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

[BruceJohnJennerLawso]

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.

:hesaid:

Radiation will be a fairly relevant issue with going to Mars, but hearing someone say "We cant go to Mars because of the radiation", I don't buy it at all. Its a somewhat minor, solvable issue, not an impassable problem.

Its frustrating how much space-related media seems to lack this context :facepalm:

 

[N_Molson]

Human body is clearly not adapted to the environnement encountered in space. Radiation is only one of the many hazards to face up there. It's not a playground. Yes, it seems obvious that in the current context, there will be no manned mission to Mars before 2030 (and I'd even say 2035-2050). But with time will come solutions, I'm also pretty sure of that. I just hope to live long enough to see the results.

 

[Urwumpe]

Human body is clearly not adapted to the environnement encountered in space.

By what I can tell by the medical issues with microgravity, I would say that the human body is maybe not adapted to it, but it is tolerant for it.

Being in space does not kill you. Entering microgravity doesn't kill you, even if you are unprepared. Switching from space into normal gravity again can kill you without preparation.

Also, humans are not more or less vulnerable to radiation in space than other objects. Even massive steel trusses age quickly in space, without the sometimes faulty capability for self-repair, that humans have.

You are right, we are perfectly adapted for living on Earth. We need to take Earth with us. But we can survive with much less Earth than we usually have.

As long as we are more busy finding reasons, why going to Mars is impossible or not wise, we will NEVER go there. We should discover some optimism. We will never do everything right on the first flight to Mars anyway, so we are we so focussed on perfectionism, that we will never go at all?

 

[N_Molson]

Being in space does not kill you

That's not what I meant. I wrote the human body, meaning that if you put someone naked in orbit, he won't live more than a minute in any case. Of course, we can say the same on some place on Earth : if you drop someone in the same conditions in the midst of a South Pole blizzard storm (like -90°C), he won't last very much longer. But of course we aren't Australopithecus anymore and can build technological devices to even the odds : an EVA suit already solves a good part of the inadaptation problems.

That's also true there is worse than space, typically Venus surface, gas giants, and of course stars. In that last case we can convert "minute" in "nanosecond".

We should discover some optimism.

Here I 100% agree. I'm completely convinced that a Manned Mars landing is doable in 10 years, given a real political will. We all know that the problem is there. And (in theory), the citizens like you and me should be the People that put pressure on politics. Maybe our world suffers from fatalism. :hmm:

 

[Urwumpe]

Well, we have MANY problems to solve today - on Earth as well. And most people hope that somebody else solves them for them. What is fatal.

The next economic crisis is already forming and I don't want to imagine what happens then, if not many self-declared "decision makers" get their lazy asses kicked.

 

[N_Molson]

Yeah. I don't want to make too much politics here, as it is not the place, but I was a bit saddened that the german Chancelor got elected for the 3rd time in a row. Seems that people are happy with the current mediocrity or what ?? Germany made better that other european countries, but still, the situation is far from being a panacea. So she is probably going to sit on her laurels and do nothing during the next years... Cool...

More on the topic, there is another option to overcome that radiation issue. Find a cancer cure (that has no irreversible side effects and isn't more expensive that other medications). Just treat the 'nauts as they get back from the trip. It would help a lot on Earth too.

 

[PhantomCruiser]

I agree that we won't be headed to Mars anytime in the near future. But, the arguements for the "planning of" such a venture are that it will lead to many more breakthrough technologies.

Look at all the advances that we already owe to human spaceflight. As we figure out how to do things "up there", we get better at doing things "down here". I'm particularly interested in the food issues. I don't think it'll ever be a "closed loop", but as techniqes are developed to grow food (or that engineered meat stuff even) that kind of tech will benefit us all.

 

[T.Neo]

I think several questions need to be asked, the first is by what margin typical radiation exposure for a Mars mission would increase lifetime cancer risk for an astronaut.

The second is what percentage of the total risk of mission-caused death, involves cancer due to radiation exposure. The astronauts are already being exposed to things that markedly increases their risk of dying, compared to your average person. How much of the total risk is radiation-related? If it is a small amount (which I personally suspect, but can't validate statistically) why the major focus on radiation rather than, say, engine start reliability?

I'm not at all saying that a more lax position toward astronaut safety should be adopted, or necessarily even that the radiation limits should be slightly bent or ignored in the case of near-term Mars missions, but it's something worth discussing as different solutions to the problem are speculated about.

 

[Capt_hensley]

See this thread for info about Radiation Shielding
http://orbiter-forum.com/showthread.php?p=262564&postcount=19

Can't say, but there is a book from Mary Roach entitled, Packing for MARS

It shed some light, with humor, on many subjects about going to mars. Its written as fact, based on real research, and interviews of real astronauts who have been in space. I enjoyed reading it, and I don't read for entertainment.

