Getting to Mars is incredibly difficult. Earth and Mars line up in their orbits once every two years, creating a launch window for spacecraft traveling from one world to the other. Our current propulsion technology can send a craft from Earth to Mars – a journey of 300 million miles - in about 6 months. That is a very long trip indeed.
Life on board the International Space Station (ISS) seems pretty cool. You get to float around in micro-gravity, you can look out the window and see millions of stars or, even better, our beautiful planet Earth.
Flying through space to Mars might seem fun too, but both have their downsides. NASA’s Human Research Program has identified five major hazards, and 32 specific risks associated with human spaceflight.
Physiological effects such as bone mass loss, muscle loss, and vision problems affect every astronaut. Radiation exposure is another issue, especially on long duration missions.
Earth is our protector in so many ways. The core of the Earth acts as a dynamo and generates a global magnetic field. Earth’s magnetic field shields us from harmful charged particles streaming from the Sun and other sources, while our atmosphere stops many wavelengths of dangerous radiation. Once we move outside of the protection of Earth, things get a lot harder on the human body.
Exposure to harmful space radiation can have both immediate and long-term consequences. In the short term, exposure to large doses of radiation can make astronauts very sick, while large enough exposures can be fatal. There is no way to predict if a random coronal mass ejection will slam into a Mars-bound spacecraft. Massive multi-layered radiation shielding would be required to protect astronauts from such a hazard, adding a tremendous amount of weight to the spacecraft. Even if the spacecraft generated its own magnetic field, powerful cosmic ray particles may still penetrate such shielding. Over the course of the journey to and from the red planet, exposure to the background radiation of interplanetary space may lead to cancer and other negative health impacts as astronauts age.
Other challenges await astronauts as they journey to Mars. Mechanical failure or micrometeoroid impact could be mission ending, while the psychological hazards of a mission to Mars are so numerous they deserve their own column. Astronauts would still have to actually land safely on Mars, live and work there for nearly two years, and then make the journey back to Earth.
The Weekly Roundup.
The Morning Sky
Neptune rises side by side with Saturn this week in the eastern morning sky. You’ll need telescopic aid to spot the most distant planet in our solar system. How distant? It takes light more than four hours to travel the nearly three billion miles that separate Neptune and Earth. The Moon shows itself as a slim silver crescent on Saturday morning, with brilliant Venus to its right.
The Evening Sky
Mars is still in a pretty good spot, high in the western sky as darkness descends. Jupiter, on the other hand, continues to inch closer to the Sun every day. The Moon returns to the night on Tuesday, very low on the western horizon at sunset. Wednesday finds the Moon just above Jupiter, still only a thin crescent, around 12% full.
Dan Price is a NASA/JPL Solar System Ambassador and informal educator. Have a question about astronomy or space science? Send an email to dan@starpointestudio.com and it might be featured in a future column.
A timely read, considering yet another dramatic failure for Starship today.