Enterprise (space shuttle)

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The Enterprise on launch pad SLC-6 at Vandenberg Air Force Base (1985)

The Enterprise ( English for business , enterprise ) is a prototype for the space shuttles from the Space Shuttle program of the US space agency NASA . The internal name is OV-101 . The name "Enterprise" goes back to the fictional spaceship Enterprise from the science fiction series Star Trek .

The space shuttle was used from 1977 to test the flight capabilities of the space shuttles in the atmosphere. In addition, it was built without some important components such as the engine and heat shield and was therefore not capable of flights into space . Plans to retrofit them for this were not implemented for cost reasons. Although the Enterprise remained a prototype, NASA calls it the “first space shuttle”. In 1983 and 1984 it was demonstrated in various European countries, Canada and the USA, and in 1985 it was finally given to the Smithsonian Institution , which exhibited it in the National Air and Space Museum . In April 2012, the space shuttle was brought to New York, where it has since been exhibited in the Intrepid Sea-Air-Space Museum .

history

development

In the 1950s and 1960s, the Soviet Union and the USA competed in the so-called " space race " to see which nation was the first to penetrate into space with a satellite and later with a manned spaceship , which would establish a space station first and which would land the first moon would succeed. Both sides relied on techniques that could only be used once, which was particularly uneconomical because of the high costs. In the USA, therefore, from the mid-1960s onwards, the idea of ​​developing a reusable space transporter that starts like a rocket and returns to earth like an airplane is increased. This should significantly reduce the costs of a space flight and thus herald the commercialization of space travel. Even after the first drafts, however, it quickly became clear that a completely reusable system would be technically disproportionately complex and therefore uneconomical due to its high overall weight. NASA therefore decided on March 15, 1972 on a three-part concept consisting of an orbiter , an external tank and two solid fuel boosters . Only the external tank burns up in the atmosphere after takeoff; the other components return to earth in different ways and can be used again.

Construction and naming

NASA employees and actors from the television series Starship Enterprise in front of the space shuttle on the day of the rollout

On July 26, 1972, NASA awarded the contract to build the orbiter to the aircraft and armaments manufacturer Rockwell . The contract was worth $ 2.6 billion. Agreements followed with Martin Marietta on the production of the external tank on August 16, 1973 and with Morton Thiokol on the production of the solid fuel booster on June 27, 1974.

After extensive detailed planning, on June 4, 1974, Rockwell began manufacturing work on the OV-101 at Air Force Plant 42 in Palmdale, California . The letter combination 'OV' in the internal name stands for “Orbiter Vehicle” (German: “Orbiter Vehicle”), which means the space shuttle without tank and booster. The assembly was completed on March 12, 1976. The main engine and the heat shield were dispensed with, since OV-101 was initially only intended to be used to test how a space shuttle can be flown and landed in the atmosphere. The option of retrofitting the orbiter to full operational capability was ultimately discarded.

On September 17, 1976, the anniversary of the United States Constitution , the space shuttle left the construction site hangar and was unveiled to the public. It was originally supposed to be called "Constitution". However, tens of thousands of fans of the science fiction television series Star Trek (German: Raumschiff Enterprise ) had sent letters to the White House asking the then US President Gerald Ford to name the orbiter after the spaceship from this series . At the same time, the name “Enterprise” has a long tradition in naming US warships and stands for human striving forwards. Star Trek inventor Gene Roddenberry and the actors of the television series were invited to the public premiere of the orbiter and the theme music from Star Trek was played.

Atmospheric flight and landing tests

On January 31, 1977, the Enterprise was transported from Palmdale overland to the Dryden Flight Research Center (DFRC) at Edwards Air Force Base , some 60 kilometers away . There it was subjected to various tests over the next nine months, which were summarized under the name Approach and Landing Tests (literally: "Approach and landing tests"), or ALT for short . Not only was the usability of the space shuttles examined, but also the possibility of piggybacking them on the Shuttle Carrier Aircraft (SCA), a modified Boeing 747 . The ALT program can be divided into three phases: roll tests, coupled flights and free flights.

