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Saturday, February 25, 2017

SETI: Part 3 A Fatal Flaw for Space Travel?

So what should be Humanity's priorities regarding outer space?

  • If our Sun will consume Planet Earth in a few years or centuries, then we absolute must find a second Earth revolving around another star and find a way to send humans there.
  • However, the latest speculation is that our Sun will swell into a Red Giant and swallow our globe in 5 billion years, so escape can await a few billion years.
  • Mind you, the USA just had to get to the Moon first, but the motivation was geopolitical.  Whether it was John F. Kennedy or Ronald Reagan most responsible for our success, our conflict with the Soviet Union was deadly.  One way to win the Cold War was to bankrupt the enemy, and our space exploits helped serve to doom our rival.  Whew, there went a possible nuclear winter and our society survived a vital Tipping Point.
  • Today, there is no urgency to spend many billions on major projects like Project Mars.  What could possibly be the point of getting to Mars now when there are enough problems to overcome on terra firma.  
There is also a possible fatal flaw regarding long-term space travel.  Scientific American this month published a paper by Charles Limoli entitled Deep Space Breaker.   You can read the details, but let me summarize:
  • In short, recent studies showed that cosmic radiation is  dangerous to astronauts' brains.
  • It is possible that humanity will never be able to travel throughout our solar system and beyond.
  • Specifically, galactic cosmic rays, charged atomic nuclei flying at nearly the speed of light originating from supernova remnants of dead stars, are of concern.
  • For a Mars-type journey, an additional factor  could well be ionized hydrogen (protons) ejected by our Sun. 
  • Both types of radiation pass right through the hulls of spacecraft and any current protective suit.
  • While no scientific study has been tried with humans, rats, unfortunately for them, have been subjected to low level particles and after six weeks their cognitive ability dropped by 90%.    Closer investigation showed that neurons called dendrites in the medial prefrontal cortex were affected.  In short, future astronauts will suffer from problem solving and judgement.
  • Turns out that the magnetic fields surrounding our planet deflect most of these particles.
There is hope, of course, that science will develop solutions to overcome this problem, or, that this worry will turn out to be of minimal consequence.  However,  this is but one of a whole range of unknowns to be faced by future space travelers.  

So if humans will not be able to travel into space, what are other options?  Part 4 will suggest priority pathways, including perhaps Project Starshot (left).

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