|HST Primer for Cycle 25|
7.2 The HST Data ArchiveAll science and calibration data are placed in the HST Data Archive. Science data become immediately available (after pipeline processing) to a program’s Principal Investigator (PI), as well as those designated by the PI as long as they are authorized to retrieve the data. These data may be retrieved after the PI has registered for an STScI single sign-on (SSO) account and are normally proprietary for a period of six months from the date of observation (see Section 5.1 of the Call for Proposals for information on data rights).On average, science data from HST flow through the production pipeline and into the Archive within one day after observation on the telescope. Some data may take as long as three to five days. Observers are notified by e-mail when the first datasets reach the Archive. They are also provided with Web tools to track a visit’s completeness and to retrieve the data generated by the pipeline.The time required for retrieving data from the Archive depends on whether the data are available for direct download or need to be reprocessed, the speed of the user’s connection, the size of the requested dataset, and the load on the Archive. As of October 1, 2016, the HST Data Archive contains over 126 TB of data. During the first quarter of 2017, all of the HST data, including proprietary data, should be online and available for direct download through the Data Discovery Portal. To retrieve proprietary data users must have a MyST account and be authorized to do so.If there are strict scientific requirements for data receipt within days after execution, such as to provide pointing corrections for tightly scheduled visits, there are resource-intensive methods to expedite delivery of data. Such requirements must be stated in the proposal so that the resource needs can be determined and reviewed (see Section 9.3 of the Call for Proposals).7.2.1 Web Access to the HST Data ArchiveThe Archive may be accessed through a number of web-based interfaces. The HST search page, also available under the “Mission Search” menu tab at the MAST webpage, allows qualified searches for HST data, and download of those data and their reference files. The MAST Portal provides a number of capabilities to search for, inspect, and download data. Its interface includes integrated access to the Digitized Sky Survey (DSS) and enables users to access a coordinate resolver to look up the coordinates of an object by name. In both interfaces it is possible to request specific data products instead of the entire complement of files. Requesters of proprietary data will be required to log in to their MyST Single Sign-On (SSO) System account. Starview only allows searches of instrument-specific databases and requires users to sign in using their SSO account. All of the MAST search interfaces provide previews of most publicly available images and spectra.