The Deep Underground Science and Engineering Laboratory, or DUSEL is a major project under consideration by the National Science Foundation. DUSEL will be a series of large laboratories, caverns, and cleanrooms serving the field of underground science. The main impetus for DUSEL is the study of extremely rare nuclear physics processes, like neutrino scattering, dark matter interactions, and neutrinoless double beta decay, which can only be studied in the absence of cosmic rays. (Cosmic ray muons on the Earth's surface cause backgrounds in these types of detectors, but the particles cannot penetrate great depths in rock.) Easy access to these great depths will open new frontiers in geomicrobiology, geosciences, and mining engineering, making DUSEL a multidisciplinary facility.
Various proposals for an American underground science facility have existed for at least a decade. Eight teams submitted proposals in 2005, including both existing mines (which need only be retrofitted and enlarged) and "green sites" from which a new facility could be excavated. Of these eight, via various downselections, the NSF gave R&D grants to two proposals, Homestake Mine (South Dakota) and the Henderson molybdenum mine in Colorado. In July 2007 the NSF gave its approval to Homestake.
If completed, Homestake will be the deepest underground science facility in the world, 8,000 feet (2,400 m) below ground (7200 meters of water equivalent, for cosmic-ray shielding purposes), deeper than the current record holder, SNOLAB in Sudbury, Ontario at 6,800 feet (2,100 m) below (6000 mwe). The next-deepest US facilities are the Waste Isolation Pilot Plant at 2300 mwe and Soudan mine at 2200 mwe.
Gaining access to that depth will take some time, since as of 10 August 2009 the mine is flooded to the 4,992-foot (1,522 m) depth and will need to be pumped dry and rusted equipment repaired. Plans are to construct an interim laboratory, at the 4,850-foot (1,480 m) level. This "Sanford Underground Laboratory at Homestake", currently funded by T. Denny Sanford ($70 million) and the state of South Dakota ($35 million) will support a National Science Foundation grant application for the full DUSEL (est. $550 million) in 2011.
In 2008, the Rapid City Public Library created a DUSEL wiki that collects news articles, photos, and information pertaining to the experiments that will take place in Homestake Mine. It also includes a list of other underground science facilities and a forum for community discussion.
^ NSF (2007-07-10). "07-075: Team Selected for the Proposed Design of the Deep Underground Science and Engineering Laboratory". Press release. Retrieved 2007-08-28.