Service module

A service module (or equipment module) is a spacecraft compartment containing a variety of support systems used for spacecraft operations. Usually located in the uninhabited area of the spacecraft, the service module is jettisoned upon the completion of the mission, and usually burns up during atmospheric reentry. The service module is the equivalent to the spacecraft bus assembly on unmanned spacecraft.

Design

Depending upon the spacecraft architecture and system design, a typical service module will usually contain the following:^{[citation needed]}

• Fuel cells, solar panels, or batteries to provide electrical power to the spacecraft (batteries are also used in the crew capsule)
• Liquid hydrogen (LH₂) and liquid oxygen (LOX) for fuel cell operation and water production, with LOX also being used to provide breathing oxygen for the crew.
• Pressurized helium or nitrogen to force consumables and fuel from source tanks to their destinations.
• Guidance computer systems and related sensors
• Fuel and oxidizer for reaction control and propulsion systems.
• Thermal control systems for proper heating and cooling of above systems.

While this would be used for a "baseline" service module, a service module may also be modified for additional functions. An example would be the equipment module on Gemini IX-A, when it was modified to carry the U.S. Air Force-developed Astronaut Maneuvering Unit that would have been tested by astronaut Eugene Cernan, but was cancelled when his spacesuit overheated, causing his visor to fog up. But the best example would be the final three Apollo missions, in which the J-series service modules included scientific instrument module (SIM) bays that took pictures and other readouts in lunar orbit. In addition to the film cameras, similar to those used on the Lunar Orbiter spacecraft and requiring the Command Module Pilot to perform a deep-space EVA during the return trip, two of the SIM bays, on Apollos 15 and 16, also launched a lunar "subsatellite" before the astronauts performed the Trans-Earth Injection burn with the onboard service propulsion system.^{[citation needed]}

Russian variation

The Russian phrase for service module for the Soyuz spacecraft is sometimes more directly translated "Instrument-Assembly Compartment." This comes from the design feature of having the guidance and other computer systems in a separate pressure chamber (the instruments) from the rocket engines, their propellant tanks, and the life support tanks (from the German Aggregat, which gets translated "assembly"). The Russians do not use the word "module" for their own spacecraft, though it is in the Russian language.

List of service modules

Current spacecraft

• Soyuz service module
• Shenzhou service module

Retired spacecraft

• Vostok equipment module
• Voskhod equipment module
• Gemini equipment module
• Apollo service module
• Apollo lunar module descent stage

Proposed, cancelled, or in development

• Orion service module (In development)
• Crewed ATV service module (Proposed)
• CSTS service module (Cancelled)
• Kliper service module (Cancelled)
• Hermes resource module (Cancelled)

See also

• Orbital module
• Reentry capsule
• Command module
• Space capsule

References

v t e Soyuz programme Main topics Soyuz (rocket family) Soyuz (spacecraft) List of Soviet manned space missions List of Russian manned space missions Unmanned missions Kosmos 133 Kosmos 140 Kosmos 186 Kosmos 188 Kosmos 212 Kosmos 213 Kosmos 238 Soyuz 2 Kosmos 379 Kosmos 396 Kosmos 434 Kosmos 496 Kosmos 573 Kosmos 613 Kosmos 638 Kosmos 656 Kosmos 670 Kosmos 672 Kosmos 772 Soyuz 20 Kosmos 869 Kosmos 1001 Soyuz 32 (at landing) Kosmos 1074 Soyuz 34 (at start) Soyuz T-1 Soyuz TM-1 Manned missions Past Soyuz 7K-OK (1967–1970) 1 3 4 5 6 7 8 9 Soyuz 7K-OKS (1971) 10 11 Soyuz 7K-T (1973–1981) 12 13 14 15 17 18a 18 21 23 24 25 26 27 28 29 30 31 32 (at start) 33 34 (at landing) 35 36 37 38 39 40 Soyuz 7K-TM (1974–1976) 16 19 22 Soyuz-T (1976–1986) T-2 T-3 T-4 T-5 T-6 T-7 T-8 T-9 T-10-1 T-10 T-11 T-12 T-13 T-14 T-15 Soyuz-TM (1986–2003) TM-2 TM-3 TM-4 TM-5 TM-6 TM-7 TM-8 TM-9 TM-10 TM-11 TM-12 TM-13 TM-14 TM-15 TM-16 TM-17 TM-18 TM-19 TM-20 TM-21 TM-22 TM-23 TM-24 TM-25 TM-26 TM-27 TM-28 TM-29 TM-30 TM-31 TM-32 TM-33 TM-34 Soyuz-TMA (2003–2012) TMA-1 TMA-2 TMA-3 TMA-4 TMA-5 TMA-6 TMA-7 TMA-8 TMA-9 TMA-10 TMA-11 TMA-12 TMA-13 TMA-14 TMA-15 TMA-16 TMA-17 TMA-18 TMA-19 TMA-20 TMA-21 TMA-22 Soyuz-TMA-M (2010–2013) TMA-01M TMA-02M TMA-03M TMA-04M TMA-05M TMA-06M TMA-07M TMA-08M TMA-09M Current Soyuz-TMA-M (2013–2014) TMA-10M TMA-11M Planned Soyuz-TMA-M (2014–2015) TMA-12M TMA-13M TMA-14M TMA-15M TMA-16M TMA-17M TMA-18M TMA-19M Launch sites Baikonur Cosmodrome Site 1/5 Site 31/6

v t e Missions of the Apollo program Rocket tests SA-1 SA-2 SA-3 SA-4 SA-5 AS-203 Abort tests QTV Pad Abort Test-1 A-001 A-002 A-003 Pad Abort Test-2 A-004 Boilerplate tests A-101 A-102 A-103 A-104 A-105 Unmanned missions AS-201 AS-202 Apollo 4 Apollo 5 Apollo 6 Skylab 1 Low Earth orbit missions Apollo 7 Apollo 9 Skylab 2 Skylab 3 Skylab 4 Apollo–Soyuz Test Project Lunar orbit missions Apollo 8 Apollo 10 Lunar landing missions Apollo 11 Apollo 12 Apollo 14 Apollo 15 Apollo 16 Apollo 17 Failed missions Apollo 1 (AS-204) Apollo 13 List of missions Mission types Canceled missions

v t e Constellation program Launch tests Ares I-X Pad Abort 1 Ares I-Y (cancelled) Ares V-Y (cancelled) Later missions List of Constellation missions Orion Asteroid Mission Orion Mars Mission Components Orion Crew Exploration Vehicle Ares I Ares V Earth Departure Stage Altair J-2X RS-68 Shuttle-Derived Launch Vehicle Launch sites Kennedy Space Center Launch Complex 39 Abort Orion abort modes Orion Abort Test Booster Launch Abort System (LAS) Max Launch Abort System (MLAS) Related topics Vision for Space Exploration Exploration Systems Architecture Study DIRECT Constellation Space Suit Advanced Technology Large-Aperture Space Telescope (AT-LAST) NASA Authorization Act of 2005 Augustine Commission List of missions