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antoniseb
2005-Aug-01, 04:02 PM
Here's a New Scientist story about a study that states that radiation will be a serious problem for Missions to Mars, and make missions to Jupiter and beyond prohibitive without having massive shielding or much faster propulsion.

http://www.newscientistspace.com/article.ns?id=dn7753

Basically, it says that just on the basis of unblocked cosmic rays about one astronaut in 5 will develop a fatal cancer (later in life) from the exposure during a 2 or 3 year mission. Other problems are also noted.

Twitch
2005-Aug-01, 04:05 PM
So, in other words, sportscar or bulldozer are the only two options?

antoniseb
2005-Aug-01, 04:15 PM
Originally posted by the_twitchy1@Aug 1 2005, 04:05 PM
sportscar or bulldozer are the only two options?
You can read the article. They suggest other options too, such as improving medicine to help eliminate cancer.

Another serious possibility (not specifically mentioned in the article) would be to create a large heavily shielded (say with several meters of moon rock) vessel (cruise ship by your analogy) that orbits the Sun in a way that passes near Earth and Mars on a regular basis, and that we would need some little sports cars (or speed boats) to get passengers to and from this vessel as it makes the close approaches. This would be very expensive to build and get into such an orbit, so it will probably not be the way we get to Mars initially.

Fraser
2005-Aug-02, 04:36 PM
SUMMARY: One of the risks for sending humans to Mars is the lethal doses of radiation coming off the Sun in coronal mass ejections (CMEs). Researchers from the University of Warwick are proposing ways we can fill gaps in understanding about these processes and ensure astronaut safety. In addition to watching the far side of the Sun for CMEs, and developing detection equipment the astronauts can carry on their spacecraft, the researchers think we need to better understand how CMEs travel in the regions between Earth and Mars.

View full article (http://www.universetoday.com/am/publish/space__weather__hole_blocks_manned_mars_mission_.h tml)

What do you think about this story? Post your comments below.

suitti
2005-Aug-02, 06:12 PM
I have about 100,000,000,000 objections to the ISS - all of them are dollars. Too many of them were once mine. One of the big problems with it is that it doesn't do much science. The other is that it does not advance operations in space. In particular, it doesn't advance artificial gravity (typically with rotation). Since it lives in low Earth orbit inside the Earth's magnetic field, it doesn't advance radiation screening. Even the Mars Institute people say it's basically useless for doing anything interesting. It's time to say, "OK, we did it. Let's move on.".

ISS went up, and it was known in advance that it wouldn't really accomplish anything. Worse, it was put there with the Shuttle, which is the most expensive launcher in history, which was billed as cheap, but was known to be expensive before it was started.

This article restates something we knew about Apollo - we were just lucky. Perhaps if Apollo 18 or 19 were funded, we'd have fried three astronauts. I'm not at all interested in funding a program which fries astronauts. This has to be solved before the mission goes. Perhaps magnetic shielding, along with a meter of water and some other stuff could be done. The Mars decent/ascent stage could be unshielded, since it's short duration, and we could have some warning. However, the living habitat on Mars has to be in place an shielded before they get there.

We abandoned the Saturn V. Despite the fact that Energia would have saved money to put up the ISS, it was abandoned too. A heavy lift launcher is needed for Mars.

lswinford
2005-Aug-02, 07:00 PM
suitti, "too many of them were once mine", I think I need to get to know you better. ;)

Back in the 1960's, when space exploration seems so intrinsicly simple, common descriptions and artistic renderings showed the crew compartment of interplanetary probes nestled nicely within the cluster of massive fuel tanks. (picture the shuttle, sans wings, surrounded by several even larger external fuel tanks, but these were not to be discarded) This was to protect the crew.

BTW: Speaking of fuel tanks, they used to say, at various times, that if the shuttle fuel tanks were parked in orbit, instead of discarded to burn up in the atmosphere, they could be used in future space developments (fuel or materials storage, housing, equipment storage, or refilled for future missions still further along).

cran
2005-Aug-03, 06:43 AM
Originally posted by fraser@Aug 3 2005, 12:36 AM
SUMMARY: One of the risks for sending humans to Mars is the lethal doses of radiation coming off the Sun in coronal mass ejections (CMEs)...
What do you think about this story? Post your comments below.

Just to get this back on track...sort of...doesn't this risk of radiation from CMEs reduce the other risk of contamination by illegally migrating microbes?

Eric Vaxxine
2005-Aug-03, 08:42 AM
This where the robots earn their living ... or are we heading towards the bionic hominids? Replace the parts that suffer radiation damage.

I would be surprised if Russia or America haven't already 'looked into' a breed of humanot for space work. Maybe that is what the ISS has been doing.

Svemir
2005-Aug-03, 09:59 AM
I was ponderenig on an idea of Mars exploration by humans living in the caves (natural or artificial).
Still, the problem of radiation during the travel remains.
What about magnetic shielding?

aeolus
2005-Aug-03, 10:39 AM
Originally posted by Eric Vaxxine@Aug 3 2005, 08:42 AM
This where the robots earn their living ... or are we heading towards the bionic hominids? Replace the parts that suffer radiation damage.

