No future Astros, only former Astros with birthdays today ~
RHP Ron Willis (died November 21, 1977 at age 34)
Willis was purchased by Houston from the St. Louis Cardinals in August of 1969 and returned to the Cardinals in November of 1969. I'd call that a rental. He only pitched 2.1 innings for the Astros in three games, but had a 0.00 ERA and a 1.286 WHIP.
RHP Scipio Spinks (65)
One of the better names in Astros history, Spinks was signed by Houston as an amateur free agent in 1966. In 11 appearances over three years with the big club from 1969 to 1971, he had a 5.40 ERA and a 1.400 WHIP before being traded to the Cardinals in April of 1972. He had a very successful season for the Cardinals (5-5 in 16 starts with a 2.67 ERA) before injuring his knee in a collision at the plate with Johnny Bench.