News We probably won't be going to Mars anytime soon.

[PhantomCruiser]

Is that really all that we're worried about, seems to me tha risk of cancer is a pretty small price to pay to walk on another planet.

besides 2-3 mSv a day is low enough that you could get away with taking anti-rad pills. Crap I got exposed to worse on a regular basis just flying around a carrier battle group.

Agreed, I lost several wristwatches after being zapped by the SPY-1 from the San Jacinto.

As more money is spent in research, and we learn things accordingly, proper shielding would alleviate many of the concerns.

I'd be more currently more concerned about too many alpha-males in a small group than radiation. I work around enough egotistical (fill in blank space here) as it is.

 

[Swigert]

Not only that, but due to the extreme budget cuts that NASA has been receiving could also be part of it too.

 

[RGClark]

In addition to the health effects including radiation which won't be solved by artificial gravity (and btw we also don't know the effects of centrifugal force acting on a long term), there is also the possibility of mechanical breakdowns for such missions of two or more years duration:

NASA equips astronauts with snorkels, absorbent pads.
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION

As it turns out, this is the second problem with a coolant loop A pump module in the past three years. But space station Program Manager Mike Suffredini said different components in the module malfunctioned and "this is not an ISS-aging-vehicle issue."
http://spaceflightnow.com/station/exp38/131218spacewalks/

Bob Clark

---------- Post added at 10:13 PM ---------- Previous post was at 09:56 PM ----------

Further on the damage to eyesight during long space missions: the altered vision might be due actually to damage to the optic nerve:

Researching Changes To Astronaut Vision In Space.
Posted by Keith Cowing - Source: NASA Posted December 12, 2013 12:52 PM

The Zanello study also reports the presence of two indicators of optic nerve damage, glial fibrilar acidic protein (GFAP) and beta-amyloid. GFAP is known to be elevated by stress and inflammation in the central nervous system and present following retina injury. Studies have found beta-amyloid in tissue following traumatic brain injury and as evidence of optic nerve damage in shaken-baby syndrome.
http://spaceref.com/space-medicine/researching-changes-to-astronaut-vision-in-space.html

Bob Clark

 

[richfororbit]

If and when the MPCV is powered up, to the moon and a close by Asteroid would be better stepping stone than just heading to Mars as the challenges have yet to be solved.

But eitherway a mission to that actual planet is certainly decades away. I'd be fifty or more years old by that time, I would of thought. Born in 1989.

I have personally thought a mission to Mars more to perhaps the year I was born when I'm a hundred, not that I think I'd be around then, but for a that lucky generation to see it happen in that time.

As for a return to the Moon by personnel by any nation long term, or by America specifically could be by the one hundredth anniversary of the missions that went there.

It all depends obviously on economics and other global problems that may stunt the personnel space program for decades. It might even seem rather negative, but in 2007 not many cared to realise the severe debt problems, and years later nothing fundamental has changed in societies in the western world, except may be the Icelandic state.

 

[RGClark]

Further on the damage to eyesight during long space missions: the altered vision might be due actually to damage to the optic nerve:

Researching Changes To Astronaut Vision In Space.
Posted by Keith Cowing - Source: NASA Posted December 12, 2013 12:52 PM

The Zanello study also reports the presence of two indicators of optic nerve damage, glial fibrilar acidic protein (GFAP) and beta-amyloid. GFAP is known to be elevated by stress and inflammation in the central nervous system and present following retina injury. Studies have found beta-amyloid in tissue following traumatic brain injury and as evidence of optic nerve damage in shaken-baby syndrome.
http://spaceref.com/space-medicine/researching-changes-to-astronaut-vision-in-space.html

We now have visual evidence of damage to the optic nerve during long periods of spaceflight:

