George Mueller was making ambitious projections for the Apollo Applications Program in 1966, and if they developed, more scientists would be needed for its crews. In September 1966 the National Academy of Sciences and NASA announced that applications for a second group of scientist-astronauts would be accepted. [see Chapter 5] Nearly a thousand hopefuls applied; the Academy's selection committee forwarded 69 names to NASA in March 1967, and five months later 11 new astronaut trainees, 9 Ph.D.s and 2 M.D.s, were named. [see Appendix 6] The group contained not a single qualified pilot; after six months of orientation and basic "ground school" training at MSC, they would all be sent to Air Force flight training.4
Addition of this class of candidates brought the astronaut corps to a strength of 56 - more than Apollo seemed to need, since no more than 10 lunar missions were contemplated.* The qualifications of the new group - who were mostly physicists, astronomers, or physicians, not earth scientists - suggests that MSC was preparing for Apollo Applications missions rather than lunar exploration. When they were chosen in mid-1967, however, even that prospect was growing dim and would be dimmer yet by the time they had finished flight training. Headquarters program officials continued to talk of frequent Apollo Applications missions,5 and Slayton had to be prepared to supply crews for whatever missions should be assigned and to anticipate some degree of attrition. On the other hand, if the program did not materialize as planned, the astronaut corps would be overstaffed and many aspiring space explorers would have small chance of flying in space. That could be an especially touchy point with scientists, who risked their careers by enlisting as astronauts.** In interviews with the scientist applicants, Slayton tried not to raise their expectations about the availability of flight assignments, to the point of frankly admitting that the astronaut corps had no urgent need for them at the moment. With that understanding, however, they were welcome in Houston, because the astronaut corps needed all kinds of talent to support MSC's missions.6 Members of the new group soon dubbed themselves "The Excess Eleven," or "XSXI."
* Given Slayton's system of promoting a backup crew to prime crew three missions later, and assuming that no crewman would be assigned to more than one mission in any capacity, 10 lunar missions would have required 55 astronauts (if support crews later became backup and prime crews). Slayton's preference for flight experience in crew members, however, makes that assumption questionable; hence fewer astronauts could have filled the positions on prime, backup, and support crews. On the 7 lunar landing missions flown, 39 astronauts filled 63 available crew positions.
** So did the pilot-astronauts, for that matter, but provision was made for them to keep their professional skills (flying) well honed as part of the program. The scientists enjoyed no such concession, as was repeatedly pointed out by NASA's outside scientific consultants.
4. NASA Release 67-211, Aug. 4, 1967.
5. W. David Compton and Charles D. Benson, Living and Working in Space: A History of Skylab, NASA SP-4208 (Washington, 1983), pp. 84-86.
6. Interview with Donald K. Slayton, Oct. 15, 1984.