Curbed LA and the LA Times talk about the history of disguised oil drilling rigs just off the coast of Long Beach, but neither article mention the names for the man-made islands…
The islands are named after four astronauts who were killed in the line of duty in the early space program. Grissom, White, & Chaffee (the three islands closest to shore) were killed in the Apollo 1 fire in 1967, and Freeman was killed in 1964 when his T-38 was struck by bird in 1964. Here’s the ubiquitous Google map.