3…2…1 Liftoff!

As most know, NASA’s iconic space shuttles have been retired and will live the rest of their days housed in museums, never to see space again. All would agree that the engineering and production of these vehicles is nothing short of brilliant. We often think of them floating in the outer atmosphere collecting data and connecting with the International Space Station. But what did it take just to get them off the ground and into orbit around the Earth? Today we’ll find out.
First you have to know the components of a shuttle. There are four main parts which are easily observed when the shuttle is on the pad.
External fuel tank (ET) – This is the most dominant structure attached to the aircraft. This is the large orange silo located underneath the shuttle. It holds 526,000 gallons of fuel which will be depleted during launch at a rate of a family sized swimming pool every 10 seconds. It is made of aluminum and aluminum composite materials, so it is very light weight despite its size. The orange color familiar to many is the foam covering that is sprayed on to keep the fuel cool. At one time it used to be painted white but it was discovered that without paint, the shuttle shaved 600 lbs off of its total weight.

Two SRBs (solid rocket boosters)-These boosters provide 71% of the thrust and cannot be shut off once ignited, which is why they are the last to be lit. Their fuel reserve is fully contained within each booster, and they do not receive any fuel from the external fuel tank. Not only do they provide most of the thrust, they also support the entire 4.5 million pounds of the shuttle while it is on the pad.
Three Main Engines– provide the remaining 29% thrust. These engines receive their fuel from an external fuel tank which is composed of liquid hydrogen and liquid oxygen which must be mixed at a ratio of 6:1- six parts liquid hydrogen to one part liquid oxygen.
Orbital Maneuvering System (OMS)-This system is located at the end of the shuttle craft. This provides supplementary thrust during launch, but is mainly used in orbit for orbit injection and during re-entry for orbital correction.
You may have seen a shuttle launch on TV or YouTube and while watching you were probably not thinking about how much noise it was producing. Once the engines fired the sound waves produced would measure up to 220 decibels which is enough pressure through sound to ignite grass over a mile away and completely kill everything within several hundred meters of the launch pad. But being that NASA is so smart they counteracted this tremendous sound and pressure by dumping 900,000 gallons of water per minute into a pool beneath the shuttle to break apart the sound waves and prevent them from destroying the shuttle or the area nearby.
From initial lift off it took about two minutes for the shuttle to reach a distance of 28 miles above the Earth, at which point the SRBs separated from the shuttle while the main engines continued to fire. The SRBs would parachute down into the ocean where they would be reused in future missions.
8.5 minutes after lift off the main engines shut off and at 9 minutes the ET separates from the shuttle and is burned up in the atmosphere.
Though we’re talking about a launch, it’s interesting to note that once the shuttle was in orbit it sped around the Earth at 17,500 miles per hour. Fast enough for the crew to see a sunrise or sunset every 45 minutes.

References

How Stuff Works
http://science.howstuffworks.com/space-shuttle1.htm

It’s Okay to be Smart

Space.com
http://www.space.com/12127-8-surprising-space-shuttle-facts.html

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