Science
Beings Not Made for Space.
By KENNETH CHANG JAN. 27, 2014

...
NASA officials often talk about the “unknown unknowns” — the unforeseen problems that catch them by surprise. The eye issue caught them by surprise, and they are happy it did not happen in the middle of a mission to Mars.
In 2009, during his six-month stay on the International Space Station, Dr. Michael R. Barratt, a NASA astronaut who is also a physician, noticed he was having some trouble seeing things close up, as did another member of the six-member crew, Dr. Robert B. Thirsk, a Canadian astronaut who is also a doctor. So the two performed eye exams on each other, confirming the vision shift toward farsightedness.
They also saw hints of swelling in their optic nerves and blemishes on their retinas. On the next cargo ship, NASA sent up a high-resolution camera so that they could take clearer images of their eyes, which confirmed the suspicions. Ultrasound images showed that their eyes had become somewhat squeezed.
NASA is now checking astronauts’ eyesight before, during and after trips to the space station.
The issue turns out not to be new. Many space shuttle astronauts had complained of changes in eyesight, but no one had studied the matter.
“It is now a recognized occupational hazard of spaceflight,” Dr. Barratt said. “We uncovered something that has been right under our noses forever.”

An astronaut's eyeball before a spaceflight, top left, and after a flight, top right, showing pressure against the back of the eyeball. In the bottom image, the arrows point to abnormal bends in the optic nerve following spaceflight. Radiological Society of North America
http://www.nytimes.com/2014/01/28/science/bodies-not-made-for-space.html

NASA should have an increased focus on shortening the flight times of a Mars mission. One way is to have propellant depots fueled by lunar derived hydrolox. Then you could have virtually unlimited propellant supplies to shorten the travel time, which would be prohibitively expensive if this propellant were launched from Earth.

Another way would be to use plasma propulsion systems such as VASIMR that can achieve high speeds due to their high exhaust velocities. A problem with such plasma drives is the need for high electrical power that it was thought required nuclear power at a technologically unfeasible lightweight. This was the objection raised by Robert Zubrin.

However, recent advances in lightweight solar power may mean we can do plasma propulsion using solar powered plasma propulsion.

Bob Clark

 

[Urwumpe]

Really, am I the only one, who finds the jumps over all facts to the conclusion a bit disturbing?

It sounds like:

It is pretty cold in here and many people are freezing, so we should use genetic engineering to have dragons!



Please note: Nobody yet knows the cause of the eye nerve damage. Jumping to conclusions what could fix this is not helpful without understanding the cause.

What if the actual trigger is the high acceleration for prolonged periods of time during launch and the microgravity environment is just hindering the healing process? Can you tell? I can't, I need more data.

 

[Ghostrider]

It is pretty cold in here and many people are freezing, so we should use genetic engineering to have dragons!

I'm going to gather signatures to submit this proposal to popular vote!:thumbup:

 

[C3PO]

I'm going to gather signatures to submit this proposal to popular vote!:thumbup:

I'm in!:thumbup:

But it has nothing to do with the local temperature.

 

[RGClark]

...
Please note: Nobody yet knows the cause of the eye nerve damage. Jumping to conclusions what could fix this is not helpful without understanding the cause.
What if the actual trigger is the high acceleration for prolonged periods of time during launch and the microgravity environment is just hindering the healing process? Can you tell? I can't, I need more data.

The evidence suggests it gets worse for longer times in orbit. Then in that case even if it were just weightlessness hindering healing, it would still be serious for long times in orbit.


Bob Clark

 

[Urwumpe]

The evidence suggests it gets worse for longer times in orbit. Then in that case even if it were just weightlessness hindering healing, it would still be serious for long times in orbit.

Sorry, that is wrong. "Evidence suggests" is one of the biggest sources of pseudo science in the world.

Evidence suggests that global warming is caused by the lack of pirates.

 

[Hlynkacg]

Sorry, that is wrong. "Evidence suggests" is one of the biggest sources of pseudo science in the world.

Evidence suggests that global warming is caused by the lack of pirates.

Totally stealing that pirate line for future use. :lol:

 

[jroly]

I am nearsighted so going into space would fix my eyes.

Jokes aside thou, the problem is serious but interestingly women's sight has been found to not be effected, the problem only arose in men. With the increased amount of blood moving to the head in micro gravity, this is probably what is squeezing the eyeballs out of shape. Women have less blood, around 20% less on average, so there is less blood to squeeze the eyeballs.

