They could send dead humans there for sure - could have done that with the Apollo era technology (the Apollo technology could have sent the lunar lander on a flight path to impact Mars, had enough delta v). But living humans - not so certain myself. And in any case - you don't want to send humans to the Mars surface quite yet. Whether we ever do it might be another matter.
But right now we are doing a search for past and present day life on Mars. And that's a delicate search involving instruments that are hoping to detect sensitive biosignatures.
It has to be very sensitive because
But we could send humans to Mars orbit to search for life. So - I'm all in favour of that if we can do it in a way that makes absolutely sure that the humans can't crash land on the surface of Mars.
The problem there though is - that we have no experience at all, since Apollo, of sending humans away from Earth for long periods of time without supply from Earth. In the ISS - then they have supplies sent to the station several times a year - and they dump wastes back into the Earth atmosphere several times a year. And in case of an emergency we can send oxygen from Earth to help them out (did happen a few times in the early days especially) - and can evacuate them back to Earth in worst case scenarios - they have a permanent "lifeboat" Soyuz kept attached to the ISS for just that eventuality.
And nobody has yet spent as much as two years in space - ever. Not even as long as the Inspiration Mars trip of 500 days.
In case of Mars then is impossible to resupply them every few months with current spaceships. And is no chance at all of a "lifeboat" that could get them back to Earth in less than six months - and depending on the position of the planets in their orbits - it could be a lot longer than that.
Also have communication delays of up to 40 minutes in worst case scenario. If there are problems on the ISS they can chat to Earth and it's easy to find out what the issue is. If there are problems at Mars orbit then they are very much on their own - especially if there is any kind of a crisis, Apollo 13 style - then it might well all be over before they can communicate what the problem is to Earth sufficiently well so that we understand.
And - those who are keen on going to Mars - they talk about using plants for oxygen and food - but nobody has yet demonstrated that working in space. Nearest is the Biosphere II project which came close - perhaps - but failed - and the experiments in Russia with supplying oxygen using algae - which were promising - supplied all the oxygen needed - but were never flown.
And if you send all your supplies for the entire trip - then there's the issue of making sure the food can't go off - limiting choice there - or some disaster that destroys all your supplies of oxygen or contaminates all the water - or whatever it is that's essential to the trip.
And if you send all your supplies - the amounts are surprisingly huge - tons per person - and also the amount of wastes from the human body that accumulate over a multi-year mission are also surprisingly huge, see
Is it practical to send humans to distance of Mars orbit (say) using technology of the ISS by Robert Walker on Mars and Space
And - there is also the issue of zero gravity for the trip there - and when you get to Mars orbit - needing to generate artificial gravity - and I think myself that we need artificial gravity for the flight out as well - otherwise especially in a small spacecraft rather smaller than the ISS - is going to be hard for them to do enough exercise - and even with exercise every day - it's not possible to stay healthy in zero g - your health slowly decreases.
+ the increased risk of cancer - ideally you want to have some way of protecting from cosmic radiation - so more mass for the spacecraft.
So - technically I think we could send the mass to Mars by then quite probably. But not living functioning humans.
With Apollo - they did 10 precursor missions before they went to the Moon - and that's just for the Apollo technology - they had a similar number of precursors for Gemini for the technology to go to LEO and stay healthy in LEO.
Those precursors included round trips of the Moon - and also - even Apollo 10 which did everything except land on the Moon - the lunar module went down nearly to the surface but returned to orbit - and it turned up an issue that could have killed everyone if they had proceeded to the surface - fixed for Apollo 11.
For something as big as a trip to Mars then I think they need many precursors also. But this time - the precursors would need to be long duration flights done close to Earth. I think an ideal location is the L2 position at far side of the Moon myself. Been several proposed missions to go there - and the advantage is that you can do telepresence exploration of the far side of the Moon - that's why it's been suggested.
That's ideal since the very thing they would be doing in Mars orbit is telepresence exploration. And being at the far side of the Moon - it would also have the isolation of not being able to see Earth - only the Moon - and the Moon itself also unfamiliar looking, as it's the mountainous far side.
This is what they would see.
If you can spend several years with that as the sight you see out of the window with no view at all of Earth - and can enjoy spending several years exploring those craters by telepresence from the L2 position - then I think that shows you can handle a mission to Mars.
