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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| European Service Module | 2/3 | https://en.wikipedia.org/wiki/European_Service_Module | reference | science, encyclopedia | 2026-05-05T13:10:39.020562+00:00 | kb-cron |
=== Cost reviews and scope changes === A review of the Constellation program in 2009 by the new Augustine Commission prompted by the then new Obama administration had found that five years in, the service module development program was already running four years behind its 2020 lunar target and was woefully underfunded. The only element worth continuing was the Crew Exploration Vehicle in the role of a space station escape capsule. This led in 2010 to the Administration cancelling the program by withdrawing funding in the proposed 2011 budget. A public outcry led to the program being frozen rather than outright cancelled and a review launched in to how costs could be cut, which found that it was possible to continue if there was an emphasis on finding alternate funding, reducing the complexity by narrowing the scope to focus on the Moon and deep space rather than Mars, and by reusing existing hardware, reducing the range of equipment requiring development. The Ares I launcher intended for crew flights had significant design issues such as being overweight and prone to dangerous vibration, and in the case of a catastrophic failure its blast radius exceeded the escape system's ejection range. Its role as the Orion launch vehicle was replaced by the Space Launch System, and the three different Crew Exploration Vehicle designs were merged in to a single Multipurpose Crew Exploration Vehicle.
=== European ATV-based module ===
In May 2011, ESA's director general announced a possible collaboration with NASA to work on a successor to ESA's Automated Transfer Vehicle (ATV). ESA's provision of this successor could be counted towards its 8% share of the operating costs of the International Space Station (ISS); the ATV missions resupplying the station only covered this obligation up to 2017. On 21 June 2012, Astrium announced that it had been awarded two separate studies to evaluate possible future missions building on the technology and experience gained from its development of ATV and the Columbus laboratory. The first study looked into the construction of a service module which would be used in tandem with the Orion capsule. The second examined the production of a versatile multi-purpose orbital vehicle. Each study was worth €6.5 million. In November 2012, ESA obtained the commitment of its member states for it to construct an ATV-derived service module for Orion, to fly on the maiden flight of the Space Launch System, thereby meeting ESA's budgetary obligation to NASA regarding the ISS for 2017–2020. No decision was made about supplying the module for later Orion flights. In January 2013, NASA announced its agreement, made the preceding December, that ESA would build the service module for Exploration Mission-1 (renamed Artemis I), then scheduled to take place in 2017. This service module was not required for Exploration Flight Test-1 in 2014, as this used a test service module supplied by Lockheed Martin. On 17 November 2014 ESA signed a €390 million fixed price contract with Airbus Defence and Space for the development and construction of the first ATV-based service module. In December 2016, ESA's member states agreed it would extend its commitment to the ISS to 2024, and would supply a second service module, as part of the resulting budgetary obligation.
=== Design ===
The service module is approximately 5.0 metres (16.5 ft) in diameter and 4.0 metres (13 ft) in length, and made of aluminium-lithium alloy.
For the first six service modules, the main engine will be a NASA-provided refurbished AJ10-190 previously used with the Space Shuttle Orbital Maneuvering System. For example, the engine used on Artemis I had previously flown on 19 Space Shuttle missions, performing a total of 89 burns. The engine provides 26.6 kilonewtons (6,000 lbf) of thrust. The AJ10 design itself has a long heritage, dating back to 1957 when it was developed for the Vanguard rocket, one of America's earliest launch vehicles. A variant of the AJ10 was also used on the Apollo service module. For future missions, Aerojet Rocketdyne will deliver up to 20 new Orion Main Engines (OME), based on the AJ10 design. In comparison with the Apollo command and service module, which previously took astronauts to the Moon, the European Service Module (ESM) generates approximately twice as much electricity (11.2 kW vs 6.3 kW), weighs nearly 40% less when fully fueled (15,461 kg, vs 24,520 kg) and is roughly the same size (4 m in length excluding engine and 4.1 m vs 3.9 m in diameter) supporting the environment for a slightly (45%) larger habitable volume on the crew module (8.95 m3 vs 6.17 m3) though it will carry 50% less propellant for orbital maneuvers (8,600 kg usable propellant vs 18,584 kg). The ESM will be able to support a crew of four for 21 days which exceeds the 14 day endurance for the three-man Apollo. The new design for the solar arrays, replacing ATK's decagonal (labeled "circular") UltraFlex design, is by Airbus Defence and Space, whose subsidiary, Airbus Netherlands (then known as Dutch Space), built the ATV's X-shaped array of four panels. The ATV's array was expected to generate 4.6 kilowatts. The upgraded version for the service module will generate about 11 kilowatts, and will span about 19 m (62 ft) when extended. In September 2015, Thales Alenia Space signed a contract with Airbus Defence and Space to develop and produce thermomechanical systems for the service module, including structure and micrometeoroid protection, thermal control and consumable storage and distribution. Lockheed Martin is building the two adapters, connecting the service module to the crew module and to the upper stage of the Space Launch System, and also the three fairing panels that are jettisoned after protecting the service module during launch and ascent.
==== From 2017 ====