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Criticism of the Space Shuttle program stemmed from claims that NASA's Space Shuttle program failed to achieve its promised cost and utility goals, as well as design, cost, management, and safety issues. Fundamentally, it failed in the goal of reducing the cost of space access. Space Shuttle incremental per-pound launch costs ultimately turned out to be considerably higher than those of expendable launchers. In 2010, the incremental cost per flight of the Space Shuttle was $409 million, or $14,186 per kilogram ($6,435 per pound) to low Earth orbit (LEO). In contrast, the comparable Proton launch vehicle cost was $141 million, or $6,721 per kilogram ($3,049 per pound) to LEO and the Soyuz 2.1 was $55 million, or $6,665 per kilogram ($3,023 per pound), despite these launch vehicles not being reusable. When all design and maintenance costs are taken into account, the final cost of the Space Shuttle program, averaged over all missions and adjusted for inflation (2008), was estimated to come out to $1.5 billion per launch, or $60,000 per kilogram ($27,000 per pound) to LEO. This should be contrasted with the originally envisioned costs of $260 per kilogram ($118 per pound) of payload in 1972 dollars (approximately $555 per pound adjusting for inflation to 2019). While the shuttle did serve a purpose servicing satellites and space stations in orbit, it failed at its original goal of achieving routine, reliable access to space, partly due to multi-year interruptions in launches following Shuttle failures. It was never as economical as expendable rockets for the task of launching satellites. NASA budget pressures partly caused by the chronically high NASA Space Shuttle program costs have eliminated NASA crewed space flight beyond low earth orbit since Apollo, and severely curtailed use of uncrewed probes. NASA's promotion of and reliance on the Shuttle slowed domestic commercial expendable launch vehicle (ELV) programs until after the 1986 Challenger disaster. Two out of the five spacecraft were destroyed in accidents, killing 14 astronauts, the largest loss of life in space flight. Purpose of the system The "Space Transportation System" (NASA's formal name for the overall Shuttle program) was created to transport crewmembers and payloads into low Earth orbits. It would afford the opportunity to conduct science experiments on board the shuttle to be used to study the effects of space flight on humans, animals and plants. Other experiments would study how things can be manufactured in space. The shuttle would also enable astronauts to launch satellites from the shuttle and even repair satellites already out in space. The Shuttle was also intended for research into the human response to zero-g. The Shuttle was originally billed as a space vehicle that would be able to launch once a week and give low launch costs through amortization. Development costs were expected to be recouped through frequent access to space. These claims were made in an effort to obtain budgetary funding from the United States Congress. Beginning in 1981, the space shuttle began to be used for space travel. However, by the mid-1980s the concept of flying that many shuttle missions proved unrealistic and scheduled launch expectations were reduced 50%. Following the Challenger accident in 1986, missions were halted pending safety review. This hiatus became lengthy and ultimately lasted almost three years as arguments over funding and the safety of the program continued. Eventually the military resumed the use of expendable launch vehicles instead. Missions were put on hold again after the loss of Columbia in 2003. Overall, 135 missions were launched during the 30 years after the first orbital flight of Columbia, averaging approximately one every 3 months. Costs Some reasons for the higher-than-expected operational costs were: NASA secured funding from the US Air Force's budget in exchange for USAF input to the design process. In order to fulfill the USAF's mission to launch payloads into polar orbit, the USAF insisted on a very large cross-range requirement. This necessitated the Shuttle's huge delta wings, which are far larger than the stub wings of the original design. Besides adding drag and weight (almost 20 percent), the excessive number of heat tiles needed to protect the delta wings added greatly to maintenance costs, besides increasing operational risks such as those that resulted in the Columbia disaster. At Vandenberg Air Force Base in California, the USAF duplicated the entire infrastructure needed to launch and service the Space Shuttle, at a cost of over 4 billion dollars. Following the Challenger explosion, the facility was dismantled after never having launched a single Shuttle mission. Aerospace engineer Robert Zubrin describes the Shuttle as having been designed "backwards" in that the Orbiter, the harder-to-recover portion, is made recoverable, while part of the booster (the liquid fuel tank) is thrown away even though it is easier to recover since it does not fly so high or fast. Maintenance of the thermal protection tiles was a very labor-intensive and costly process, with some 35,000 tiles needing to be inspected individually and with each tile specifically manufactured for one specific slot on the shuttle. Due to the complexity of the RS-25 engines, following each flight they required removal for thorough inspection and meticulous maintenance. Prior to the delivery of the Block II engines, the primary engine component, the turbopump, had to be removed, disassembled, and overhauled after each use. The toxic propellants used for the OMS/RCS thrusters required special handling, during which time no other activities could be performed in areas sharing the same ventilation system. This increased turn-around time. The launch rate was significantly lower than initially expected. While not reducing absolute operating costs, more launches per year gives a lower cost per launch. Some early hypothetical studies examined the possibility of making 55 launches per year (see above), but the maximum possible launch rate was limited to 24 per year based on manufacturing capacity of the Michoud facility in Louisiana that constructs the external tank. Early in shuttle development, the expected launch rate was about 12 per year. Launch rates reached a peak of 9 per year in 1985 but averaged 4.5 for the entire program. When the decision was made on the main shuttle contractors in 1972, work was spread among companies to make the program more attractive to Congress, such as the contract for the Solid Rocket Boosters to Morton Thiokol in Utah. Over the course of the program, this raised operational costs, though the consolidation of the US aerospace industry in the 1990s meant that the majority of the Shuttle program expenditure was now with one company: the United Space Alliance, a joint venture of Boeing and Lockheed Martin. Cultural issues and problems For a successful technology, reality must take .... Discover the Pat Duggins popular books. Find the top 100 most popular Pat Duggins books.