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C-11A Shuttle Training Aircraft
Role	Advanced trainer
Manufacturer	Grumman
Status	Operational
Primary user	NASA
Number built	4
Developed from	Grumman Gulfstream II
Variants	Grumman C-11

The Shuttle Training Aircraft (STA) is a NASA training vehicle that duplicates the Space Shuttle's approach profile and handling qualities, allowing Space Shuttle pilots to simulate Shuttle landings under controlled conditions before attempting the task on board the orbiter.

[edit] Development

The aircraft's exterior has been modified to withstand the high aerodynamic forces incurred during training sorties. A redesigned cockpit provides a high-fidelity simulation of the Shuttle Orbiter's controls and pilot vantage point; even the seats are fitted in the same position as those in the Space Shuttle.

[edit] Operational history

The four STAs are normally located at the NASA Forward Operating Location in El Paso, Texas and rotated through Ellington Field (southeast of Houston, Texas) for maintenance.^[1] The STA is also used at Kennedy Space Center in Florida. It is primarily flown by astronauts practicing landings at the Shuttle Landing Facility and White Sands Space Harbor as well as to assess weather conditions prior to Space Shuttle launches.

[edit] Flight profile

The STA is particularly critical for Shuttle pilots in training because the Orbiter lacks the atmospheric engines that would allow the craft to "go around" after a poor approach. After re-entry, the Shuttle is a very heavy glider (it is sometimes referred to as a 'flying brick'), and as such has only one chance to land.

In order to match the descent rate and drag profile of the real Shuttle at 37,000 feet (11,300 m), the main landing gear is lowered (the nose gear stays retracted due to wind load constraints) and engine thrust is reversed. Its flaps may deflect upwards to decrease lift as well as downwards to increase lift.

Covers are placed on the left hand cockpit windows to provide the same view as from a Shuttle cockpit, and the left-hand pilot's seat is fitted with the same controls as a Shuttle. The STA's normal flight controls are moved to the right, where the instructor sits. Both seat positions have a Head Up Display (HUD).

In a normal exercise, the pilot descends to 20,000 feet (6,000 m) at an airspeed of 280 knots (519 km/h), 15 miles (24 km) from the landing target. The pilot then rolls the STA at 12,000 feet (3,700 m), 7 miles (11 km) from landing. The nose of the aircraft is then dropped to increase speed to 300 knots (560 km/h), descending at a 20-degree angle. At 1,750 feet (533 m) the pilot flares to reduce the descent angle to a more gradual 3 degrees. The shuttle landing gear release is simulated at 300 feet (90 m) above the ground surface, since the STA main gear has been down for the whole simulation. The nose gear of the STA is lowered at 150 ft (46 m) AGL in case of an inadvertent touchdown with the runway surface.

If the speed is correct, a green light on the instrument panel simulates shuttle landing when the pilot's eyes are 32 feet (10 m) above the runway. This is the exact position that the pilot's head would be in during actual landing. In the exercise, the STA is still flying 20 feet (6 m) above the ground. The instructor pilot deselects the simulation mode, stows the thrust reversers, and the instructor flies around the runway, never actually landing the aircraft.

[edit] Avionics

The Shuttle Training Aircraft's cockpit. The commander's side of the cockpit, at left, features a Shuttle-type heads-up display (HUD), a rotational hand controller (RHC) used to fly the vehicle, and multi-function displays. The instructor pilot, who occupies the right-hand side of the STA cockpit, has access to a similar heads-up display, as well as conventional aircraft controls and instruments.

A sophisticated computer system installed on board the STA simulates the flight dynamics of the orbiter with nearly perfect accuracy. The STA's highly realistic simulation of the Orbiter is not limited to handling characteristics, but also implements the shuttle control interfaces for the pilot.

The pilot then navigates the STA around a heading alignment cylinder (HAC), a maneuver which aligns the shuttle's (or training aircraft's) flight path with the landing runway.

An onboard computer called the Advanced Digital Avionics System (ADAS) controls the Direct Lift Control (DLC) and the in-flight reverse thrust during Simulation Mode.^[2]

Every Shuttle Commander has practiced at least 1000 landings in this manner, as has each mission's Shuttle Pilot.^[1]

[edit] List of Shuttle Training Aircraft

Four Gulfstream II aircraft constitute the current STA fleet, although other Gulfstream II aircraft, lacking STA capabilities, are also used by NASA for personnel transport purposes. Although the majority of the fleet have markings similar to those pictured above, paint schemes do vary slightly across aircraft. Current STA tail numbers are:

• N944NA (sn144)
• N945NA (sn118)
• N946NA (sn146)
• N947NA (sn147)

[edit] Other uses

In the event NASA's T-38 Talons are not available, the STAs are used for transporting crewmembers between major sites, namely from Johnson Space Center in Houston to Kennedy Space Center in Cape Canaveral, Florida.

[edit] See also

Shuttle Mission Simulator

[edit] References

v • d • e NASA Space Shuttle (STS) Core topics Space Shuttle · Space Shuttle program  · Missions Components Orbiter Vehicle (OV) · Solid Rocket Booster (SRB) · External Tank (ET) Main Engine (SSME) · Orbital Maneuvering System (OMS) · Reaction Control System (RCS)  · Thermal Protection System  · Booster separation motor Orbiters Enterprise · Columbia · Challenger · Discovery · Atlantis · Endeavour Orbiter Add-ons Spacelab (ESA)  · RMS  · Extended Duration Orbiter  · Remote Controlled Orbiter  · MPLM Launch & Landing sites Kennedy Space Center LC-39  · Landing sites  · Abort Landing Sites Operations Missions (cancelled  · rollbacks ) · Crews  · Mission timeline  · Abort modes · Rendezvous pitch maneuver Testing Pathfinder · MPTA · MPTA-ET · Approach and Landing Tests Disasters Columbia disaster (report)  · Challenger disaster (report) Logistical Support Crawler-transporter · Shuttle Carrier Aircraft  · Orbiter Processing Facility  · NASA recovery ship  · Shuttle Training Aircraft  · Shuttle Avionics Integration Laboratory (SAIL) Special Programs Deutschland-1  · Getaway Special  · Teacher in Space Project Selected derivatives Shuttle-Derived Launch Vehicle (SDLV) · Shuttle-C · Ares · HLLV Related topics Space Shuttle design process · Space Shuttle Explorer (shuttle replica) · Inertial Upper Stage  · Payload Assist Module  · ISS See also: Space shuttles in fiction · Space Shuttle America (motion simulator ride)