The Space Shuttle Program

 

By
Gerard Hillenbrand, P.E.

The Space Shuttle Program was the subject of the Metropolitan Section’s May 19, 2011 Technical Dinner Held at Con Edison Headquarters on East 14th Street in Manhattan. This was the second of these lectures this spring covering the important History and Heritage section of ASME’s activities. The evening’s expert speaker was Burton Dicht, Managing Director of ASME’s Knowledge and Community Sector and a long-time friend and very helpful participant in Metropolitan Section activities. Burt Dicht has headed the Knowledge and Community Sector since 1999 and has been an ASME employee for 30 years. Up until 1980 Burt was working at NASA on various space projects so his knowledge of the space program is vast and unequaled among Metropolitan Section Engineers. The official title of Burt Dichts Presentation was “The Long road to Columbia – A History of the Space and Shuttle Program.” This program received its first government funding in 1972 during the Nixon administration. The space shuttle Columbia made its first space flight in 1981 and, by the conclusion of the program, this nation’s space shuttle fleet will have made 135 space flights.

The development of the shuttle program was long and arduous. The achievements of the previous space capsule and moon landing programs had been extraordinarily expensive and severely limited in size and versatility. Plus, the scheduled construction of the international space station, and its future expansion and maintenance, required a different kind of access vehicle. First of all, it had to be much less expensive than competing systems and it had to be large enough to carry a much greater payload such as space station modules and replacement fuels. Furthermore, it should be a reusable vehicle to contain development and operational costs. Also its design had to overcome certain limitations of the previous and competing designs. The resulting shuttle vehicle was based partly on an amalgam of other NASA projects, most of, which were successful but retired because of functional limitations and huge costs.

Among the important prior NASA innovations were the X-15 Rocket Plane which achieved unprecedented speeds of Mach 5 and altitudes of 260,000 feet and also provided a thermal protection system to dissipate the enormous heat generated.

 Also the X-20 Byna-Soar vehicle (canceled in 1963) which advanced the limits of hypersonic flight and provided relatively uniform lift over a broad range of speeds.

By 1967 the Skylab Program achieved important cost reductions in space vehicle manufacture and maintenance. The Lockheed Star Clipper Program employed a cluster of three external rockets providing 1.5 million pounds of thrust. The U.S. Air Force’s Saturn V Ballistic Missile System perfected the system of booster rockets with subsequent staged propulsion. Also, development of the Air Force’s advanced aircraft showed the advantages of the Delta Wing configuration and the utilization of a blunt body form to direct generated heat away from the high-speed spacecraft.

By 1968-1969 the $5.2 Billion Shuttle program had developed several feasible competing designs, but the estimated cost had increased to more than $10 Billion. The Nixon administration asked for substantial cost reductions and more reusable components, with costs reduced to $5 Billion. By 1971 the proposed recovery of Booster Rockets and reusable rocket fuel canisters had achieved the required economies and during 1972 the final configuration of the space shuttle had been determined. The program was finally approved with a $5.5 billion budget, and stated missions of servicing the orbiting space station, and the checking and repair of satellites and redeeming those which had become disabled. The projected first flight was scheduled for 1979 with a $10 million budget, and a 100 to 400 mile orbiting range in space. Actual development time was nine years until the first shuttle flight in 1981. Schedule and cost over-runs were caused by booster problems, huge variations in required fuel temperature (400oF to 5000oF), and the failure of many heat-resistant tiles on the shuttle surfaces. Solutions to these problems included increased use of solid fuel rocket boosters (reusable as many as 25 times), utilization of super-cool hydrogen and oxygen fuels in external tanks (Ludox developed by Du Pont) capable of withstanding heats as high as 2300oF.

Ultimately, five space shuttle vehicles were built: – Atlantis, Columbia, Challenger, Discovery and Endeavor, and this group made a total of 135 flights over a 30-year period. The total cost of the shuttle program was $174 billion, which averages out to $1.3 Billion per flight. 100 of the shuttle flights carried supplies and expansion capsules into orbit for the space station with the remainder employed for satellite servicing and the memorable flights for reconstruction of the Hubbell Telescope. The maximum employment of the space shuttle occurred in 1985 with nine flights that year. Two tragedies have marred the program: – The lift off explosion of Challenger in 1986 (caused by defective O-Ring Fuel Seals), and the destruction of Columbia in 2003 during re-entry into the Earth’s atmosphere (caused by defective tiles and a hole inflicted to the wing during the lift off). All told, 15,000 people and 355 astronauts worked on various aspects of the shuttle program.

In 2004 the G. W. Bush administration proposed a “New Vision” for the space program which envisioned privatizing the shuttle program and encouraging competition for new designs for propulsion and vehicle configuration. In 2010 the Obama administration endorsed this new program. So far there are four commercial proposals to implement the competitive nature of the program, one of which seeks to achieve 17,500 miles per hour of vehicle propulsion. Of these proposals, the most promising appears to be the “Space X-Falcon 9” proposal for a 2015 first shuttle flight. This group has already launched its first successful space capsule. Later this year this group plans to launch an unmanned rocket to deliver food and supplies to the space station.

 The question and answer period was equally stimulating. For example, after vehicle improvements were made after shuttle flight #2, 600 pounds of total weight was saved by removal of the outer layer of white paint. Each vehicle was designed to last for 100 flights and carry 20,000-pound payloads. Over the years more than three million pounds was delivered into orbit. Total space shuttle mileage was almost 530 million miles. Although the space shuttle vehicles were far from obsolete, economics and cost finally doomed the program. However, budget problems should not prevent us from realizing that the space shuttle is an engineering marvel, the world’s first reusable spacecraft’s, and proof positive testimony to that ingenuity and dedication of its designers, engineers, operators, and builders. Great job one and all!

For a more complete, detailed and comprehensive history of the space shuttle program, Metropolitan Section members should consult Burt Dicht’s feature article “Shuttle Diplomacy” in the July 2011 issue of Mechanical Engineering Magazine. As usual Burt, another superb job!

 Posted by at 7:55 pm