President Richard M. Nixon, Congress, and the Office of Management and Budget (OMB) were all skeptical of the shuttle, proving high reliability was crucial to the program’s continued funding. One reason was economic. According to George Rodney, NASA’s associate administrator of safety, reliability, maintain­ability and quality assurance, it is not hard to get time and cycle data, “but it’s expensive and a big bookkeeping problem.” NASA’s “management methodology” for collection of data and determination of risk was laid out in NASA’s 1985 safety analysis for Galileo. The Johnson space center authors explained: “Early in the program it was decided not to use reliability (or probability) numbers in the design of the Shuttle” because the magnitude of testing required to statistically verify the numerical predictions “is not considered practical.” Furthermore, they noted, “experience has shown that with the safety, reliability, and quality assurance requirements imposed on manned space­flight contractors, standard failure rate data are pessimistic.”

Space Modeling HobbySpace - Space Modeling

When funding for the program came into question, there were concerns that the project might be canceled. This led to an effort to interest the US Air Force in using the shuttle for their missions as well. The Air Force was mildly interested but demanded a much larger vehicle, far larger than the original concepts, which NASA accepted since it was also beneficial to their own plans. To lower the development costs of the resulting designs, boosters were added, a throw-away fuel tank was adopted, and many other changes were made that greatly lowered the reusability and greatly added to the vehicle and operational costs. With the Air Force's assistance, the system emerged in its operational form. Also to examine the shuttle as a system, NASA conducted a one-time critical functions assessment in 1978, which searched for multiple and cascading failures. The information from all these studies fed one way into an overall mission safety assessment. Initially, the orbiter was to carry its own liquid propellant. However, studies showed carrying the propellant in an external tank allowed a larger payload bay in an otherwise much smaller craft. It also meant throwing away the tank after each launch, but this was a relatively small portion of operating costs. The NRC committee had several criticisms. In practice, the FMEA was the sole basis for some engineering change decisions and all engineering waivers and rationales for re taining certain high-risk design features. However, the NRC report noted, hazard analyses for some important, high-risk subsystems “were not updated for years at a time even though design changes had occurred or dangerous failures were experienced.” On one procedural flow chart, the report noted, “the ‘Hazard Analysis As Required ’ is a dead-end box with inputs but no output with respect to waiver approval decisions.” As another incentive for the military to use the shuttle, Congress reportedly told DoD that it would not pay for any satellites not designed to fit into the shuttle cargo bay. [6] Although NRO did not redesign existing satellites for the shuttle, the vehicle retained the ability to retrieve large cargos such as the KH-9 HEXAGON from orbit for refurbishment, and the agency studied resupplying the satellite in space. [7]A great project to do if you are interested in stretching the limits of your abilities and learning new or honing your skills. Another reason was NASA’s “normal program development: you don’t continue to take data; you certify the components and get on with it,” said Rodney’s deputy, James Ehl. “People think that since we’ve flown 28 times, then we have 28 times as much data, but we don ’t. We have maybe three or four tests from the first development flights.” The Johnson authors’ value of 1 in 100 000 implied, as Feynman spelled out, that “one could put a Shuttle up each day for 300 years expecting to lose only one.” Yet even after the Challenger accident, NASA’s chief engineer Milton Silveira, in a hearing on the Galileo thermonuclear generator held March 4, 1986, before the U.S. House of Representatives Committee on Science and Technology, said: “We think that using a number like 10 to the minus 3, as suggested, is probably a little pessimistic.” In his view, the actual risk “would be 10 to the minus 5, and that is our design objective.” When asked how the number was deduced, Silveira replied, “We came to those probabilities based on engineering judgment in review of the design rather than taking a statistical data base, because we didn’t feel we had that.” I made a 1:78 scale model of the NASA Space Shuttle completely out of recycled materials using tools that are common and can be found in an average house. I mainly used cardboard and Elmer's glue.

Space Shuttle Model - Etsy UK

Before the Apollo 11 Moon landing in 1969, NASA began studies of Space Shuttle designs as early as October 1968. The early studies were denoted "Phase A", and in June 1970, "Phase B", which were more detailed and specific. The primary intended use of the Space Shuttle was supporting the future space station, ferrying a minimum crew of four and about 20,000 pounds (9,100kg) of cargo, and being able to be rapidly turned around for future flights.

Products of Space Shuttle Models

Causes: inadequate original design (booster joint rotated farther open than intended); faulty judgment (managers decided to launch despite record low temperatures and ice on launch pad); possible unanticipated external events (severe wind shear may have been a contributing factor). The Space Shuttle program used the HAL/S programming language. [10] The first microprocessor used was the 8088 and later the 80386. The Space Shuttle orbiter avionics computer was the IBM AP-101.