NASA SPACE SHUTTLE CHALLENGER ACTUAL SPECIMEN POLYSTYRENE SPHERES LIMITED EDITION WOODEN PLAQUE.
*** MADE IN SPACE ABOARD THE SPACE SHUTTLE CHALLENGER ON THE STS-6 MISSION IN 1983 ***
*** THE VIAL CONTAINS POLYSTYRENE SPHERES ( 10 MICROMETERS IN DIAMETER ) IN SOLUTION THAT WERE MANUFACTURED IN SPACE ABOARD THE SPACE SHUTTLE CHALLENGER DURING NASA STS-6 MISSION APRIL 4-9TH 1983 - CHALLENGER'S MAIDEN FLIGHT ***
*** THESE MICROSCOPIC PLASTIC BEADS ARE SO SMALL THAT 18,000 COULD FIT ON THE HEAD OF A PIN.
*** LIMITED EDITION # 2633 ***
*** THEY ARE USED FOR THE CALIBRATION OF PARTICLE SIZE MEASURING INSTRUMENTS INCLUDING OPTICAL AND ELECTRON MICROSCOPES ***
*** NASA STS-6 CHALLENGER SPACE FLOWN AND MADE***