The space shuttle can reach a runway or a lower-than-planned orbit in the event of a single main engine failure at any point after liftoff. An engine failure in the first two minutes and 19 seconds or so of flight would result in a return-to-launch-site - RTLS - abort. Between approximately 2:19 and 4:33, an engine failure would result in a trans-Atlantic landing - TAL - in either Spain or Africa. After 4:33, Atlantis would be able to abort into a safe but lower-than-planned orbit, or ATO. The only in-flight abort in shuttle history was an ATO on July 29, 1985, when Challenger's center engine shut down five minutes and 45 seconds into the 19th shuttle mission (STS-51F).

NOTE: Inertial velocity includes contribution from Earth's rotation.