Doubts About Crew Health on NASA's #JourneyToMars
NASA’s Efforts to Manage Health and Human Performance Risks for Space Exploration, NASA OIG
“Although NASA continues to improve its process for identifying and managing health and human performance risks associated with space flight, we believe that given the current state of knowledge, the Agency’s risk mitigation schedule is optimistic and NASA will not develop countermeasures for many deep space risks until the 2030s, at the earliest.”
Oh well. It’s not like they’ll be making any extended stays beyond Low Earth Orbit until the 2030s anyways – Orion’s only good for 21 days by itself.
Speaking of #JourneytoMars, if they’re planning to send a crew in microgravity the whole way for both an orbital mission and a landing mission, shouldn’t they be trying out some really extended stays, like 2-3 years on ISS?
Leave our astronauts up there for three years till they are blind, great idea?
If they decide to do an Orbital Mission first (which seems likely) and also do it entirely in microgravity (which also seems likely if unfortunate), then they’re going to have to do a test extended stay sooner or later.
Yes, I think they will do extended ISS stays, but they won’t plan them until the results of the 1 year stay are evaluated. I would guess they will do them in additional 6-month increments, i.e. 18 months, then 24 months, then 30 months.
The problem is that the response of individual astronauts to micro-g varies greatly and there aren’t enough slots to do enough systematic tests to work out why. And even within the limitations of that small sample size, astronauts are not chosen for particular ISS mission slots the way you would choose test subjects for disease research or an early drug trial, for example.
The longer the stay, the fewer astronauts who would have done it, hence the smaller the sample size, hence the less relevance the results have to subsequent Mars crews.
Well, we do at least know that a year in space is survivable without too much damage for most of the astronauts (provided they do their exercises right). So if we decide to do a landing mission right away, then “all” we’d need to know is how 1/3rd Earth’s gravity affects human beings. I guess they’ll either have to wing it, or actually do a long-term centripetal gravity simulation experiment with people in orbit.
. . . It might almost be easier if they just bit the bullet and did tethering experiments, to see if they can do tethered simulated gravity on the trip out.
I can think of myriad issues related to objects fastened to spinning tethers in space and I’m not an engineer, just a guy who took some engineering and math courses in college. The idea is cool as hell though.
Me too. It would add extra testing requirements, although in the long run it might be worth it if it ultimately helps you do longer duration crewed missions.
del
Tether and spin-up to a full gee during transit. Position supplies relative to crew during transit (50 cm). On Mars, telerobotically cover the inflatable habitat with about two meters of regolith. Shield the cab of the rover. This would reduce total radiation during transit by about 83% and by 90+% on the surface.
Doug, why do you think that nasa doesn’t move forward with some of these spin-up ideas? Are they afraid of vibration damage?
It’s a fair question. My guess is that it was a set of non-nefarious reasons the top reason being budget item hogs leading to trimming of the ISS AG module and technology development. Studying zero-gravity effects cost less in the near-term and, incidentally, we don’t absolutely need to know the gravity Rx immediately so it isn’t a high priority.
I myself believe that we can have a program to go to the moon, let crew use an indoor centrifuge during their sedentary time, and then use biomedical indicators as to when the crew needs to return to Earth due to developing health problems. Then, during those extended stays, the crew could be conducting animal experiments to nail down what the AG Rx is for mammals including primates (e.g. marmosets). So we don’t have to hold off establishing the first off-Earth permanent base.
As for Mars, I think that initial Mars missions (flyby and a Phobos-Deimos mission) are short enough that we can do them. But when sending crew to the surface, it would be good to have the option of letting the crew remain for an additional conjunction at least. But this probably means we would need to know the AG Rx by that time.
I can’t quite get the 90+%/on the surface number to work. Mars gives you 50%. The regolith on the roof gives you 100% when they are inside. Shielding on the cab of a rover won’t help much, and shielding on EVA is essentially zero. That adds up to 83% if they are outside 8 hours each day, and 90+% means averaging about four days a week inside the habitat, with only ~3, eight hour trips out per week.
