SPACE SHUTTLE   
Shuttle Basics

Parts of the Space Transportation System The Space Shuttle is the world's first reusable spacecraft, and the first spacecraft in history that can carry large satellites both to and from orbit. The Shuttle launches like a rocket, maneuvers in Earth orbit like a spacecraft and lands like an airplane. Each of the three Space Shuttle orbiters now in operation -- Discovery, Atlantis and Endeavour -- is designed to fly at least 100 missions. So far, altogether they have flown a combined total of less than one-fourth of that.

Columbia was the first Space Shuttle orbiter to be delivered to NASA's Kennedy Space Center, Fla., in March 1979. Columbia and the STS-107 crew were lost Feb. 1, 2003, during re-entry. The Orbiter Challenger was delivered to KSC in July 1982 and was destroyed in an explosion during ascent in January 1986. Discovery was delivered in November 1983. Atlantis was delivered in April 1985. Endeavour was built as a replacement following the Challenger accident and was delivered to Florida in May 1991. An early Space Shuttle Orbiter, the Enterprise, never flew in space but was used for approach and landing tests at the Dryden Flight Research Center and several launch pad studies in the late 1970s.

The Space Shuttle consists of three major components: the Orbiter which houses the crew; a large External Tank that holds fuel for the main engines; and two Solid Rocket Boosters which provide most of the Shuttle's lift during the first two minutes of flight. All of the components are reused except for the external fuel tank, which burns up in the atmosphere after each launch.

The longest the Shuttle has stayed in orbit on any single mission is 17.5 days on mission STS-80 in November 1996. Normally, missions may be planned for anywhere from five to 16 days in duration. The smallest crew ever to fly on the Shuttle numbered two people on the first few missions. The largest crew numbered eight people. Normally, crews may range in size from five to seven people. The Shuttle is designed to reach orbits ranging from about 185 kilometers to 643 kilometers (115 statute miles to 400 statute miles) high.

The Shuttle has the most reliable launch record of any rocket now in operation. Since 1981, it has boosted more than 1.36 million kilograms (3 million pounds) of cargo into orbit. More than than 600 crew members have flown on its missions. Although it has been in operation for almost 20 years, the Shuttle has continually evolved and is significantly different today than when it first was launched. NASA has made literally thousands of major and minor modifications to the original design that have made it safer, more reliable and more capable today than ever before.

Since 1992 alone, NASA has made engine and system improvements that are estimated to have tripled the safety of flying the Space Shuttle, and the number of problems experienced while a Space Shuttle is in flight has decreased by 70 percent. During the same period, the cost of operating the Shuttle has decreased by one and a quarter billion dollars annually -- a reduction of more than 40 percent. At the same time, because of weight reductions and other improvements, the cargo the Shuttle can carry has increased by 7.3 metric tons (8 tons.)

In managing and operating the Space Shuttle, NASA holds the safety of the crew as its highest priority.

The Orbiter

The Orbiter is both the brains and heart of the Space Transportation System. About the same size and weight as a DC-9 aircraft, the Orbiter contains the pressurized crew compartment (which can normally carry up to seven crew members), the huge cargo bay, and the three main engines mounted on its aft end.


The cockpit, living quarters and experiment operator's station are located in the forward fuselage of the Orbiter vehicle. Payloads are carried in the mid-fuselage payload bay, and the Orbiter's main engines and maneuvering thrusters are located in the aft fuselage.

Forward Fuselage

The cockpit, living quarters and experiment operator's station are located in the forward fuselage. This area houses the pressurized crew module and provides support for the nose section, the nose gear and the nose gear wheel well and doors.

Crew Module

The 65.8-cubic-meter (2,325-cubic-foot) crew station module is a three-section pressurized working, living and stowage compartment in the forward portion of the Orbiter. It consists of the flight deck, the middeck/equipment bay and an airlock. Outside the aft bulkhead of the crew module in the payload bay, a docking module and a transfer tunnel with an adapter can be fitted to allow crew and equipment transfer for docking, Spacelab and extravehicular operations.

The two-level crew module has a forward flight deck with the commander's seat positioned on the left and the pilot's seat on the right.

