Robb Michael Kulin (born December 7, 1983) is an American aerospace engineer, entrepreneur, and former NASA astronaut candidate.

[4] Prior to starting the doctoral program, Kulin was a Fulbright Fellow for one year at the Politecnico di Milano.

[2] At the time of his selection as astronaut candidate in June 2017, Kulin was senior manager for flight reliability at SpaceX, leading the Launch Chief Engineering group in Hawthorne, California, where he had worked since 2011.

[1][4][2] In August 2018, Kulin became the first NASA astronaut candidate in fifty years to resign prior to completing the initial training program.

[3] Kulin joined Firefly Aerospace in April 2019 as Director of Engineering for its Alpha small satellite launch vehicle and later served as COO.