Humans on Mars. Safety first?

[woods170]

http://spacenews.com/letter-safety-cant-come-first-if-we-want-to-put-humans-on-mars/

If humanity ever wants to send people to any deep-space destination in the solar system at any price, let alone one the nation or world can afford, we must be prepared to take risks and lose astronauts.

[Oli]

Why bring back astronauts anyway, its not like they're worth billions...


But seriously, this article is devoid of content. What would be an acceptable loss of crew (LOC) probability according to him? 1%, 5%, 10%?

From what we know NASA is aiming for a 1:270 LOC ratio for commercial crew (~0.4%).

For lunar missions (with Ares etc.) I've seen LOC probabilities of ~1.5-2%.

[Russel]

It isn't just about cost versus risk though. It also depends on how much thought has gone into the architecture.
My point here is that while I'm in principle comfortable with trading cost and risk, what I don't think we should do is trade off risk versus an earlier launch date. Lets get there knowing we've at least though the whole thing through carefully and given a serious airing to every possible architecture.

[redliox]

Losing an astronaut is like losing a celebrity or a high class official; too much attention on them versus the minimal attention to casualties on Earth (car wrecks, war, ect.).  NASA can't afford either a bold mission or a televised death (again).  As the article implied, that fearful attention will only vanish when people start taking space travel casually...which won't be for half-a-century if not a full one.

Personally I think there's a balance in there somewhere, although we should be slightly bold otherwise we'll never get anywhere.

[the_other_Doug]

Rant mode on.

I dispute the statement that NASA cannot afford another "televised death." Death is a fact of life.  I live in Minneapolis, and a construction worker putting in roof panels in the new Vikings stadium currently under construction fell about 40 feet and killed himself a few weeks ago.

They didn't stop building the half-completed stadium, and the nameless worker was named and mourned for a few days, and then life went on.

Every major construction project (at least in the U.S., I assume elsewhere in the world, as well) has a budget line item for casualties.  The inevitable loss of life is recognized as just that, no matter how careful everyone is, when you're undertaking a large and occasionally dangerous job.

Anyone (read:politicans) who would use loss of life on a Mars mission to halt crewed exploration programs would be coming from an agenda where he/she/it was already opposed to such programs, and would see it as a means of beating his/her/its political enemies over the head.  That is when the demagoguery starts.

No one gets out of this life alive.  Period.  People die every day doing dangerous things.  They are mourned, but no one uses their deaths as an excuse to stop doing those dangerous things.

That's because most of the truly worthwhile things one can do in life carry a certain danger.  Those who wish to be completely safe cower in their homes and never step outside onto the sidewalk.

And never accomplish anything.  At all.

Now, having a "televised death" while doing something dangerous, but which the public hasn't been well-enough educated to see that the endeavor is worthwhile and ought to continue, is a problem, I grant you.  The solution to that is to try and make certain you don't do pointless or useless things that needlessly put your people in harm's way, and that when you are doing things that are useful and have a point, that you educate the public that anyone who dies doing them did not die a useless or pointless death.

Rant mode off.

[Vultur]

From what we know NASA is aiming for a 1:270 LOC ratio for commercial crew (~0.4%).

For lunar missions (with Ares etc.) I've seen LOC probabilities of ~1.5-2%.

Those risks sound reasonable for LEO and Moon respectively, but those have been done before.

For the earliest missions to Mars I'd say 10%*, which IIRC is not out of scope with the early 20th century Antarctic expeditions.

*of death on the mission - I would not include cancer probabilities 20-30 years later. (By then - 2060 or so assuming a first Mars mission in the mid-2030s - medicine will probably have radically reduced cancer death rates anyway).

Obviously it would reduce as more missions were done, infrastructure increased and technology improved.

[guckyfan]

For the earliest missions to Mars I'd say 10%*, which IIRC is not out of scope with the early 20th century Antarctic expeditions.

Sounds realistic to me. At least for minimalistic missions.

