Seriously guys. You're reaching, BiGLY!
Those "Jets" are compressed gas reaction control jets and maneuvering thrusters. I believe the former are used to provide fine control stability when flinging things around with the robot arm and the latter are used for changing the attitude of the entire orbiter. They are on the nose end as well. The large rocket cones at the rear can be gimbled to provide course correction during powered flight until the main tank falls away.
There are no conventional air breathing jet engines on the shuttles.