NASA SLS/Orion/Payloads

[DDE]

9 minutes ago, DAL59 said:

But why aren't they concerned about the equal amount of radiation experienced of the ISS?  

Exposure being reduced in half, the magnetic field removing part of the issue... and NASA missions still being comparatively short.

[Canopus]

Although i don‘t have the numbers now i‘m pretty sure the radiation you receive at the ISS is less than half of that you get at the surface of the moon.

[DAL59]

23 minutes ago, DDE said:

Exposure being reduced in half, the magnetic field removing part of the issue... and NASA missions still being comparatively short.

The cumulative radiation dose of a round trip mission to Mars has been experienced by soem astronauts.  

[PB666]

15 minutes ago, DAL59 said:

The cumulative radiation dose of a round trip mission to Mars has been experienced by soem astronauts.  

I should note that while all the other numbers are dT the Mars gives no numbers. Number of days they are using, nor do they give time spent on Mars.

IOW, its an invalid comparison.

[DAL59]

6 minutes ago, PB666 said:

Number of days they are using, nor do they give time spent on Mars.

They do earlier in the presentation.  

Its for a 500 day surface mission.

[PB666]

41 minutes ago, DAL59 said:

They do earlier in the presentation.  

Its for a 500 day surface mission.

Whoever made that chart misread the data, thats 500 days on Mars, not in transit.

150 mSv per year for ISS = 0.42 mSv / day. . . . . .Average 742 day stay would be 311.64 mSv

16.34 months transiting to Mars would be 960 mSv
16.34 month on Mars would be 330 mSv.

Kerr, Richard (31 May 2013). "Radiation Will Make Astronauts' Trip to Mars Even Riskier". Science. 340 (6136): 1031.
Zeitlin, C.; et al. (31 May 2013). "Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory". Science. 340 (6136): 1080–1084.
Chang, Kenneth (30 May 2013). "Data Point to Radiation Risk for Travelers to Mars". New York Times. Retrieved 31 May 2013.
 

Quote

The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert. -http://science.sciencemag.org/content/340/6136/1080

660 mSv is twice the average highest exposure on ISS.

Where are Robert Zubrin's references for his values?

[DDE]

2 hours ago, DAL59 said:

The cumulative radiation dose of a round trip mission to Mars has been experienced by soem astronauts.  

I think I even know the Zubrin article you’re borrowing it from.

You see, only the bottom three datapoints are relevant when discussing NASA. And maybe now Kelly, who would be barely above the “shielded” estimate, while “shielded” also requires research.

It’s a little bit hard to stave off a hysteria about a “Mars suicide mission” by citing Russian data these days...

[DAL59]

5 minutes ago, DDE said:

t’s a little bit hard to stave off a hysteria about a “Mars suicide mission” by citing Russian data these days...

Those 4 russian astronauts are all still alive.  

Radiation Hucksters Strike Again
By Dr. Robert Zubrin, Mars Society President, 06.08.17

According to a publicity campaign launched on behalf of a paper authored by University of Nevada Las Vegas Professor Frank Cucinotta, new findings show "collateral damage from cosmic rays increases cancer risks for Mars astronauts."

However an examination of the paper itself shows no discussion of experimental methods or results, because no experiments were done and no data was taken. Rather the much-ballyhooed paper is a discussion of a computer model that Prof. Cucinotta has created that claims to have the power to predict radiation-induced cancer occurrences. In short, there’s no real news. Furthermore, to the extent that the model in question has any empirical foundation, it is based on irrelevant prior experiments done in which researchers subjected mice to radiation dose rates millions of times greater than astronauts would receive on their way to Mars.

For example in one such illustrative piece of nonsense entitled “What happens to your brain on the way to Mars” published on May 2, 2015 in the open-access journal Science Advances, a group of radiation researchers claimed that their recent work causing memory loss to mice by administering very large doses of galactic cosmic ray (GCR)-like high energy radiation has serious implications for human Mars exploration. According to the authors, similar effects might severely impact astronauts going to Mars, thereby placing the feasibility of such enterprises in serious question.

However, in this typical mouse experiment, the victims were given a dose of 30 rads (0.3 Gray) at a rate of 100 rads per minute. On a Mars mission, astronauts would receive a dose of 1 rad per month during the 6 month outbound and return transfers, and about 0.5 rad per month during 18 months on Mars, for a total of 21 Rads. ( 1 Gray = 100 rads = 100 cGray. For GCR 1 Gray =6 Sieverts = 600 rem. Space dose  rates can be found in “The Cosmic Ray Radiation Dose in Interplanetary Space – Present Day and Worst-Case Evaluations” R.A. Mewaldt, et al, 2005.