I guess when you have MCT style mass available the chances should be a lot better. Supplies for 2 or 3 synods give time to send replacements if something goes wrong. At least double, probably triple dissimilar redundancy for life support. At least two, probably more landings of the same kind of vehicle before people are sent. Landing, ascent and return to earth before a manned mission with the same kind of hardware. If not from Mars then a testflight to the moon with landing and return. That should retire many risks. Of course not all. Some risk will always be involved.

[MATTBLAK]

[Russel]

Early expeditions weren't played live on a billion screens.

And the MCT. When it blows up, its going to take a lot of people with it.

I just want to restate something more clearly. All else being equal, there is a trade off between risk and cost. However, all else is quite definitely not equal. There are less risky and more risky architectures, for a given cost. There are risks that are associated with impatience. With wanting to get there real soon now because if we don't, then everyone will get bored and never want to go to Mars? What? It will always be there.

My point here is that we need to get the planning right. Ok, at the end of the day there will always be a risk. And we'll be going, knowing that yet more redundancy and yet more tests will reduce risk. But the single biggest thing we have control over is getting the concept, the architecture right.

It pretty clear no one has a monopoly on good ideas. No one has a perfect architecture, or even a really good one, yet. That's why we need to put our heads together and come up with better solutions. That's why we need to be patient.

If Apollo 13 taught us anything, its that we ignore redundancy to our peril. Even unintentional redundancy such as was the case. What I mean about going to Mars in style, is that we do so, knowing we have thought through everything as carefully as we can, and provided as much intentional redundancy as we can, but also we've allowed ourselves enough margins in the design such that when things go south (and they will) that there's still room for unplanned solutions.

What I keep pushing is a deep space habitat that consists of two identical halves. Each with their own independent power systems, thrusters and basic life support. Even if you were to go ahead and build just one tin can, you'd end up duplicating much of this anyhow, if not carrying extra spares. Being able to split the vehicle means you've got contingency solutions - even ones you may not have planned. It means that if one vehicle loses integrity for whatever reason, your crew can still survive. And this all can happen with minimal extra mass. Indeed it enables certain efficiencies.

What we most need to invest in is mechanical systems that "just work".. and keep working without maintenance, for years. That's the hardest part and the part that needs testing sooner rather than later.

We also need to get over the temptation to land a whacking great mass on Mars (a habitat or whatever) and land the crew along with it. Its going to be safer (for a given cost) to land the crew separately and, I would argue, fully propulsively. Because if you take a large mass, strap the crew to it, and then try to land it, then you start inventing extra things to reduce the risk of it crashing (because its got crew on board). And because its massive, that extra risk-aversion is going to be costly. If you accept a certain risk level of cratering a non-manned cargo onto the surface of Mars (and since this is done in advance its not life-critical) then you can spend more on protecting the crew.

And finally. The single biggest risk apart from landing (and I beg people to consider landing the crew separately) is of course getting safely back to habitat in orbit. That's why I originally placed a couple of "safe refuges" in low Mars orbit for this purpose. If this is not the case and you expect the ascent vehicle to meet up with a propulsion unit to get it to high orbit (say) then that propulsion unit had better be there. It had better work. And the ascent had better be on course. Otherwise you might regret not leaving in orbit spares.

Anyhow if the overall theme is that exploration is risky, then yes it is. But impatience is riskier. And if you go back to the days of early (and badly failed) explorations on Earth, the common thread is how thought out and how well prepared those missions were.

[KelvinZero]

Im very interested in space colonisation and yes there will be risks but I don't think daring astronauts with the right stuff has much to do with it anymore.

IMO HSF budgets are not effectively spent on the goal of space colonisation. A lot of (comparatively) cheap, safe and necessary research is not being done. If we have not proven our DSH over years safely on the ground or in LEO, or practiced landing large payloads on Mars several times robotically, and send humans on missions with high risks of failure here then when people ask what they died for we can tell them they died for a stunt.

Nothing magical will happen when humans set foot on Mars. It is not that we should avoid risks but surviving there long term is the goal itself. That is what colonisation means. Getting there and back at high risk of failure is not a victory, it probably means we are spending our money on sensationalist rather than effective goals.

