Spacelab

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Section through the Spacelab: tunnel, printing module and two pallets (from left)

The Spacelab was a reusable space laboratory for carrying out scientific experiments and observations in weightlessness, which was designed exclusively for use with the space shuttle . It could also be integrated into the orbiter's cargo bay. The Spacelab was developed and built on behalf of ESA by a European consortium of companies under the leadership of the German main contractor VFW-Fokker / ERNO .

The Spacelab first flew in 1983 on the STS-9 mission and was deployed a total of 22 times before it was decommissioned in 1998. Of these 22 Spacelab missions, 16 were carried out with and 6 without the pressure module. In addition, NASA repeatedly uses the pallets to be able to transport individual payloads or instrument assemblies. By the end of the shuttle, these carriers had been used on 19 other missions and, among other things, brought radar antennas into space ( STS-99 ) or components to the International Space Station (ISS). These pallets were last used for the transport of the Dextre robotic hand in March 2008 and the last HST-SM4 mission to modernize the Hubble space telescope in May 2009.

In April 1998, the STS-90 was the last deployment of the Spacelab module, which was then decommissioned. Since then, scientific missions have been flown with the smaller Spacehab . NASA needed most of the shuttle capacity to bring the space station's modules into orbit. Since the ISS was put into operation by the first crew in early November 2000, research has mainly taken place there.

Development history

Even before the first moon landing , NASA made the European Space Research Organization (ESRO), ESA's predecessor , an offer in 1969 to participate in the US space program of the post- Apollo era. Spacelab was also among the proposals from NASA. Shortly after the USA officially made the decision to build the space shuttle in 1972 , the science ministers announced at the European space conference in December that they would develop and build the space shuttle laboratory. The final contract between ESRO and NASA was signed in September 1973. And in June of the following year, the European space organization awarded the contract to build the Spacelab to the consortium of companies led by VFW-Fokker / ERNO.

The European-American agreement stipulated that ESRO would be responsible for the design, development, construction and delivery of the Spacelab at its own expense. NASA committed to its use and operation with the shuttle and also agreed to support the company consortium in the development. Europe had to deliver an engineering model, a flight unit, two facilities for ground tests, spare parts and the associated documentation. The order for further flight units and the associated equipment was also part of the contract. NASA had to order this from the Europeans at a price to be negotiated.

A total of three consortia applied for the Spacelab tender: Cosmos under the direction of Messerschmitt-Bölkow-Blohm , the star group led by BAC and MESH with ERNO at the top.

In 1972 ESRO commissioned three feasibility studies for a room laboratory. This should describe the prerequisites and requirements and present initial concepts. Very early in 1973, Star withdrew his application. The two other bidders prepared definition studies and submitted their offers in February 1974. The modular principle proposed by MESH convinced ESRO because it could be flexibly adapted to the different tasks. Above all, the superior technical concept and the higher level of preparation were highlighted.

construction

Spacelab was a modular system that consisted of four elements that could be combined with each other and put together depending on the task: a cylindrical pressure module, a connecting tunnel, the pallet and a tracking unit called Instrument Pointing System (IPS). There was also the igloo, which was responsible for the energy supply, communication and data processing for pallet-only flights.

Print module

The printing module was developed by Aeritalia , now Alenia , in Turin. It was made of a special aluminum alloy and consisted of the core and the experiment segment. Although all module flights were carried out with this long version, it was also possible to use only the short module consisting of the core segment (length 4.27 meters).

Structure of the double module

The Long Module was 6.96 meters long and had an outer diameter of 4.12 meters and a curb weight of 7.5 tons (maximum payload 5.5 tons). It offered space for three scientific astronauts and was equipped with storage cupboards on the sides in which the experiments were housed. If necessary, a window or an airlock could be built into the ceiling of each segment through a 1.30 meter wide opening (these options were never flown due to NASA safety concerns). The power supply and air conditioning were housed under the floor panels.

The compilation and assembly of the various storage cabinets took place outside the module: Once the planning of a mission was completed, the required payload cabinets were installed on the removable bottom of the pressure module. This “payload train” was functionally tested with a simulator, pushed into the module and closed with the rear cone. The dismantling after the flight was done in reverse order.

