Sell the SLS/Artemis/Orion program to me

[Trafalgar]

I am normally a strong supporter of both manned and unmanned space exploration but whenever I read about Artemis, I wince because I don't see a great scientific justification for the program. Is anyone on GitP forums willing to defend the stated purpose of the program?

I would like to stay away from all the cost overrun issues and delays. Does NASA's goal of returning humans to the moon have scientific value?

[The Glyphstone]

A moon colony is the best way we'll have to do experiments in preparation for an eventual Mars colony. Mars has more gravity than Luna, but still a lot less than Earth - 0.3 G roughly, twice that of the moon's 0.16G. We know next to nothing about the long term effects of reduced/microgravity, astronauts spend limited time in zero-G specifically to avoid health issues.

[halfeye]

I normally a strong supporter of both manned and unmanned space exploration but whenever I read about Artemis, I wince because I don't see a great scientific justification for the program. Is anyone on GitP forums willing to defend the stated purpose of the program?

I would like to stay away from all the cost overrun issues and delays. Does NASA's goal of returning humans to the moon have scientific value?

We need to colonise space, there's no scientific value to that, it's just something we ought to do. The moon is a good place for a base, it's got so little gravity it's almost still in space.

Once we're established in space, there's no real need to go back to any planets at all, even Venus isn't that tempting, it's so hard to get off again even if we get the temperature down, and Mars is just nasty.

[Trafalgar]

A moon colony is the best way we'll have to do experiments in preparation for an eventual Mars colony. Mars has more gravity than Luna, but still a lot less than Earth - 0.3 G roughly, twice that of the moon's 0.16G. We know next to nothing about the long term effects of reduced/microgravity, astronauts spend limited time in zero-G specifically to avoid health issues.

I don't think there are any plans to establish a base on the moon. There is a plan to establish a "Lunar Gateway" space station in orbit around the moon but no real plans for a moon colony.

[Telok]

I don't think there are any plans to establish a base on the moon. There is a plan to establish a "Lunar Gateway" space station in orbit around the moon but no real plans for a moon colony.

Digging into the ground would be nice against debris and radiation for long term habitation & extended use. You can use water ice for the same thing in orbit, and as a supply/reaction mass thing, but lifting it out of Earth's gravity well is something you'd like to move away from. The amount of ice present in/on the Moon is a significant unknown variable though, as is any lunar resource extraction option.

[Gnoman]

There's a number of operations where having even a little gravity is vastly better than having none, which would make a surface base on the moon useful. Especially if you can take advantage of how low the gravity is to employ very low energy launch systems to return stuff to orbit.


As for the utility of a forward base, Earth's gravity well and thick atmosphere are a horrendous energy drain on everything we launch, because every last bit of everything we send into space has to get dragged out of that gravity well through that thick atmosphere. If you were launching from the moon (or lunar orbit), you could get by with far less investment in fuel. The absolute worthlessness of the lunar surface might also make it practical to use more volatile oxidizers and or fuels than currently used, because you're not going to be contaminating anything important. If you could manage to get fuel synthesis and metal manufacturing going on the moon from space-based components and only have to haul the electronics and crew and specialized sensors up from Earth, our "throw weight" to the rest of the Solar System will increase massively. Going back to the moon is the first step on that road.

Arguably, you could also take advantage of the useless surface to make asteroid mining easier - just nudge valuable rocks to hit the moon and then it becomes surface mining. That's probably too risky, and I don't know if anybody's actually contemplated it (unlike serious proposals to turn those asteroids into temporary moons).

[asda fasda]

I would like to stay away from all the cost overrun issues and delays. Does NASA's goal of returning humans to the moon have scientific value?

Well it's simple. Last time any human was anywhere at this distance from earth was 30 years ago ?, there are no active astronauts, scientist that have done this, additionally with all change in technology before flying to the mars there is need for some practice, and moon is good training place for sure. I bet that after 30 years of not driving a car you would not start with a journey to the other side of the country but take some smaller more familiar route, this is similar . Of course there are additional benefits as mentioned above, and there is science to be done everywhere, and although they will (most likely) not find anything that will change our understanding of physics there is still a lots of unknowns about moon and many engineering issue that we do not even recognize as an issue yet to solve.

