NASA has pushed back its original plan and now intends to send the first humans to Mars by the 2040s. It wants to find ways to ensure humans can survive the 225 million kilometer-long trip and stay alive on the planet's deadly surface.
In the interim, it will deploy a rover to Mars with the mission of finding out if humans can actually live and thrive on the radioactive Red Planet.
The rover will be sent on its nine-month-long journeys to Mars in 2020. NASA said it will be possible to land humans on Mars within 25 years provided the truly daunting technological and medical challenges can be overcome.
NASA won't be the first organization to send humans to Mars, however. That honor might fall to SpaceX, which still plans to land the first humans on the Red Planet before 2040.
NASA is deeply worried that lethal radiation that will bathe astronauts on their nine-month-long trek to Mars might be a hurdle too difficult to surmount. The agency is also worried about a myriad of potential medical issues that will affect humans making the dangerous trip.
Among these dangers: potential vision loss (even blindness); bone atrophy; greatly weakened muscles; more brittle bones and severe changes to the human body as a result of prolonged weightlessness and exposure to radiation. All these medical challenges, not to mention the immense and costly technical difficulties, might take a quarter of a century to conquer, said NASA.
The easiest way to minimize much of the danger from lethal radiation would be to slash the nine-month-long travel time to Mars. Former NASA astronaut Tom Jones, who flew on four Space Shuttle missions before retiring in 2001, urges the development of hitherto shunned nuclear propulsion systems.
He said that if we start now, "in 25 years we might have these technologies available to help us and protect us from these long transit times."
Similar worried hound SpaceX but haven't deterred this space transportation company from altering its aspirational goal of landing humans on Mars by 2024. This forecast made by CEO Elon Musk in June 2016 seems increasingly unrealistic given the unending series of delays in building the massive rocket that will get SpaceX to Mars.
Only last March, Paul Wooster, SpaceX's principal Mars development engineer, said the company still plans to land the first people toward Mars in 2024. Colonization of the planet will follow.
Musk has repeatedly said his aspirational timeline is to launch cargo missions to Mars by 2022. Crewed missions will follow in 2024.
Musk ultimately wants to build cities on Mars and permanently colonize the planet as a "backup drive" for humanity in case a global cataclysm destroys the Mother Planet.