The first test phase consisted of three taxi tests , so-called taxi tests , all of which took place on February 15, 1977. When taxiing the movement is referred to an aircraft on the ground under its own power. First, the behavior of the piggyback team consisting of the space shuttle and SCA was examined. The Enterprise was mounted on the back of the SCA and had an aerodynamic engine cowling, but remained without a crew and switched off. The SCA accelerated the team up to 253 km / h without taking off from the runway.

The second test phase began three days later when the SCA took off with the Enterprise for the first time . From February to July 1977 the piggyback team completed a total of eight coupled flights ( captive tests ). The engine cowling was all mounted on the stern of the Enterprise . The first five of these flights were only intended to show the team's ability to fly, so that the Enterprise remained switched off and unmanned here as well. The other coupled flights in June and July 1977 also served to prepare for the upcoming free flights. A crew of two astronauts was on board the Enterprise to try out different procedures. For example, at the end of the last coupled flight, the crew extended the landing gear of the Enterprise .

In the third test phase, the Enterprise made a total of five attempts at free flights . The SCA brought the space shuttle to an altitude of between 16,000 and 30,000 feet (about 4.8 to 9.1 kilometers), in which it was separated from the SCA for the first time on August 12, 1977, in order to then independently manage an approach and a landing . The last two free flights were carried out without the aerodynamic fairing in order to simulate an approach including landing as realistically as possible. The space shuttle was still not equipped with its own propulsion system and was landed in gliding flight , as it was later to happen after space missions. The first four landings were on a dry lake, the last on a runway at Edwards Air Force Base.

The approach and landing tests largely corresponded to the courses previously assumed. Some of the problems discovered in the process were resolved immediately. The flight behavior of the Enterprise even exceeded expectations.

  • Team of SCA and Enterprise on the first flight

  • The Enterprise on the second free flight, still with the engine cowling

  • The Enterprise decouples from the SCA in flight

  • Approach and landing without tail fairing

Vibration tests

The Enterprise is heaved into the test stand for a vibration test

Upon completion of the ALT program, the Enterprise was returned to NASA's hangar at DFRC, where it was prepped for subsequent vibration tests. On March 13, 1978, the SCA transported the orbiter to NASA's Marshall Space Flight Center in Huntsville, Alabama . There the orbiter was connected to the external tank and the solid fuel boosters. For the first time, all three main components of the launch configuration of a space shuttle were combined. The combination was subjected to a series of vibration tests , so-called Vertical Ground Vibration Tests , in order to check the stability of the connection and the individual elements and to compare the results with the theoretical mathematical models. In March 1979 these tests were completed. The results essentially confirmed data that had been calculated from experiments with smaller, true-to-scale models. Nevertheless, they led to several changes to the design of the space shuttle, for example the solid fuel boosters in the front part were reinforced. The engineers were confident that the space shuttle would withstand the vibrations of a flight.

Preparations for the first space shuttle mission

The Enterprise on Launch Pad 39A of the Kennedy Space Center

On April 10, 1979, the orbiter was transferred to the Kennedy Space Center by means of the SCA. Preparations for the STS-1 mission , the first space flight of a space shuttle, were already in full swing. The designated shuttle, the Columbia , had arrived two and a half weeks earlier and was being prepared for its maiden flight. Its heat shield was still incomplete, and the main and OMS engines and a large number of sensors were missing . In the meantime, the Enterprise was connected to the outer tank and the solid fuel boosters in the Vehicle Assembly Building and brought from there to launch pad 39A on May 1, 1979 . This came from the Apollo program and had been converted for the space shuttle launches. The adjustments were checked with the help of Enterprise . In particular, it was verified that a space shuttle with an external tank and boosters fit into the launch pad and that the access and maintenance levels were in the right places. During a dress rehearsal lasting almost three months, various procedures were also practiced, for example refueling.

