(written from a Production point of view)
Samuel Lloyd Haynes (19 September 1934 – 31 December 1986; age 52), better known simply as Lloyd Haynes, was the actor who played Lieutenant Alden in the Star Trek: The Original Series first season episode "Where No Man Has Gone Before". Alden was one of his first television roles. He is best known for playing high school teacher Pete Dixon in the television series Room 222 from 1969 through 1974.
Haynes was born in South Bend, Indiana, on 19 September 1934. He served in the Marine Corps from 1952 through 1964 and fought in the Korean War. He was also a public-affairs officer for the United States Navy Reserve, holding the rank of commander. 
Following his military service, Haynes studied acting at the Film Industries Workshop and Actors West in Los Angeles, California.  He married and divorced twice; his third marriage to Carolyn Inglis produced one child.
Haynes began acting in television shows in 1965, making his first appearance in January 1966 on an episode of The Fugitive. That episode's director, Richard Donner, then cast Haynes in an episode of The F.B.I., a crime drama on which Stephen Brooks was a regular cast member. In the episode, "The Spy-Master", Haynes and TOS guest actor William Wintersole played two of three unnamed Special Agents. Also appearing in Haynes' episode of The F.B.I. were Whit Bissell and Keye Luke.
In September 1966, Haynes made a second appearance on The Fugitive, in an episode with William Bramley, Peter Brocco, Ted Gehring, and Michael Strong. Haynes again appeared with Peter Brocco in a 1966 segment of Bob Hope Presents the Chrysler Theatre written by Richard Matheson. A third episode of The Fugitive followed for Haynes in August 1967, which also featured Joseph Campanella, Seymour Cassel, Paul Comi, Paul Sorensen, and Arch Whiting.
Haynes played the role of Lord Chancellor in two back-to-back episodes of Batman in March 1967, working alongside fellow TOS performers Lee Meriwether and Grace Lee Whitney. That same month, Haynes appeared on The Green Hornet in a two-part episode with Arthur Batanides. Haynes then made several appearances on the Tarzan series, working with James Gregory and William Marshall. Haynes again worked with James Gregory in a 1968 episode of Lancer.
From 1969 through 1974, Haynes starred as high school teacher Pete Dixon in the Emmy Award-winning comedy-drama series Room 222. Haynes himself received an Emmy Award nomination for his work on this series, as well as a Golden Globe nomination. In 2006, Haynes received a posthumous nomination from the TV Land Awards in the "Teacher of the Year" category for his role on Room 222. Several Star Trek alumni made appearances on Room 222, including Ed Begley, Jr., Terri Garr, and Jan Shutan.
In 1971, Haynes reteamed with his TOS co-star Leonard Nimoy on the TV movie Assault on the Wayne, which also starred William Windom, Malachi Throne, and John Winston. After Room 222 ended its run in 1974, Haynes guest-starred on such television series as Emergency! (with Kevin Tighe), Marcus Welby, M.D. (with Richard Derr), and T.J. Hooker (with William Shatner, James Darren, Richard Herd, Marc Alaimo, and Robert O'Reilly).
In 1981, Haynes had a recurring role as Judge Horatio Quinlan on the prime-time soap opera Dynasty, which starred Joan Collins and, at the time, Lee Bergere. That same year, Haynes co-starred with Dean Stockwell and Joy Garrett in the TV movie Born to Be Sold. Haynes' last role was that of "Ken Morgan" on the soap opera General Hospital, from 1984 until his death from cancer in 1986. He was 52 years old.
Following the airing of the second Star Trek pilot in 1966, Haynes appeared in several films. His first was the 1968 crime drama Madigan, in which he co-starred with fellow TOS performers Michael Dunn, Steve Ihnat, Warren Stevens, Dallas Mitchell, Gloria Calomee, and William Bramley. Star Trek III: The Search for Spock actor Paul Sorenson, Star Trek: The Next Generation guest actor John McLiam, and Star Trek: Deep Space Nine co-star Albert Henderson also appeared in this film.
That same year, Haynes and fellow Trek alumnni Joseph Bernard, William O'Connell, Jonathan Lippe, Michael Rougas, Buddy Garion, Gary Downey, and Jim Goodwin worked together on the action thriller Ice Station Zebra. This was followed in 1969 with a supporting role in the horror film The Mad Room.
In 1977, Haynes played boxer Muhammad Ali's manager in the biographical film The Greatest, co-starring Paul Winfield, David Huddleston, Malachi Throne, Skip Homeier, and David Clennon. Haynes' last feature film was the 1978 action-thriller Good Guys Wear Black, which also featured Don Pike and David Starwalt.
- "Lloyd Haynes, eulogy by Eric Niderost, Starlog, issue 128, March 1988, p. 61