Hi fcary,
I’m going off of this graph from NASA:
http://srag.jsc.nasa.gov/Pu…
As well as the commonly mentioned understanding that the GCR and solar cosmic radiation are roughly equal (plus or minus with the solar cycle) as well as that solar cosmic rays are nearly completely stopped with only a modest amount of shielding (e.g. 10 cm) including storms.
I read the graph to say that, with the equivalent of about 50 cm thick of water (31 cm thick regolith at 1.6 g/cm3) GCR radiation is reduced by about 2/3rds.
Applied to the various contexts:
– In transit with water and water-containing provisions of 50 cm thick positioned around the crew results in 100% reduction of solar cosmic ray and 66% of GCR = 83%.
– Regolith of say 2-3 meters on the tops and sides of a habitat = 50% reduction due to Mars; 50% of remaining due to protection from solar cosmic rays; 80% of remaining reduction due to protection from GCRs = 95%.
– The crew initially mostly not doing outdoor geology but working indoors to master steps towards increased Earth independence.
– The cab of a rover with 50 cm thick of the equivalent of water = 50% due to Mars, 50% of remaining due to protection from solar cosmic rays, 2/3rds of remaining GCRs = 92%.
– Very little walking outside of the rover in a spacesuit (toxic dust, radiation, accident), rather, driving up to a rock of interest, and using external manipulators to examine and sample into a small airlock to the vehicle. 50% reduction when walking in suit due to Mars.
If this thinking is correct then it should be possible for crew to stay within their lifetime career limits for many years.
e.g. 30 year old female (470 mSv career limit)
129 mSv – Transit to & from Mars.
.095 mSv/day – Indoors in shielded habitat.
= 9.8 years of indoor living before career limit is met.
I think you’ve stated our disagreement. “The crew initially mostly not doing outdoor geology but working indoors…” You can certainly reduce radiation exposure that way. With a well-designed habitat, you could potentially reduce it to Earth-like levels. But what’s the point? Why go to all the trouble and expense to send someone to Mars if they are required to stay inside all the time? The benefits to having astronauts on Mars derive from being on Mars, not inside a habitat. That will require some level of risk, from radiation as well as other things, but this is something we should deal with. Let’s not solve it by making the whole thing pointless.
I don’t have a problem with the crew leaving the habitat doing geology provided that they do so in such a way so as to stay within their career radiation budget. I do believe that having the crew in a shielded cab can help significantly with that. But the whole crew doesn’t need to be outdoors for large portions of the day, every day. And geology isn’t the only reason to send crew to Mars.
Establishing and expanding a permanent base, preparing it for later crew, and developing the processes to becoming increasingly Earth independent thereby significantly reducing the costs — these all are important thing for the crew to do indoors. Along those lines, for every time the crew can remain on Mars beyond another return window, that is the equivalent of not having the expense of launching a return crew. So, keeping the crew mostly indoors and within their radiation career limits would save a tremendous amount of money.
Finally, there’s the old humans vs robots argument. The area within easy driving distance of a permanent base would be explored early on. Interesting locations far from the base could and should be explored via telerobotics.
The current issues are only issues if the time of travel remains at the mercy of chemical rockets. Build a propulsion architecture that reduces the flight time to weeks instead of years and many problems go away. NASA has the VASMIR engine under development. I don’t understand why that engine is not part of the long term plan for Mars.
Because it is barely a prototype and has enormous problems scaling its power output to the task.
Maybe a VASMIR drive is what Chris knows about: https://twitter.com/NASASpa…
You know, this is the 2nd time in less than a year that someone from NASA or retired from NASA(W. Hale)has said that something very big is on the horizon. If it’s BIG, I mean REALLY REALLY BIG what could it be?
