Description:
- The Approach and Landing Tests were a series of taxi and flight trials of the prototype Space Shuttle Enterprise, conducted in 1977 to test the vehicle′s flight characteristics both on its own and when mated to the Shuttle Carrier Aircraft, prior to the operational debut of the shuttle system.
- The Space Shuttle program originated in the late 1960s as a means of reducing the cost of spaceflight by introducing a reusable spacecraft. The final agreed design would feature a reusable spaceplane, a disposable external tank and reusable solid-fuel rocket boosters. The contract to build the spaceplane, which eventually came to be known as the "orbiter", was awarded to North American Rockwell (later Rockwell International), with the first complete orbiter rolled out in 1976. Originally planned to be named Constitution (due to its completion being in the year of the United States Bicentennial), a letter-writing campaign by Star Trek fans persuaded President Ford to change the name of the prototype to Enterprise. It was unveiled to the public on September 17, 1976, with several members of the Star Trek cast in attendance.
- Upon the orbiter′s entry into service, NASA began an extensive program of tests using Enterprise to ensure all of the systems it had put in place for the Shuttle program functioned as designed. These tests would encompass not only the flight tests planned to test the flight characteristics of the orbiter, but also ground-based testing of the launch pad systems and procedures. In January 1977, Enterprise was taken by road from the Rockwell plant at Palmdale, California to the Dryden Flight Research Center at Edwards Air Force Base to begin the flight test phase of the program, which had been christened by NASA as the Approach and Landing Tests (ALT).
Crew
|
| |||||||||||||||||||||
Notes:
- Haise had previously flown as the lunar module pilot of Apollo 13. Fullerton later flew as the pilot of STS-3 and commanded STS-51-F.
- The 2e crew later flew on STS-2.
- Engle was originally the Lunar Module Pilot for Apollo 17, but was bumped in favor of Harrison Schmitt due to pressure from the scientific community when Apollo 18 was cancelled.
Shuttle carrier aircraft Crew
In addition to the two assigned shuttle crews, who would alternate crewing the orbiter, a single flight crew was attached to the Boeing 747 Shuttle Carrier Aircraft (SCA) for the entire program.| Name | Job |
| Fulton, Fitzhugh L., Jr | Captain |
| McMurtry, Thomas | co-Pilot |
| Guidry, Louis E., Jr | Flight angineer |
| Horton, Victot W. | Flight angineer |
ALT program:
The ALT program was divided into three distinct phases. The first phase was designated as the "taxi-test" phase, which involved the SCA and orbiter in a mated formation conducting taxi tests at Edwards Air Force Base to verify the taxiing characteristics of the aircraft while carrying the orbiter. These tests did not involve the orbiter in any way beyond it being mated to the aircraft, so consequently it remained powered down and uncrewed. A total of three taxi-tests were performed on February 15, 1977. Following this, the program moved into its next phase.Captive flights:
The captive flight phase of ALT saw the SCA/orbiter combination in flight as a test of the SCA′s flying characteristics while mated to the orbiter, and as an initial test of the orbiter systems in flight. This was subdivided into two phases:Captive – inert: There were a total of five captive-inert flights designed to test the flight and handling characteristics of the aircraft while it was mated to the orbiter. As with the taxi tests, this did not involve the orbiter beyond it being mated to the SCA, so it remained unpowered and uncrewed.
Captive – active: The captive-active flights were intended to determine the optimum profile required for Enterprise to separate from the SCA during the orbiter′s free-flights. These were also intended to refine and test the orbiter crew procedures and to ensure the operational readiness of the orbiter′s systems. For these three flights, although Enterprise remained mated to the SCA, it was powered and crewed.
 OV-101 atop NASA′s first Shuttle Carrier Aircraft (SCA), during a |
 OV-101 crew: Fullerton, Haise, Engle and Truly |
Free-flights:
- The final phase of flight testing involved free-flights. These saw Enterprise mated to the SCA and carried to a launch altitude, before being jettisoned by the use of explosive bolts to glide to a landing on the runways at Edwards AFB. The intention of these flights was to test the flight characteristics of the orbiter itself, on a typical approach and landing profile from orbit.
