The How Space Shuttle Launches work.



How do Space Shuttle launches work?

For just about a decade mankind has been fascinated with space. Wanting to know what it contained, how people could live there, if there were other beings living there already and how they could reach it to get artifacts that could be brought back and studied on earth. Many movies have been made on man’s exploration into space simply because it is so interesting to just about anyone. One of the most fascinating elements of space exploration is the life of an astronaut while they are in space. What is life like aboard a space shuttle? How do they cope with the environment? The life of an astronaut is mainly contained to a space shuttle and these are enthralling contraptions! Here is how one works.

NASA has made incredible moves in continuously expanding their knowledge about space and the design of their space shuttles. But one cannot think of the steps forward without thinking of the casualties along the way. In 1986 the Challenger’s trip was brought to an abrupt halt when it exploded during liftoff. There were no other major incidents until 2003 when the Columbia was on its return mission into Texas and broke apart. Afterwards all missions were grounded until 2005 when Discovery was supposed to takeoff but was also grounded due to a piece of foam coming loose from the external fuel tank. One year later the Discovery and Atlantis both made successful missions due to NASA’s part in continuously trying to provide the safest and most innovative spacecraft.

For a standard mission into space an aircraft will have four major parts: The SRBs are solid rocket boosters and there are usually two of these on the spacecraft. They are absolutely essential to the launch taking place. The ET is the external fuel tank and this will provide the craft with the fuel it needs for liftoff. The orbiter is what contains the astronauts and all of their necessary on-hand equipment. Once all of the equipment is ready and the astronauts are buckled in and ready to go, there is the mission. This is much more than simply taking off and landing on the moon. A mission is a process of many detailed steps, every one critical to the mission being successful. These steps are: Launch, SRB Separation, Fuel Tank Separation, Orbit, Retrofire, Entry, Approach, and Landing. A shuttle mission is usually completed within six to eight days but very detailed or long missions can last up to two weeks.

Launching the space shuttle is a very exciting thing to be a part of! The once-in-a-lifetime opportunity to watch the great rockets liftoff is a good time to get caught up in the drama of it all but there are many things necessary for a successful launch. The parts used are the SRBs, the ET, and two main pieces of the orbiter: its three main engines and the orbital maneuvering system (OMS.) The solid rocket boosters are one of the most important components of lifting the massive 4.5 million pound space shuttle off the ground. They consist of a number of separate components including: solid rocket motor, solid propellant, jointed structure, synthetic rubber o-rings between joints, flight instruments, recovery systems, explosive charges which allow it to separate from the ETs, thrust control systems, and a self-destruct component. Because they are so powerful, they cannot be shut down once they have been lit. Because of this, they are the last component to be started during launch.

The main engines located around the orbiter are another vital component of the space shuttle. These provide the little twenty-nine percent power for liftoff that the SRBs do not. They are situated in the back of the spacecraft and they weigh about 6,700 pounds each! The engine takes the fuel out of the ETs and burns it to provide the spacecraft with power. It takes fuel at an astonishing rate – comparable to emptying out one family-sized swimming pool per second! Within the engine, the fuel is literally burned and the exhaust provides enough power to lift the shuttle from its pad into orbit and keep it suspended while there. Every engine sits on its own gimbal, which are round bearings that direct the exhaust fumes to the back of the shuttle, causing it to move forward.

The external fuel tank (ET) is also made up of many different pieces. It is actually a tube comprised of aluminum and aluminum composite. Within this tube are two different tanks. The tank that sits in front as called the forward tank and it holds oxygen. The aft tank sits behind it and that holds hydrogen. These two tanks are separated with an intertank region. Polyisocyanurate foam insulation is sprayed onto the outer tube to provide many different forms of protection. The insulation keeps the fuel at a cool temperature, which will prevent it from getting too hot during liftoff. It will also build up on the outside of the ET and prevent ice from forming. Because it was this insulation that broke off from Columbia, the left wing of the orbiter broke where the insulation had come off.

There are other engines needed for successful launch other than the three main engines. These are the orbital maneuvering systems’ (OMS) engines. These are located at the back of the orbiter and there is one located on each side of the orbiter’s tail. These engines burn two types of gases: monomethyl hydrazine fuel and nitrogen tetroxide oxidizer. When these two gases come together, they will light without a need for oxygen. They are kept in separate helium-pressured tanks and the helium pressures the gases out of their tanks and through the valves so that they can meet and ignite. The valves work so that the gases can go out but not come back in. The engines can be turned on and off approximately 1,000 times and can burn for approximately fifteen hours.

The series of happenings within a launch occurs in what is known as T-minus 31 seconds. The process starts during the last few seconds of the shuttle’s time on the pad until it is in orbit. There are twelve different steps and here they are:
  1. T-minus 31 seconds: the computers in the orbiter take control of the launch sequence.
  2. T-minus 6.6 seconds: the main engines of the shuttle will light one at a time, about 0.12 seconds after another.
  3. T-minus 3 seconds: the engines are in full position for liftoff.
  4. T-minus 0 seconds: the rocket boosters are lit and the shuttle begins to lift up and off the pad.
  5. T-plus 20 seconds: the shuttle will start to 180 degrees to the right.
  6. T-plus 60 seconds: the shuttle engines are at full power.
  7. T-plus 2 minutes: the rocket booster will begin to detach from the orbiter and fuel tank at an altitude of about 28 miles. The parachutes will drop from the rocket boosters and land about 140 miles off the coast of Florida in the Atlantic Ocean. Ships will later be sent to retrieve the boosters and carry them back to Cape Canaveral so that they may be reused.
  8. T-plus 7.7 minutes: the main engines will begin to decrease in power so that the full throttle does not negatively impact the orbiter.
  9. T-plus 8.5 minutes: the main engines will completely shut down.
  10. T-plus 9 minutes: the ET will detach from the orbiter and will become burned up as it re-enters.
  11. T-plus 10.5 minutes: the OMS engines will fire to keep the shuttle in orbit.
  12. T-plus 45 minutes: the OMS engines will fire one more time to place the shuttle into higher orbit.
    Now liftoff has occurred, the shuttle is in orbit, and the mission can proceed!

A Space Shuttle Launch

Space Shuttle Launches.

 The How Space Shuttle Launches work of Space Shuttle Launches.

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