If you want to be super realistic - you could simulate a varying, up to 40 minute time delay in communications with Earth to make you even more isolated just as you would be on Mars.
But if you get an emergency - can return to Earth within a day or two or get emergency supplies sent up from Earth or LEO quickly also.
Interesting mission exploring the lunar poles for ice, and building telescopes on the far side of the Moon - and searching for Earth meteorites on Mars and exploring its geology.
So - there could be other ways of doing it of course, but seems to me an excellent approach - so you'd do several Mars duration flights to the L2 position - so would have a permanent outpost there - but unlike LEO instead of sending new people there every few months - you send them there every few years.
And the spacecraft designed to be self sustaining not needing resupply from Earth any more often than every few years.
So - though it would be a long duration mission - it would be inexpensive - cost probably not much more than 1 year of supply missions to the ISS - and with lots of good science return finding out about the far side of the Moon and its poles, and building those radio telescopes which would give our first glimpse of the galaxy in many wavelengths not available on Earth because of terrestrial interference (the Moon is gigantic block on the radio waves from Earth).
If that seems a major challenge - as it might well do - well then the Mars missions are far more challenging and shouldn't be attempted until we can do this.
And before that we need flights to LEO just testing the closed system habitats in space - and also testing artificial gravity in space.
So - all of that I think would add an extra decade, so call it more like 20 years.
Of course if it all went quickly - the LEO closed habitat and artificial gravity experiments all pass with flying colours - and immediately send a mission to L2 and that goes fine with no problems at all for say 5 years - then you might think of doing it more quickly, say in 15 years.
As for 10 years - maybe possible but seems a bit fast to me. And that would be for a first orbital mission to Mars operating rovers on the surface by telepresence.
As for adequately exploring Mars to the point where we think about sending humans there - depends on how quickly it goes.
But - could be another 50 years easily. And if we decided we wanted to attempt to terraform Mars - then you might decide you don't want to send humans there at all for the first few centuries while you establish cyanobacteria and other simple microbes to generate a more Earth like habitat - if you do the step by step "ecopoesis" type transformation of Mars.
Or if we find interestingly different Mars life - which I think is reasonably likely - maybe 50%, maybe 25% chance, hard to say - then you might well decide never to send humans there.
Instead we might remove or sterilize all rovers and crash sites on Mars - and "Mars Form" it to make it optimal for the Martian life - or at the very least spend quite a few decades studying it while we learn more and decide what to do.
Are plenty of other places in the solar system for humans to visit. And if you want to set up space settlements for whatever reason - can do that in free space using materials from the asteroids - after all Mars atmosphere is a "laboratory vacuum" anyway and the place is not at all Earth like apart from its close to 24 hour day.
Why land them on the one planet in the solar system which they are most likely to contaminate with Earth life? It's not as if it is even remotely as hospitable as the worst areas for colonization on the Earth.
But fascinating to explore especially if interested in present day or past life, so that I think is more likely to succeed as a motivation for humans to Mars. A human mission in orbit around Mars could do as much work in a few days operating rovers on the surface in real time using telepresence as Curiosity or Opportunity can do in decades. Even using 1970s technology - the Russian Lunaknod traveled as far in a few months as Opportunity has traveled so far in its entire mission to Mars.
See also
Trouble With Terraforming Mars
But right now we are doing a search for past and present day life on Mars. And that's a delicate search involving instruments that are hoping to detect sensitive biosignatures.
It has to be very sensitive because
- Past life on Mars will be seriously degraded by cosmic radiation and the radiation in the rocks. On the surface, a thousand tons of amino acids degrades to a milligram, rest turning mainly to CO2 and water - over the history of Mars. If quickly buried at least ten meters beneath the surface and then quickly unearthed again - it could last far longer - but still degrades and needs careful detective work to separate out the signature of life from the amino acids you find in comets and meteorites (which also have a chiral signature).
- Present day life is expected to be sparse - the most habitable places on Mars correspond to the least habitable on Earth such as the Atacama desert - so for instance - even if you landed Curiosity in the most likely places on Mars to find life - the chances are that it wouldn't spot it - if it is there. ExoMars could spot it but is being sent to the wrong part of Mars for present day life to be likely.
