STScI Software

Astronomer's Proposal Tool

Used to write, validate and submit proposals for the Hubble Space Telescope and the James Webb Space Telescope.

Exposure Time Calculator

Assists Hubble astronomers and engineers in preparing Phase I and Phase II observing proposals for submission to the Space Telescope Science Institute (STScI).


Additional Software Tools

Name Description
aXe The aXe software package is designed for the extraction, calibration, visualization, and simulation of spectra from slitless spectroscopic instruments.
DrizzlePac DrizzlePac is a software package for aligning and combining HST images, bringing an array of new features and algorithmic improvements over the prior, widely-used MultiDrizzle software.
Hcompress An image compression package used to compress the STScI Digitized Sky Survey and has also been used to compress the preview images in the Hubble Data Archive.
OPUS Telemetry processing system that converts the incoming telemetry from the Hubble Space Telescope into standard output. OPUS software is based on the blackboard architecture and, as a result, is highly robust and portable.

Installation Instructions  |  User's Guide  |  Document Index
Percy An interactive computer program which provides ephemeris and geometrical event information about solar system objects.
PyRAF Command language for running IRAF tasks that is based on the Python scripting language. As of October 1, 2019, STScI no longer supports PyRAF. Users will still be able to access an installation of PyRAF through Astroconda. However, STScI will no longer answer help calls related to PyRAF installation, bugs, or other usage questions.


pysynphot simulates photometric data and spectra as they are observed with the Hubble Space Telescope (HST). It is an object-oriented replacement for STSDAS SYNPHOT synthetic photometry package in IRAF.
Spike A multi-mission planning and scheduling system used for HST and other astronomical missions.
STSDAS Software package for reducing and analyzing astronomical data. It is layered on top of IRAF and provides general-purpose tools for astronomical data analysis as well as routines specifically designed for HST data. STSDAS is distributed through Astroconda and STScI offers partial support for this package.
TABLES External package in IRAF that provides support for tabular data for STSDAS and other packages. TABLES is distributed through Astroconda and STScI offers partial support for this package.