STScI . ... What is STScI . ... Staff Directory . ... Missions . HST . ... Future Missions and . ... Missions Office . ... Research . Research Staff Directory . ... Talks . ... Local Attractions . ... More than two decades ago the distance scale was uncertain by a factor of two, and the resolution of this conundrum had been a major driver for HST. ... Space permitting, workshop talks are open to faculty and staff from all local (Maryland Washington DC) institutions without registering. ...