Human spaceflight, which began on 12th April 1961 with Soviet cosmonaut Yuri Gagarin, is progressively becoming more daring and complex, and of longer duration. The idea of a journey to the planet Mars has mobilised space agencies and scientists from various parts of the globe; NASA promises to accomplish this feat by 2030. However, although Mars is our neighbour and relatively close in astronomical terms, a manned mission to the red planet may be further away than it seems. Two recent discoveries could put the brake on plans for long-duration missions and interplanetary travel.
The first relates to an increase in intracranial pressure suffered by astronauts, a consequence that appears to be secondary to exposure to microgravity. Still under study, there is not yet a complete understanding of all the physiological mechanisms involved in this alteration. Unhappily, however, it is something that can jeopardise the health of space travellers, and thus, it can limit their cosmic travel.
The second discovery, as disturbing as the first, was recently published in a prestigious scientific journal and points to the effects of cosmic radiation on human heart tissue. According to research, some Apollo space project astronauts developed heart disease resulting from radiation exposure, as they exceeded the limits of the protection provided by the Earth's magnetosphere when traveling to the Moon - something that does not occur during space missions around the Earth.
"The Earth is the cradle of humanity but one cannot live in the cradle forever" Carl Sagan used to say. Could he perhaps have been wrong?
Original article in Portuguese can be read in the Diário Popular Pelotas newspaper by clicking the link.