The 4-million fold difference in dose rate between such lab studies and spaceflight is of critical importance. It is a well-known finding of both chemical and radiation toxicology that the effects of large doses of toxins delivered suddenly is entirely different from the effect of the same amount of toxin delivered in very small amounts over a long period of time. The difference is that the body’s self-repair systems cannot deal with a sudden dose, that they can easily manage if received over an extended period. For example, if an individual were to drink one shot of vodka per second for 100 seconds, he would die. But if the same person drank one shot of vodka a month for 100 months, he would experience no ill effects at all. This is about the same ratio of dose rates as that which separates the invalid work reported in the “What happens to your brain on the way to Mars” paper (1.6 rad per second) from that which would be experienced by astronauts in space (1 rad per month).

It should also be added that mouse studies are not an accurate predictor of cancer occurrence in humans. It is possible to induce tumors in mice by rubbing their stomachs. Such treatment is not known to be a hazard to people.

It is true that small amounts of toxins received over a long period can statistically increase a person’s risk of ill effects – at least according to the hyper-conservative Linear-No Threshold (LNT) model of toxicology. However, we already have data that shows that the accumulation of slow rates of cosmic ray radiation received during long duration spaceflight is not a show stopper for human Mars exploration. GCR dose rates in low Earth orbit are about half those in interplanetary space. Thus there are a dozen cosmonauts and astronauts who have already received Mars mission equivalent GCR doses (Padalka, Malenchenko Avdeyev, Polyakov, Solovyov, Krikalyov, Titov, Manarov, Foale, Fincke, Pettit, Walz, Kelly, Whitson) during extended space missions without any radiological casualties. Furthermore, since the International Space Station (ISS) is continually manned, while Mars missions are only in space about 40 percent of their mission time, the total GCR dose (measured in person-rems) that the ISS program crews will receive over the next ten years of planned operations is about the same as would be received by a series of five crews of five people each if they were launched to Mars every other year over the same period. Thus, in fact the ISS program has already accepted the same level of GCR risk for its crews as would be faced by an ongoing human Mars exploration program.

Galactic cosmic radiation is not a show stopper for human Mars exploration and should not be used as an excuse for delay.  The space program costs many billions of dollars, which are spent at a real cost to meeting human needs elsewhere. That fact imposes a moral obligation on the program to move forward as quickly and efficiently as possible. It is understandable that radiation researchers should want to justify their funding, but they should not spread misinformation to promote themselves at such extraordinary expense to the public.

[DDE]

9 hours ago, DAL59 said:

Those 4 russian astronauts are all still alive.  

"That's what the Russians are telling you".

As said, I'm operating under the conditions of a hypothetical smear campaign against Musk, targeted at laymen.

[tater]

WRT Musk, you’re not talking about a mars “mission,” but raising kids there. Entirely different thing.

Zubrin is entirely unconcerned with radiation at all, and I think others are concerned, but not paralyzed by it. It’s rational to be concerned enough to mitigate exposure, without being dismissive of it entirely.

[kerbiloid]

Spoiler

3 hours ago, tater said:

raising kids there. Entirely different thing.

Really.
Just imagine: no school, no street, no cinema, no another possibility to hide from them. All day long.

 

[PB666]

1 hour ago, kerbiloid said:

  Hide contents

Really.
Just imagine: no school, no street, no cinema, no another possibility to hide from them. All day long.

 

Not to worry, you'll be hiding from Galactic cosmic rays.

[insert_name]

Trumps budget proposal has the DSG propulsion module launching on a commercial LV before EM1, mentions privately developed lunar landers

https://spaceflightnow.com/2018/02/12/trump-budget-aims-to-kick-start-lunar-exploration-but-cancels-major-space-telescope/

[kerbiloid]

Spoiler

2 hours ago, PB666 said:

Not to worry, you'll be hiding from Galactic cosmic rays.

I guess, you have invented an unbreakable eternal bearing for a rotating carbon world which you are going to replace every century.

 

[DAL59]

8 hours ago, tater said:

WRT Musk, you’re not talking about a mars “mission,” but raising kids there. Entirely different thing.

Zubrin is entirely unconcerned with radiation at all, and I think others are concerned, but not paralyzed by it. It’s rational to be concerned enough to mitigate exposure, without being dismissive of it entirely.