[Russel]

I don't see the need for colonisation. In fact, unless we as a species grow up, I'm antipathetic to the idea. What I do want to see is a permanent but limited presence, largely for scientific and exploration reasons.

Either way there is no need for panic. We should do this carefully, thoroughly and confidently. Mars aint going to go away in any hurry, is it?

[MATTBLAK]

That's never the point, I feel. I think most Space 'fans' want to see a manned landing on Mars in their lifetimes. To me, it's not just a 'bucket list' requirement: I genuinely want to see the human species progress and progressing out into the solar system - however symbolic some might deem that to be - I feel it will be an important step in our evolution. It's almost a 'selfish' requirement for me - I just wanna see it happen!! I'm 50 years old soon and I've wanted to see it since I was about 10 years old. It's something like a very long odyssey to merely live through all these years, waiting for something other than wars, terrorism and natural disasters to dominate the headlines.

Like a famous song once said; 'The waiting is the hardest part...'

[guckyfan]

Either way there is no need for panic. We should do this carefully, thoroughly and confidently. Mars aint going to go away in any hurry, is it?

I am completely with Elon Musk on this. He argued the window is open now. We don't know how long it will be open. So now is the time to go.

This does not mean to unreasonable hurry but also no reason to unnecessary delay.

[Russel]

Either way there is no need for panic. We should do this carefully, thoroughly and confidently. Mars aint going to go away in any hurry, is it?

I am completely with Elon Musk on this. He argued the window is open now. We don't know how long it will be open. So now is the time to go.

This does not mean to unreasonable hurry but also no reason to unnecessary delay.

I've no idea what he meant by a window.

[cro-magnon gramps]

Either way there is no need for panic. We should do this carefully, thoroughly and confidently. Mars aint going to go away in any hurry, is it?

I am completely with Elon Musk on this. He argued the window is open now. We don't know how long it will be open. So now is the time to go.

This does not mean to unreasonable hurry but also no reason to unnecessary delay.

I've no idea what he meant by a window.

This is something that has been discussed in Sci-fi and Scientific circle for a few decades at least... I remember discussing it with some University Types in the late 60's. They were all against going into Space when we had so many problems here on Earth that hadn't been dealt with.
 It is a Technological and Sociological Window of Opportunity... We are like a Train, that has a heavy load, starting slowly, 9,000 years ago and building up speed (momentum) as we pull the cars behind us... This Train has been gathering steam for 600+ years, as Western Society has developed from early Nation States based on Feudalism to the Present...
  The problem is, as we have seen in the past couple of decades, there are forces that would derail that train for their own purposes, (Religious Extremists, Ecological / Environmental Activists, International Mega-Corps [the 1%] etc ) or RUD's on a Planetary Scale (as in Global Climate Change, or Catastrophic Geological/Solar Events we can't predict)... (was having a hard time coming up with a term that covered adequately  )
   So while Musk and others will talk about making life multi-planetary (human life) and talk about stuff like Asteroids or Climate Change, there are a whole multitude of events that can close this Window of Opportunity. We have had an unprecedented Century of Advances, supported by Fossil Fuel and Nuclear Energy, but those are hazardous to our long term health, as we have found out, and in the case of FF, we are running out of easily obtainable sources. if a regression in society and technology were to happen, we would have a harder time building up to where we are today.
   That is the Window that Musk is concerned with... we have 50-100 years to build a Space Faring Species, and to Make Life Multi-Planetary. The chances of any one of the hazards to this project happening are probably slim, but they are non the less real...

Gramps

edit spelling

[kch]

We should do this carefully, thoroughly and confidently.

Indeed we should.

Mars aint going to go away in any hurry, is it?

Well, no, it isn't -- but we might. 

[nadreck]

This is something that has been discussed in Sci-fi and Scientific circle for a few decades at least... I remember discussing it with some University Types in the late 60's. They were all against going into Space when we had so many problems here on Earth that hadn't been dealt with.

