Question: What is the official name of the the united states air force service that the person nicknamed `` Digger `` served in ?

text: List of U.S. Air Force Test Pilot School alumni
Famous alumni -- Astronauts
Col. Frank Borman , USAF , first lunar orbit as Apollo 8 commander Col. Eileen Collins , USAF , first female shuttle pilot , first female shuttle commander MGen . Michael Collins , USAF , Apollo 11 command module pilot Capt . Robert Crippen , USN , STS-1 pilot , STS commander Col. Jack D. Fischer , USAF , flight engineer , Soyuz MS-04 ( Expedition 51/52 ) Maj. William `` Pete '' Knight by modified X-15A-2 after record-setting flight Maj. Robert Henry Lawrence Jr. , USAF , first African-American astronaut MGen . Robert Rushworth , USAF , X-15 test pilot VADM . Richard H. Truly , USN , NASA administrator , STS commander and pilot Lt. Col. Ed White , USAF , first U.S. spacewalk MGen . Bob White , USAF , first to exceed Mach 4 , 5 and 6 * Individual was killed in a work-related ( aviation ) accident .
The U.S. Air Force Test Pilot School (TPS) graduated the following notable alumni who made significant contributions to the aerospace field. The school's mission is to produce experimental test pilots, flight test engineers, and flight test navigators to lead and conduct test and evaluation of aerospace weapon systems. The school was established on September 9, 1944, as the Flight Test Training Unit at Wright-Patterson Air Force Base (AFB) in Dayton, Ohio. To take advantage of the uncongested skies and superb flying weather, the school was moved on February 4, 1951, to its present location at Edwards Air Force Base in the Mojave Desert of Southern California. Edwards AFB is the home of the Air Force Flight Test Center and has been an integral part of flight testing for over fifty years. Between 1962 and 1972, the Test Pilot School expanded its role to include astronaut training for military test pilots. Thirty-seven TPS graduates of this era were selected for the U.S. space program, and twenty-six went on to earn astronaut's wings by flying in the X-15, Gemini, Apollo, and Space Shuttle programs. Although the school no longer trains astronauts, many TPS graduates since 1972 have been selected by the National Aeronautics and Space Administration (NASA) for duties in space. The school encourages applications from civilians, personnel from other U.S. military services, and individuals from foreign countries. An exchange program allows selected students to attend other test pilot schools including the United States Naval Test Pilot School, the United Kingdom's Empire Test Pilots' School, and France's EPNER.
Name Service Rank Class Notable events
Michael J. Adams * USAF O-04 Major 1962-03 62C , IV , MOL X-15 Flight 191 , 1965 USAF MOL Group
Thomas Akers USAF O-06 Colonel 1982-02 82B STS-41 , STS-49 , STS-61 , STS-79
Dominic A. Antonelli USN O-05 Commander 1997-02 97B STS-119 , STS-132
Lee Archambault USAF O-06 Colonel 1994-02 94B STS-117 , STS-119
Charles Bassett * USAF O-03 Captain 1962-01 62A , III 1963 NASA Group 3
Robert Behnken USAF O-06 Colonel 1998-02 98B STS-123 , STS-130
John E. Blaha USAF O-06 Colonel 1971-01 71A STS-29 , STS-33 , STS-43 , STS-58 , STS-79 , Mir-22 , STS-81
Michael J. Bloomfield USAF O-06 Colonel 1992-01 92A STS-86 , STS-97 , STS-110
Karol J. Bobko USAF O-06 Colonel 1965-02 65B , MOL STS-6 , STS-51-D , STS-51-J
Eric A. Boe USAF O-06 Colonel 1997-01 97A STS-126 , STS-133
Frank Borman USAF O-06 Colonel 1960-03 60C , I Gemini 7 , Apollo 8
Ken Bowersox USN O-06 Captain 1985-01 85A STS-50 , STS-61 , STS-73 , STS-82 , STS-113 , Expedition 6 , Soyuz TMA-1
Roy D. Bridges Jr USAF O-08 Major General 1970-02 70B STS-51-F
Curtis Brown USAF O-06 Colonel 1985-02 85B STS-47 , STS-66 , STS-77 , STS-85 , STS-95 , STS-103
Duane G. Carey USAF O-05 Lt Colonel 1992-01 92A STS-109
John Casper USAF O-06 Colonel 1974-01 74A STS-36 , STS-54 , STS-62 , STS-77
Kevin P. Chilton USAF O-10 General 1984-01 84A STS-49 , STS-59 , STS-76
Eileen Collins USAF O-06 Colonel 1989-02 89B STS-63 ( first female shuttle pilot ) , STS-84 , STS-93 ( first female shuttle commander ) , STS-114 ( Return to Flight after Columbia Disaster )
Michael Collins USAFR O-08 Major General 1960-03 60C , III Gemini 10 , Apollo 11
Gordon Cooper USAF O-06 Colonel 1956-04 56D Mercury 9 , Gemini 5