There have been several vegetarian astronauts. Timothy J. (TJ) Creamer (Lieutenant Colonel, USA) NASA Astronaut (Mission Specialist Candidate).
Kalpana Chawla was both a strict vegetarian and an astronaut. She died when the shuttle Columbia broke up in 2003.
In April, 2001, Italian astronaut Umberto Guidoni and Canadian Astronaut Chris Hadfield brought some luxury food items with them to the International Space Station, Regiano Parmesan cheese and Canadian salmon.
When Neil Armstrong and Edwin 'Buzz' Aldrin sat down to eat their first meal on the moon, their foil food packets contained roasted turkey and all of the trimmings.
Tang, a powdered orange drink was introduced in 1965 by General Foods. NASA added Tang to the galley of the Gemini astronauts, and in July 1969 it traveled to the Moon on the Apollo mission.
The first American to orbit the Earth, astronaut John Glenn, carried pureed applesauce in squeezable tubes on his initial space flight. Ham with applesauce was served to Gemini astronauts.