I think we should do both. It is not an "either / or". It's not practical for humans to explore the ocean depths. But that's also true for many locations in space. Indeed a lot in common between the two.
Space locations are also very inhospitable to humans - high radiation levels or high temperatures - or at very least, almost everywhere is vacuum.
Though it's possible to explore with spacesuits, for long EVAs it's likely to remain very dangerous in near future. Only suitable for careful and disciplined people - and ones who can go through check lists, and obey complex orders and protocols without a mistake. In the near future at least. Far more complex and dangerous than a diver diving with an aqualung.
If your air hose gets disconnected, or you fall and break your faceplate, or some such, you die. Nobody has ever spent more than a few hours in a spacesuit. And the astronauts for Apollo made sure they never traveled further from the base than the distance they could walk back with their remaining oxygen, if their rover broke down.
If you get far from your base, you'll have to keep an eye on oxygen and make sure at all times that you've enough to get back - not unlike deep sea diving. And you are always endangered by micrometeorites - and have accumulated cosmic radiation which can't be shielded for by a spacesuit - and if there is a solar storm have to get straight back to base rapidly.
Oceanographers do actually live long term below the ocean in FLIP
And in future soon will be exploring in Sea Orbiter
SeaOrbiter - the Ocean's Sentinel
SeaOrbiter - World's First Vertical Vessel to Be Completed by 2013
It would also be possible to live on the shallow continental shelf sea bed. Far more habitable than any suggestion for a space colony anywhere outside Earth, and far easier to make sustainable.
Will we ever... live in underwater cities?
This is really not unlike space, where we have humans in LEO and robots further afield. Eventually we'll have humans I think in orbit around the Moon or on the surface and in orbit around Mars - but because space is so inhospitable - far more so than the shallow sea - and also because we want to keep Earth life away from places where present day life exists if we are lucky enough to find it - I think we'll be able to explore in a similar way.
As with space, the sea has "hot spots" of hydrothermal vents. And we are continuing to discover new vents every year.
MBARI researchers discover deepest known hydrothermal vents in Pacific Ocean
Delicate carbonate spires found in one of the newly discovered vents.
There is also the possibility of liquid (supercritical) CO2 in the ocean depths, something we know almost nothing about, as an example of how little we know about the deep ocean. We know of reserves at relatively shallow depths, but there are probably much more extensive reserves deep down which we don't know yet. I'll add this in a comment, more details.
The NASA Telerobotics Symposium brought out this close parallel between telerobotic exploration of the sea and the likely future telerobotic explorations in space. The image shown shows how humans in Mars orbit could use telerobotics to explore its surface.
The two technologies have a lot in common for that reason.
As for budget, there is no reason at all why we can't do both.
For instance, NASA's yearly budget is $18.4 billion. With a US population of 318.9 million, that's $58 per person spent on NASA per year.
The ESA budget is $5.15 billion, and European Union population about 503 million. So that's a little over $10 spent per person per year.
ROSCOSMOS budget similar, $5.6 billion, for a smaller 143 million people, so $39 per person.
These are not huge amounts. By comparison the US defense budget is $581 billion, so $1,827 per person every year.
If we can spend $10-$50 per person per year on space, we can afford to spend similar amounts on exploring the oceans. As well as humanitarian projects as well.
I think we should rather use the amount spent on space as motivation for suggesting to politicians that is worth spending more on other science mega projects, as well as humanitarian projects - rather than to try to pit them against each other like this. It's not so much a lack of money available, as a matter of whether or not people think it is worth spending this amount of money - the money is there if people feel it is worth it.
INHOSPITABILITY OF SPACE AND DEEP SEA
Space locations are also very inhospitable to humans - high radiation levels or high temperatures - or at very least, almost everywhere is vacuum.
Though it's possible to explore with spacesuits, for long EVAs it's likely to remain very dangerous in near future. Only suitable for careful and disciplined people - and ones who can go through check lists, and obey complex orders and protocols without a mistake. In the near future at least. Far more complex and dangerous than a diver diving with an aqualung.
If your air hose gets disconnected, or you fall and break your faceplate, or some such, you die. Nobody has ever spent more than a few hours in a spacesuit. And the astronauts for Apollo made sure they never traveled further from the base than the distance they could walk back with their remaining oxygen, if their rover broke down.
If you get far from your base, you'll have to keep an eye on oxygen and make sure at all times that you've enough to get back - not unlike deep sea diving. And you are always endangered by micrometeorites - and have accumulated cosmic radiation which can't be shielded for by a spacesuit - and if there is a solar storm have to get straight back to base rapidly.
Oceanographers do actually live long term below the ocean in FLIP
And in future soon will be exploring in Sea Orbiter
SeaOrbiter - the Ocean's Sentinel
It would also be possible to live on the shallow continental shelf sea bed. Far more habitable than any suggestion for a space colony anywhere outside Earth, and far easier to make sustainable.
Will we ever... live in underwater cities?
This is really not unlike space, where we have humans in LEO and robots further afield. Eventually we'll have humans I think in orbit around the Moon or on the surface and in orbit around Mars - but because space is so inhospitable - far more so than the shallow sea - and also because we want to keep Earth life away from places where present day life exists if we are lucky enough to find it - I think we'll be able to explore in a similar way.
As with space, the sea has "hot spots" of hydrothermal vents. And we are continuing to discover new vents every year.
MBARI researchers discover deepest known hydrothermal vents in Pacific Ocean
There is also the possibility of liquid (supercritical) CO2 in the ocean depths, something we know almost nothing about, as an example of how little we know about the deep ocean. We know of reserves at relatively shallow depths, but there are probably much more extensive reserves deep down which we don't know yet. I'll add this in a comment, more details.
ROBOTS FOR DEEP SEA WORK AND IN SPACE
Yes, we send robots for deep sea work. Same also likely to happen increasingly in space. Curiosity etc are really long distance operated telerobots. But they could be so much more capable with various advances in the technology. Also likely to use telerobots for repairing satellites and for exploring the Moon, from Earth - or from humans in orbit or in bases on the Moon.The two technologies have a lot in common for that reason.
BUDGET CONSIDERATIONS
As for budget, there is no reason at all why we can't do both.
For instance, NASA's yearly budget is $18.4 billion. With a US population of 318.9 million, that's $58 per person spent on NASA per year.
The ESA budget is $5.15 billion, and European Union population about 503 million. So that's a little over $10 spent per person per year.
ROSCOSMOS budget similar, $5.6 billion, for a smaller 143 million people, so $39 per person.
These are not huge amounts. By comparison the US defense budget is $581 billion, so $1,827 per person every year.
If we can spend $10-$50 per person per year on space, we can afford to spend similar amounts on exploring the oceans. As well as humanitarian projects as well.
I think we should rather use the amount spent on space as motivation for suggesting to politicians that is worth spending more on other science mega projects, as well as humanitarian projects - rather than to try to pit them against each other like this. It's not so much a lack of money available, as a matter of whether or not people think it is worth spending this amount of money - the money is there if people feel it is worth it.
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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