Question for the experts: what are the tests and analysis that we cannot do via a rover-based lab and hence need to send the samples to Earth? Asking out of curiosity (pun not intended!).
Simple answer from a space nerd: Rovers are small, light, and have very little energy. So what we can't do is anything that requires a large or heavy device or anything that requires significant energy. They break/fail. They take forever to make happen.
Want to burn 20kg of soil to see if there's any trace of specific elements? You'll need a furnace. Those are both heavy and high-energy. You could do a smaller scale test on a rover of 2g perhaps, but what if the traces are very, very small? Plus, whatever analysis tools you would use now have to also be extremely small and light, which means less capabilities.
Also, rovers have limited size: we can only do a small number of tests per rover because the rover's utility belt of tools is only so large. If your experiment is really easy to do but it's not a high enough priority, it won't happen.
Lastly, rovers die. You might spend 5 years building a tool, 2 years sending it on the next rover to Mars, only to have it crash or die before it's time to run your experiment.
But if we sent 300kg of soil back from Mars, we could do every test we can think of, carefully, with the best tools humanity can make and as much energy as we need.
Edit: +1 to what Something1234 said too! You can't clean out apparatuses easily after an experiment!
These are all reasons why sending humans is so important. They will explore more of Mars in a week than rivers have in 50 years. They will arrive with a testing lab and do all sorts of tests immediately.
If Starship meets its performance targets, it’s first missions will bring hundreds of scientists to a Mars, with thousands of tons of equipment and supplies. In-orbit and in-situ refueling are game changing technologies that will literally reduce the cost of deep space manned missions by a thousandfold.
So instead of sending a rover with 4x or 10x energy, the answer is a mission that requires enough energy to launch the samples all the way back to Earth? This makes me smile.
I do agree though. We can expend 1000x the energy of the return trip once the samples are back on earth. And we also have the luxury of unlimited time to invent new tests and new tech to apply to whatever is left of the samples.
Not an expert, but the test chambers on a rover can't be cleaned easily or without a massive amount of complexity. They are also fairly limited and very limited use. While a sample collected and sent back can be split and used in many ways.
Better question: What will we learn that we cannot learn from all the Martian rocks we already have on earth.
There have been plenty or Martian meteors found in Antarctica, and no doubt many more if we redoubled our efforts to find them. Many once claimed to have found evidence of life in these rocks already. Some of us are even old enough to remember President Clinton's speech on the subject. (That isn't a deepfake video. The US president really did talk about the discovery of life on mars.)
> Better question: What will we learn that we cannot learn from all the Martian rocks we already have on earth.
These particular samples will be from the present-day surface, with known geographic (aerographic?) origin, not affected by potentially millions of years of interplanetary travel, and not contaminated by sitting around on Earth for who knows how long.
There is a big, big difference between, "we found a rock on earth that is probably from Mars that was blasted here some time in the past," and, "we went to a specific area of Mars and got a rock and brought it back." Not least of which is the intrinsic value and aspirational nature of us actually fetching things from other planets ourselves, with intent and purpose, rather than luckily stumbling upon some.
Excellent question. Obviously there are lots of things they couldn't afford to get into a lander. Question is what could they have put into a lander, for much less than $billions, that they still haven't?
I am no expert, but I can imagine there are many kinds of laboratory equipment that is way too heavy to pit on a rover, perhaps mass spectrometers, etc.
Biological wxperiments is a big one. There is kind of outstanding question of perclorates in martian soil and its toxicity to earth organisms, plants, etc.
The mars rover does have a spectrometer. It's called ChemCam [1], it uses a laser to vaporize a small amount of matter and them captures the spectrographs of the resulting plasma with a camera. That doesn't take away from your point, but it is a cool piece of equipment.
Can't we just shoot a orbital space laser at mars then from mars orbit? If we're already sending a very heavy craft that way... should be able to do spectral analysis from space.
mabbo|5 years ago
Want to burn 20kg of soil to see if there's any trace of specific elements? You'll need a furnace. Those are both heavy and high-energy. You could do a smaller scale test on a rover of 2g perhaps, but what if the traces are very, very small? Plus, whatever analysis tools you would use now have to also be extremely small and light, which means less capabilities.
Also, rovers have limited size: we can only do a small number of tests per rover because the rover's utility belt of tools is only so large. If your experiment is really easy to do but it's not a high enough priority, it won't happen.
Lastly, rovers die. You might spend 5 years building a tool, 2 years sending it on the next rover to Mars, only to have it crash or die before it's time to run your experiment.
But if we sent 300kg of soil back from Mars, we could do every test we can think of, carefully, with the best tools humanity can make and as much energy as we need.
Edit: +1 to what Something1234 said too! You can't clean out apparatuses easily after an experiment!
valuearb|5 years ago
If Starship meets its performance targets, it’s first missions will bring hundreds of scientists to a Mars, with thousands of tons of equipment and supplies. In-orbit and in-situ refueling are game changing technologies that will literally reduce the cost of deep space manned missions by a thousandfold.
freeopinion|5 years ago
So instead of sending a rover with 4x or 10x energy, the answer is a mission that requires enough energy to launch the samples all the way back to Earth? This makes me smile.
I do agree though. We can expend 1000x the energy of the return trip once the samples are back on earth. And we also have the luxury of unlimited time to invent new tests and new tech to apply to whatever is left of the samples.
jessriedel|5 years ago
Something1234|5 years ago
sandworm101|5 years ago
There have been plenty or Martian meteors found in Antarctica, and no doubt many more if we redoubled our efforts to find them. Many once claimed to have found evidence of life in these rocks already. Some of us are even old enough to remember President Clinton's speech on the subject. (That isn't a deepfake video. The US president really did talk about the discovery of life on mars.)
ceejayoz|5 years ago
These particular samples will be from the present-day surface, with known geographic (aerographic?) origin, not affected by potentially millions of years of interplanetary travel, and not contaminated by sitting around on Earth for who knows how long.
dylan604|5 years ago
hoorayimhelping|5 years ago
valuearb|5 years ago
ncmncm|5 years ago
Like, a microscope?
ClumsyPilot|5 years ago
Biological wxperiments is a big one. There is kind of outstanding question of perclorates in martian soil and its toxicity to earth organisms, plants, etc.
ta8594505930|5 years ago
[1] https://mars.nasa.gov/msl/spacecraft/instruments/chemcam/
Apofis|5 years ago
hoorayimhelping|5 years ago
valuearb|5 years ago
emilfihlman|5 years ago