 

[RGClark]

:hesaid:
Radiation will be a fairly relevant issue with going to Mars, but hearing someone say "We cant go to Mars because of the radiation", I don't buy it at all. Its a somewhat minor, solvable issue, not an impassable problem.
Its frustrating how much space-related media seems to lack this context :facepalm:

Actually it's what the NASA scientists are saying:

Manned mission to Mars an unlikely proposition.
Current limits on exposure to radiation make chances of flight in near future pretty slim.
Sep. 22, 2013

It’s “the elephant in the room,” NASA Chief Astronaut Robert Behnken recently told a National Academy of Sciences committee.“We’re talking about a lot of ionizing radiation, almost a guarantee for cancer, and you are really close to the edge of the range for lethal exposure,” said Kristin Shrader-Frechette, a University of Notre Dame professor and a specialist in ethical issues that arise in scientific research and technology development. “If we can’t get shorter transit times in space, and we can’t get better shielding, then we really can’t do (a Mars) spaceflight.”

http://www.floridatoday.com/article...6/Manned-mission-Mars-an-unlikely-proposition

I also think the problem is solvable even in this decade by currently available chemical propulsion. So as not to derail this discussion though, see the discussion in this thread "Math needed for 5-week flight from Earth to Mars".

Bob Clark

 

[Urwumpe]

two missions, 708 hours in space and is already chief astronaut... if you EVER wondered what is wrong with NASA, there is a fine example...

A Russian cosmonaut would ask what he did the other 11 months of the year...

 

[csanders]

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]

I'm just giving them a topic of study for their PhD. http://engineering.dartmouth.edu/~d76205x/research/shielding/docs/Hoffman_I-final.pdf

You're welcome again!

I'll be here all week.

 

[BruceJohnJennerLawso]

I also think the problem is solvable even in this decade by currently available chemical propulsion.

Shorter flight times? Please forgive my skepticism with that. A slightly higher DV TMI might be reasonable enough for that, but trying to do a Mars mission with transfer times in weeks instead of months both ways just isnt doable. It cuts far too much into mass budgets for structural strength, consumables, redundant systems, etc.

 

[C3PO]

A room full of nerds with pocket protectors, coffee, and slide rulers got us to the moon as my grandfather used to say.

And 4% of the US budget.

IMHO the biggest difference between the Apollo-era missions and a Mars mission today is the aversion against risk. When NASA was designing the Ares-1 stack they aimed for a safety factor of 1/1250. It's not an absolute safety factor, rather a relative one. It's (supposed to be) used to compare the safety of different design options. When the same model was applied to the STS it came out at 1/280. After the fatal accidents the model was adjusted and it came out at 1/50. Using the same model an Apollo moon landing mission scored a nice and even 1/4.
In other words, comparing Apollo to today's manned space travel is useless!

 

[BruceJohnJennerLawso]

And 4% of the US budget.

IMHO the biggest difference between the Apollo-era missions and a Mars mission today is the aversion against risk. When NASA was designing the Ares-1 stack they aimed for a safety factor of 1/1250. It's not an absolute safety factor, rather a relative one. It's (supposed to be) used to compare the safety of different design options. When the same model was applied to the STS it came out at 1/280. After the fatal accidents the model was adjusted and it came out at 1/50. Using the same model an Apollo moon landing mission scored a nice and even 1/4.
In other words, comparing Apollo to today's manned space travel is useless!

Okay, fine

But how are those odds derived?

 

[N_Molson]

But how are those odds derived?

From hardware testing I guess. And they stay what they are : statistical odds. You cannot have the warranty that, even at 1/1250, the first three flight won't be consecutive catastrophic failures.

 

[C3PO]

From hardware testing I guess.

Combined with system analysis and actual flight data. It's a statistical model to compare one system to another. The actual model is evolving as experience is gained.

The resulting number is the odds on losing crew and mission, but as with all odds it has no real meaning for an individual flight. The risk doesn't increase with every successful flight.

 

[Urwumpe]

Also, any statistic is only as correct as the model behind it.

 

[Andy44]

The odds for an Apollo moon-landing mission would be far different than for an Apollo Skylab mission.

The latter had lots of redundancy built in, and there was even a rescue Apollo vehicle on standby, while the former got progressively more dangerous once you did the TLI burn and started expending parts of the Apollo stack, forcing your crew to rely on more single-point failures such as only one engine to get off the surface of the moon, and only one engine to break lunar orbit and head for home.

Going to Mars will be even riskier. At least from the moon you are only a few days from home at most. A Mars mission involves committing to months or years away, so reducing and managing the risk bacomes more expensive.

It's not impossible, but you have to keep these things in mind. Managing radiation dosage is one of these things. An Apollo landing mission gambled that there would be no major solar flares for the few days the crew was exposed. A Mars mission won't have that option; they WILL experience radiation hazards over the course of such a lengthy mission.

 

[RGClark]

Shorter flight times? Please forgive my skepticism with that. A slightly higher DV TMI might be reasonable enough for that, but trying to do a Mars mission with transfer times in weeks instead of months both ways just isnt doable. It cuts far too much into mass budgets for structural strength, consumables, redundant systems, etc.

I don't want to go off topic so we can continue this discussion on that other thread.

Bob Clark

---------- Post added at 03:49 AM ---------- Previous post was at 01:59 AM ----------

The radiation measurements by Curiosity in space pretty much confirmed what scientists already knew. Here's an article from 2006 that discusses the problem:

Shielding Space Travelers.
The perils of cosmic rays pose severe, perhaps insurmountable, hurdles to human spaceflight to Mars and beyond.
By Eugene N. Parker
Scientific American, February 20, 2006
http://engineering.dartmouth.edu/~d76205x/research/shielding/docs/Parker_06.pdf

Bob Clark