1. NASA and SpaceX combine forces to send humans to Mars? Nah, nobody is going to spend that much money.
2. SpaceX has invented a new propulsion system? Could be I guess but if so I’ll be shocked.
I’m completely at a loss to figure out what it is. Maybe it’s nothing all that big but man I am really intrigued. I guess we’ll know soon enough..
Ok, I just found out it’s the plain ole’ MCT. I guess that’s pretty cool.
Musk has mentioned that he recognizes the need to reduce travel time. SpaceX has also hired people in electric propulsion, but I have no idea how advanced that work is.
First get some money to build a rocket, habitat module for the journey, lander, and God knows what else it takes put someone (and return from) the surface of Mars.
The problem as I see it is fear. Columbus would still be stuck in Spain if he had waited until their were no risks.
If we are ever going to get anywhere we need to just boldly go.
As it stands we have no plan to go anywhere.
The only thing keeping NASA funded at all is congressional pork barrel spending by a few politicians.
The United States has given up on space exploration, For those of us who see space exploration as part of mankind’s future it’s time to put our hopes in some other nation.
Their was a time we had the will and ability to get to the moon now we can’t get into LEO. You will never get anywhere without a plan for now we are just blindly spending money with no goal.
Musk has a goal, and it wisely spending money.
How far will his rockets take us? We will see.
USA does have a manned Exploration program. It is SpaceX.
Only question is how government chooses to support it. I think the NASA we are going to Mars line “plan” is a long term attempt to support SpaceX. NASA has no plan because SpaceX hasn’t released their details yet.
Their long term plan is to let someone else come up with a plan, until then let’s continue to wander aimlessly.
What was the long term plan when NACA helped the airplane industry???
The big grand government plan mission like Apollo to the moon or mars or asteroid is not the answer.
Lots of what NASA does is great, like investing in asteroid recovery tech, if they could only get rid of SLS and Orion.
We the people/customer have to decide what to do with Space transporting once it is cheap enough.
The grand plan needs to be make airplanes I’m mean launch vehicles spaceships habitates, satellites more affordable and safer.
That is it???
Honestly, this is the part I have never gotten about #JourneyToMars and whether the technology exists. We talk on and on about sending astronauts to Mars, but I have yet to see anything that shows astronauts can survive the extended period (let along an extended period in close quarters in something much, much, much smaller than the ISS with no mental hope of a quick return to Earth). And no, there’s no way in a hell we’re going to build something that looks like the Hermes by the mid-2030s.
I don’t know about the Hermes, but in The Martian they actually had a plan-something NASA is missing. They had a Hermes which obviously was built to be maintained and continuously used or reused. They had vehicles for Mars transport. They had a way to get from Earth to Hermes and back. Right now the US has two other capsules on the way, ahead of the Orion schedule. There is also an option to use other’s capsules, like Soyuz. So the last thing needed is a redundant capsule. Yet that is where a lot of the money is going. And from what I can tell we are not even thinking seriously about the other pieces. I’ve heard we might be able to use a discarded MPLM for a habitat.
but graphics! they have graphics!
A lot of this comes back to losses between 1993 and 2003.
Then, health and human performance was put on the back burner. Equipment was not properly designed, built or tested. A lot of the health equipment on board collapsed and failed in the first weeks of ISS manned operations. That was because the program did not think health equipment was critical and funding was shortchanged. The ISS managers were spending their overruns somewhere but it wasn’t on critical equipment for the crew. Then in a cost savings they decided to cancel the ISS Hab module and the Centrifuge Module. Apparently no need for life science experimentation. It wasn’t the only area shortchanged-payloads and science got no attention until just the last few years. Last couple program managers said they had not really paid attention.
I wouldn’t worry about it too much. We still have 10 or 15 years to straighten out ISS. We still have about 35 years by my estimation before any NASA astros are leaving cis-lunar space to go look at Mars.
