NASA-LLIS-0194

Abstract

<strong>Description of Driving Event:</strong> <br>The space shuttle system presently includes an autoland system that provides automated guidance capable of navigating the orbiter to the selected landing runway. <br>The increased duration of space shuttle flights as part of the extended duration orbiter program (EDO) has raised the issue of the need to qualify the existing system during actual flights. It also raises the issue of the possible need to fully automate all landing, rollout, and braking functions so that the orbiter could be returned safely from orbit without any crew intervention, if necessary. <br>The existing automated approach guidance system never has been fully flight tested. The second space shuttle flight, STS-2, left the auto mode engaged until the latter part of the team region and demonstrated that the system was capable of returning the vehicle to a flyable energy state from a low energy state. STS-3 left the system in auto until the commander's scheduled takeover at 125 feet. The system was on energy and trajectory at takeover, but the pilot had difficulty getting "into the loop," and an uncomfortable situation developed. The final several thousand feet of the shuttle's descent involves relatively complex flare maneuvers with which a pilot might be expected to have difficulty when retaking command.