Flight Deck

The flight deck is designed in the usual pilot/copilot arrangement, which permits the vehicle to be piloted from either seat and permits one-man emergency return. Each seat has manual flight controls, including rotation and translation hand controllers, rudder pedals and speed-brake controllers. The flight deck seats four. The on-orbit displays and controls are at the aft end of the flight deck/crew compartment. The displays and controls on the left are for operating the Orbiter, and those on the right are for operating and handling the payloads. More than 2,020 separate displays and controls are located on the flight deck.

Six pressure windshields, two overhead windows and two rear-viewing payload bay windows are located in the upper flight deck of the crew module, and a window is located in the crew entrance/exit hatch located in the midsection, or deck, of the crew module.

Middeck

The middeck contains provisions and stowage facilities for four crew sleep stations. Stowage for the lithium hydroxide canisters and other gear, the waste management system, the personal hygiene station and the work/dining table is also provided in the middeck.

The nominal maximum crew size is seven. The middeck can be reconfigured by adding three rescue seats in place of the modular stowage and sleeping provisions. The seating capacity will then accommodate the rescue flight crew of three and a maximum rescued crew of seven.

Airlock

The airlock provides access for spacewalks, known as extravehicular activity, or EVA. It can be located in one of several places: inside the Orbiter crew module in the middeck area mounted to the aft bulkhead, outside the cabin also mounted to the bulkhead or on top of a tunnel adapter that can connect the pressurized Spacehab module with the Orbiter cabin. A docking module can also serve as an EVA airlock.

The airlock contains two spacesuits, expendables for two six-hour payload EVAs and one contingency or emergency EVA, and mobility aids such as handrails to enable the crew to perform a variety of tasks. The airlock allows two crewmen room for changing spacesuits.

Midfuselage

In addition to forming the payload bay of the Orbiter, the midfuselage supports the payload bay doors, hinges and tiedown fittings, the forward wing glove and various Orbiter system components.


Each payload bay door supports four radiator panels. When the doors are opened, the tilting radiators are unlatched and moved to the proper position. This allows heat radiation from both sides of the panels, whereas the four aft radiator panels radiate from the upper side only.

Some payloads may not be attached directly to the Orbiter but to payload carriers that are attached to the Orbiter. The inertial upper stage, pressurized modules or any specialized cradle for holding a payload are typical carriers.

The Remote Manipulator System, or RMS, is a 15.2-meter (50-foot) long articulating arm remotely controlled from the flight deck of the Orbiter. The elbow and wrist movements permit payloads to be grappled for deployment out of the payload bay or retrieved and secured for return to Earth.

A television camera and lights near the outer end of the arm permit the operator to see on television monitors what his hands are doing. In addition, three floodlights are located along each side of the payload bay.

Aft Fuselage

The aft fuselage consists of the left and right orbital maneuvering systems, Space Shuttle main engines, body flap, vertical tail and Orbiter/external tank rear attachments.

The forward bulkhead closes off the aft fuselage from the midfuselage. The upper portion of the bulkhead attaches to the vertical tail. The internal thrust structure supports the three Space Shuttle main engines, low pressure turbopumps and propellant lines.

Space Shuttle Main Engines

The three Space Shuttle Main Engines, in conjunction with the Solid Rocket Boosters, provide the thrust to lift the Orbiter off the ground for the initial ascent. The main engines continue to operate for 8.5 minutes after launch, the duration of the Shuttle's powered flight.


After the solid rockets are jettisoned, the main engines provide thrust which accelerates the Shuttle from 4,828 kilometers per hour (3,000 mph) to over 27,358 kilometers per hour (17,000 mph) in just six minutes to reach orbit. They create a combined maximum thrust of more than 1.2 million pounds.

As the Shuttle accelerates, the main engines burn a half-million gallons of liquid propellant provided by the large, orange external fuel tank. The main engines burn liquid hydrogen -- the second coldest liquid on Earth at minus 423 degrees Fahrenheit (minus 252.8 degrees Celsius) -- and liquid oxygen.

The engines' exhaust is primarily water vapor as the hydrogen and oxygen combine. As they push the Shuttle toward orbit, the engines consume liquid fuel at a rate that would drain an average family swimming pool in under 25 seconds generating over 37 million horsepower. Their turbines spin almost 13 times as fast as an automobile engine spins when it is running at highway speed.