I would be surprised if Russia or America haven't already 'looked into' a breed of humanot for space work. Maybe that is what the ISS has been doing.
Which parts? The brain, heart, skin, eyes, liver, throat, lungs, stomach, bones, blood, "ahem"s, etc?

If you replaced all that, your bionic man would be significantly bionic and insignificantly man. Basically you're describing a robot with fingerails. And teeth:

The Radiation-Resistant Bionic Humanoid (http://i8.photobucket.com/albums/a1/aeolusborealis/bionic.jpg)

Ola D.
2005-Aug-03, 11:39 AM
Originally posted by Eric Vaxxine@Aug 3 2005, 08:42 AM
This where the robots earn their living ... or are we heading towards the bionic hominids? Replace the parts that suffer radiation damage.
Developing a heavy sheild sounds more reasonable to me.


doesn't this risk of radiation from CMEs reduce the other risk of contamination by illegally migrating microbes?
Still not quite a solution, since it'll be deadly for all.


What about magnetic shielding?
Could that be the solution? http://www.universetoday.com/am/publish/ma...t.html?17112004 (http://www.universetoday.com/am/publish/magnetic_bubble_protect.html?17112004)

Eric Vaxxine
2005-Aug-03, 12:32 PM
We are not remotely evolved for space life. But if we could 'grow' a decent radiation absorbing/refelecting skin, you'd only need to protect the eyes.
There might also be energy to be gained from radiation.

Sound crazy? So did replacing hearts, kidneys and lungs 200 years ago.

I can't believe we will want to be clambering around in bulky suits for 300 years.

Find something/someplant on Mars that is surviving said radiation and extract the active principle.

Andy Holland
2005-Aug-03, 01:17 PM
There is an engineering answer to the shielding problem that combines with the propulsion problem, but the real issue is why anyone would want to go to Mars or anywhere else without some tangible benefit.

Small nuclear rocket engines have been developed that have 5 times the specific impulse of the Saturn V. Between the engine and the crew compart there must be a rather sizable amount of gamma and neutron shielding. Using such an approach, Mars transit time goes from 18 months to 6 months.

The reactor shielding can be pointed in the direction of incoming solar wind - it can serve double duty nicely. We actually had workable, excellent designs well beyond NERVA at Westinghouse.

The real question is why would anyone bother doing any of this? Robots, nano-technology and computers obviate the need for such "exploration" by humans.

If Venus or Mars had wonderful tropical climates, we'd have built such machines twenty years ago. As they are barren rocks and nothing is there - who cares?

The whole point of Apollo was to removed short political commentary

antoniseb
2005-Aug-03, 01:31 PM
Originally posted by Andy Holland@Aug 3 2005, 01:17 PM
The real question is why would anyone bother doing any of this? Robots, nano-technology and computers obviate the need for such "exploration" by humans.
I agree. Robotic exploration and development of Mars, the Moon, the asteroids, etc is much more cost effective, safer, and realistic. Perhaps in a century or two the robots will have built pleasant and safe human habitats in some of these places, but unless/until that happens, why send people? The argument that people are more adaptive and can get results faster won't last too many more decades.

aeolus
2005-Aug-03, 03:32 PM
Originally posted by antoniseb@Aug 3 2005, 01:31 PM
Perhaps in a century or two the robots will have built pleasant and safe human habitats in some of these places, but unless/until that happens, why send people? The argument that people are more adaptive and can get results faster won't last too many more decades.
It exists now, though. There was a cost-effective, reliable mission to service Hubble that was in the works this past January that was cancelled because people didn't like the idea of trusting a robot to do repairs on HST. Eventually we'll develop robotics that are smart enough, adaptive enough, and reliable enough to do stuff for us out in space. The problem I see is that people won't be confident in that idea until they see results from a mission. But robotic missions won't be launched until people trust robotics. But people need a robotic mission to trust robots. But robotic missions won't be launched.......

I'd like to say this is analogous to the pioneers of aviation, but I think cost and risk are factors too large. Guys who got aviation rolling made bicycles.

The guys who are getting space rolling now aren't hading in the direction of robotic exploration.

hmmm... I kinda went off on a tangent I think. My cat is trying to eat my chemistry assignment and I'm getting distracted. I think my post has enough stuff to keep, though. Good kitty...

antoniseb
2005-Aug-03, 03:55 PM
Originally posted by aeolus@Aug 3 2005, 03:32 PM
But robotic missions won't be launched until people trust robotics. But people need a robotic mission to trust robots.
I expect that we will have a lot of terrestrial missions for robots that will increase our capabilities of using them, and our trust in them, including:

Robotic search tools for working in collapsed buildings
Robotic fire-fighters
Automobile autopilots
Automatic coffee makers (we have and trust these)
Robotic workers for ultra-cleanrooms
Robotic workers for hazardous waste cleanup
Robotic surgical tools and assistants
Robotic soldiers & police (I'm not happy about this one)

All of these things are pretty likely to exist within the next twenty years. It is a small leap to the idea of using these things in space.

