Space Shuttle orbiter
From Wikipedia, the free encyclopedia
 The Discovery orbiter approaches the ISS on STS-121 |
|
| Organization | NASA |
|---|---|
| Mission type | Orbiter |
| Satellite of | Earth |
| Launch vehicle | Space Shuttle Solid Rocket Booster |
| Launch site | Kennedy Space Center |
| Home page | Space Shuttle Home |
The Space Shuttle orbiters are the orbital spacecraft of the Space Shuttle program operated by NASA, the space agency of the United States.[1] Each orbiter is a reusable winged "spaceplane", a mixture of rocket, spacecraft, and aircraft. The spaceplane can carry crews and payloads into Earth orbit, perform on-orbit operations, then re-enter the atmosphere and land as a glider, returning its crew and any on-board payload to Earth.
In addition to the crew and payload the reusable orbiter carries most of the main propulsion system, but the propellant for its three main engines is fed from an external tank, and two reusable solid rocket boosters help propel both the orbiter and the external tank during the first two minutes of ascent.
Contents |
[edit] Description
[edit] Attitude control
The Orbiter resembles an aircraft with double-delta wings, swept 81° at the inner leading edge and 45° at the outer leading edge. Its vertical stabilizer's leading edge is swept back at a 45° angle. The four elevons, mounted at the trailing edge of the wings, and the rudder/speed brake, attached at the trailing edge of the stabilizer, with a movable body flap, control the Orbiter during the later stages of descent and landing. It is roughly the size of a McDonnell Douglas DC-9.
The Reaction Control System (RCS) comprises 44 smaller thrusters and provides attitude control and translation along the pitch, roll, and yaw axes during the flight phases of orbit insertion, orbit, and re-entry. The forward RCS jets near the nose of the Orbiter include 12 primary and two vernier RCS engines. The aft RCS engines are located in the OMS pods of the vehicle and include 12 primary and two vernier RCS engines in each pod. The RCS system provides fine control of the Orbiter and is used for the maneuvering during the rendezvous pitch maneuver, docking and undocking with the International Space Station as well as for controlling attitude during much of the reentry.[2]
[edit] Crew provisions
The Orbiter's crew cabin consists of three levels: the flight deck, the mid-deck, and the utility area. The uppermost is the flight deck which seats the commander and pilot, with two mission specialists behind them. The mid-deck, which is below the flight deck, has three more seats for the rest of the crew members. The galley, toilet, sleep locations, storage lockers, and the side hatch for entering and exiting the vehicle are also located on the mid-deck, as is the airlock hatch. The airlock has another hatch into the payload bay. It allows two astronauts, wearing their Extravehicular Mobility Unit (EMU) space suits, to depressurize before a space walk.
[edit] Payload bay
The Orbiter has a large 60 by 15 ft (18 m by 4.6 m) payload bay which is vented to vacuum, filling most of the mid-fuselage. The payload bay doors have heat radiators mounted on their inner surfaces, and so are kept open for thermal control while the Shuttle is in orbit. Thermal control is also maintained by adjusting the orientation of the Shuttle relative to Earth and Sun. Inside the payload bay is the Shuttle Remote Manipulator System (SMRS), also known as the "Canadarm", a robot arm used to retrieve and deploy payloads. Until the loss of Columbia, the Canadarm had been used only on those missions where it was needed. Since that mission, the arm has become a crucial part of the thermal protection inspection procedures now required for Shuttle flights. Therefore, it is likely that the Canadarm will be included on all future flights.[citation needed] Three fuel cells are located under the payload bay area. They consume onboard liquid oxygen and liquid hydrogen stores to generate all the electrical power for the vehicle from launch to landing.
[edit] Propulsion
Three Space Shuttle Main Engines (SSMEs) are mounted on the Orbiter's aft fuselage in a triangular pattern. The three engines can swivel 10.5 degrees up and down and 8.5 degrees from side to side during ascent to change the direction of their thrust and steer the Shuttle as well as provide thrust. The aft fuselage also houses three auxiliary power units. The APUs are hydrazine-fueled turbopumps to provide hydraulic pressure for the hydraulic system, which gimbals the three main engines, controls aerosurfaces, and deploys the landing gear.
