Joe H. Engle, US Air Force. X-15 Pilot No. 8.

courtesy North American Aviation

Vice President Hubert Humphrey (left photo) visited Edwards. Joe Engle served as a docent (right photo).

courtesy Armstrong Flight Research Center and National Museum of the US Air Force

First of two photos from high altitude on the X-15. The thin line of Earth's atmosphere.

courtesy Armstrong Flight Research Center

Las Vegas area with the Colorado River winding toward the right from 155,000 feet.

courtesy Armstrong Flight Research Center

Dr. Wernher von Braun checks out the view from the X-15 cockpit: 30 Nov. 1961.

courtesy Armstrong Flight Research Center

Engle lands X-15 No. 1 after a run to Mach 4.75: 1-41-65 on 14 Nov. 1963.

courtesy NASA Headquarters

Engle is in X-15 No. 3, but would not launch this day: 3-A-56 on 23 Sep. 1964.

courtesy North American Aviation

Engle pulls away from the B-52's shadow after launch: 3-35-57 on 28 Sep. 1964.

courtesy Armstrong Flight Research Center

Right-side upper vertical tail ablative test sample (pink area): 3-41-64 on 23 Apr. 1965.

courtesy Armstrong Flight Research Center

Preparing for launch on Engle's final X-15 flight: 1-61-101 on 14 Oct. 1965.

courtesy Armstrong Flight Research Center

Bob Rushworth with Engle: Aug. 1965.

courtesy Armstrong Flight Research Center

Engle, Rushwortth, McKay, Knight, Thompson, and Dana: 2 Dec. 1965.

courtesy Armstrong Flight Research Center

You Tube documentary about Operation Desert Strike, which affected X-15 operations, as described in chapter 8 of "The X-15 Rocket Plane."

Joe in front of a North American F-100 Super Sabre.

courtesy author's collection

Video image of Engle entering his pressure suit prior to an X-15 flight.

courtesy author's collection

The X-15 soars toward space.

courtesy author's collection

Ballistic control system jets fire in the nose and wing to stabilize the X-15's attitude in space, providing a stable platform for experiments, as well as safe control for reentry.

computer art courtesy Thommy Eriksson

Engle is greeted on the lakebed by his wife Mary, after an X-15 flight.

courtesy author's collection

Engle with wife, Mary, and children, Jon and Laurie.

courtesy author's collection

Engle sporting a flight jacket with an early X-15 patch. Only the second known photo of the patch at the time of the X-15 program.

courtesy author's collection

Joe Engle poses in front of the X-15A-2 on 2 Dec. 1965. He was supposed to inherit this program from Bob Rushworth, but instead went to the NASA Astronaut Office. Pete Knight eventually took over the A-2, flying Mach 6.7 on 3 October 1967.

courtesy author's collection

Cast and crew of the "Star Trek" television series visit NASA at Edwards: 13 Apr. 1967.

courtesy Armstrong Flight Research Center

The women of NASA in front of X-15 No. 3. They served as the "computers."

courtesy Tahir Rahman collection

The patch created by the Apollo 14 backup crew of Engle, Cernan, and Evans.

courtesy author's collection

Original Apollo 17 crew was to be Joe Engle, Gene Cernan, and Ron Evans.

courtesy author's collection

Space Shuttle Commander Joe H. Engle with Richard H. Truly: STS-2 in Nov. 1981.

courtesy NASA Headquarters

Joe Engle bringing home Space Shuttle Columbia: 14 Nov. 1981.

photo by the author

Joe Engle lands Space Shuttle Discovery at the end of mission STS-51I: 3 Sep. 1985.

photo by the author

Joe Engle and AW&ST Senior Editor William Scott go through a simulated mission on the X-30 National Aerospaceplane (NASP) mockup.

courtesy Aviation Week & Space Technology

Joe Engle dons a pressure suit to test NASP human factors design.

courtesy Aviation Week & Space Technology

B-52 Pilot Fitz Fulton and X-15 Pilot Joe Engle at the San Diego Air &Space Museum Legends of Flight installation 1 Nov. 2014.

courtesy San Diego Air & Space Museum

Engle in the cockpit of the X-15A-2 on 2 Oct. 2015. The X-15 had just been moved to its new home in Hangar 4 at the National Museum of the US Air Force.

courtesy National Museum of the US Air Force