And this line of reasoning could be applied to the iPod/Phone/Pad and the trillion or more dollars of value ascribed to all those companies or parts of companies(facebook, youtube, twitter, etc) that do no more than allow us to share our self centered little world view with anyone who will pay attention. What good does the ability to take a cat video and share it world wide do to those who are starving, victims of abuse (from individuals or oppressive regimes), etc.

However no one says Apple's net worth should be forfeited to help those less fortunate (though one can argue that Bill and Melinda Gates took 1/4 of the value of Bil Gates and moved it to help those less fortunate).  Still the argument persists against space endeavours. You can rationalize the cost of the Mars effort (as you can with my other examples) but rationalization is not the goal, getting out and doing it by the powers that can with the people who want to is the goal. While deliberately misleading people about the risks involved would not be right, allowing people to participate in a high risk activity should not be at issue. Like an Everest climb, each individual's risk is different, and perceived differently, but the group going doesn't go without expecting the group to succeed despite much higher risks that some individuals within the group fail. The Martian (the book, I have not seen the movie yet) puts the risk at a level like a mountaineering expedition, and includes the obligatory tragic communications with the doomed person (see books like The Path of 8, Into Thin Air, etc) which is dramatic, tragic, but also indicative of human strength and determination to persist in risk taking for a perceived goal. No one wants to die, we all know we will die, and many would rather face death risk taking than wasting away.

To me Dylan Thomas' was right with Do not go gentle into that good night we don't want to die, but if we know we must then go with gusto fighting and trying every step of the way and not deterred by the fear of death just inspired by the will that we should constantly strive to defeat it. So yes strive for safety, but don't put safety above doing since life is just not a safe condition to live in anyway.

[arachnitect]

This zombie argument is based on the false premise that NASA has unreasonably high safety standards.

1. NASA does accept risk. We are not grounded due to safety standards.

2. The industries NASA is compared to also have "safety first" philosophies (at least in most "developed" countries). They do not just passively accept that "people die" as some space cadets seem happy to believe. A construction worker falling to his death due to improper fall protection on a billion+ dollar project is NOT "acceptable."

3. The industries NASA is compared to are orders of magnitude safer than spaceflight. Construction safety hovers around 1/10,000 deaths per FTE employee. NASA, which is supposedly paralyzed by risk aversion aspires to a much more lenient standard than this (and continually fails to achieve it).

People who want to expand humanity into space should argue for higher safety standards, not lower ones. People don't fly on commercial airliners because they're enamored of humanity's technological prowess... they fly on airliners because they're safe.

[colbourne]

It is not just the astronauts who travel to Mars whose safety  is of concern. Construction on Earth and in LEO will have the risk of casualties as well. The larger the mass sent to Mars the more likely people are to be killed here on Earth.

I think the safest (ie least casualties) Mars manned mission would be a small one way mission with a small crew who could hopefully be rescued, if they so wish, at a later unspecified date. They will have the option of  avoiding  the inherent risks of a Mars ascent, which must be the most dangerous part of a Mars mission. The massive savings in landed mass for the return craft and fuel or fuel generation equipment can be used to make their base much more safe and comfortable. Not having to produce fuel will also free up much of their time to carry out scientific work and maybe for recreation.

[Russel]

We should do this carefully, thoroughly and confidently.

Indeed we should.

Mars aint going to go away in any hurry, is it?

Well, no, it isn't -- but we might. 

a) If we are the kind of species likely to do ourselves in that quickly (next few decades) then aren't we also pretty much guaranteed to repeat our mistakes and do ourselves in on Mars as well? Stands to reason, doesn't it.

b) Perhaps we humans should have a bit of humility and figure out that at the very least there's a responsibility that comes with having a planet to play with and if we are so uncivilised as to wreck this planet maybe we haven't actually earned the right to colonize another.

I do support the urge to explore and discover. And from that learn, gain a sense of humility, and become more civilized in the process. And that urge simply isn't going to go away. We're humans after all. Not unless we end up back in the dark ages and print text books that explain clearly how Mars is a myth. And if we do, maybe there's a lesson in that too.