Two Orbital Maneuvering System (OMS) thusters are mounted in two separate pods in the Orbiter's aft fuselage, located between the SSMEs and the vertical stabilizer of the Orbiter. The OMS engines provide significant thrust for coarse orbital maneuvers, including insertion, circularization, transfer, rendezvous, deorbit, abort to orbit, and abort once around[3].
[edit] Thermal protection
The Thermal Protection System (TPS) covers the outside of the Orbiter, protecting it from the cold soak of -121 °C (-250 °F) in space to the 1649 °C (3000 °F) heat of re-entry.
[edit] Structure
The orbiter structure is made primarily from aluminum alloy, although the engine thrust structure is made from titanium alloy. The windows are made of aluminum silicate glass and fused silica glass, and comprise an internal pressure pane, a 1.3 inch thick optical pane, and an external thermal pane[4]. The windows are tinted with the same ink used to make American banknotes[5].
[edit] Undercarriage
The orbiter has 3 sets of wheels that deploy downwards through the heat shield. Once deployed they cannot be retracted in flight, and as premature deployment could be catastrophic, they are the only flight function that must be manually activated.
[edit]
The shuttle has neither anti-collision, navigation nor landing lights. When landing at night the runway is flooded with light from ground spotlights.
[edit] Specifications
(for Endeavour, OV-105)
- Length: 122.17 ft (37.24 m)
- Wingspan: 78.06 ft (23.79 m)
- Height: 58.58 ft (17.25 m)
- Empty Weight: 151,205 lbs (68,586.6 kg)
- Gross Liftoff Weight: 240,000 lbs (109,000 kg)
- Maximum Landing Weight: 230,000 lbs (104,000 kg)
- Main Engines: Three Rocketdyne Block 2 A SSMEs, each with a sea level thrust of 393,800 lbf (178,624 kgf / 1.75MN)
- Maximum Payload: 55,250 lb (25,061.4 kg)
- Payload Bay dimensions: 15 ft by 60 ft (4.6 m by 18.3 m)
- Operational Altitude: 100 to 520 nm (185 to 1,000 km)
- Speed: 25,404 ft/s (7,743 m/s, 27,875 km/h, 17,321 mph)
- Crossrange: 1,085 nautical miles (2,009.4 km)
- Crew: 6-7 (Commander, Pilot, 4-5 Mission Specialists and/or Payload Specialists), 2 (Commander and Pilot) for minimum.
- Crew Compartment Space: 2,325 cu.ft (With internal airlock) or 2,625 cu.ft (With external airlock inside the payload bay)
The orbiter's maximum glide ratio/lift-to-drag ratio varies considerably with speed, ranging from 1:1 at hypersonic speeds, 2:1 at supersonic speeds and reaching 4.5:1 at subsonic speeds during approach and landing.[6]
[edit] Fleet
Individual Orbiters are both named in a manner similar to ships, and numbered using the NASA Orbiter Vehicle Designation system. While all Orbiters are externally very similar, they have minor internal differences; new equipment is fitted on a rotating basis as they are maintained, and the newer Orbiters tend to have a lighter structure.
| Test Articles | |||
|---|---|---|---|
| Number | Name | Notes | |
|
|
- | Shuttle Avionics Integration Laboratory replica for avionic system testing and training | |
|
|
Pathfinder | Orbiter Simulator for moving and handling tests | |
|
|
- | Testbed for propulsion and fuel delivery systems | |
|
|
- | Structural test article used for stress and thermal testing, later became Challenger | |
|
|
Enterprise | Used for approach and landing tests, not suitable for spaceflight | |
| Orbiters | |||
| Number | Name | Notes | |
|
|
Challenger | Destroyed after liftoff - January 28, 1986 | |
|
|
Columbia | Destroyed during reentry February 1, 2003 | |
|
|
Discovery | First launched on August 30, 1984 | |
|
|
Atlantis | First launched on October 3, 1985 | |
|
|
Endeavour | First launched on May 7, 1992 | |
- Enterprise was a prototype designed to test Space Shuttle behavior in atmospheric flight. It is currently on display at the Smithsonian's National Air and Space Museum Steven F. Udvar-Hazy Center at Dulles International Airport.
