Outline of Material Covered During our Meeting January 18, 2001

I. Space Shuttle Main Segments ( All three segments combined is called a “Full Stack”)

A. Orbiter (or OV—Orbiter Vehicle)

1. The Orbiter is both a spacecraft and glider-plane.

a) It is a spacecraft because it is designed and built to work in the deadly vacuum of space.

b) It is a glider plane because it is designed and built to glide in the Earth’s atmosphere like a glider or airplane. There are no engines to help it land. Since it is a glider and not a true airplane, it must make a perfect landing on its first attempt. The Orbiter has no second chance to fly around and try to land again.

2. The Orbiter is where the astronaut crew rides

a) The area in which the crew rides is very small, about 160 square feet. It is called the Crew Compartment.

(1) Crew Compartment Facts:

(a) The Crew Compartment is a “shirt sleeve” environment. This simply means that the astronauts do not have to wear any special suits or masks to stay alive and healthy. This is because it is pressurized with artificial air which provides air pressure and oxygen.

(b) There are three main sections of the Crew Compartment:

(i) The Flight Deck: This is where the CDR, PLT, MS1, and MS2 ride during liftoff and landing. It is where almost all of the controls to fly and land the Orbiter are located, and it looks like an airplane cockpit.

(ii) The Mid Deck: This is the “living area” of the Orbiter. Most of the experiments are done on the Mid Deck. It also houses the bathroom (Mr. Thirsty), the Galley (kitchen), the Airlock, and lots of Storage Lockers.

The Mid Deck is located directly below the Flight Deck, and it only has one small window on the side.

(iii) The Lower Deck: No one actually goes into the Lower Deck. It is used to store equipment and parts.

B. 2 SRBs (Solid Rocket Booster)

1. Contains Solid Rocket Fuel (NOTE: Solid rocket fuel is like the powder you find inside a model rocket engine or a bottle rocket. Liquid fuel would be something like the gasoline that powers your family’s car).

a) Fuel—Aluminum Powder. Note: The fuel is what is actually burning. The wood in your fireplace is an example of fuel.

b) Oxidizer—Ammonium Perchlorate Note: The oxidizer provides oxygen so that the burning can take place. The air going into your fireplace could be thought of as an oxidizer because it provides oxygen for the fire.

c) Binder—The binder is a chemical that helps the oxidizer and fuel “stick” together.

2. SRBs are attached to the ET (and the Orbiter is attached to the ET)

3. SRBs separate about two minutes after liftoff

a) Splashdown in the Atlantic Ocean about 150 NM (nautical miles) from the launch pad (NOTE: A nautical mile is exactly 1.15 “Statute Miles,” or SM. An SM is a mile like we are used to using in our everyday lives to describe things how far we drove our car or how many miles we walked down the Silver Comet Trail.)

b) NASA’s recovery ships tug the SRBs back to Kennedy Space Center so that they can be reused.

4. Advantages of the SRBs

a) Provide most of the liftoff thrust for the Space Shuttle (3.3 million pounds of thrust in each SRB—that’s 3,300,000 lbs.).

5. Disadvantages of the SRBs

a) They cannot be shutdown after ignition. Think about that poor beetle!

b) Their thrust (power) cannot be easily controlled. Think about that poor beetle one more time!

6. The SRBs are labeled SRB A and SRB B. If you are sitting in the Orbiter, SRB A is on the left and SRB B is on the right.

7. The SRBs are attached to the ET which is attached to the Orbiter. Before liftoff, the only thing holding the Shuttle on the ground are six “Hold Down Bolts” attached to the base of each SRB. At about T minus 1 second, these bolts are blown apart by explosives—called pyrotechnics, or just “pyros”--so that the Shuttle can liftoff of the pad. Each hold down bolt is about as thick as a grown man’s bicep.

INTERESTING NOTE: When the Hold Down Bolt pyros are blown, the Shuttle actually rocks forward several feet and the swings back. The SRBs are timed to ignite as soon the Shuttle rocks back to a 90 degree vertical position (straight up). This rocking motion is called “The Twang.” Watch for it the next time you watch a video tape of a Shuttle liftoff, especially if it’s a close up view.

(The third main segment of the Shuttle is the ET—External Tank. We’ll cover it this week).