THE STUDENT PLT WAS ON HIS 1ST SOLO LAUNCH USING AN AUTO TOW & A NOSE HOOK. DURING THE LAUNCH, THE GLIDER BECAME AIRBORNE AT ABOUT 42 MPH. THEREAFTER, THE STUDENT CLIMBED SUCCESSFULLY TO AN ESTIMATED ALT OF APRX 200 FT. AT ABOUT THAT TIME, THE STUDENT'S INSTRUCTOR PLT (IP), WHO WAS DRIVING THE LAUNCH VEHICLE, OBSERVED SAND SAILERS AT HIS 10 TO 11 O'CLOCK POSITION. TO AVOID A CONFRONTATION & TO PROTECT THE SAND SAILERS FROM THE TOW LINE BEING DROPPED IN THEIR VICINITY, THE IP ALTERED HIS COURSE ABOUT 30 DEG TO THE RIGHT. THE TOW LINE BECAME SLACK & THE STUDENT THOUGHT THE LAUNCH VEHICLE WAS SLOWING (BUT IT WAS REPORTED ACCELERATING). THE STUDENT RELEASED THE TOW CABLE, THEN TURNED TO LAND ON THE DRY LAKE BED/STRIP. HOWEVER, THE GLIDER STALLED. THE STUDENT SAID THAT HE MADE AN INCOMPLETE RECOVERY PRIOR TO A VERY HARD LANDING & GROUND LOOP.