(written from a Production point of view)
Robert Dierx (born 15 May 1983; age 35) is an actor, stand-in performer, and production assistant who worked as a background Starfleet cadet in J.J. Abrams' Star Trek.  He filmed his scenes in March 2008 in front of the green screen at the CSUN campus which stood in for the Starfleet Academy.
Dierx was born as Robert Holden Dierx in Burlington, Ontario, Canada and has mainly worked as a background performer in the television series 24, Monk, The Unit, Desperate Housewives (2008, starring Teri Hatcher and Brenda Strong), Bones, How I Met Your Mother, Ghost Whisperer, CSI: Miami, Greek, Roommates, Brothers and Sisters, The Cleaner, Shark, Hyperion, and 90210. He also did background work on several feature films, including the comedies The Marc Pease Experience (2008) and Role Models (2008, with Cindy Sorenson), the fantasy film TiMER (2008, with Mark Harelik), the thriller Eagle Eye (2008, with Bill Smitrovich, William Sadler, Deborah Strang, J. Patrick McCormack, Manny Perry, Colby French, Chase Penny, and Peggy Roeder), the drama The Nanny Express (2009, with Dean Stockwell), and the comedies Fired Up (2009, with Tiffany Collie and Bertrand Roberson, Jr.) and 17 Again (2009, with Renee Taglia, Jonathan Newkerk, and Wednesday Mourning).
In addition, Dierx worked as photo double in CSI: Miami and Prison Break, and as stand-in on The Cleaner, Ghost Whisperer, Star Maker, and Dollhouse.
Beside his acting appearances, he worked as production assistant for the comedy Foreign Exchange (2008), the television series Swing Town (2008), the reality game show Cha$e (2008), and the action film Fast & Furious (2009).