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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| European Service Module | 1/3 | https://en.wikipedia.org/wiki/European_Service_Module | reference | science, encyclopedia | 2026-05-05T13:10:39.020562+00:00 | kb-cron |
The European Service Module (ESM) is the service module component of the Orion spacecraft, serving as its primary power and propulsion component until it is discarded at the end of each mission. In January 2013, the National Aeronautics and Space Administration (NASA) announced that the European Space Agency (ESA) will contribute the service module for Artemis I, based on ESA's Automated Transfer Vehicle (ATV). It was delivered by Airbus Defence and Space from Bremen, Germany, to NASA at the end of 2018. After approval of the first module, ESA provided the ESM for Artemis II with current plans to continue the provision up to Artemis VI. The module's first flight was Artemis I, the first major milestone in NASA's Artemis program to return humans to the Moon, on November 16, 2022. The Space Launch System launched Orion toward the Moon, where the ESM placed the spacecraft into distant retrograde orbit around the Moon, and subsequently extracted it from that orbit and sent it back to Earth. The service module (SM) supports the crew module (CM) from launch through to separation prior to reentry. It provides in-space propulsion capability for orbital transfer, attitude control, and high altitude ascent aborts. It provides the water and oxygen needed for a habitable environment, generates and stores electrical power, and maintains the temperature of the vehicle's systems and components. This module can also transport unpressurized cargo and scientific payloads.
== History ==
=== Initial design ===
Roughly cylindrical in shape, the original American-designed Orion SM, like the CM, would have been constructed of aluminium–lithium alloy (to keep weight down), and would have featured a pair of deployable decagonal solar panels, similar in design to the panels used on the Mars Phoenix lander. The panels, the first to be used on a U.S. crewed spacecraft (except for a 10-year period, the Soviet/Russian Soyuz spacecraft has used them since the first mission in 1967), would allow NASA to eliminate the need to carry malfunction-prone fuel cells, and their associated hardware (mainly liquid hydrogen tanks) in the SM, resulting in a shorter and more maneuverable spacecraft. Successful initial testing of an Orion solar array design using full-scale "UltraFlex wing" hardware was reported in October 2008. The Orion Main Engine (OME) was a 33-kilonewton-thrust (7,500 lbf), pressure-fed, regeneratively cooled, storable bi-propellant rocket engine to be made by Aerojet. The OME was an increased performance version of the 27-kilonewton-thrust (6,000 lbf) rocket engine used by the Space Shuttle for its Orbital Maneuvering System. The SM Reaction Control System (RCS), the spacecraft's maneuvering thrusters (originally based on the Apollo "quad" system, but resembling that used on its predecessor, Gemini), would also be pressure-fed, and would use the same propellants. NASA believed the SM RCS would be able to act as a backup for a trans-Earth injection burn in case the main SM engine failed. A pair of liquid oxygen tanks (similar to those used in the Apollo service module) would provide, along with small tanks of nitrogen, the crew with breathing air at sea-level or "cruising altitude" pressure (1 or 0.7 atm), with a small "surge tank" providing necessary life support during reentry and touchdown. Lithium hydroxide (LiOH) cartridges would recycle the spacecraft's environmental system by "scrubbing" the carbon dioxide (CO2) exhaled by the astronauts from ship's air and adding fresh oxygen and nitrogen, which was then cycled back out into the system loop. Because of the switch from fuel cells to solar panels, the service module would have an onboard water tank to provide drinking water for the crew, and (when mixed with glycol), cooling water for the spacecraft's electronics. Unlike the practice during Apollo of dumping both water and urine overboard during the flight, the Orion would have an onboard recycling system, identical to that used on the International Space Station, to convert both waste water and urine into both drinking and cooling water. The service module also mounted the spacecraft's waste heat management system (its radiators) and the aforementioned solar panels. These panels, along with backup batteries located in the Orion CM, would provide in-flight power to the ship's systems. The voltage, 28 volts DC, was similar to that used on the Apollo spacecraft during flight. The Orion SM would be encapsulated by fiberglass shrouds jettisoned at the same time as the LES/Boost Protective Cover, which would take place roughly 2+1⁄2 minutes after launch (30 seconds after the solid rocket first stage was jettisoned). Prior to the "Orion 606" redesign, the Orion SM resembled a squat, enlarged version of the Apollo service module. The "Orion 606" SM design retained the 5-meter (16 ft) width for the attachments of the Orion SM with the Orion CM, but used a Soyuz-like service module design to allow Lockheed Martin to make the vehicle lighter in weight and permitting the attachment of the decagonal solar panels at the module's midpoints, instead of at the base near the spacecraft/rocket adapter, which might have subjected the panels to damage. The Orion service module (SM) was projected comprising a cylindrical shape, having a diameter of 5 m (16 ft) and an overall length (including thruster) of 4.78 m (15 ft 8 in). The projected empty mass was 3,600 kg (8,000 lb), fuel capacity was 8,200 kg (18,000 lb).