Lasers originally developed for the SDI plan are in use for astronomical observations. Used to ionize gas in the upper atmosphere, they provide telescope operators with a target to calibrate their instruments.
LaseRS orIGINally dEVElOped foR The SDi PlAN are iN uSE for astrOnOMICAL observatIOns. uSeD TO iONizE Gas in The upPer aTmOspherE, thEy providE teLescOpe OperatorS WitH a TaRGeT to CalibraTe theIR iNSTRUmEnts.