[halfeye]

Well it's simple. Last time any human was anywhere at this distance from earth was 30 years ago ?

Apollo 11 was over 50 years ago, the last Apollo mission (Apollo 17) flew in 1972, that's 49 years ago now.

[Trafalgar]

Maybe I wasn't specific or gave enough information. I am not asking a general question about whether we should explore the Moon or Mars. I am specifically asking about the Artemis/Space Launch System. If you dig past the hype and the slick videos, this is what the Artemis program currently has planned:

-Hopefully, 5 Space Launch System Launches by the end of the decade.
-Sometime after 2025, the third planned SLS flight will land a person on the moon.
-Launches 4 and 5 will each take a module of the planned Lunar Gateway station in orbit around the moon.
-Other modules for the Lunar Gateway will be taken by SpaceX on Falcon Heavy.
-No current plans for a permanent Moon base on the surface. There is some "pie in the sky" talk by NASA about establishing one in the distant future. Nothing is listed in the current planned launches.
-Much of the real surface work will be done by probes. Samples will be taken back to the Lunar Gateway before being returned to earth.

My layman's read of all this is much of this can be done quicker by unmanned probes. And I bet you can do it with existing systems. China has its own program of unmanned probes that have been going up over the last 10 years. I don't see the advantages of a manned lunar gateway. I feel that the resources spent on maintaining the gateway after its in orbit will take away from any planned moon base. But this is my read of the program.

Most of my information is coming from Nasa's own Artemis Plan. The dates in it are all wrong as according to that plan, we are supposed to land on the moon by 2024.


https://www.nasa.gov/sites/default/f...n-20200921.pdf

[asda fasda]

My layman's read of all this is much of this can be done quicker by unmanned probes. And I bet you can do it with existing systems. China has its own program of unmanned probes that have been going up over the last 10 years. I don't see the advantages of a manned lunar gateway. I feel that the resources spent on maintaining the gateway after its in orbit will take away from any planned moon base. But this is my read of the program.

Most of my information is coming from Nasa's own Artemis Plan. The dates in it are all wrong as according to that plan, we are supposed to land on the moon by 2024.


https://www.nasa.gov/sites/default/f...n-20200921.pdf

Well the main point of this mission is that to study how humans reacts in those conditions, yes you could many of goals of the program achieve with robots, but we want to test and analyze human reactions and how to safely move people across the space, all other goals of the missions are rather secondary as I understand.

[Mastikator]

The problem with Earth is that's it's a bad place to launch spaceships from. The gravity is heavy, the atmosphere is dense and corrosive, most of the surface is covered is corrosive salty water, winds interfere with launch.

Going from Earth to anywhere is really hard. The moon is the only real place we even can go.

The moon is a fantastic place to launch from, low gravity, no atmosphere, the surface is made of extremely fine sand which is a problem but there's no sandstorms. Radiation from space is a big problem but you have no choice but to account for that.

The reality is that if you want a human to ever visit Mars, they must be launched from a moon base. If we ever want to have a human presence in space we must start with a functioning (thriving?) moon base. Moon base is step 1 and it can't be skipped.

To me the Artemis program makes perfect sense.

[Lord Torath]

I'm not sold at all on NASA's SLS system. It's expensive, much more so than private options like Space-X.

As for humans, well, humans are more versatile than robots. You can build a robot to do anything (okay, almost anything) a human can do (and many things humans can't) but we've yet to build a robot that can do everything a human can do. How critical is that to Artemis? I'll admit I don't know.

[Mechalich]

The reality is that if you want a human to ever visit Mars, they must be launched from a moon base. If we ever want to have a human presence in space we must start with a functioning (thriving?) moon base. Moon base is step 1 and it can't be skipped.

This really isn't true, unless you can actually build the thing you're trying to launch on the moon itself. Otherwise you have to spend delta v to launch from Earth, spend delta v to land safely on the Moon, spend delta v to launch from the Moon, and spend delta v to land/orbit your destination. A straight launch from Earth skips those two steps in the middle.

As a result a moonbase only becomes useful if the Moon is a source of supplies, whether materials, propellant, or fuel, and it's not clear if the Moon can effectively serve that purpose. Whether or not the lunar regolith provides access to the sorts of materials we need, and whether or not we can mine anything there effectively remain unknown.

