Without proper shielding, the crews of missions beyond low Earth orbit might be at risk from high-energy protons emitted by solar flares and associated solar particle events (SPEs). Lawrence Townsend of the University of Tennessee and others have studied the overall most powerful solar storm ever recorded. The flare was seen by the British astronomer Richard Carrington in September 1859. Radiation doses astronauts would receive from a Carrington-type storm could cause acute radiation sickness and possibly even death. Another storm that could have inflicted a lethal radiation dose on astronauts outside Earth's protective magnetosphere occurred during the Space Age, shortly after Apollo 16 landed and before Apollo 17 launched. This solar storm of August 1972 would likely have caused acute illness, at least.