Print module before installation in the payload bay (STS-94)

In total - in addition to a hard mock-up, which is now in the Deutsches Museum in Munich, an engineering model (EM) that was delivered to NASA for interface tests - two airworthy print modules were built: FU 1 (Flight Unit 1; serial number MD001) was made by paid by ESA and made available to NASA in exchange for flight opportunities for European astronauts; the FOP (Follow-On Production; serial number MD002) was bought by NASA. The main contractor of the Spacelab was the forerunner of EADS Space Transportation , VFW-Fokker / ERNO in Bremen. The engineering model (EM) is in a warehouse at NASA Ames Flight Research Center near San Francisco and cannot be viewed.

The first module to be built is now on the premises of Dulles International Airport near Washington (DC) . The laboratory is part of the Steven F. Udvar-Hazy Center of the National Air and Space Museum and is located right next to the space shuttle Discovery .

The second Spacelab module (MD002) was officially handed over to ESA in April 1999 and brought to its “home town” and then stood for ten years at Bremen Airport in the “Bremenhalle”. Before it got its final location, the Spacelab was the main exhibit of the city of Bremen in the German Pavilion in the summer of 2000 at the Expo in Hanover. The Spacelab module has been in building 4c of the Airbus Space and Defense company (formerly: Astrium) near Bremen Airport since 2010. It can only be viewed as part of guided tours through the BTZ (Bremer Tourismus Zentrale).

Connecting tunnel

The pressure module could not be connected directly to the crew cabin of the space shuttle because it was not allowed to be installed in the front part of the cargo hold. This would have shifted the orbiter's center of gravity and it would have become bow-heavy.

Spacelab connecting tunnel

A connecting tunnel was used to ensure constant access for the astronauts. This firmly connected the Spacelab module to the shuttle's airlock. It could be used in two lengths (2.66 meters and 5.75 meters), had an inner diameter of 1.02 meters and was manufactured by McDonnell Douglas in California .

Pallets

Computer graphics of a palette

British Aerospace developed pallets for instruments and experiments that were to be directly exposed to space . Like the pressure module, they were firmly anchored in the payload bay. For example, test setups for research in a vacuum or telescopes that had such a large field of view could be mounted on them. The pallets were U-shaped, each 2.87 meters long and a maximum of 4.35 meters wide (upper inner diameter 3.95 meters). The width of the floor space and the interior height were 1.78 meters each. A pallet had a mass of 725 kilograms and could carry a maximum load of 3100 kilograms.

IPS

The IPS systems
40 Pf postage stamp of the definitive series Industry and Technology of the Deutsche Bundespost

Dornier developed the tracking unit called IPS (Instrument Pointing System) especially for telescopes and radar systems. This had the task of aligning the devices installed on the pallets to a specific point (star) and tracking them over a longer period of time. The IPS had a net weight of 1180 kilograms, was 3-axis stabilized and designed for instruments with a mass of up to 7000 kilograms. The alignment accuracy was 2.0  arc seconds and the precision of the tracking was 1.2 arc seconds. A total of two IPS were built. Serial number 1 is in the Steven F. Udvar-Hazy Center of the National Air and Space Museum near Washington, DC . The serial number 2 is in the exhibition of the Dornier Museum in Friedrichshafen.

igloo

Another Spacelab element was the igloo. It was a pressure-regulated aluminum container that was attached vertically to the front of the foremost pallet. It contained the experiments mounted on the pallets and the subsystems necessary for the Freon cooling circuit. The igloo was always used when a mission was carried out exclusively with pallets. Otherwise, the supply was via the pressure module. The cylindrical igloo was 2.37 meters high, 1.08 meters in diameter and weighed 250 kilograms when empty. Equipped with the electronics, the cooling circuit and the data processing, the weight was 625 kilograms.

