Alpha Centauri 2

Community => Recreation Commons => Destination: Alpha Centauri => Topic started by: Buster's Uncle on November 13, 2017, 03:40:26 pm

Title: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Buster's Uncle on November 13, 2017, 03:40:26 pm

Humans traveling to Mars may soon be possible. Whether they can survive the trip is another story
CNBC
Michael Sheetz  •November 12, 2017


(https://s.yimg.com/ny/api/res/1.2/7aK_e0Bldd20KQf2HWjsHw--/YXBwaWQ9aGlnaGxhbmRlcjtzbT0xO3c9ODAw/http://media.zenfs.com/en-US/homerun/cnbc.com/29231f0152f03476069617dda31ed50c)
NASA | Getty Images. Plans to rocket humans to Earth's closest neighbor continue to advance, with goals as near-term as 2024 under development.



Plans to rocket humans to Earth's closest neighbor continue to advance, with the year 2024 a near-term goal —

at least if Elon Musk has his way.Yet space medicine expert Jim Logan said recently the effects on the human body from spending extensive time outside of Earth's gravity remain unresolved."We need a huge sample size and right now we have a sample size of one, and soon maybe two," Logan told CNBC at the New Worlds conference in Austin, Texas. Logan referenced astronauts Scott Kelly, who spent 340 days in space; and Peggy Whitson, who recently returned from the International Space Station after 290 days."We need to fly a lot of people, for long durations, if we're going to make any progress. You cannot talk about human colonization without that," Logan said.Logan spent 20 years helping diagnose and treat NASA's astronauts. He said the main obstacle to sending humans to Mars is what he calls "the gravity prescription."He said: "We know what Earth's gravity – one G for 24 hours a day – does. And we know that zero gravity, after four months, begins serious health deterioration."Bone mineralization is one of those lack-of-gravity problems. For each month in space, Logan says the human body loses 1 percent of its bone mass. And, once back on Earth, the bones don't grow back."I'm not trying to throw cold water on the idea of going to Mars. I want to make sure we can survive if we do go," Logan said.He says, if putting humans on Mars is truly a near-term goal, it means studies today must focus on Martian gravity, or 0.38 Gs."If we study the effect of 0.38 on the body around the clock, and it doesn't work, you can cross off Mars as a human settlement site until we do sort out the medical diagnosis," Logan said.After medically serving 25 space shuttle missions, Logan stated current measures are stop-gaps that do little to actually counteract the effects of weightlessness on the body.For "each deleterious effect," Logan says there's a new mechanical or pharmaceutical countermeasure that only "retards the deconditioning. They don't neutralize it and they don't reduce it," Logan said."We need to start sending more people into space if we're actually going to get somewhere, with even problems we know like the gravity prescription," he added.The scientist also said that it is critical to use the words "outpost" and "settlement" distinctly when talking about space exploration."Let's stop playing fast and loose with this idea that the ISS [International Space Station] is our first settlement in space. We have a permanent presence, but with rotating crews," Logan added. "Settlement is men, women, children, over multiple generations."

Plans to rocket humans to Earth's closest neighbor continue to advance, with the year 2024 a near-term goal —

at least if Elon Musk has his way.

Yet space medicine expert Jim Logan said recently the effects on the human body from spending extensive time outside of Earth's gravity remain unresolved.

"We need a huge sample size and right now we have a sample size of one, and soon maybe two," Logan told CNBC at the New Worlds conference in Austin, Texas. Logan referenced astronauts Scott Kelly, who spent 340 days in space; and Peggy Whitson, who recently returned from the International Space Station after 290 days.

"We need to fly a lot of people, for long durations, if we're going to make any progress. You cannot talk about human colonization without that," Logan said.

Logan spent 20 years helping diagnose and treat NASA's astronauts. He said the main obstacle to sending humans to Mars is what he calls "the gravity prescription."

He said: "We know what Earth's gravity – one G for 24 hours a day – does. And we know that zero gravity, after four months, begins serious health deterioration."

Bone mineralization is one of those lack-of-gravity problems. For each month in space, Logan says the human body loses 1 percent of its bone mass. And, once back on Earth, the bones don't grow back.

"I'm not trying to throw cold water on the idea of going to Mars. I want to make sure we can survive if we do go," Logan said.

He says, if putting humans on Mars is truly a near-term goal, it means studies today must focus on Martian gravity, or 0.38 Gs.

"If we study the effect of 0.38 on the body around the clock, and it doesn't work, you can cross off Mars as a human settlement site until we do sort out the medical diagnosis," Logan said.

After medically serving 25 space shuttle missions, Logan stated current measures are stop-gaps that do little to actually counteract the effects of weightlessness on the body.

For "each deleterious effect," Logan says there's a new mechanical or pharmaceutical countermeasure that only "retards the deconditioning. They don't neutralize it and they don't reduce it," Logan said.