If you are staying on Mars to colonize, you have time to shove some dirt on top of your habitat.  

[Canopus]

1 hour ago, insert_name said:

Trumps budget proposal has the DSG propulsion module launching on a commercial LV before EM1, mentions privately developed lunar landers

https://spaceflightnow.com/2018/02/12/trump-budget-aims-to-kick-start-lunar-exploration-but-cancels-major-space-telescope/

Makes sense. Too bad about WFIRST though.

[PB666]

13 minutes ago, Canopus said:

Makes sense. Too bad about WFIRST though.

Maybe an NGO will pick it up.

[tater]

Where “some” is meters. 

[Canopus]

https://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/

[_Augustus_]

On 2/13/2018 at 2:33 PM, insert_name said:

Trumps budget proposal has the DSG propulsion module launching on a commercial LV

That was the original plan. Glad they're reverting back to it.

[Kerbal7]

On 2/10/2018 at 4:39 PM, ZooNamedGames said:

As bad as SLS is, it at least is being developed and is guaranteed funding. SpaceX is funded by investors and goes where the money trail is. So if a massive new contract lands at their doorstep or a large portion of their investors decides that the next big step is a lunar colony and that Falcon 9 Expendable is the future, then they may have to halt development until money returns.

To me, BFR is just Sea Dragon 2. It's big and it holds great promise, but only exists on paper. Meanwhile the expensive SLS is currently being tested and is being developed and has left the blueprints and is becoming a reality with every passing day.

From what I can tell, NASA decided on this issue long ago. Its manned deep space exploration missions are going to use the SLS and Orion. The pencils have been put down and they're bending metal. And that's fine with me because I'm ready to go with what we got rather than wait for some other system that is as real as the star-ship Enterprise. Let's go. Let's go to the moon. Let's get this train moving. That's how I feel about it. 

This does make me think a human rated BFR will never actually be built. NASA has no interest in it. Like I said, they got the rocket they want and the BFR aint it. So who is it for? Colonist going to Mars? That's a pipe dream. Thirty minute flights to Asia? Can you get it to really work, safely? Do you have the money to build the massive infrastructure to service such a thing? Will the general public want to ride a rocket? Will they feel safe enough to get on it? I just asked a girl if she would and she said, "no way." But she feels safe enough to get on a plane for trips.  

[PB666]

2 minutes ago, Kerbal7 said:

From what I can tell, NASA decided on this issue long ago. Its manned deep space exploration missions are going to use the SLS and Orion. The pencils have been put down and they're bending metal. And that's fine with me because I'm ready to go with what we got rather than wait for some other system that is as real as the star-ship Enterprise. Let's go. Let's go to the moon. Let's get this train moving. That's how I feel about it. 

This does make me think a human rated BFR will never actually be built. NASA has no interest in it. Like I said, they got the rocket they want and the BFR aint it. So who is it for? Colonist going to Mars? That's a pipe dream. Thirty minute flights to Asia? Can you get it to really work, safely? Do you have the money to build the massive infrastructure to service such a thing? Will the general public want to ride a rocket? Will they feel safe enough to get on it? I just asked a girl if she would and she said, "no way." But she feels safe enough to get on a plane for trips.  

Orion and its service module have been under construction for the better part of a decade the service module is still under construction by the ESA having begun construction in 2015. The SLS began construction also is 2014 the first launched in 2019.

 

[T-10a]

To be honest, as much of a boondoggle as the SLS is, it seems to finally be getting somewhere at last. I'd be impressed if they can make the SLS go above and beyond all the naysayer talk, but I'm doubting if such a thing is possible considering the bickering beast that is Congress.

[DAL59]

10 hours ago, Kerbal7 said:

Will the general public want to ride a rocket?

A signifigant portion will.  You only need a small percent.  Also, its main importance might be for military dropships.

10 hours ago, Kerbal7 said:

Let's go. Let's go to the moon. Let's get this train moving. That's how I feel about it. 

No point if SpaceX can send dozens at once.  

10 hours ago, Kerbal7 said:

NASA has no interest in it

So?  Its Musk's ship.

[Canopus]

8 minutes ago, DAL59 said:

A signifigant portion will.  You only need a small percent.  Also, its main importance might be for military dropships.

Of all the crazy ideas for the BFR this is easily the silliest. Sorry but i doubt anyone is seriously thinking about that.