 

[RGClark]

In addition to the health effects including radiation which won't be solved by artificial gravity (and btw we also don't know the effects of centrifugal force acting on a long term), there is also the possibility of mechanical breakdowns for such missions of two or more years duration:

NASA equips astronauts with snorkels, absorbent pads.
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
http://spaceflightnow.com/station/exp38/131218spacewalks/

More difficulty with the ISS coolant system:

ISS has another coolant problem says NASA.
Mar 21, 2014
http://www.slashgear.com/iss-has-another-coolant-problem-says-nasa-21321573/


Bob Clark

 

[Admiral_Ritt]

You know we assume centrifugal force is a good substitute for
gravity.

Let me Point out:

1) No one has done LONG TERM studies of the effects of this type of artificial
gravity.

2) If there turns out to be real physiological damage over months of
Artificial gravity: It would put not only long term missions by humans
out of bounds but any ETI's as well. If creating Artificial gravity requires you to have real mass (compressed presumably) to be equal to planetary versions. It might be another great barrier to interstellar travel.

3) I am mostly concerned with the torque effects and the difference in gravity
strength of heat compared to your feet. I have not done the math, I do
know that there is minimum radius a rotating station must be to avoid
more acute problems of just moving around casually.

 

[Izack]

Before trying to compress mass, I would first try simply increasing the radius of the centrifuge to mitigate whatever effects living in one may have.

 

[Hlynkacg]

2) If there turns out to be real physiological damage over months of
Artificial gravity: It would put not only long term missions by humans
out of bounds but any ETI's as well. If creating Artificial gravity requires you to have real mass (compressed presumably) to be equal to planetary versions. It might be another great barrier to interstellar travel.

Why would gravity require physical mass? Why not 9.81 m/s^2 of acceleration?

Likewise the causes of micro gravity's physiological effects are fairly well understood. Basically it comes down to atrophy and the fact that is no longer flowing down-hill.

 

[Admiral_Ritt]

Microgravity is not equivalent to centrifugal force at 1 G.
I don't see how one tells you about the other.

The 1G acceleration due to centrifugal force comes with
a Torque when moving perpendicular to direction of rotation.

If your Radius is too short, It will cause problems moving around.
You can make a large radius and remove the obvious effect.

What I am talking about is physiological damage: Do
we know for a fact that centrifugal force OVER EXTENDED.
PERIODS (6 months say) causes no harm to tissues/cells.
For a Station the radius of 300m ( Size of wheel in film2001 Spc Odys. for Example.)

 

[BruceJohnJennerLawso]

Why would gravity require physical mass? Why not 9.81 m/s^2 of acceleration?

Likewise the causes of micro gravity's physiological effects are fairly well understood. Basically it comes down to atrophy and the fact that is no longer flowing down-hill.

Agreed.

The only major issue with this sort of setup is the nausea caused by different acceleration between your head and your feet (as well as oddness caused by the fact that you are spinning, like faucets emptying at a slight angle and so on). As far as I'm concerned, that's a non-issue, zero-gee already causes significant nausea for crew as it is, and having centrifugal induced gravity solves plenty of practical problems in spaceflight. Hell, Im sure most astronauts would go with it just for the opportunity to use the bathroom in a normal way.

Youre not going to get to Mars handling waste Apollo style. :lol:

---------- Post added at 15:27 ---------- Previous post was at 15:24 ----------

What I am talking about is physiological damage: Do
we know for a fact that centrifugal force OVER EXTENDED.
PERIODS (6 months say) causes no harm to tissues/cells.
For a Station the radius of 300m ( Size of wheel in film2001 Spc Odys. for Example.)

No we don't know, but why would it? I'm all for being proactive in dealing with potential problems, but there needs to be a valid reason as to why we should be concerned before we start worrying about it.

 

[Hlynkacg]

What I am talking about is physiological damage

You also haven't explained why gravity derived from mass is different from gravity through acceleration. Even if it were, the engineering tolerances of the human body are easy enough to measure right here on earth.

---------- Post added at 07:45 ---------- Previous post was at 07:41 ----------

Im sure most astronauts would go with it just for the opportunity to use the bathroom in a normal way.

Or take a shower

 

[Keatah]

Well for one difference between centrifugal gravity and mass gravity.. you have no torque.

With the torque removed when you return to earth.. You might walk lopsided and kinked for a while!