Pretty much, depressingly so, on the mark.
Though not rigorously analyzed for budgetary consideratios,, the general constraint has trickled down that SLS is very expensive, so before you knew it we started generating ideas that stretched mission plans, which meant stretching when the many elements get emplaced, which meant longer trip times – more so as cheaper SEP entered the equation.
Viola…the rad issue.
I like the positive attitude.
History will show that 2005 resulted in the worse space policy ever, guaranteeing that economic access would not occur for at least two decades, and yet another shift of $ away from ‘directionless honeypots of open ended research’.
1) no commonality between EELV/NASA rockets
2) no humans on EELV
3) guaranteed fixed costs for two EELVs
4) restricted funding to alternative LVs
5) the wrong architecture and excessively sized LV
6) Maintain/resurrect decades old expendable hardware
7) A 28 day capsule that forgot Apollo 13 with Avcoat on solids for a 1 yr trip to mars, + 5 expendable engine programs
One cannot work the Space Grand Challenges without adequate funding and working higher payoff technologies and the program planners realized for decades that they need a flexible path forward. Risk takers could head to Mars with inefficient trajectories that *require* depots, but the solution ‘for the benefit of all’ is TBD as pointed out by D.W.
‘select’ folks testify at hearings. You cannot even ask them questions, and if you do they never answer it. Only fools believe. Google George Carlin.
http://www.nasa.gov/sites/d…
http://www.rand.org/content…
https://www.nasa.gov/pdf/50…
These are real problems and I do not want to trivialize them. But at the same time these problems have logical solutions that may very well simply need to be tested and verified.
In the case of the visual problems, there is a continuous flow in the brain, in which fluid is forced out of capilaries by blood pressure, flows through the brain into the cerebrospinal fluid or CSF, and then is absorbed by little tangles of veins on the inner lining of the skull called arachnoid granulations. (i.e. granulated spiders. Don’t ask.)
In 0-G the fluid shift from the legs increases venous pressure in the upper body and in some people this is just enough to impede CSF absorption, and the CSF builds up, causing pressure on the optic nerves.
However this is very similar to a terrestrial disease called intracrainial hypertension, which is fairly common and effectively treated with a common and very old drug called acetazolamide. Most likely the same treatment would work in space; it just has to be tested and verified.
The problem of radiation does not have a simple solution, but there are proposals for magnetic shielding. Failing this, we need to measure the radiation levels better, determine the risk, and if it is too high the best strategy would be to accelerate travel through better propulsion methods such as solar and nuclear electric propulsion.
So Dan’l, what you are saying is that except for radiation, everything can be resolved with artificial G. It might also be helped with shorter missions, which would also help a lot of other things like the psych aspects. Funny how we keep pursuing the situation which if most difficult for the human instead of trying to do some serious technology development.
No, I am saying there is currently no reason to believe that artificial gravity is even needed. The radiation hazard is not precisely known as it seems to depend on the still poorly understood interaction of iron nucleii in cosmic rays and stem cells in the brain. The radiation hazard to other body tissues for a single Mars mission would be acceptable.
The long duration flights on Mir in the 1990s caused irreversible 20% bone loss in
one cosmonaut. Note the word ‘irreversible’. Soon NASA will have their first data point.
Could you put that 20% in context? I know a common problem associated with old age a loss of bone mass, but I don’t know if that is a 5% or a 20% loss. If it’s 20%, then you are saying an astronaut on a Mars mission might, assuming no changes in preventative or post-mission treatment, return with a medical condition she might have ended up with anyway, after another 30 years. I suspect most astronauts would be willing to take that chance for a trip to Mars.
The Space Grand Challenge question remains: what happens long term for all? and can effects be mitigated for all? One theory is that gravity determines a portion of the loss rate after the peak and no amount of dynamic exercise or food or drugs can change this % of the loss rate. IOW, the slope is down after age ~ 30, and gravity determines part of the slope.
