What's missing to get humans to Mars? - Orbit 11.28


Simon, The 2 main issues you mention are Lack of gravity and radiation. These have been considered by spacex and have been deemed acceptable risks. First radiation exposure for the trip is estimated at 1% increase in health risks, so if you get a smoker and take him to mars and not give him cigarettes, you get a net reduction in health risks for that person :slight_smile: .

  1. The BFR is an interplanetary ship with “gravity” if you join 2 of them together (which they already can do) and spin them. However, they may not want to do that due to Operational Risks and accept the loss in bone density and muscle degeneration as acceptable risks which was shown to be quickly recoverable(on earth) once they land on mars with 38% gravity… Note we dont know what 38% gravity will do for the human body in terms of recovery. but They have deemed it as acceptable risks and expect good recovery. I would think spinning up 2 crewed Mated-BFR is a good option. Problem is the solar cells will only be half as efficient. Maybe they need to mount the solar cells on a central mating non spinning section… but its probably too complex to do in time. Or just use nuclear generators …

  2. the 1% increase in health risks due to transit radiation has been deemed acceptable. the radiation on the surface of mars can be mitigated someway by good dwellings materials. There has been research results learnt from the ISS as to what material helps. and i am sure it will be applied on mars … Excavating underground dwellings has been considered and will also probably be built over time.

  3. The plan has been that there will be a total of 6 BFR on Mars, that is landed mass of 150*6 = 900 metric tonnes (including humans). That seems to be enough supplies for 3 years and tools.

Dont be overwhelmed by “everything” and do nothing.

There are lots of other issues you have not mentioned… and they have been considered and mitigated or the risks have been accepted. My biggest concern is the perchlorates (Poisons) in the soil and dust. … Cant see how they can mitigate that effectively without the whole team dying within the 3 years mission or after they comeback to earth .


Perchlorates are water soluble. Wash them out of any soil you want to use for gardening. Spray yourself down when you come in from outside before you take off the suit.

They’ll have to obtain water from the local environment. Luckily Mars has a fair amount of water you can get various ways. Either from ice deposits or just warming up the soil or maybe even as simple as drilling a well.

And perchlorates are quite useful so extracting them would be one of the goals of in situ resource utilization. Heck lithium perchlorate can be used as a source of Oxygen.


I think that is a simplistic view/solution that is insufficient to mitigate the problem.
eg have a look at the perchlorate issue on earth and multiply that by 1000 times for Mars Perchlorate removal in contaminated ground water

Not to mention the dust getting into any air filters or equipment… You cant just rinse off electric equipment with water… unless its made/design for it…
see also : Toxic Mars dust could hamper planned human missions | New Scientist

Oxygen wont be an I ssue I think… Space X aims to manufacture it by the Tonne as fuel.


I’m not seeing an issue. That article clearly indicates water can easily wash it away. And Mars has an easy distilling method… low pressure boil things without needing to heat them.

I view most concerns about the dust as sensational exaggerations. Just people looking for excuses not to go. It does not appear to me to be a large concern.


Hmm… Yes you can wash most of it it off your space suit but its still in the water. You cant use the water for anything, are you saying we just chuck that water down the “drain”? water would be pretty precious on Mars an( and it don’t flow. Imagine a huge pile of ice out side the buildings LOL). You cant use the water to “Plant” veg since it will be in the plants and you cant eat it. You cant use it for humans or stuff that get in contact with humans. Once the water dries the poison is still there and gets distributed again and it wont even look like dust anymore it will be everywhere, if it is not contained.

I am not making an excuse to not go. I am saying its an issue that has not been addressed. Sure its not an issue if you have people exposed to it for 1-2 months and then come back to earth with the full force of our medical facilities but we are talking about people living there exposed to this poison for at least 3 years or permanently, at levels possibly 10000-1000000 times above what is available on earth.

No, I am saying there needs to be a concerted effort to remove this poison in the areas for humans. There needs to be a full fledged purification plant for water and processes to “wash” items, soil, robots, everything with “clean” water.

There also needs to be medical solution for testing and counteracting the poison in the body since it seems to me that there will be no way to be fully uncontaminated.

I am not saying dont go. I am saying more thought and mitigation needs to be put into this issue or the whole community will be dead or dying in a few dozen years… … Imagine we have about 10,000 people on mars in 20 years, when they all start dropping like flies. then what? Oh when that happens we will deal with it? after we lose 5000 people ?

I am sure there will be many more unknown issues to deal with when we arrive… why not deal with an issue we already know about before we get there…


What part of distilling is throwing it down the drain? It’d be pretty easy to purify the water.

Getting the water just got even easier with the discovery of liquid water lakes under the ice just announced today. Drill and pump.

The perchlorates will probably be one of Mar’s main resources to mine in the early days as it can be made into solid rocket fuel. I can envision soil processing machines that just roll along digging up the ground in front, washing the perchorates out, concentrating them, and dumping clean soil out the back.