- In case of both past and present day life - some possible habitats may be uninhabited. For present day life - that's because it may take a while for life to colonize a new habitat - and for past life - because we don't know where life started on Mars - or how robust it was and how quickly it spread throughout the planet + the organics have to be deposited quickly to get a thick enough deposit to be preserved, quickly buried, and then preserved (e.g. not washed out again by later flooding). It is likely to be as tricky as finding well preserved fossils of ancient life on Earth - and you have as much terrain to search as the entire surface of the Earth.
- The instruments planned for future missions, including ones on ExoMars - they can detect a single amino acid in a sample. So easily disturbed by contamination.
And - if anyone tells you it is easy to distinguish Mars from Earth life - that is simply not true. How can you distinguish a Mars amino acid from one introduced by Earth life?
And indeed also even if you could DNA sequence ancient or present day Mars life - likely to be a while before we can do that - and only if it is DNA based of course - only a tiny fraction of Earth life has been DNA sequenced - and Earth may also even have non DNA based life not yet detected - we know that little about microbes on Earth - the issues of Microbial Dark Matter and the possibility of a Shadow biosphere
And as well - if it did turn out to be based on DNA and with common ancestor and same biochemistry etc - well the archaea on Earth readily swap gene sequences all the time between totally unrelated species (and even happens between fungi and aphids) via Gene transfer agent - so if Mars does have present day archaea - any Earth archaea introduced to Mars would start swapping DNA with it also muddying the picture.
But we could send humans to Mars orbit to search for life. So - I'm all in favour of that if we can do it in a way that makes absolutely sure that the humans can't crash land on the surface of Mars.
The problem there though is - that we have no experience at all, since Apollo, of sending humans away from Earth for long periods of time without supply from Earth. In the ISS - then they have supplies sent to the station several times a year - and they dump wastes back into the Earth atmosphere several times a year. And in case of an emergency we can send oxygen from Earth to help them out (did happen a few times in the early days especially) - and can evacuate them back to Earth in worst case scenarios - they have a permanent "lifeboat" Soyuz kept attached to the ISS for just that eventuality.
And nobody has yet spent as much as two years in space - ever. Not even as long as the Inspiration Mars trip of 500 days.
In case of Mars then is impossible to resupply them every few months with current spaceships. And is no chance at all of a "lifeboat" that could get them back to Earth in less than six months - and depending on the position of the planets in their orbits - it could be a lot longer than that.
Also have communication delays of up to 40 minutes in worst case scenario. If there are problems on the ISS they can chat to Earth and it's easy to find out what the issue is. If there are problems at Mars orbit then they are very much on their own - especially if there is any kind of a crisis, Apollo 13 style - then it might well all be over before they can communicate what the problem is to Earth sufficiently well so that we understand.
And - those who are keen on going to Mars - they talk about using plants for oxygen and food - but nobody has yet demonstrated that working in space. Nearest is the Biosphere II project which came close - perhaps - but failed - and the experiments in Russia with supplying oxygen using algae - which were promising - supplied all the oxygen needed - but were never flown.
And if you send all your supplies for the entire trip - then there's the issue of making sure the food can't go off - limiting choice there - or some disaster that destroys all your supplies of oxygen or contaminates all the water - or whatever it is that's essential to the trip.
And if you send all your supplies - the amounts are surprisingly huge - tons per person - and also the amount of wastes from the human body that accumulate over a multi-year mission are also surprisingly huge, see
Is it practical to send humans to distance of Mars orbit (say) using technology of the ISS by Robert Walker on Mars and Space
And - there is also the issue of zero gravity for the trip there - and when you get to Mars orbit - needing to generate artificial gravity - and I think myself that we need artificial gravity for the flight out as well - otherwise especially in a small spacecraft rather smaller than the ISS - is going to be hard for them to do enough exercise - and even with exercise every day - it's not possible to stay healthy in zero g - your health slowly decreases.
+ the increased risk of cancer - ideally you want to have some way of protecting from cosmic radiation - so more mass for the spacecraft.
So - technically I think we could send the mass to Mars by then quite probably. But not living functioning humans.
With Apollo - they did 10 precursor missions before they went to the Moon - and that's just for the Apollo technology - they had a similar number of precursors for Gemini for the technology to go to LEO and stay healthy in LEO.
