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Hubble Space Telescope
Proposal Information

Proposal Process Information

The HST General Observer proposal process is divided into two phases, Phase I and Phase II.
  • Phase I proposals contain the scientific justification and an abbreviated technical specification for an observing program which is submitted for review by the Telescope Allocation Committee (TAC).
  • Phase II proposals contain all of the technical details required for successful execution of the approved observing program.

Supporting Documentation for Phases I and II

Phase I Info Phase II Info Exposure Time Calculator (ETC)
  • The ETC is a web-based application developed in Python to assists Hubble astronomers and engineers in preparing Phase I and Phase II observing proposals. The ETC’s sole purpose is to calculate the Signal-To-Noise (SNR) Ratio for a given exposure time, or, calculate the exposure time for a give SNR Ratio.