But that’s long term. For short term missions and the initial colonists washing will have to be the basic risk mitigation. All food would be grown inside in ground prepared expressly for that purpose.

The stuff also isn’t all that dangerous… it’s not like getting some on you is the end of you… After the movie The Martian several scientists said the perchlorates in the soil if they hadn’t been washed out would mean the potatoes wouldn’t be very healthy for him to eat but also wouldn’t kill him during the length of time he was eating them… So I think the whole perchlorate concern is vastly over hyped.

But I will point out that I am not an expert. I for one would love to hear from an expert on this. I acknowledge that It could be way more of a concern than I think.


Just checked out the news about the liquid water on mars… Exciting indeed for the possibility of finding Life on Mars !

Re:perchlorates, You are right its not instant death … but it causes cancers in the lungs and thyroid and then the rest of the body…Not a good way for a community to die. once people start dropping it may be too late to stop the other 50%-90% from perishing. Better to get serious mitigation processes and research going now. Imagine the terrible backlash of public opinion if 50-90% of the bright eyed bushy-tailed “celebrities” that have bonded with the public via youtube channels and reality tv start dying painful cancerous deaths. Exploring mars may be put off indefinitely and that may be an even bigger tragedy.


Indeed it’s an issue that will or can have an answer … that may be a simple a solar stills to generate drinkable water … the soil and growing things is a bigger issue I’m sure someone will come up with an answer, but as we can’t get humans there yet and even Elon time is saying 2024 at the earliest there is still time for this problem to be solved.


I am not saying that there isn’t a set of processes that would mitigate the problem… I am just saying that there does not seem to be a proactive effort to solve this problem. It would seem that most are just going to “take it as it comes”, “we will cross the bridge when we get there” it just seems that the consensus is we will solve this as we normally do in a “reactive” manner. Even Robert Zubrin seems to have this attitude. What I am saying is that the risk of not solving this could derail the whole Mars efforts for decades… and I really don’t want to see that happen.

Professionally I am a solutions architect, and this is one of the Risk factors which is a “High Impact, High probability” issue. It needs to be red flagged and mitigated or the mission/project will not “meet its deadline” or have a successful outcome. Most of each facet of this problem can be solved currently on earth. But I have not seen solutions for almost every facet of this problem on Mars. I guess we do have 4-5 years to solve it. BUT how long will it take to have a Medical Pill Researched and certified for the Mars Project? From what I can see there is almost no research going on right now and almost certainly there wont be a Pill to bring to Mars to help with even one of the 2 main effects of perclorate poisoning. We need to have a task force to start looking into getting resources allocated to solve this NOW! 4-5 years is not that long, Drugs can take decades to be certified. But I am afraid we will probably have a huge tragedy on Mars in a few years before some research is done… and that is Sad… when the Mars mission should not be so. What would be written in the history books? “The Mars Tragedy” chapter?


I hope they do find a way to reduce the risks involved in time for 2024 but delaying longer to allow for development of said soloution. Lets face it we have waited this long whats a few more years. Waiting would also allow longer to build up supplies and possibly even a base or orbital platform pre landing. I guess it depends on do we visit first or go all out to colunize. I agree it could only hurt the effort for there to be a tragedy that more time could avoid. A return to the Moon should help us with some of the technology without having to wait so long for favourble transfer windows etc. I am sure BFR and SLS will make that possible. A lunar base/s seem to be a sensible testing ground. However should the chance happen that we can make a manned visit and return to Mars it should be taken … Even if no landing is made like the first moon shots sling and return would be a massive acheviment that would no doubt provide useful data and experiance. After all we didnt just land on the moon striaght off there was a scientfically controlled step by step even during the ‘Space Race’ With so many parties sending things to and developing for the moon now that it is in reach. I can’t see that not happening for Mars. Elon has said he is just making the transport and that others will need to work on what the transport is used for. We have had the ability to get to the Moon for decades and not used it. I hope that will not be the case with Mars. It is certainly a most intresting time in history.


I’m sorry, i was not clear enough. I’m not saying i know all obstacles. And i doubt anyone knows atm. I just want to give an obstacles-solutions in rows (well in some kind of priority).
So again we need a interplanetary ship. And again BFR isnt that kind of ship. Yes its very nice as a cargo. Yes its awesome for earth-moon system as a transport (cargo and people) but its not suitable for humans if you plan to go to Mars or somewhere else beyond the moon. Except if you have needed infrastructure and medical staff on Mars. Tobi_Foong you cant join 2 BFR together in order to get artificial “gravity”. They are not designed for this purpose.
And yes You all are right there are a lot of more known problems and much more still unknown.
But i think there are some priorities somehow. I do not want to say that all others problems must not be investigated but without artificial “gravity” we are going nowhere. And i’m not overwhelmed by “everything” I just suggest solving problems step by step. Imho interplanetary ship with artificial “gravity” for human transportation - the step number one. Its not so easy as may sound. None did it before except Hollywood :slight_smile:
p.s. Tobi_Foong about radiation issues what is acceptable or not its just a speculation. 1% increase…ok, maybe but what if your ship will be caught by solar storm? We simple do not have any required data. No one has been for so long outside from earth’s magnetosphere. ISS research cant provide needed data on radiation but it gives as very good hint what will happens with you body after 6+ month trip in 0 gravity.


