Radiation on Mars manageable for manned mission

According to the Curiosity Rover the radiation on the trip to Mars plus a 500 day stay on the Red Planet would be within the acceptable limits. In a conspiracy twist, I wonder how long the PTB have know this and why this information is coming out now. There's so much going on in Space right now and there's a huge push to get "out there" and exploit our solar system: The Moon, Mars, Asteroids, etc...It's very exciting to see this all unfold. However, I ask why now?

www.space.com...

lostbook
According to the Curiosity Rover the radiation on the trip to Mars plus a 500 day stay on the Red Planet would be within the acceptable limits. In a conspiracy twist, I wonder how long the PTB have know this and why this information is coming out now. There's so much going on in Space right now and there's a huge push to get "out there" and exploit our solar system: The Moon, Mars, Asteroids, etc...It's very exciting to see this all unfold. However, I ask why now?

www.space.com...

This is good news. I wish one of the space-age countries would just man up and go all out on a Mars mission. China, if China did that they assure themselves of the "Chinese Century" (probably assured anyway, but that would put the candles on the cake). Russia, getting mixed reviews of good and bad policies and press, could just go for broke and Mars it up. The U.S., I don't think they have it in them anymore (but if they do, go for it! Mars before 2020 or bust).

There's probably one of two students at every high school in the world who can write the code for a mission to Mars on their laptop. The world is in a place now where it really needs that kind of moon-landing enthusiasm again, and this time it just needs one of the key nations to once again let loose the frontier spirit of human nature and step up.

You know what's funny is that if private individuals have their way, we'll have a colony on Mars before Nasa goes to Mars. Nasa plans to go there in the mid 2030's, however Mars One plans to take colonists on one way trips to the Red planet starting in 2023 to establish a colony there. Nasa will go there to find life in 2035! I'm willing to bet money that they'll find it!

I ask why now?

reply to post by lostbook


Cause all those Sattelites, rowers and what not they have sent out there in the last many years, have now done their job and collected all the data nessesary to send manned mission out there.

You don't just take one reading and then, Looks fine, lets go! It all takes time and better equipment.

They are preparing to send people out further than the Moon, even though there is no real point to it other than curiosity...

reply to post by lostbook

That article doesn't really address the real radiation problem.

helios.gsfc.nasa.gov...

Intense SEP events contain very high levels of radiation, more than a million times the normal daily dose of a human on Earth. Radiation sickness can result when humans are outside the protective magnetosphere of the Earth, as in missions to the moon and to Mars.

Take the trip to the moon for example. The background radiation was no problem for that trip either. But, had the timing been different where the astronauts were exposed to a solar flare or CME, it wouldn't have been safe. The way this risk was managed on moon missions was by hoping they would get lucky and not have any massive radiation bursts for the short trip to the moon and back.

Sickening Solar Flares

...protons can burrow through 11 centimeters of water. A thin-skinned spacesuit would have offered little resistance.

"An astronaut caught outside when the storm hit would've gotten sick," says Francis Cucinotta, NASA's radiation health officer at the Johnson Space Center. At first, he'd feel fine, but a few days later symptoms of radiation sickness would appear: vomiting, fatigue, low blood counts.

The problem with a trip to Mars is, the trip is much longer than a short trip to the moon, so the chances of being exposed to a CME become much greater on a longer trip. That is the biggest hazard, and always has been (and still is). That article doesn't really mention anything about exposure to CMEs.

reply to post by Arbitrageur


Do you think the Mars-bound spacecraft will offer some protection, especially if they design it that way. And while on Mars, EVAs would only be allowed when there's no CME hitting them.

lostbook
According to the Curiosity Rover the radiation on the trip to Mars plus a 500 day stay on the Red Planet would be within the acceptable limits. In a conspiracy twist, I wonder how long the PTB have know this and why this information is coming out now.

Because they have collected data over time, as Curiosity was measuting it during its mission on Mars.