Public relations and retirement

Team of SCA and Enterprise at Cologne / Bonn Airport in May 1983
The Enterprise at Vandenberg AFB Space Launch Complex 6 in February 1985

On August 16, 1979, the Enterprise flew piggyback on the SCA back to the DFRC, from where it was in turn transported overland to the Rockwell manufacturing facility in Palmdale. There, various components were dismantled from the orbiter and prepared so that they could be installed in other space shuttles. After that, the Enterprise was brought back to the DFRC on September 6, 1981.

Meanwhile, in April 1981, Columbia was the first space shuttle to undertake a space flight. It was originally planned to equip the Enterprise with the same systems as the Columbia after its test operations . The installation of engines, heat shields and other components would have made the ferry suitable for space flights, and it would have become the second space shuttle in space after the Columbia . However, because the design of the space shuttles was changed during the construction of the Columbia to save weight, this plan was discarded. In order to adapt the Enterprise to the rest of the shuttle fleet, numerous changes would have been necessary, which is why NASA ultimately decided against such a conversion due to the high costs.

In May and June of 1983 the Enterprise was exhibited in various countries. In France it could be seen at the Paris Air Show , in Germany at Cologne / Bonn Airport , and also in Italy, England and Canada. In 1984 it was shown as an exhibit at the World's Fair in New Orleans .

After that, the space shuttle had its last official mission: the space shuttle was brought from the World's Fair in November 1984 to Vandenberg Air Force Base in California . At the air force base, the SLC-6 launch pad had been rebuilt for space shuttles, and the Enterprise was supposed to prove, as it did at the Kennedy Space Center, that the modifications were successful. It was placed on the ramp together with the external tank and boosters and used for several drainage tests. After the successful tests, the SCA transported the Enterprise back to the DFRC on May 24, 1985. The project was abandoned after the Challenger disaster , so that no other space shuttle was ever on this launch pad.

On November 18, 1985, the Enterprise was transported by the DFRC to Washington, DC , donated to the Smithsonian Institution and thus officially decommissioned.

After the Challenger disaster

On January 28, 1986, the space shuttle Challenger broke 73 seconds after take-off at a height of around 15 kilometers. All seven crew members were killed in the accident, the Challenger disaster was the greatest disaster in space history at the time.

NASA then examined various options for expanding the space shuttle fleet, which now only consists of three orbiters. Among other things, it was considered again to use the Enterprise as a replacement for the Challenger . However, retrofitting them with all the necessary equipment for use in space was too costly. The decision was made in favor of a cheaper new building made from spare parts that had been made during the production of the space shuttles Discovery and Atlantis . The new ferry was named Endeavor .

After the Columbia accident

Shortly before the end of the STS-107 mission , on February 1, 2003, the space shuttle Columbia broke apart while descending over Texas. All seven crew members were killed. Investigations into the crash revealed that damage to the heat shield was the most likely cause. A piece of the foam insulation of the outer tank had broken off during take-off and hit the left wing. In order to show the effects of such a hit, the impact of the foam part was adjusted. For the tests, parts of the leading edge of a wing of the Enterprise were dismantled and foam from the outer tank insulation was shot in the laboratory. The tests confirmed that such a hit could break through the heat shield and thus lead to the destruction of the shuttle upon re-entry .

Museum exhibit

After the Smithsonian received the Enterprise in 1985, it initially stored the ferry inaccessible to the public in a hangar at Washington Dulles International Airport and later exhibited it in the Steven F. Udvar-Hazy Center of the National Air and Space Museum, which was completed in 2003 . There it was the central exhibit for several years.

With the end of the space shuttle program, NASA distributed the fleet as exhibits to various museums in the USA. The National Air and Space Museum was awarded the Discovery, the longest-serving and most widely traveled shuttle. In return, she passed the Enterprise on to another museum. On December 11, 2011, the prototype was sold to New York's Intrepid Sea, Air & Space Museum . On April 17, 2012, the Discovery via SCA arrived in Washington, two days later it replaced the Enterprise there as part of a ceremony outside the museum. After investigations had already shown in early 2010 that a transport of the Enterprise was still safe even after the long standing time, the shuttle was flown by SCA to New York's JFK Airport on April 27, 2012 , where it was loaded onto a barge on June 3, with which it arrived at the Intrepid Sea, Air & Space Museum three days later . The Enterprise was located there on the former aircraft carrier USS Intrepid . During transport, the Enterprise was slightly damaged on a wing tip when it hit a bridge pillar. It has been open to the public as an exhibit since August 30, 2012.