The main engines develop thrust by using high-energy propellants in a staged combustion cycle. The propellants are partially combusted in dual preburners to produce high-pressure hot gas to drive the turbopumps.

Combustion is completed in the main combustion chamber. Temperatures in the main engine combustion chamber can reach as high as 6,000 degrees Fahrenheit (3,315.6 degrees Celsius).


Each Space Shuttle Main Engine operates at a liquid oxygen/liquid hydrogen mixture ratio of 6 to 1 to produce a sea level thrust of 179,097 kilograms (375,000 pounds) and a vacuum thrust of 213,188 (470,000 pounds).

The engines can be throttled over a thrust range of 65 percent to 109 percent, which provides for a high thrust level during liftoff and the initial ascent phase but allows thrust to be reduced to limit acceleration to 3 g's during the final ascent phase. The engines are gimbaled to provide pitch, yaw and roll control during the ascent.

The External Tank, or ET, is the "gas tank" for the Orbiter; it contains the propellants used by the Space Shuttle Main Engines.

The tank is also the "backbone" of the Shuttle during the launch, providing structural support for attachment with the solid rocket boosters and orbiter.

The tank is the only component of the Space Shuttle that is not reused. Approximately 8.5 minutes into the flight, with its propellant used, the tank is jettisoned.

At liftoff, the External Tank absorbs the total (7.8 million pounds) thrust loads of the three main engines and the two solid rocket motors.

When the Solid Rocket Boosters separate at an altitude of approximately 45 kilometers (28 miles), the orbiter, with the main engines still burning, carries the external tank piggyback to near orbital velocity, approximately 113 kilometers (70 miles) above the Earth. The now nearly empty tank separates and falls in a preplanned trajectory with the majority of it disintegrating in the atmosphere and the rest falling into the ocean.

The three main components of the External Tank are an oxygen tank, located in the forward position, an aft-positioned hydrogen tank, and a collar-like intertank, which connects the two propellant tanks, houses instrumentation and processing equipment, and provides the attachment structure for the forward end of the solid rocket boosters ( + View Graphic Showing Parts of ET ).

The hydrogen tank is 2.5 times larger than the oxygen tank but weighs only one-third as much when filled to capacity. The reason for the difference in weight is that liquid oxygen is 16 times heavier than liquid hydrogen.

The skin of the External Tank is covered with a thermal protection system that is a 2.5-centimeter (1-inch) thick coating of spray-on polyisocyanurate foam. The purpose of the thermal protection system is to maintain the propellants at an acceptable temperature, to protect the skin surface from aerodynamic heat and to minimize ice formation.

The External Tank includes a propellant feed system to duct the propellants to the Orbiter engines, a pressurization and vent system to regulate the tank pressure, an environmental conditioning system to regulate the temperature and render the atmosphere in the intertank area inert, and an electrical system to distribute power and instrumentation signals and provide lightning protection.

The tank's propellants are fed to the Orbiter through a 43-centimeter (17-inch) diameter connection that branches inside the orbiter to feed each main engine.

Solid Rocket Boosters

The Solid Rocket Boosters (SRBs) operate in parallel with the main engines for the first two minutes of flight to provide the additional thrust needed for the Orbiter to escape the gravitational pull of the Earth. At an altitude of approximately 45 km (24 nautical miles), the boosters separate from the orbiter/external tank, descend on parachutes, and land in the Atlantic Ocean (+ View Video: SRB Processing). They are recovered by ships, returned to land, and refurbished for reuse. The boosters also assist in guiding the entire vehicle during initial ascent. Thrust of both boosters is equal to 5,300,000 lbs.

In addition to the solid rocket motor, the booster contains the structural, thrust vector control, separation, recovery, and electrical and instrumentation subsystems. ( + View Diagram )


The solid rocket motor is the largest solid propellant motor ever developed for space flight and the first built to be used on a manned craft. The huge motor is composed of a segmented motor case loaded with solid propellants, an ignition system, a movable nozzle and the necessary instrumentation and integration hardware.

Each solid rocket motor contains more than 450,000 kg (1,000,000 lb.) of propellant, which requires an extensive mixing and casting operation at a plant in Utah. The propellant is mixed in 600 gallon bowls located in three different mixer buildings. The propellant is then taken to special casting buildings and poured into the casting segments.

