The U.S. Spectrum-X-Gamma Coordination Facility is located at
Smithsonian Astrophysical Observatory
60 Garden Street
Cambridge, MA 02138
Currently, the staff comprises
Maps of the 60 Garden St. campus (GIF or postscript) are available.
GIF or postscript maps of the MBTA (Boston's Subway system) are available. The MBTA provides free shuttle buses from Logan Airport to the Airport subway stop on the Blue Line. To get to Cambridge, take the "inbound" train to Government Center, change trains to the Green Line, inbound, to Park St., and finally change at Park St. to the Red Line, "outbound". Get off at the The Harvard Square Red Line stop. It is about a 15 minute walk from Harvard Square to 60 Garden St. In case of inclement weather, take the 72, 74, or 78 bus from Harvard Square (board from the upper level subway bus ramp) and get off at Concord Ave. between Bond and Madison Sts.
There are a number of WWW pages containing interesting or even useful information about the cities of Cambridge and Boston. Harvard and MIT pages are also recommended.