February[]
- February 15: Stardust visits the comet Tempel 1.
March[]
- March 18: MESSENGER enters into orbit of Mercury.
- March 24: Stardust is deactivated.
June[]
July[]
- July 16: Dawn enters into orbit of the asteroid Vesta.
August[]
- August 5: Juno (spacecraft) is launched.
September[]
- September 10: The two GRAIL spacecraft are launched.
- September 27: S/2011 J 1 and S/2011 J 2 are discovered.
December[]
- December 31: The GRAIL spacecraft called Ebb entered service.