Space Telescope Science Institute
Call for Proposals and HST Primer
help@stsci.edu
Table of Contents Previous Next Print


Hubble Space Telescope Call for Proposals for Cycle 22 > Chapter 10: Proposal Implementation and Execution > 10.10 Failed Observations

10.10 Failed Observations
HST observations fail at a rate of a few percent. Some of these failures result from occasional guide stars that cannot be acquired, or from an instrument anomaly, or the telescope happening to be in a safe mode when a particular observation was scheduled. Such failures, which are obviously beyond the proposer’s control, can usually be scheduled for a repeat observation. When this is the case, the proposer receives a notice of the failure and information on obtaining a repeat observation.
A smaller fraction of failures do not have a clear cause, and may not be evident from our internal reviews of data quality. If you believe your observation has failed or is seriously degraded, then you may request a repeat for your program using the Hubble Observation Problem Report (HOPR) website available from the HST Program Information Page. The HOPR must be filed within 90 days after the observations are taken. In cases where the failure resulted from proposer error (e.g., incorrect target coordinates), a repeat will not be granted. In cases where the failure was a result of incorrect instrument performance, or incorrect information provided by STScI, a repeat is usually granted.
The policies that apply to failures and repeats are described in the Policy Document for the Telescope Time Review Board (TTRB). We wish to emphasize in particular:
If a Snapshot exposure fails during execution it will not be repeated, regardless of the cause of the failure.

Hubble Space Telescope Call for Proposals for Cycle 22 > Chapter 10: Proposal Implementation and Execution > 10.10 Failed Observations

Table of Contents Previous Next Print