Aft Reaction Control System
The small holes (3 pointing down, 2 pointing aft and 4 out to the side) are vernier thrusters, used for very small movements of the space shuttle in orbit. They are too weak to work in atmosphere. The larger nozzle about them is one of 2 orbital maneuvering engines, they move the shuttle from higher to lower orbits (and vice cersa). They also perform the deorbit burn that takes the shuttle out of orbit when it is time to come home. The large nozzle on the left is one of 3 space shuttle main engines (SSMEs), the engines that use fuel from the external tank at lift off and get the shuttle to orbit (along with the solid rockets boosters). Once the external tank is jettisoned, the shuttle uses the orbital manvering engine and thrusters.
NASA didn't clean up the shuttle a bit after her last flight, you can easily tell this bird has been through the atmosphere the hard way.
Aft Reaction Control System
The small holes (3 pointing down, 2 pointing aft and 4 out to the side) are vernier thrusters, used for very small movements of the space shuttle in orbit. They are too weak to work in atmosphere. The larger nozzle about them is one of 2 orbital maneuvering engines, they move the shuttle from higher to lower orbits (and vice cersa). They also perform the deorbit burn that takes the shuttle out of orbit when it is time to come home. The large nozzle on the left is one of 3 space shuttle main engines (SSMEs), the engines that use fuel from the external tank at lift off and get the shuttle to orbit (along with the solid rockets boosters). Once the external tank is jettisoned, the shuttle uses the orbital manvering engine and thrusters.
NASA didn't clean up the shuttle a bit after her last flight, you can easily tell this bird has been through the atmosphere the hard way.