- Columbia first launched on April 12, 1981. On February 1, 2003, Columbia disintegrated during re-entry on its 28th mission.
- Challenger first launched on April 4, 1983. On January 28, 1986 it broke up 73 seconds after the launch of its 10th mission.
- Discovery first launched on August 30, 1984. It has flown 35 missions and is still operational today. It was NASA's Return to Flight vehicle, following the Challenger and Columbia disasters. It is due to be retired in 2010.
- Atlantis first launched on October 3, 1985. It has flown 30 missions and is still operational today. It is scheduled to be retired in 2010.
- Endeavour first launched on May 7, 1992. It has flown 22 missions and is still operational today. It is due to be retired in 2010.
In addition to the test articles and Orbiters produced for use in the Shuttle program, there are also various mockups on display throughout the world:
- Space Shuttle Explorer, a full scale replica of an Orbiter at the Kennedy Space Center visitor's complex
- Space Shuttle Adventure, a full scale mockup of an Orbiter mid-deck and flight deck at Space Center Houston
- Space Shuttle America, a full-scale mockup of the actual space shuttle for a theme park attraction
- Space Shuttle Pathfinder, a full-scale mockup of the actual space shuttle displayed at Space Camp in Huntsville, Alabama
[edit] Flight statistics
| Shuttle | Flights | Flight days | Orbits | Longest flight | First flight | Last flight | Mir/ISS docking |
||
|---|---|---|---|---|---|---|---|---|---|
| STS | Date | STS | Date | ||||||
| Columbia † | 28 | 300d 17h 46m 42s | 4,808 | 17d 15h 53m 18s | STS-1 | Apr 13, 1981 | STS-107 † | Jan 16, 2003 | 0 / 0 |
| Challenger † | 10 | 62d 07h 56m 15s | 995 | 08d 05h 23m 33s | STS-6 | Apr 04, 1983 | STS-51-L † | Jan 28, 1986 | 0 / 0 |
| Discovery | 37 | 337d 01h 13m 19s | 4,764 | 15d 02h 24m 02s | STS-41-D | Aug 30, 1984 | STS-128 | Aug 28, 2009 | 1 / 10 |
| Atlantis | 31 | 282d 00h 00m 28s | 4,602 | 13d 20h 12m 44s | STS-51-J | Oct 03, 1985 | STS-129 | Nov 16, 2009 | 7 / 10 |
| Endeavour | 23 | 266d 15h 33m 20s | 4,212 | 16d 15h 08m 48s | STS-49 | May 07, 1992 | STS-127 | Jul 15, 2009 | 1 / 10 |
| Total | 129 | 1248d 18h 30m 04s | 19,381 | 9 / 30 | |||||
† No longer in service (destroyed)
[edit] See also
 |
Wikimedia Commons has media related to: Space Shuttle orbiters |
[edit] References
- ^ "Facts About the Space Shuttles". NASA. http://www.nasa.gov/centers/kennedy/shuttleoperations/orbiters/orbiters_toc.html.
- ^ "HSF - The Shuttle". Spaceflight.nasa.gov. http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/rcs/overview.html. Retrieved 2009-07-17.
- ^ "Orbital Maneuvering System". Science.ksc.nasa.gov. http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-oms.html#sts-oms. Retrieved 2009-07-17.
- ^ "STS-113 Space Shuttle Processing Questions & Answers (NASA KSC)". Ksc.nasa.gov. 2002-11-15. http://www.ksc.nasa.gov/nasadirect/archives/KSCDirect/archives/launch/sts113/day1/sspqa.htm. Retrieved 2009-07-17.
- ^ "www.kansascity.com". Web.archive.org. http://web.archive.org/web/20080117121138/http://www.kansascity.com/105/story/441167-p4.html. Retrieved 2009-07-17.
- ^ http://klabs.org/DEI/Processor/shuttle/shuttle_tech_conf/1985008580.pdf
[edit] External links
|
||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||