Cured propellant looks and feels like a hard rubber typewriter eraser. The combined polymer and its curing agent is a synthetic rubber. Flexibility of the propellant is controlled by the ratio of binder to curing agent and the solid ingredients, namely oxidizer and aluminum. The solid fuel is actually powdered aluminum -- a form similar to the foil wraps in your kitchen -- mixed with oxygen provided by a chemical called ammonium perchlorate.

   

dobri podaci i slike naravno
More than than 600 crew members have flown on its missions
ova recenica mi je privukla paznju

to je podatak koji govori da se sve vise ljudi bavi radom u svemiru

i uopste naukom

odlicna tema

Space Shuttle Overview: Atlantis (OV-104)

NASA's fourth space-rated Space Shuttle orbiter, OV-104 "Atlantis," was named after the two-masted boat that served as the primary research vessel for the Woods Hole Oceanographic Institute in Massachusetts from 1930 to 1966. The boat had a 17-member crew and accommodated up to five scientists who worked in two onboard laboratories, examining water samples and marine life. The crew also used the first electronic sounding devices to map the ocean floor.

Construction of the orbiter Atlantis began on March 3, 1980. Thanks to lessons learned in the construction and testing of orbiters Enterprise, Columbia and Challenger, Atlantis was completed in about half the time in man-hours spent on Columbia. This is largely attributed to the use of large thermal protection blankets on the orbiter's upper body, rather than individual tiles requiring more attention.

Weighing in at 151,315 pounds when it rolled out of the assembly plant in Palmdale, Calif., Atlantis was nearly 3.5 tons lighter than Columbia. The new orbiter arrived at NASA's Kennedy Space Center in Florida on April 9, 1985, and over the next seven months was prepared for her maiden voyage.

Like her seafaring predecessor, orbiter Atlantis has carried on the spirit of exploration with several important missions of her own. On Oct. 3, 1985, Atlantis launched on her first space flight, STS-51-J, with a classified payload for the U.S. Department of Defense. The vehicle went on to carry four more DOD payloads on later missions.

Atlantis also served as the on-orbit launch site for many noteworthy spacecraft, including planetary probes Magellan and Galileo, as well as the Compton Gamma Ray Observatory. An impressive array of onboard science experiments took place during most missions to further enhance space research in low Earth orbit.

Starting with STS-71, Atlantis pioneered the Shuttle-Mir missions, flying the first seven missions to dock with the Russian space station. When linked, Atlantis and Mir together formed the largest spacecraft in orbit at the time. The missions to Mir included the first on-orbit U.S. crew exchanges, now a common occurrence on the International Space Station. On STS-79, the fourth docking mission, Atlantis ferried astronaut Shannon Lucid back to Earth after her record-setting 188 days in orbit aboard Mir.

In recent years, Atlantis has delivered several vital components to the International Space Station, including the U.S. laboratory module, Destiny, as well as the Joint Airlock Quest and multiple sections of the Integrated Truss structure that makes up the Station's backbone. As NASA seeks to fulfill the Vision for Space Exploration, beginning with the completion of the Station, Atlantis will be called upon for many missions to come.

Construction Milestones - OV-104

Jan. 29, 1979    Contract Award
March 30, 1980    Start structural assembly of crew module
Nov. 23, 1981    Start structural assembly of aft-fuselage
June 13, 1983    Wings arrive at Palmdale from Grumman
Dec. 2, 1983    Start of Final Assembly
April 10, 1984    Completed final assembly
March 6, 1985    Rollout from Palmdale
April 3, 1985    Overland transport from Palmdale to Edwards
April 9, 1985    Delivery to Kennedy Space Center
Sept. 5, 1985    Flight Readiness Firing
Oct. 3, 1985    First Flight (STS-51-J)

Upgrades and Features

By early 2005, Atlantis had undergone two overhauls known as Orbiter Maintenance Down Periods. Some of the most significant upgrades and new features included:

    * Installation of the drag chute
    * New plumbing lines and electrical connections configuring the orbiter for extended duration missions
    * New insulation for the main landing gear doors
    * Improved nosewheel steering
    * Preparations for the Mir Orbiter Docking System unit later installed at Kennedy
    * Installation of the International Space Station airlock and Orbiter Docking System
    * Installation of the Multifunction Electronic Display System, or "glass cockpit"