|Affiliation:||United Earth Starfleet|
|Status:||destroyed (March 10, 2156)|
As of Thursday, May 22, 2155, Challenger was still under construction in the skies above San Francisco. On that date, while on an assignment to patrol Earth Cargo Service trade routes, Captain Jonathan Archer of the Enterprise (NX-01) pondered whether he might be able to persuade Starfleet to rush the Challenger into service, re-christening her the Sisyphus, to take on his less than engaging mission. (ENT novel: Kobayashi Maru).
It was launched circa August, 2155, alongside the Discovery (NX-04). In 2156, it was destroyed in the Battle of Andoria, when Captain Roy Dunsel activated the ship's self destruct and rammed the Romulan warbird Drivael in a successful effort to prevent it from attacking Andoria and take control of Challenger. All hands were lost. (ENT novel: Beneath the Raptor's Wing).
- Captain Roy Dunsel
- Ensign Kaye
- ENT episode: "Fortunate Son" (indirect mention)
- ENT novel: Kobayashi Maru (mentioned only)
- ENT novel: Beneath the Raptor's Wing