Flight configurations

Flight configurations

The Spacelab system was designed for eight flight configurations. This made it possible to carry out a variety of experiments both within the module and on the pallets under the space environment. The maximum payload mass shown served for the first mission planning; As soon as the payload was defined, the local restrictions had to be taken into account (e.g. the space shuttle at the end of the payload bay can only take lighter loads than in the middle, so that one rear pallet may be less loaded with the same load-bearing capacity of the pallets). With the final payload, dynamic analyzes coupled with the Space Shuttle, Spacelab including the payload and any other additional loads were then carried out by NASA in order to show that all loads were within the specified limits.

Each element was qualified for a life of ten years or 50 missions, whichever comes first. NASA carefully monitored each element and found no aging, so most elements could be used for more than ten years. The pallets in particular (without igloo) were used until the very end as carriers when transporting ISS parts through the space shuttle.

Spacelab missions

flight date Orbiter designation elements
STS-2 November 1981 Columbia OSTA-1 1 pallet
STS-3 March 1982 Columbia OSS-1 1 pallet
STS-9 November / December 1983 Columbia Spacelab 1 Module (MD001) + 1 pallet
STS-41-G October 1984 Challenger OSTA-3 1 pallet
STS-51-A October 1984 Discovery Retrieval 2 Com-Sats 2 pallets
STS-51-B April / May 1985 Challenger Spacelab 3 Module (MD001)
STS-51-F July / August 1985 Challenger Spacelab 2 3 pallets + igloo + IPS
STS-61-A October / November 1985 Challenger Spacelab D1 Module (MD002)
STS-35 December 1990 Columbia Astro-1 2 pallets + igloo + IPS
STS-40 June 1991 Columbia SLS-1 Module (MD001)
STS-42 January 1992 Discovery IML-1 Module (MD002)
STS-45 March / April 1992 Atlantis ATLAS-1 2 pallets + igloo
STS-50 June / July 1992 Columbia USML-1 Module (MD001)
STS-46 July / August 1992 Atlantis TSS-1 1 pallet
STS-47 September 1992 Endeavor Spacelab-J Module (MD002)
STS-56 April 1993 Discovery ATLAS-2 1 pallet + igloo
STS-55 April / May 1993 Columbia Spacelab D-2 Module (MD001)
STS-58 October / November 1993 Columbia SLS-2 Module (MD002)
STS-61 December 1993 Endeavor HST-SM1 1 pallet
STS-59 April 1994 Endeavor SRL-1 1 pallet
STS-65 July 1994 Columbia IML-2 Module (MD001)
STS-64 September 1994 Discovery LITE 1 pallet
STS-68 September / October 1994 Endeavor SRL-2 1 pallet
STS-66 November 1994 Atlantis ATLAS-3 1 pallet + igloo
STS-67 March 1995 Endeavor Astro-2 2 pallets + igloo + IPS
STS-71 June / July 1995 Atlantis Spacelab-Mir Module (MD002)
STS-73 October / November 1995 Columbia USML-2 Module (MD001)
STS-78 June / July 1996 Columbia LMS Module (MD002)
STS-82 February 1997 Discovery HST-SM2 1 pallet
STS-83 April 1997 Columbia MSL-1 Module (MD001)
STS-94 July 1997 Columbia MSL-1R Module (MD001)
STS-90 April / May 1998 Columbia Neurolab Module (MD002)
STS-103 December 1999 Discovery HST-SM3 1 pallet
STS-99 February 2000 Endeavor SRTM 1 pallet
STS-92 October 2000 Discovery ISS 3A 1 pallet
STS-100 April / May 2001 Endeavor ISS-6A 1 pallet
STS-104 July 2001 Atlantis ISS-7A 2 pallets
STS-109 March 2002 Columbia HST-SM 3B 1 pallet
STS-123 September 2008 Endeavor ISS-1J / A 1 pallet
STS-125 May 2009 Atlantis HST-SM4 1 pallet

See also

literature

  • Niklas Reinke: History of the German space policy. Concepts, influencing factors and interdependencies 1923–2002. Oldenbourg, Munich 2004, ISBN 3-486-56842-6 , pp. 144-153.
  • Horst Wilhelm: Spacelab. Volume 1: Europe's entry into manned space travel. Stedinger Verlag, Lemwerder 2010, ISBN 978-3-927697-59-1 .

Web links

Commons : Spacelab  - collection of images, videos and audio files