In context, bone loss is mostly reversible and small for short term stays. Mir data said that after a certain amount of time in ug, the loss *can* become irreversible.
In general terms (many variables) in 1g, bone increases to the peak at ~age 30, then men lose ~25% and women ~50% say by age 80. What are the loss rates when they return to earth, stay in ug longer, or return to ug? So can you send a male on two trips to Mars or double duration, and is the net loss 40%? Does (semi)gravity help in between or at the end?
The centrifuge was cancelled because long duration travel was not required. It was acutally ‘good for business’–send multiple crews on short trips to ug. The follow up was to pretend the moon prepares NASA for Mars, ignoring the Space Grand challenge. The health risks are used in the opposite sense to abandon BEO and limit the program to short stay LEO do loops or Apollo redux. The politics restate the objectives given to NASA, then the funded program forward complete ignores them. Will it change?!
Risk and cost go together..how long is the trip, how many trips, and how much do you want to spend? What are the effects with ug and radiation combined?
Mars of course could be reached in 3 months and would significantly reduce the health issues, but supplies and propellant must be propositioned. This is impossible with the ‘abundant chemical’ approach as Mars DRM 5 choose 6 months and was at least 900mT.
Given a flat, long term budget, it makes sense to provide the most number of missions for over say 2-3 decades. Otherwise, send a few folks and cancel the HSF program–no HLV and multiple capsules required. Catching on?
Either address the long term Space Challenge or don’t do it at all–so be it. The moon is not a stepping stone to Mars unless the trip includes a 1/6th g centrifuge.
If one chooses most number of missions to address the challenges, the *risk* then becomes what is the time increment of space duration for the next trip. For ISS, it was zero for decades.
I have done some research in this area, ranging from studies of bone density in humans with spinal cord injury to examining the microstructure of bone with atomic force microscopy.
Human bone responds to compressive loading, not to gravity per se. Almost the entire load born by the weight-bearing skeleton is applied by muscle contraction rather than by by gravity per se, so resistance exercise that is sufficient to maintain muscle strength will generally maintain bone strength as well. Over the past few years the ISS has finally gotten some adequate resistance exercise equipment so I would expect most of the crew to be able to maintain their bone strength well above this level. US and Russian crewmembers have remained in space for periods considerably longer than the outbound leg of a trip to Mars without suffering from postflight fractures.
How well does it have to be maintained? Although it depends on the starting point, generally speaking a loss of greater than 30% is felt to increase the risk of fracture. But just because some level of change is “irreversible”, i.e. doesn’t return completely to normal, doesn’t mean there is a significant risk of fracture.
Finally, there are tens of thousands of Americans with spinal cord injury who experience disuse osteporosis more severe than that seen in space. Countermeasures that work for them would be more than adequate for people in weightlessness.
The expectation is that the short term methods when the loss rates are low will extrapolate to longer term stays when the loss rates are higher. Perhaps, *if* the physics are only dependent on dynamic (hr/day) compressive loading, but ug may have all the nuances of a stiff equation. Nothing else, like pathology or fluid flow?
So what data or lack thereof lead the OIG to conclude “we believe that given the current state of knowledge, the Agency’s risk mitigation schedule is optimistic and NASA will not develop countermeasures for many deep space risks until the 2030s at the earliest”?.
Irreversible simply means not able to be undone. Even with the current, adequate (?), exercise equipment, ‘statistically significant bone loss occurs with short duration stays’. Further, the methods may reduce bone loss but the changes may compromise later bone health. How accurate are the measurements to begin with? Why spend $ on Orion/SLS when this question remains? On 8 flights that last 28 days?
Fluid flow, even in the canneliculi, is also dependent on compressive loading. There is no evidence for a direct effect of gravity on any aspect of bone loss, indeed it ocurrs more rapidly in 1-G in spinal cord injury than in 0-G in otherwise healthy flight crew.