- There were a total of five free-flights between August and October; the first three saw Enterprise remain fitted with its aerodynamic tail cone, intended to reduce drag when mounted on the SCA during flight. The final two had the tail cone removed, with the orbiter in its full operational configuration, with dummy main engines and OMS pods. Enterprise used an air data probe mounted on its nose for these flights. These five flights were to be the only time Enterprise flew alone.
- After flying missions on Columbia (STS-2) and Discovery (STS-51-I), Engle reported that the flight and handling characteristics of the operational orbiters were similar to those of Enterprise, except that he had to fly a steeper profile with the prototype, as it was much lighter than the operational spacecraft
List of ALT flights:
| Mission | Test flights | Date | Speed | Altitude | Crew | Duration | Comment |
|---|---|---|---|---|---|---|---|
| ALT-1 | Taxi test #1 | February 15, 1977 | 89 mph (143 km/h) | taxi | none | taxi | Concrete runway, tailcone on |
| ALT-2 | Taxi test #2 | 140 mph (225 km/h) | |||||
| ALT-3 | Taxi test #3 | 157 mph (253 km/h) | |||||
| ALT-4 | Captive-inert flight #1 | February 18, 1977 | 287 mph (462 km/h) | 16,000 ft 4,877 m |
2 h 5 min | Tailcone on, landed with 747 | |
| ALT-5 | Captive-inert flight #2 | February 22, 1977 | 328 mph (528 km/h) | 22,600 ft 6,888 m |
3 h 13 min | ||
| ALT-6 | Captive-inert flight #3 | February 25, 1977 | 425 mph (684 km/h) | 26,600 ft 8,108 m |
2 h 28 min | ||
| ALT-7 | Captive-inert flight #4 | February 28, 1977 | 425 mph (684 km/h) | 28,565 ft 8,707 m |
2 h 11 min | ||
| ALT-8 | Captive-inert flight #5 | March 2, 1977 | 474 mph (763 km/h) | 30,000 ft 9,144 m |
1 h 39 min | ||
| ALT-9 | Captive-active flight #1 | June 18, 1977 | 208 mph (335 km/h) | 14,970 ft 4,563 m |
Haise, Fullerton | 55 min 46 s | |
| ALT-10 | Captive-active flight #2 | June 28, 1977 | 310 mph (499 km/h) | 22,030 ft 6,715 m |
Engle, Truly | 62 min 0 s | |
| ALT-11 | Captive-active flight #3 | July 26, 1977 | 311 mph (501 km/h) | 30,292 ft 9,233 m |
Haise, Fullerton | 59 min 53 s | |
| ALT-12 | Free flight #1 | August 12, 1977 | 310 mph (499 km/h) | 24,100 ft 7,346 m |
Haise, Fullerton | 5 min 21 s | Tailcone on, lakebed landing |
| ALT-13 | Free flight #2 | September 13, 1977 | 310 mph (499 km/h) | 26,000 ft 7,925 m |
Engle, Truly | 5 min 28 s | |
| ALT-14 | Free flight #3 | September 23, 1977 | 290 mph (467 km/h) | 24,700 ft 7,529 m |
Haise, Fullerton | 5 min 34 s | |
| ALT-15 | Free flight #4 | October 12, 1977 | 278 mph (447 km/h) | 22,400 ft 6,828 m |
Engle, Truly | 2 min 34 s | Tailcone off, lakebed landing |
| ALT-16 | Free flight #5 | October 26, 1977 | 283 mph (455 km/h) | 19,000 ft 5,791 m |
Haise, Fullerton | 2 min 1 s | Tailcone off, runway landing |
Astrophilately covers (ALT - Unmaned flights):
 Shuttle OV-101 travels 35 miles over land. |
 1e mating of the 747 and OV-101 for "ALT" tests |
 Shuttle OV-101 3 Taxi runs over land. |
 Shuttle OV-101 3 Taxi runs |
 Captive-inert flight #1 |
 Captive-inert flight #2. |
 Captive-inert flight #3. |
 Captive-inert flight #4. |
 Captive-inert flight #5. |
 Parforex XVII Flight, signed Whitaker. Credit: #402 |
 New KSC cancel, 1st day. Credit: #402 |
 Fourth Ferry Qualification Flight |
| Ref.: #98 - update: 11.10.25 | Home |