This chart graphically depicts all NASA astronaut spaceflight assignments in a timeline that spans the beginning of the program through to the end of the Apollo era. The names are listed by selection group in the order of their assignment to fly. Codes as explained in the legend illustrate each person's skills and accomplishments. The graph at the top of the chart is a simplified version of the graph 'File:Space Race 1957-1975 .jpg', as added to the Wikipedia article on the Space Race.

There was a significant difference in selection criteria for the first group versus the subsequent groups. The Mercury Seven were picked for a program that had the goal of orbiting an astronaut in a capsule, with no expectation of the much more complex tasks that were to be added to the human spaceflight program under the Kennedy administration - orbital rendezvous of Project Gemini and piloting the lunar module in Project Apollo. A noted distinction is that two of the seven in the first group had not completed a bachelor's degree, while roughly two-thirds of the subsequent groups had advanced degrees, many with PhD's. Another important difference is how the requirement for being a test pilot school graduate changed. The second group had two selectees (both civilian) who had not been to Test Pilot School (TPS). Subsequent classes had members who had not even flown in the flight test field.

A common misconception is that all astronauts were military test pilots who had been fighter pilots before being selected by NASA. (One example of how this myth is perpetuated is through Hollywood such as in this quote by Wally Schirra, portrayed by Mark Harmon, from episode 3 of the 1998 From The Earth To The Moon {at ~24min}, "We're all test pilots." He makes this statement while sitting next to his crewmate Walt Cunningham who had no flight test background.) This chart clearly shows that this is not the case, with exceptions being identified where non-test pilots are listed with the caveat "No Test[-Pilot Background]". This applied to two entire groups, 4 and 6, with only two of those 17 people having experience as fighter pilots (see Grp4/Grp5 paragraph below). For those who had been test pilots but did not go through the formal test pilot training program (Test Pilot School, indicated in the paragraph above), they are listed with the caveat "No TPS". Other non-fighter pilots are listed as coming from a background of having flown large "Heavy" aircraft (including Carpenter, Mitchell and Mattingly).

Three military services were well represented since the beginning of the program, with members selected from the Navy, Air Force and Marine Corps. An issue that gets totally ignored by the vast majority of sources on the topic is that astronauts were hired to accomplish a vertical landing on the Moon and that the experts in vertical flight were Army helicopter test pilot, yet the NASA astronaut corps had absolutely no one from a helicopter background, be it Army or the other services. But there was at least one Army helicopter test pilot, Jack Kluever, who was brought in to be an instructor in the Lunar Lander Training Vehicle (LLTV) to teach the astronauts vertical flight. The Army would not get its first astronaut, Bob Stewart, until 1978 when the first class of shuttle astronauts was picked. This was long after the Lunar Module was done flying. (But ironically, the Army was well represented in fiction, with the popular tv show I Dream of Jeannie portraying one of the two astronaut leads, Roger Healey, being an Army officer.)

The entire Group 4 is listed after Group 5 because Slayton treated Group 5 as having de facto seniority, as evidenced by support and backup assignments. Slayton's rationale for this was that members of the Group 4 scientists had their NASA training delayed with one year of Air Force Undergraduate Pilot Training. All members of Group 5 were already military rated pilots, therefore did not have such a delay in astronaut training. However two members of Group 4, Michel and Kerwin, were military pilots at the time of selection. The assignment chart shows their two names left-shifted in reflection of this fact. After Haise and Mitchell had been given backup assignments, Michel resigned.

The original requirement for the Command Module Pilot was to be a veteran with rendezvous experience. This was relaxed with the assignment of Eisele as backup to Apollo 10, followed by Anders as backup to Apollo 11. Worden and Mattingly were subsequently given backup CMP assignments as rookies. The first CMP to fly with intended solo duties but having no rendezvous experience was rookie Jack Swigert on Apollo 13, having been substituted from the backup crew a few days prior to launch.

Three crews who flew Gemini together later flew together as Apollo crewmates. (Previous backup assignments that were shared by flown crews are also indicated.

The X-15 program is compressed into one single row, with the grey line spanning first free-flight to last flight. Suborbital missions above 50 miles met the USAF definition for astronaut, and all thirteen of these flights are indicated with a parabolic trajectory symbol with the initials for the pilots' last name (with Engle's duplicated with his qualifications in the Group 3 section). Fatalities for the three pilots selected to the program are listed in line, with Kincheloe dying before ever getting an X-15 flight, and with Walker dying after having flown the only two X-15 missions that exceeded the 100km international definition for astronaut. Because of that distinction, Walker's name appears in bold black letters as with the orbital astronauts who all exceeded 100km. All 14 of the X-15 pilots are listed in a table at the bottom, with only 12 getting to fly the vehicle. This table lists all free-flights (abbreviated as "fflights") as well as flights exceeding 50 miles. Captive-carry flights and abortive drops are not indicated. Walker's name is listed with two '+' symbols, representing his two flights exceeding 100km. Armstrong and Engle both have a '+' after their rows because they are the two that went on to orbital missions with NASA. In 2014, Engle became the only surviving X-15 pilot. McKay is listed with the year of death as '75 and an 'X' is included because the injuries he had sustained from his X-15 landing mishap were a major factor in his early death at age 52. See "The X-15 Rocket Plane: Flying the First Wings Into Space" by Michelle L. Evans, reporting how McKay had sustained "brain damage, lung damage, a lot of spinal cord damage" (p159) and "the autopsy, it showed quite a bit of brain damage" (p163). So the 'X' indicates that his death happened as a result of an incident that happened during the timeframe of the program.

December 8th 2016, marked the first time that an entire astronaut class became deceased, with the death of John Glenn at age 95.^[1] As of March 18, 2024, Jim Lovell is the only surviving member of NASA Group 2. Lovell is also the only surviving person to have flown to the Moon twice.

This chart was first constructed in 1997, with public distribution offered in 2001, via Usenet.