Bone loss does not accelerate with time, it reaches a limiting value (dependent on level of ongoing exercsie) and then stabilizes. A loss of less than 30% of bone density (depending on the starting density) usually does not significantly increase the risk of fracture even if permanent.
The OIG are not bone physiologists. They are looking at NASA plans for validating countermeasures, which seems to be a slow process. But from a physiological point of view the problem is not that complex.
That said, a lunar base with long term crew would answer some of these questions pretty quickly.
Not irreversible, bone mass lost does get recovered over time.
http://www.nasa.gov/mission…
As posted by others, a LOT of unknowns remain about the affects of REDUCED gravity on the human body. Solar radiation can be solved in several ways. Cosmic radiation is another matter that is being investigated by others. A 1/6g test site is only 250,000 miles away (on average), and we should establish a research base there first. In any event, artificial gravity will have to be worked enroute to Mars, and radiation attenuation must be provided. Advanced propulsion systems must be developed. Nuclear-thermal rockets are another possibiltiy, and the technology was in development in the 1950’s and ’60’s, until nuclear test ban treaty went into effect. The Moon would be a great place to develop modern hardware. But all this is useless speculation UNLESS Congress is willing to spend the money.
Use SLS and Orion money to solve these issues
Nice thought. But I don’t think that those space state politicians will ever let go of those programs. It would be like throwing their voters and lobbyists under the bus. My only hope is that newspace companies can figure out how to use nasa’s plans to further their own development. I’m thinking of the iss and how good it’s been for space x, orbitatk, made in space, bigelow, boeing, planetary resourses and maybe vasimr. That’s an impressive list of some very cool startups using a space station that many people have considered to be a total waste of time and money. 🙂
I don’t see why a Plan couldn’t be created where these companies that live on SLS and Orion pork couldn’t be doing more useful stuff.
It bothered me when Bolden said that if NASA abandons the Mars plan that NASA is doomed.
I took that to mean that if Orion SLS are canceled then NASA will get no funding and dry up.
I think that getting NASA off the cost Plus BFR thing could transform and save NACA, I mean NASA.
I agree on all counts. Bolden’s statement reminded me of Bigelow warning that if nasa didn’t get his hab to the moon quick, the Chicoms were going to claim it as another province. These guys have got their agendas and they get kinda over-excited.
Doomed, not necessarily because funding would dry up – but because funds being spent now would never be applied to an ultimate purpose, that is, if each successive administration keeps up the trend of cancelling the previous administration’s programs and changing NASA’s goals. It would just be money wasted as NASA resets to conform to the next political agenda.
“If we change our minds at any time in the next three or four years, which always is a risk when you go through a government transition, my belief is that we’re doomed.”
He’s basically begging the future politicians to not cancel anything and to let NASA stay on the course it’s on now.
Stay the course building a porky expendable Rocket???
We are DOOMED!!!!
Well, damned if you do, damned if you don’t.
I’d rather try to do something than scrap and re-work the previous 8 years of work every 8 years.
COTS!!!!!!
… at the expense of scrapping all work done under the previous administration, yeah.
Yup
The road to Mars starts on a barge! 🙂
Good one. Sounds like a slow trip.
There are plenty of people who would like to move in the direction of artificial G and there was a program to evaluate it using compact centrifuges back about ten years ago. But Griffin put an astronaut on the Constellation staff who edicted no artificial G and who cut all of the funding for the studies. They needed all their money for Ares 1 and Orion. So a ground-based study program side-tracked, several lost years of research, and no plan for a flight test program. This is how NASA got to where it is.
JAXA was building a module for ISS (Centrifuge Accommodations Module) that would have tested fractional G environments on small animals. NASA bought the project back, then abandoned it. The shell of the module was abandoned outside in Japan years ago – left to corrode away in that standard NASA fashion.
http://www.spaceref.com/iss…
https://en.wikipedia.org/wi…