One Down, 51 to Go

One Down, 51 to Go is an achievement in Halo: Reach. It was unlocked by completing a Weekly Challenge.

Following the shutdown of Xbox 360 Halo online services on January 13, 2022, this achievement is no longer attainable.

Trivia
The name comes from the number of weeks in the year which is 52. Completing one weekly challenge represents the completion of 1 out of 52 challenges.