There's so much going on in Space right now

What exactly is going on in space right now, that hasn't been already happening for billions of years?

and there's a huge push to get "out there" and exploit our solar system: The Moon, Mars, Asteroids, etc...It's very exciting to see this all unfold. However, I ask why now?

We have better technology, more knowledge, more awareness. The ISS has given us a great opportunity to learn how to live and work in space, now it's time to go beyond the low earth orbit. Manned space exploration has got to happen some day!

By using lava tubes to serve as bases, settlers will be well protected from radiation.
The journey there poses a risk but I think I read somewhere that gold foil is used as a radiation shield.
I hope I don't die from old age before I see the first human colony on Mars.
www.nss.org/settlement

www.lpi.usra.edu

wildespace
Do you think the Mars-bound spacecraft will offer some protection, especially if they design it that way. And while on Mars, EVAs would only be allowed when there's no CME hitting them.

Yes of course to the latter. But I think if you talk to spacecraft designers, they would tell you that it's not a simple thing to make the spacecraft adequately shielded for powerful CMEs. It's simple in concept to add more shielding and more weight, but the implementation of this concept is difficult, because more weight is a problem, at least with current propulsion methods, especially when you look at how much more weight might be needed. Here's an article that talks about the problem in more detail:

Researchers calculate radiation exposure associated with journey to Mars

"Understanding the radiation environment inside a spacecraft carrying humans to Mars or other deep space destinations is critical for planning future crewed missions," Zeitlin said. "Based on RAD measurements, unless propulsion systems advance rapidly, a large share of mission radiation exposure will be during outbound and return travel, when the spacecraft and its inhabitants will be exposed to the radiation environment in interplanetary space, shielded only by the spacecraft itself."

reply to post by Arbitrageur


Seems like the push is to shorten the trip length, which is understandable, but on the other hand the numbers for a VASIMR powered Mars mission don't look too happy either.

Another concern is that for a Mars mission, VASIMR would have to use a nuclear power system that doesn’t exist yet. Mars Society president Robert Zubrin warned that mission designs that used VASIMR had unrealistic expectations about the mass of such reactors. The largest space nuclear power systems, the Topaz nuclear reactors developed by the former Soviet Union, generated 10 kilowatts and had a specific power, or alpha, of 100 kilograms per kilowatt. NASA had hoped to get alpha down to 65 kg/kW with its now-cancelled Prometheus program, and Zubrin said that if one is “quite optimistic” an alpha of 20 kg/kW was possible. The VASIMR-based Mars mission concepts, he said, assume an alpha of 1 kg/kW. “That’s like steel with the weight of Styrofoam,” Zubrin said. “It has no relationship with reality.”

Assuming an alpha of 20 kg/kW, Zubrin said, means that a reactor that generates 200 megawatts would weigh 4,000 tons. (By contrast, the VASIMR mission architectures with the 39-day travel times had assumed an overall mission mass of approximately 600 tons.) Moreover, the best travel time you could get with this much more massive system is six to eight months, comparable with conventional chemical propulsion systems, Zubrin claimed. “The numbers don’t add up,” he said.

www.thespacereview.com...

I really wonder if NASA is putting too many eggs in the VASIMR basket, at least for the purpose of a Mars trip. Bolden and Chang Diaz are pretty close since they flew together as astronauts, and I hope it isn't causing NASA to have tunnel vision... VASIMR itself is solid imho, but to make it go is going to require a major breakthrough in space power generation.

Arbitrageur
Yes of course to the latter. But I think if you talk to spacecraft designers, they would tell you that it's not a simple thing to make the spacecraft adequately shielded for powerful CMEs. It's simple in concept to add more shielding and more weight, but the implementation of this concept is difficult, because more weight is a problem, at least with current propulsion methods, especially when you look at how much more weight might be needed. Here's an article that talks about the problem in more detail:

Of course we could just amend the Nuclear test ban treaty and make a 4 million ton nuclear propulsion ship with state of the art everything in a rotating design to simulate gravity and go to mars in luxury.