  • The Enterprise as an exhibit in the Steven F. Udvar-Hazy Center of the National Air and Space Museum

  • Ceremonial change in April 2012: The Discovery (right) replaces the Enterprise as an exhibit in the Steven F. Udvar-Hazy Center

  • The SCA will bring the Enterprise to New York in April 2012. Here the team flies over the Intrepid Sea-Air-Space Museum , where the orbiter is now on display.

  • In June 2012, the Enterprise reached the Intrepid Sea-Air-Space Museum

Structural features

As a prototype, initially not equipped for space flight, the Enterprise was missing important components from the start. In addition, the experience gained in its construction and the tests carried out with it resulted in a different design of the later orbiters. The Enterprise therefore differs from its successors in some striking ways.

First of all, it does not have a drive system. Their main and auxiliary power units are only mock-ups, the associated fuel tanks and lines are missing. The cockpit and crew quarters are equipped with only a few displays and control instruments compared to the space-suitable orbiters. Navigation systems such as star sensors or head-up displays are just as absent as displays for the external tank and the solid fuel booster. The Enterprise has no aft windows above the pilots' heads or in the flight deck, and there is no airlock installed. The crew quarters are not equipped for an extended stay of astronauts, for example no galley is installed. The internal power supply was based on batteries instead of the later fuel cells and could not generate the energy necessary for a space flight. The cargo bay has no payload brackets, the cargo bay doors have neither an opening mechanism nor the radiators on the inside that prevent the shuttles from overheating in space. Instead of heat protection tiles , the prototype has tiles made of polyurethane and fiberglass-reinforced plastic that would not have withstood a re-entry into the earth's atmosphere. The landing gear was extended with explosive bolts , the hydraulic mechanisms of the later orbiters are missing, as is a manual reserve system. The Enterprise stands out not only because of the many components that were saved in its construction because they would only have been necessary for space flights. It is also equipped with additional systems that the prototype could use to collect data. For example, she wears a pitot tube on her nose to measure air currents. The other space shuttles have to do without this measuring instrument, since their noses are covered with heat protection.

Mainly the vibration tests to which the Enterprise had been subjected in March 1978, resulted in a number of additional changes to the design of the orbiters built later. The new specifications required lower weight, and the wings and fuselage should be more stable. Various aluminum components were also replaced by titanium parts in the subsequent orbiters in order to save weight. For the same reasons, when the later shuttles were built, the ejection seats with which the Enterprise had been equipped were also dispensed with . In an emergency, the seats made by Lockheed could have catapulted the two pilots through two aluminum panels in the ceiling of the shuttle. Only the Columbia initially also had ejection seats; these were initially deactivated and later expanded.

If retrofitting the systems saved for the test phase had still been relatively inexpensive, the conceptual changes would have made extensive and therefore expensive adjustments necessary; the Enterprise therefore never went into space.

Web links

Commons : Enterprise (space shuttle)  - collection of images, videos and audio files

Remarks

  1. ↑ The final report on the Approach and Landing Tests contains a detailed list of the components that were missing during the test operation and should be added later : Approach and Landing Test Evaluation Team: Space Shuttle Orbiter Approach and Landing Test - Final Evaluation Report . Ed .: NASA . February 1978, Appendix A, p. A-16 ff . (English, Document Online [PDF; accessed on May 2, 2010]).

