All STScI domains will be unavailable Saturday, 23 January, 2021, 7:30 AM EST - 4:00 PM EST (12:30 - 21:00 UTC) for network maintenance.
Once observations of interest are found,
registered and anonymous users can retrieve the data. We describe here the
various retrieval options for HST data and explain the various terms
involved, which you will encounter on the retrieval page.
MAST no longer registers their own set of archive users as was done in the past.
As of April 2015, users may log into
the Archive using an STScI Single Sign-On (SSO) Portal identity.
All STScI employees by default already have this SSO identity set up and can use
these credentials for any requested login information requested by the Archive.
Non-STScI users either had their
Archive username and password migrated to SSO credentials and were
notified via email,
or they need to register for an STScI SSO external account.
If you want an archive account, you can register for one on the web. See our
http://archive.stsci.edu/registration/ page for more information.
If you register, you should receive your username and password via email in a few minutes.
This is the password that was given to you
when you registered (See Archive Username,
As of April 2015, the username and password are no longer specific to MAST
and are referred to as the STScI SSO portal identity
which will allow access to other STScI services without requiring additional
The data will be written to the Archive staging disk. You will be able
to pull from the staging disk using FTP and logging in with your archive username and password.
Only non-proprietary data
may be retrieved. You can delete your data when you are done.
You may request data to be delivered on an external hard drive
if you anticipate many GB of data retrieval.
Currently the hard drive must be returned to STScI after the data are read onto your local drive.
We have a limited number of drives for use and you MUST contact the Archive Hotseat
(410-338-4547 or firstname.lastname@example.org)
to coordinate your requests and use of the hard-drive option.
Verify Your Mailing Address
If you select one of the hard media options, we will
ask you to provide a mailing address.
If you need to make changes to your mailing address, simply make the
changes in the form before clicking the Send retrieval request to
ST-DADS button. Your request will not be sent until you click
on this button.
You currently cannot have two hard-media requests in process
at the same time with two different mailing addresses.
The name of the directory to which the data will be written.
Please make sure that this directory exists, is writeable,
and has enough space. The retrieval will fail otherwise.
(Unfortunately, for technical reasons, we can't reliably estimate the
size of your retrieval until the files are read from the optical platters,
so we can't tell you whether there is enough space there,
but generally, retrievals are rarely more than a gigabyte in total size.)
There are five characters which, if present in a password, will cause
the retrieval to fail: (, ), *,
", and /.
All the information you enter in this form will be sent to ST ScI
through an SSL (encrypted) web connection using a
Verisign certificate. The password
remains encrypted until it is needed to transfer the data to you.
The password is not retained after the data are transferred.
If your local system disallows FTP access or sftp (OpenSSH v2), and you
are requesting only public data, you can use the STAGE
option. If you are requesting proprietary data, you may select a hard-media
option (Disk, DVD).
ST ScI's On-the-fly Reprocessing (OTFR)
system for WFPC2 and STIS was opened to external users
in December of 1999. As of June 2000, ST ScI stopped
archiving calibrated data for WFPC2 and STIS.
In the first week of April 2001, we released the On The Fly Reprocessing
System for STIS and WFPC2 data. On-the-fly Reprocessing
for NICMOS data was implemented on Septmeber 26, 2001. ACS data uses the OTFR system.
Now that most WFPC2 data have been reprocessed, MAST has discontinued on-the-fly reprocessing and supplies calibrated images directly from the static archive. By default, these files are delivered in multi-extension FITS (MEF) format. If you would prefer to receive the wFITS format previously used for WFPC2 data, check the box below. For details, see the WFPC2 Reprocessing page http://www.stsci.edu/hst/wfpc2/wfpc2_reproc.html.
Files used for calibration. You may select either the files
that were used when the data was originally calibrated just
before archiving, or the calibration files that should be used
if you plan to recalibrate the data for non-OTFR instruments.
Only the best files are available for data from OTFR instruments.
Enter the specific three-letter file extension if it is not listed in the
scrolling listbox. Remember that science data is archived in FITS format
(not GEIS), so for example, the .c0h and .c0d
files will be combined into a single extension: c0f.
For common questions about retrievals see our