Andy Holland
2005-Aug-03, 04:13 PM
Perhaps there is a real mission for the ISS after all (SHORT "POLITICAL" COMMENT NOT INSERTED).

One could use it as a platform for robot workers.

1. Robots only have to go one way (Up).
2. They don't make trash
3. If they are built correctly, newer, more advanced models would eat
a. Empty rocket stages
b. previous models
4. In low earth orbit (ISS), they are protected from radiation.
5. They could be generically designed and tooled.

The entire engineering effort/expense would be well worth it in terms of automation technology and the ability to build flexible factories with robot components. You could increase payloads considerably with one-way rockets.

Still, you need a reason to send them. Materials research make sense; it is best automated, as molten metals are too dangerous in space around people. In a low g environment, you can make some fairly wild light-weight alloys.

Eric Vaxxine
2005-Aug-03, 04:21 PM
I don't think we need to fear robots, we'll build them to serve. The intelligence will be in how it finds what we want and the speed and accuracy it delivers that information.

It is human adventure and personal experience which drives people to want to land on other planets.

We'll always have humans going to these places.

Guest_James
2005-Aug-03, 05:55 PM
Four things can be incorporated into the shielding of a mars-bound spacecraft!
1) I know that a simple bar magnet can create a magnetic field many times the teslas than the Earth's own magnetic field.
2) I know that wearing SPF 75 sunscreen at the beach, where there is a hole in the ozone layer, will protect people against infrared radiation, along with UVA and UVB radiation.
3) I know that microwave radiation gets easily absorbed by water (cup of noodles).
4) Finally, I know that leaded radiation suits will protect against gamma and X-ray radiation.

Although the spacecraft gets a lot more massive (and necessary), we can still launch nuclear rockets off the moon. The amount of force released by the strong nuclear force is thousands of times stronger than the force that any chemical reaction produces.

Would someone please come up with a good reason for sending people to mars?! God knows that we shouldn't just do it, you know, just for the sake of doing it!

aeolus
2005-Aug-03, 07:00 PM
Sunscreen might keep your skin from getting red, but it won't help your bones from becoming iridescent (and you dying) when high-power radiation from a CME or GRB hits you in the side.

lswinford
2005-Aug-03, 07:49 PM
Andy, your list is good:

1. Robots only have to go one way (Up).
2. They don't make trash
3. If they are built correctly, newer, more advanced models would eat
a. Empty rocket stages
b. previous models
4. In low earth orbit (ISS), they are protected from radiation.
5. They could be generically designed and tooled.


But
1. We've had several Mars exploration failures when probes were going down
2. When a probe or associated apparatus is finished or failed it becomes trash.
3. My notion of being "built correctly" is that the whole thing 'returns to sender' when done
a. They've been talking of recycling stages for decades and reusing the Shuttle boosters is about all they've managed so far.
b. umm, used equipment goes cheap in the junk yards for a reason (and its not often a good reason), but some forms of recycling and equipment cannibalism are desireable.
4. But if all we can do is pitch a cot in a comparatively safe harbor so close to home, why bother?
5. 'Generic tooling' is based on economies of scale in a 'going concern'. We wait until politics prods another spurt of direction, by that time technology has leap-frogged over the previous standard pattern. Take nuclear energy plants on earth, for instance. The only thing close to 'generically designed and tooled' we have there are in navy ships for perhaps three countries. There were three reactors near Phoenix in Arizona that were supposed to be of a common, repeatable plan. The contractors dropped the ball and the utility was left with: one reactor that was for a long time a model of efficiency, one reactor that was usually down as often as it was up and running, and another that had so many problems they simply closed it. If we aren't technologically (and politically) ready for the obvious advantages of safe fission power plants, we probably aren't ready for off-the-shelf assembly of space probes and vehicles.

I'm not saying you're wrong, it was a good list, just expressing my pessimism over your list, for what little its worth. :unsure:

Guest_James
2005-Aug-03, 09:24 PM
Sunscreen will protect your bones if you just glob a lot on! Jeeze!

Seriously though, how can the high power radiation from a CME or GRB make it through a high tesla magnetic field, 1 meter of water, a leaded radiation suit, and SPF 75 sunscreen? The correct answer is that it can't possibly make it that far! The Earth provides even less protection from CME's than this type of shield does. You don't believe me, then provide some test results proving otherwise.

antoniseb
2005-Aug-03, 09:37 PM
Originally posted by Guest_James@Aug 3 2005, 09:24 PM
how can the high power radiation from a CME or GRB make it through a high tesla magnetic field, 1 meter of water, a leaded radiation suit, and SPF 75 sunscreen? ... The Earth provides even less protection from CME's than this type of shield does.
The Earth's atmosphere provides about as much protection against cosmic rays as about 10 meters of water. The magnetic field is good against slower moving radiation such as the stuff coming out of the Sun.

Generally, though you are right that the amount of material needed to protect against these things is heavy but not completely unfeasible.