But no, we hold ourselves and use piece of crap chem rockets that can only launch rickety tin cans in to space.


The orion project was the way forward and we scraped it........

ngchunter
Seems like the push is to shorten the trip length, which is understandable, but on the other hand the numbers for a VASIMR powered Mars mission don't look too happy either.

The shorter trip will definitely reduce the risk and the short trip to the moon was one of the factors in the success of the Apollo missions. However even with those short trips to the moon, the radiation may have caused or accelerated the formation of cataracts:

www.nasa.gov...

At least 39 former astronauts have suffered some form of cataracts after flying in space, according to a 2001 study by Francis Cucinotta of NASA's Johnson Space Center (see journal references below). Of those 39 astronauts, 36 had flown on high-radiation missions such as the Apollo Moon landings. Some cataracts appeared as soon as 4 or 5 years after the mission, but others took 10 or more years to manifest.

Scientists have long known of this link between radiation and cataracts, but they've never fully understood it. What exactly does radiation do to the lens of the eye to make it cloudy?

The cornea of the eye is probably the most sensitive part of the body to radiation.

As for Vasimir, I don't know how they will generate the power needed to operate it at a reasonable power plant weight.

reply to post by crazyewok

Yes that's fascinating technology, and weight is no problem. I think the plans called for spacecraft from 8000 to 8,000,000 tons.

The main problem there is instead of putting the lives of the astronauts at risk, you're putting the risk on the lives of Earthlings. I think Freeman Dyson said maybe a dozen people could have died planet-wide from their calculated radiation exposure levels, but even today our most advanced models of deaths due to low level radiation have inadequate data to support them, so we don't really know the true risk.

Arbitrageur
[ I think Freeman Dyson said maybe a dozen people could have died planet-wide from their calculated radiation exposure levels, but even today our most advanced models of deaths due to low level radiation have inadequate data to support them, so we don't really know the true risk.

I thought they managed to reduce the fallout to almost zero using efficient "clean" nukes but by this point the NTB treaty was put into effect and that was it, research cancelled. Plus you could reduce the fallout risk further by putting the launch site at sea which was one of the ideas plus at 8 million tons you wouldn't need more than 1 launch every few years, hell you could just do one and use it to launch the necessary infrastructure for orbital ship construction. Anyway the later daedauls project look very promising.

But I think 12 people is a small price to pay anyway for the survival of humans and Solar explotation could solve almost all our resource problems and even possible overpopluation. 12 for 6 billion? The goverment makes worse risk/reward descions everyday.

crazyewok
I thought they managed to reduce the fallout to almost zero using efficient "clean" nukes but by this point the NTB treaty was put into effect and that was it, research cancelled.

I don't think clean nukes were part of Orion, though Orion did have a way to launch the 8,000,000 ton craft with the same amount of fissionable materials and fallout as the 8,000 ton craft...by using more regular explosives. Other projects like Daedalus considered "cleaner" technology that planned to mine He3 from Jupiter for 20 years, which is further beyond our present capabilities than Orion which could mostly use materials and technologies on hand.

However the estimate of 12 deaths globally could be over or understated, we just don't have accurate enough data on low level radiation exposure risk. The 12 deaths was probably based on the no threshold model and I think in the future when we do have more data that model will be proven false, and that there actually is a threshold, meaning the 12 extra deaths may not even happen.

And yes, 12 lives would be a small price to pay to save humanity if that's the cost of colonizing another world to make us less vulnerable than we are on a single planet. We claim to be more intelligent than the dinosaurs but if we aren't willing to sacrifice 12 people to avoid meeting the same fate as them, then maybe we deserve the same fate.

The American Lung Association said 13,000 people die a year from coal power plant pollution, so 12 deaths seems pretty small in comparison to that. It's a psychological thing though; people should be more afraid of coal power pollution than a small amount of radiation, but they have it backwards and seem to fear a little radiation a lot more than coal power, which doesn't bode well for the future of Project Orion even if there was a way to get an exception from the nuclear ban treaty.