[4] The Apollo 11 mission represented the first contact of humans with a non-Earth surface and concern was expressed by the National Academies of Science that the returning astronauts and spacecraft might inadvertently carry extraterrestrial life which could pose a "catastrophic" risk to humankind.

[5] To address these issues, a Mobile Quarantine Facility (MQF) was installed aboard the ship in which the returning astronauts, as well as flight surgeon William Carpentier, would be isolated.

[5] According to Hirasaki, four NASA engineers responded to a call for volunteers for a technician to be present inside the MQF during the quarantine period for necessary maintenance, and to physically remove the lunar rocks that had been recovered by the mission.

[8] Hirasaki noted that, prior to the mission, he had read the Michael Crichton book The Andromeda Strain; however, he felt the risks to his personal safety were "very, very minimal.

[2][6] In his 1974 autobiography, Carrying the Fire, Michael Collins described Hirasaki as "quiet, flexible, unobtrusive" and said that both he and William Carpentier were "good choices" to join the astronauts in the MQF.