The Hubble Origins Probe (HOP) was a proposal for an orbital

telescope A telescope is a device used to observe distant objects by their emission, Absorption (electromagnetic radiation), absorption, or Reflection (physics), reflection of electromagnetic radiation. Originally, it was an optical instrument using len ...

made in 2005 in response to the first cancellation of the fourth

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

(HST) servicing mission. It would have used an

Atlas V rocket Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was developed by Lockheed Martin and has been operated by United Launch Alliance (ULA) since 2006. Primarily used to launch payloads for t ...

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. Funding for the mission was never allocated; in February 2005,

Sean O'Keefe Sean Charles O'Keefe (born January 27, 1956) is a university professor at Syracuse University Maxwell School, former chairman of Airbus Group, Inc., former Secretary of the Navy, former Administrator of NASA, and former chancellor of Louisiana ...

, the NASA administrator who had cancelled SM4, resigned. Michael D. Griffin,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

administrator after O'Keefe, reinstated the servicing missions, making HOP redundant.

References

External links

Hubble Origins ProbeReplacing Hubble by Francis Reddy on astronomy.com
* ttp://www.nasa.gov/mission_pages/hubble/servicing/SM4/main/ NASA Mission Pages: Service Mission 4 (SM4)br>Hubble Space Telescope (HST) Service Mission 4 (SM4) Crew Training video (archive.com)
{{Space observatories Hubble Space Telescope Space telescopes