Individual evidence

  1. ↑ a b c d e f g h i j Enterprise (OV-101). NASA, accessed January 29, 2020 .
  2. ^ Günter Siefarth : History of space travel . CH Beck, Munich 2001, ISBN 3-406-44753-8 , p. 87-88 .
  3. ↑ Background and Status. NASA, accessed March 27, 2010 .
  4. ↑ a b Bernd Leitenberger: The history of the space shuttle. Retrieved January 29, 2020 .
  5. ↑ a b Enterprise in the Encyclopedia Astronautica , accessed on March 27, 2010 (English).
  6. ^ Grassroots Enterprise: How the Space Shuttle got its name. April 23, 2007, accessed January 29, 2020 .
  7. ^ A b Clifford J. Lethbridge: Space Shuttle Approach and Landing Tests Fact Sheet. (No longer available online.) 1998, archived from the original on September 17, 2009 ; accessed on May 26, 2019 (English).
  8. ^ A b Shuttle Enterprise Free Flight. (No longer available online.) NASA, archived from the original on March 7, 2013 ; accessed on May 26, 2019 (English).
  9. ^ Karl Urban: Enterprise (OV-101). February 2, 2002, accessed March 27, 2010 .
  10. ↑ Approach and Landing Test Evaluation Team: Space Shuttle Orbiter Approach and Landing Test - Final Evaluation Report . Ed .: NASA . February 1978 (English, document online [PDF; accessed on May 2, 2010] final report on the ALT program ).
  11. ↑ a b c d Ben Evans: Space shuttle Challenger: ten journeys into the unknown . Springer, 2007, ISBN 978-0-387-46355-1 , pp. 7 (English, preview in Google Book Search [accessed December 21, 2010]).
  12. ^ Dennis R. Jenkins: Space Shuttle: The History of the National Space Transportation System: the First 100 Missions . 3. Edition. Specialty Pr, 2001, ISBN 0-9633974-5-1 (English).
  13. ↑ a b c d e f Molly Swanson: NASA Space Shuttle Enterprise. January 7, 2007, accessed March 28, 2010 .
  14. ↑ Space Shuttle Overview: Challenger (OV-099). NASA, accessed March 28, 2010 .
  15. ^ NASA - Space Shuttle and International Space Station. NASA , accessed April 22, 2010 .
  16. ↑ Space Shuttle Overview: Endeavor (OV-105). NASA, accessed March 28, 2010 .
  17. ^ William Harwood: Critical foam impact test planned for Thursday. June 4, 2003, accessed March 28, 2010 .
  18. ↑ Keith Cowing: Space Shuttle Enterprise Has a New Home. November 22, 2003, accessed May 5, 2010 .
  19. ↑ Mike Thomas: Enterprise Held Space Promise Not Yet Realized. In: Orlando Sentinel. February 16, 2003, accessed May 5, 2010 .
  20. ^ Shuttle Enterprise at Center of Museum's Space Hangar. NASA, October 29, 2004, accessed March 28, 2010 .
  21. ↑ NASA cuts price for retired space shuttles. January 15, 2010, accessed March 28, 2010 .
  22. ^ New Homes for Space Shuttle Orbiters After Retirement. NASA, April 12, 2011, accessed April 13, 2011 .
  23. ^ NASA Transfers Enterprise Title to Intrepid Sea, Air & Space Museum in New York City. NASA, November 23, 2012, accessed April 1, 2012 .
  24. ↑ NASA readies retired test shuttle Enterprise for one last flight. March 15, 2010, accessed March 28, 2010 .
  25. ↑ Chris Bergin: Enterprise in good condition for potential SCA ferry from Smithsonian NASM. March 14, 2010, accessed March 27, 2010 .
  26. ↑ Space Shuttle "Enterprise" landed in New York. April 27, 2012. Retrieved April 27, 2012 .
  27. ^ "Enterprise" is sailing to the museum. In: Welt Online . June 6, 2012, accessed September 12, 2012 .
  28. ↑ "Enterprise" hits New York bridge piers. In: Welt Online . June 6, 2012, accessed June 11, 2012 .
  29. ↑ Meet the space shuttle Enterprise. (No longer available online.) Intrepid Museum, Aug 30, 2012, archived from the original on Sep 12, 2012 ; accessed on May 26, 2019 (English).
  30. ↑ Columbia in the Encyclopedia Astronautica , accessed May 4, 2010.
  31. ↑ "They couldn't do anything". In: Spiegel Online . February 4, 2003, accessed May 2, 2010 (interview on the Columbia accident).
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