De-Orbital Burn and Re-Entry. Whilst every phase of a space shuttle mission is not without its own share of danger, the phase which comes next is the one which must be at the top of the list every time � re-entry. Working in conjunction with the shuttles pilot the commander of the craft brings their craft into the exact orbital position before firing the forward Reaction Control System or RCS to slow the shuttle just enough for Earth�s gravity to take hold of it and start to drag it toward the surface far, far below. Too short a burn duration and the shuttle will bounce off the Earth�s atmosphere and go hurtling into deep space, too long burn duration and the shuttle will enter the atmosphere too steeply and burn up. Even with the correct burn duration, at the correct re-entry angle, and at the correct orbital position, the underside of the shuttle will still heat up to a fantastic temperature, a temperature nearly as hot as the surface of the Sun as it starts its fiery decent toward the Earth so very, very far below.