In 1993 NASA chose NCSA's HDF format to be the standard file format for storing data from the Earth Observing System (EOS), which is the data gathering system of sensors (mainly satellites) supporting the Global Climate Change Research Program.
Since NASA's selection of HDF, NCSA (and now the HDF Group) has been working with NASA to prepare for the enormous data management challenges that will come when the system is fully functional. This has included the development of a specialized form of HDF called HDF-EOS, which deals specifically with the kinds of data that EOS produces. "Terra", the first satellite to fly as part of the EOS, was launched in December, 1999, and began delivering data officially in April, 2000. Other satellites have been launched since then.
Each of the EOS satellites deliver a terabyte or more of data per day from many different instruments. The quality and flexibility of the HDF format and supporting software is central to the success of the project. About 1,000 project scientists are the front-line users of the data, and there are an estimated 30,000 secondary users, ranging from GIS applications to school kids.
Partly because of NASA's commitment, several other organizations have also adopted HDF, including some foreign space agencies. One example is Landsat 7 (launched spring 1999), which uses HDF as a standard.