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Mission Statement

The staff of the archive branch and the multi-mission archive at STScI provides:

  • world-wide technical and scientific leadership in archive system design
  • secure storage and reliable retrieval services for data from HST and all MAST-supported missions
  • user-friendly and scientifically useful search and cross-correlation tools
  • development and support for inter-archive communication and data transfer standards
  • accurate and useful mission archive documentation
  • helpful user support services with a 1 business day response time
  • free public access to all our data products after any proprietary constraints are lifted


Barbara MikulskiThe Space Telescope Science Institute (STScI) was already operating an efficient archive for distribution of the Hubble Space Telescope data in 1997, when the International Ultraviolet Explorer mission ended and NASA began to search for a permanent home for the IUE data archive. The clear synergy between HST and IUE science made it logical to combine the data into a single archive. Soon thereafter NASA made STScI the archive center for data from similar space-based missions with data in the Ultraviolet/Optical/Near-IR range. The name Multimission Archive at STScI (MAST) was chosen to convey that the broader focus of the extended archive. On April 5, 2012, the archive was named the Barbara A. Mikulski Archive for Space Telescopes (MAST) to honor Senator Mikulski for her career-long achievements and becoming the longest-serving woman in U.S. Congressional history.


Pride of BaltimoreOnce the acronym MAST was selected, the team began to think about a logo for the project. The team felt that using a picture of a mast in a sea of stars would symbolize the goal of helping our users navigate the sea of data gathered for galaxies, stars and dust from all the missions in the archive. STScI is based in Baltimore, Maryland, located on the Chesapeake Bay and home to a proud maritime tradition. Acknowledging this heritage, the mast included in the logo is a photograph of the memorial for an authentic reproduction of a 19th-century Baltimore clipper schooner known as the Pride of Baltimore. The schooner was tragically lost at sea with four of its 12 crew on May 15, 1986.


MAST supports a variety of astronomical data archives, with a primary focus on scientifically related data sets in the optical, ultraviolet, and near-infrared parts of the spectrum. See https://archive.stsci.edu/missions.html for a full list of the mission, survey, and catalog data distributed by MAST. MAST is a component of NASA's distributed Space Science Data Services (SSDS).

MAST archives a variety of spectral and image data with a range of data characteristics. To see a complete list of missions with data archived with MAST, click on the Mission Link in the top menu bar. MAST also provides a large suite of searches. In addition to customized searches for each mission, MAST provides several cross-mission searches.

MAST also archives sets of High-Level Science Products (HLSP). Users may search for High-Level Science Products by target or coordinates by using the HLSP search page. MAST actively solicits submission of High-Level Science Products related to our missions and we provide guidelines contributing them to MAST.

The MAST Users Group provides essential user perspectives on archive operations and development, including suggesting priorities for short and long term operational and scientific enhancements to the archive.

Although there is no cost involved in retrieving data from MAST, researchers are requested to include an acknowledgement (as shown in the MAST Data Use Policy) in publications that make use of MAST.

Below are links to some additional information about MAST:


The MAST staff wishes to acknowledge the work that other groups and projects have done and allowed us to use. Thank you to:

Canadian Astronomy Data Centre (CADC) for the HST preview images

NASA's Goddard Space Flight Center (GSFC) Astrophysics Data Facility staff for access to the IUE and UIT browse images, and copies of the IUE, UIT, WUPPE, and HUT datasets. ADF staff members provided background information and documentation about these datasets. Special thanks to the WISARD group for a copy of their UIT databases. ADF no longer exists as an entity after GSFC reorganization.

GSFC's Laboratory for Astronomy and Solar Physics LASP IUE Project for the IUE Documentation, the IUEDAC web pages, the IUEDAC software package, and the initial copy of the database. GSFC has been reorganized and LASP became part of GSFC's Astrophysics Science Division.

EUVE Project for initial copy of the EUVE database and various web pages.

WUPPE UIT , and HUT projects for additional information, documentation, and data.

High Energy Astrophysics Science Archive Research Center (HEASARC) for access to the on-line copies of the EUVE data

Dr. George Sonneborn and other members of the GSFC LASP for the Copernicus data, database, and associated web pages. GSFC has been reorganized and LASP became part of GSFC's Astrophysics Science Division.

The NASA Extragalactic Database (NED), and the Simbad Astronomical Database (both at CDS and its mirror site at CFA ) for their invaluable name resolver services.

MAST made extensive use of the Swift web sites at HEASARC, Penn State, ASI Science Data Center in Italy, and the University of Leicester in England. All the catalog information and data sets available from MAST were provided by the HEASARC Guest Observer Facility.

We would like to thank the EPOCh project for their help in creating the MAST EPOCh archive, especially Stephanie McLaughlin who was our main contact with the EPOCh project for the past few years. Comments about the EPOCh archive or MAST in general should be sent to archive@stsci.edu.

To acknowledge use of MAST data in any publications, see the MAST Data Use page.