Those precursors included round trips of the Moon - and also - even Apollo 10 which did everything except land on the Moon - the lunar module went down nearly to the surface but returned to orbit - and it turned up an issue that could have killed everyone if they had proceeded to the surface - fixed for Apollo 11.
For something as big as a trip to Mars then I think they need many precursors also. But this time - the precursors would need to be long duration flights done close to Earth. I think an ideal location is the L2 position at far side of the Moon myself. Been several proposed missions to go there - and the advantage is that you can do telepresence exploration of the far side of the Moon - that's why it's been suggested.
That's ideal since the very thing they would be doing in Mars orbit is telepresence exploration. And being at the far side of the Moon - it would also have the isolation of not being able to see Earth - only the Moon - and the Moon itself also unfamiliar looking, as it's the mountainous far side.
This is what they would see.
If you can spend several years with that as the sight you see out of the window with no view at all of Earth - and can enjoy spending several years exploring those craters by telepresence from the L2 position - then I think that shows you can handle a mission to Mars.
If you want to be super realistic - you could simulate a varying, up to 40 minute time delay in communications with Earth to make you even more isolated just as you would be on Mars.
But if you get an emergency - can return to Earth within a day or two or get emergency supplies sent up from Earth or LEO quickly also.
Interesting mission exploring the lunar poles for ice, and building telescopes on the far side of the Moon - and searching for Earth meteorites on Mars and exploring its geology.
So - there could be other ways of doing it of course, but seems to me an excellent approach - so you'd do several Mars duration flights to the L2 position - so would have a permanent outpost there - but unlike LEO instead of sending new people there every few months - you send them there every few years.
And the spacecraft designed to be self sustaining not needing resupply from Earth any more often than every few years.
So - though it would be a long duration mission - it would be inexpensive - cost probably not much more than 1 year of supply missions to the ISS - and with lots of good science return finding out about the far side of the Moon and its poles, and building those radio telescopes which would give our first glimpse of the galaxy in many wavelengths not available on Earth because of terrestrial interference (the Moon is gigantic block on the radio waves from Earth).
If that seems a major challenge - as it might well do - well then the Mars missions are far more challenging and shouldn't be attempted until we can do this.
And before that we need flights to LEO just testing the closed system habitats in space - and also testing artificial gravity in space.
So - all of that I think would add an extra decade, so call it more like 20 years.
Of course if it all went quickly - the LEO closed habitat and artificial gravity experiments all pass with flying colours - and immediately send a mission to L2 and that goes fine with no problems at all for say 5 years - then you might think of doing it more quickly, say in 15 years.
As for 10 years - maybe possible but seems a bit fast to me. And that would be for a first orbital mission to Mars operating rovers on the surface by telepresence.
As for adequately exploring Mars to the point where we think about sending humans there - depends on how quickly it goes.
But - could be another 50 years easily. And if we decided we wanted to attempt to terraform Mars - then you might decide you don't want to send humans there at all for the first few centuries while you establish cyanobacteria and other simple microbes to generate a more Earth like habitat - if you do the step by step "ecopoesis" type transformation of Mars.
Or if we find interestingly different Mars life - which I think is reasonably likely - maybe 50%, maybe 25% chance, hard to say - then you might well decide never to send humans there.
Instead we might remove or sterilize all rovers and crash sites on Mars - and "Mars Form" it to make it optimal for the Martian life - or at the very least spend quite a few decades studying it while we learn more and decide what to do.
Are plenty of other places in the solar system for humans to visit. And if you want to set up space settlements for whatever reason - can do that in free space using materials from the asteroids - after all Mars atmosphere is a "laboratory vacuum" anyway and the place is not at all Earth like apart from its close to 24 hour day.
Why land them on the one planet in the solar system which they are most likely to contaminate with Earth life? It's not as if it is even remotely as hospitable as the worst areas for colonization on the Earth.
But fascinating to explore especially if interested in present day or past life, so that I think is more likely to succeed as a motivation for humans to Mars. A human mission in orbit around Mars could do as much work in a few days operating rovers on the surface in real time using telepresence as Curiosity or Opportunity can do in decades. Even using 1970s technology - the Russian Lunaknod traveled as far in a few months as Opportunity has traveled so far in its entire mission to Mars.
See also
Trouble With Terraforming Mars
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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