Dr McCracken is distinguished for his application of fundamental physics to technological developments in space exploration and geophysical exploration. His instrumental developments for interplanetary spacecraft enabled measurement of flow characteristics of the solar cosmic radiation and were central to the formulation of radiation protection procedures in manned space flight and the operation of geostationary satellites. In the field of exploration geophysics; his pioneering work demonstrated the practical superiority of time domain electromagnetic methods over frequency domain methods, contrary to accepted practice at the time. His instrumental development (SIROTEM) has now gained world-wide acceptance. He is a leader in Australia in the commercialisation of scientific results.