"We need to start sending more people into space if we're actually going to get somewhere, with even problems we know like the gravity prescription," he added.

The scientist also said that it is critical to use the words "outpost" and "settlement" distinctly when talking about space exploration.

"Let's stop playing fast and loose with this idea that the ISS [International Space Station] is our first settlement in space. We have a permanent presence, but with rotating crews," Logan added. "Settlement is men, women, children, over multiple generations."


https://www.yahoo.com/news/humans-traveling-mars-may-soon-202242618.html (https://www.yahoo.com/news/humans-traveling-mars-may-soon-202242618.html)

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Geo on November 13, 2017, 06:52:09 pm

The answer is simple: a rotating section on the ship. Or whatever 'outpost' located in a freefall environment.

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Unorthodox on November 14, 2017, 04:01:30 pm

Ah yes, the spinning habitat...staple of scifi movies, and simple cure-all

The one we have no idea what effects it will have on the human body, as it either needs be so ridiculously large we can't yet construct it, or small enough there's a significant difference in gravity between the head and the feet (which I'm sure would be real fun to live with), and the only test on the matter only managed .015G... 

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Geo on November 14, 2017, 06:05:19 pm

I thought part of military pilot training was a multi-g spin simulator?

But it's a fact more research is needed on how much 'spin'-induced gravity would be enough to at the very least reduce health issues in space.

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Buster's Uncle on November 15, 2017, 09:18:06 pm

Quote from: Unorthodox on November 14, 2017, 04:01:30 pm

Ah yes, the spinning habitat...staple of scifi movies, and simple cure-all

The one we have no idea what effects it will have on the human body, as it either needs be so ridiculously large we can't yet construct it, or small enough there's a significant difference in gravity between the head and the feet (which I'm sure would be real fun to live with), and the only test on the matter only managed .015G... 

Some sort of tether deal might work...

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Unorthodox on November 16, 2017, 05:06:13 pm

Quote from: Geo on November 14, 2017, 06:05:19 pm

I thought part of military pilot training was a multi-g spin simulator?

Earthbound.  Literally nothing has been done in space to test simulated G forces.  (technically one failed test, actually) 

Quote

But it's a fact more research is needed on how much 'spin'-induced gravity would be enough to at the very least reduce health issues in space.

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Unorthodox on November 16, 2017, 05:11:27 pm

Quote from: BUncle on November 15, 2017, 09:18:06 pm

Some sort of tether deal might work...

Tether, like a huge rope swing with a vehicle at the end?  Or tethering the astronauts to the ground/treadmill/whatever to simulate gravity? 

One of the big questions is whether the inner ear will respond to the artificial gravity or not.  The high G centrifuge tests on earth can't test that, and 'zero g' flights don't actually fool that part of our anatomy. 

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Buster's Uncle on November 16, 2017, 05:14:39 pm

Rope swing - there'd be tech details to work out, but a few hundred feet spin axis ought to be doable...

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Unorthodox on November 16, 2017, 08:14:23 pm

Quote from: BUncle on November 16, 2017, 05:14:39 pm

Rope swing - there'd be tech details to work out, but a few hundred feet spin axis ought to be doable...

Yeah, the mechanics of space tethers and tether satellites is about where my understanding of celestial mechanics breaks down, but that's partially due to a relatively small data set to work with.  Suffice it to say, such a system has significant tech details to hurdle, since tethers don't quite work how you expect in space. 

A more likely build would actually be a tether attached to the center of a rotating habitat to help stabilize it's orbit.  Give the inflatable habitats a little bit to develop, and size might stop being the impediment. 

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Geo on November 16, 2017, 10:34:36 pm

Quote from: Unorthodox on November 16, 2017, 08:14:23 pm

A more likely build would actually be a tether attached to the center of a rotating habitat to help stabilize it's orbit.  Give the inflatable habitats a little bit to develop, and size might stop being the impediment.

You mean (a) tether(s) which expands outwards from a rotating habitat? How would such a small mass help stabilize a habitat's orbit? With a mass at the tether's end I could see it happening, but without?

For inflatable habitats, must get a bit awkward in one when Sol sends a flare towards it.

Title: Re: Traveling to Mars may soon be possible. Surviving the trip is another story
Post by: Unorthodox on November 16, 2017, 11:55:15 pm

I mean a tether attached perpendicularly to whatever axle the habitat rotates around.  Since your habitat likely isn't perfectly balanced as people move about, something of an anchor several to many miles away to stabilize the orientation of the spin. 

As for the inflatable habitats, the first is being tested up there for that reason, but they are not exactly a balloon as the description makes it sound, but rather a layer of foam that is allowed to expand once it's deployed in space.  Arguably safer than a lot of the thin walled craft we've sent up.  If you've ever used spray foam you have an idea...