We Have Liftoff
As launch time comes closer, dozens of technicians are watching their monitors to detect any problems. At T minus nine minutes, the countdown goes to an automatic system. Auxiliary power units are turned on at T minus five minutes. The automatic start system kicks in 31 seconds before launch. Six seconds before liftoff, the shuttle’s main engines are ignited. The solid rocket boosters are ignited at zero seconds and we have liftoff. Another successful launch.
Amazing But True
- Rockets are moved by the push of gases released during combustion. The force of the gas pushes against the solid body of the rocket and propels it forward. The larger the volume of gas produced per unit time, the more rapidly the rocket will travel. A fast release of gas produces a faster speed.
- Rocket propellants are of two basic types, both involving some form of oxidation-reduction reaction. With liquid propellants, the oxidizer and the fuel are stored in separate tanks. They are mixed in a combustion chamber and burned to propel the vehicle. The use of liquid propellants allows better control of the rocket engines. They can be started, stopped, and restarted easily. A reaction with solid propellants cannot be terminated once it has been initiated.
- The most-traveled space shuttle was the Discovery. This shuttle traveled over 148 million miles during its 39 missions. The Hubble space telescope was deployed on one of the missions and is still in operation twenty-three years later. In 1998 John Glenn (at age 77) became the oldest person to participate in a Discovery launch and space mission. Glenn was the first person (in 1962) to orbit the earth.
The space shuttle Discovery
- Watch a video of a space shuttle launch below: https://www.youtube.com/watch?v=4FROxZ5i67k
Show What You Know
Use the links below to learn more about rocket fuels. Then answer the following questions.
- When were the earliest rockets used and for what purpose?
- What was one of the oldest propellants to be used?
- What are cryogenic propellants?
- Name two homogeneous solid propellants.
- What were the major components of the space shuttle?