We do have Many space craft that have spent many years outside of Earth’s magnetosphere recording the type and amount of radiation they receive.

We know how that radiation effects people, plants, and machines. We’ve known this for decades at least… approaching a century. The methods of shielding are also well known and tested. The only bit of risk/ reward trade off work to be done is deciding how much mass to devote to said shielding. The large amount of Up-mass the BFR offers allows for lots of shielding.

Effective methods for staving off most of the degradation from micro gravity have been tested and implemented on ISS. Prolonged stays no longer reduce muscle mass or bone density much. It is possible to make the trip to Mars without using rotating artificial gravity systems and without significant degradation of the crew.

However one would prefer to have artificial gravity if one can. Once a space economy is up and running… and thousands of people are seeking transportation to Mars or else where… Maybe sooner … at the hundreds level… then I can see rotating artificial gravity systems becoming common.

Before that though rotating systems add a layer of complexity… cost… and points of failure that may be deemed too risky for the first several missions.

The first direct flights probably won’t have it… but if we build a true “space” ship… a craft that moves through space and never lands anywhere. A transport that moves from Earth orbit to Mars orbit and back again over and over, picking up or dropping off cargo and people at each end, that would benefit greatly from rotation.


Connecting 2 BFR end to end Is not a problem… but like you said its not currently designed to be “flown” that way. However, we have not built one yet. why not add this functionality into the “crew” version of the BFR?

While we are at it why not add an external “lift” Module that connects out of the storage area and slides down to the other attached BFS (or the luna/mars surface) [instead of a crane] to allows crew or cargo transfers between them or to the surface. the “rails” can be designed with cover for aerodynamics or protection if needed. these Rails could/would help with structural integrity… for spinning / stretching stresses. I think it can be done with very little extra work, since there also need to be landing “feet” included anyway.(Maybe the feet can be used to link the 2 spaceships together.) (I have always worried about landing on the surface of mars / moon with this long rocket on the rough and unstable surface of mars/moon without a landing pad. ) I am sure they are working on a solution :slight_smile:

The “lift” module could be an electric “car” similar to the ones he is planing for the "boring company"and the hyperloop…

Of course once this capability is included the crew cabins/windows will need to be redesigned as well as they would all be “upside down” when spinning. I am sure the fuel storage tanks design will also need to be revisited. as they are now “Upside down” too.


Have been thinking about a solution for the in transit radiation.

For the crewed BFR ships we could give the BFR a “Coat” to wear. Use material similar to the Bigelow inflatable units (like the BA330). The “coat” (condom? :slight_smile: ) can be brought up by one of the fueling BFR in the faring and then “worn” by the traveling BFR .

This coat will give

  1. Protection from radiation,
  2. Protection from Micrometeorites
  3. Protection from Thermal stresses

It could also have a solar energy generating surface and may also help with structural integrity somewhat.
It could also provide navigational thrusters on the surface. or even ion thrusters to help get the BFR to Mars faster !

Once the ship arrives at Mars, it can either discard the coat before landing or park it in orbit to be used as an orbital station !! Since we have 2 of them we may even be able to link them up and spin them up and provide a fairly large orbital station with gravity. ( :slight_smile: our very own Oumuamua !!) , Probably the best idea would be to leave it in orbit to be put back on for the trip back to Earth.

One more advantage would be the actual BFR wont need as much shielding for LEO use. and may be lighter and/or carry more cargo.


We also need to also think about protective suits worn by individuals as a last step protection. There are parts of the body that are more susceptible to radiation such as the intestines (because the cells are replaced frequently). Something like this: Demron® Full Body Suit – Radiation Shield Technologies


well, see that’s what I don’t get. I spent some time in a machine shop and operated CNC machines, lathes and mills. we designed to specs, set the stops and offsets, then hit start. we didn’t manually do anything once we set it going. why can’t operations, even with a lag, be like that?


I’m glad you brought that up. in fact, insitu resource utilization is the only thing I think of when performing a gap analysis on what is missing from getting humans to Mars. Once that’s licked, that’s all she wrote.


Yeah I think it’s the one thing that once a critical mass of tools and manufacturing and mining equipment is there such that you can make more of those things from the resources there then a population becomes self sustaining.


Weren’t the guys with the massive 3d printer talking about operating on the moon and mars using local materials … think they said long term goal but if they are thinking/working on it i am sure others are.


I was so wrong, so deluded myself… I thought some technology will bring as close to the Mars but its not the case. We need to rethink and keep common sense. Very refreshing way to do so:
“Space Chronicles - Facing the Ultimate Frontier” Neil Degrasse Tyson

Its a great book which gives as deeper insight about what’s missing to get humans to Mars.