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

[JonnyBGoode]

Radiation hazard will probably prevent manned missions to Mars anytime soon.

http://www.usatoday.com/story/news/...akes-manned-mission-to-mars-unlikely/2847577/

 

[Izack]

Lack of a serious Mars programme is already preventing this.

 

[RisingFury]

Necessity is the mother of all invention. I'm sure we'll figure out neat and nice little ways of actually getting around this issue assuming we take manned Mars exploration seriously and actually fund it.

 

[Donamy]

There's more to worry about, than a cancer risk.

 

[MattBaker]

Curiosity measured 1.84 mSv per day.
Dennis Tito plans a roundtrip for two taking 501 days.

Which would expose them to 920 mSv. 100 mSv were already linked to higher cancer rates.

Not until 2025.

 

[Andy44]

The human animal did not evolve with spaceflight in mind. We aren't physically cut out for it, so it's going to take a lot of work to get around that.

The mention in the article about radiation limits discriminating against women was interesting...off to the basement with that one.

 

[Mader Levap]

100 mSv were already linked to higher cancer rates.

Menaningless without information in what period of time you got that dose.

 

[Urwumpe]

Menaningless without information in what period of time you got that dose.

Exactly. Also 100 mSv also depends a lot on how you measure it. A sensor measuring radiation does not measure Sievert, but usually Becquerel. For calculating the equivalent dose in Sievert, you need to know the type of radiation pretty precise. Something that even large sensors on the ground can often do wrong in the hands of amateurs.

And where this sensor is installed, does also affect the radiation that you measure. A human in a spacecraft with some radiation shielding can get a much lower equivalent dose than a virtual human on the outside of a probe in outer space.

By what some pseudoscientists claim, we would be already dead by radiation because we sleep in our bedroom.

 

[dgatsoulis]

I always liked Dr Zubrin's reply to the cancer risks of the Mars journey. IIRC it goes something like this:

"Send smokers without their tobacco and you'll actually reduce their chances of getting cancer."

 

[BruceJohnJennerLawso]

And where this sensor is installed, does also affect the radiation that you measure. A human in a spacecraft with some radiation shielding can get a much lower equivalent dose than a virtual human on the outside of a probe in outer space.

And most critically, shielding doesn't actually have to be specialized. Generally speaking, any mass in between you and the radiation source will help with shielding.

For example, why not simply install a toilet for fecal waste in the side of the spacecraft leading into a common bulkhead that surrounds the living area. When the astronauts... you know.... , spin up the spacecraft at a reasonable number of RPM to create an artificial gravity gradient. Once they're done, spin the craft back down to its usual attitude, & seal the toilet cover. The fecal matter should hopefully spread out evenly inside the waste bulkhead, and the astronauts are now shielded a bit more from any radiation.

There you are -> Waste disposal & radiation shielding solved all at once. Of course the waste bulkhead might leak into the living quarters, but astronauts are brave people, right? :lol:

 

[Urwumpe]

And most critically, shielding doesn't actually have to be specialized. Generally speaking, any mass in between you and the radiation source will help with shielding.

Wrong.

The type of radiation is extremely important in space.

Gamma Rays will pass through almost everything. Lots of lead can't block it, but can reduce its intensity to near-zero. It is just futile because gamma rays also pass through humans without much interaction, that is why they have a much lower factor in the calculation of the equivalent dose.

Radiation of charged particles (beta, proton) will get stopped by lead so quickly, that you will get grilled by a much worse X-Ray radiation, because the energy of the charged particles is turned into Bremsstrahlung.

A few mm of aluminum or polyethylen foam (low density is important) on the other hand can reduce the intensity of such radiation enough.

 

[BruceJohnJennerLawso]

Wrong.

The type of radiation is extremely important in space.

Gamma Rays will pass through almost everything. Lots of lead can't block it, but can reduce its intensity to near-zero. It is just futile because gamma rays also pass through humans without much interaction, that is why they have a much lower factor in the calculation of the equivalent dose.

Radiation of charged particles (beta, proton) will get stopped by lead so quickly, that you will get grilled by a much worse X-Ray radiation, because the energy of the charged particles is turned into Bremsstrahlung.

A few mm of aluminum or polyethylen foam (low density is important) on the other hand can reduce the intensity of such radiation enough.

Why was there all of this talk about the Inspiration Mars mission using fecal waste as radiation shielding?

 

[Urwumpe]

Why was there all of this talk about the Inspiration Mars mission using fecal waste as radiation shielding?

No idea, how they expected this to work.

If properly done, you can get a good radiation shelter for CMEs, but if you fully enclose the spacecraft, the cosmic radiation would ruin your health.

 

[BruceJohnJennerLawso]

No idea, how they expected this to work.

If properly done, you can get a good radiation shelter for CMEs, but if you fully enclose the spacecraft, the cosmic radiation would ruin your health.

CMG= coronal mass ejection?

So a full spacecraft shielding wouldn't work mass-wise, but a small shelter might?

 

[Urwumpe]

CMG= coronal mass ejection?

So a full spacecraft shielding wouldn't work mass-wise, but a small shelter might?

Neither mass wise, nor shielding-wise, yes. Most of the travel, the radiation shelter would possibly have a higher radiation intensity than the rest of the ship.

 

[csanders]

Solution: Super conductor coil generating it's own massive magnetic field.

You're welcome.

 

[orbitingpluto]

If part of the Mars infrastructure included a NTR, would pointing the engine bell towards Sol help much during a CME? I'm assuming since the reactor's shield was made to keep the crew at safe levels while the reactor is going full bore, it should be able to keep them at least okay during a CME. I could be mistaken though, as I'm not sure exposing a reactor to more radiation is safe.

 

[N_Molson]

Radiation shields, new engines mandatory for Mars

BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: May 30, 2013

 

[RisingFury]

Solution: Super conductor coil generating it's own massive magnetic field.

You're welcome.

Problem solved. The tens of thousands of Physicists and Engineers that spent a quarter of their life studying for their PhD should have just logged on O-F and read your post. [/sarcasm]

 

[Kyle]

I'd rather this be our only barrier to Mars than our current reasons for not going. A room full of nerds with pocket protectors, coffee, and slide rulers got us to the moon as my grandfather used to say (he worked on designing the RCS values on the CSM during Apollo). No reason to think a room full of nerds with pocket protectors and an ambition for doing the impossible can't do it again.

We're not getting close to Mars until at least 2030 and it isn't because of radiation. I don't need to elaborate why.