The Hubble Origins Probe (HOP) was a proposal for an orbital telescope made in 2005 in response to the first cancellation of the fourth Hubble Space Telescope (HST) servicing mission.[1] It would have used an Atlas V rocket or similar launch vehicle to launch a much lighter, unaberrated mirror and optical telescope assembly, using the instruments that had already been built for SM4, along with a new wide-field imager. It would have cost between $700 million and $1 billion.[2]

Funding for the mission was never allocated; in February 2005, Sean O'Keefe, the NASA administrator who had cancelled SM4, resigned. Michael D. Griffin, NASA administrator after O'Keefe, reinstated the servicing missions,[3] making HOP redundant.


  1. ^ "Hubble Option" (Press release). Johns Hopkins University Applied Physics Laboratory. 2005. Archived from the original on 2005-03-06. Retrieved 30 June 2013.
  2. ^ Lawler, A. (2005). "ASTRONOMY: Hearing Highlights Dispute over Hubble's Future". Science. 307 (5711): 831. doi:10.1126/science.307.5711.831. PMID 15705817. S2CID 152395132.
  3. ^ Harwood, William (31 October 2006). "'Go' for Hubble servicing mission". CBS NEWS Space Place. Retrieved 1 July 2013.