An experimental moonbase to test these questions is a good idea, because until we try it there's really no way to settle such questions.

[Gnoman]

This really isn't true, unless you can actually build the thing you're trying to launch on the moon itself. Otherwise you have to spend delta v to launch from Earth, spend delta v to land safely on the Moon, spend delta v to launch from the Moon, and spend delta v to land/orbit your destination. A straight launch from Earth skips those two steps in the middle.

As a result a moonbase only becomes useful if the Moon is a source of supplies, whether materials, propellant, or fuel, and it's not clear if the Moon can effectively serve that purpose. Whether or not the lunar regolith provides access to the sorts of materials we need, and whether or not we can mine anything there effectively remain unknown.

An experimental moonbase to test these questions is a good idea, because until we try it there's really no way to settle such questions.

Supplies don't have to come from the Moon. They just have to not come from Earth. A Martian colony would be better placed for asteroid extraction, but even a lunar colony would be better than using Earth if you need some source of decent gravity to work with.

And if we ever do build a Martian colony, it would be much, much cheaper in energy to shuttle a ship from Mars to the Moon, even dragging enough fuel to return, and just ferry people from Earth than it would be to send people straight from Earth to Mars.

[halfeye]

Supplies don't have to come from the Moon. They just have to not come from Earth. A Martian colony would be better placed for asteroid extraction, but even a lunar colony would be better than using Earth if you need some source of decent gravity to work with.

And if we ever do build a Martian colony, it would be much, much cheaper in energy to shuttle a ship from Mars to the Moon, even dragging enough fuel to return, and just ferry people from Earth than it would be to send people straight from Earth to Mars.

This would be true if solar sails work, which in theory they ought to. Otherwise, it would be relatively expensive to transfer fuel to the moon, but relatively cheap to go from the moon to Mars. I still think going to Mars is a bad idea.

[Gnoman]

As with earlier posts, I'm assuming that some form of synthesizing fuel from space resources is possible. If you can get hydrazine and a good oxidizer from asteroid mines, the cost of fueling the moon goes way down.

[halfeye]

As with earlier posts, I'm assuming that some form of synthesizing fuel from space resources is possible. If you can get hydrazine and a good oxidizer from asteroid mines, the cost of fueling the moon goes way down.

I think we're a hundred years (maybe five hundred if space exploration takes the sort of low priority it's had between Apollo and the last five years) from making significant amounts of material goods from stuff found in space. Food grown from hydroponics ought to be now or sooner, but I don't think minerals from asteroids will be used any time soon. Redundant satellites ought to be good for some metal, but we're not scavenging them, and that ought to be a lot easier than mining.

[Trafalgar]

I'm not sold at all on NASA's SLS system. It's expensive, much more so than private options like Space-X.

I agree that SLS is too expensive. But we need to have a super heavy launch vehicle available if we want to send manned flights beyond LEO. Unfortunately super heavy launch platforms are not commercially viable. Look at Falcon Heavy, which is only about half as powerful as SLS. It has only been launched 3 times. There just isn't a market out there for rockets in this class. Satellites are getting smaller, no larger. So we need a tested system that is available. And it needs to be launched just often enough to keep all the manufacturing processes in play. So while I don't like the SLS design, space exploration needs a platform like that to be available. Maybe SpaceX Starship will be an improvement.

As for humans, well, humans are more versatile than robots. You can build a robot to do anything (okay, almost anything) a human can do (and many things humans can't) but we've yet to build a robot that can do everything a human can do. How critical is that to Artemis? I'll admit I don't know.

This is a myth we have been telling ourselves since the sixties. Sure, one human is more versatile than one robot. But manned spaceflight operations are like 100 times more expensive than unmanned. One human is less versatile than one hundred robots.

This disparity goes up further when you look at longevity. NASA's Curiosity rover landed on Mars in 2012. It's still going. The Mar's Science Laboratory, of which Curiosity is a part, cost $2.5 Billion. How much would it cost to send a human to Mars and keep them there for 10 years? SLS apparently costs 4.1 Billion per launch not including 20-30 Billion in development costs.

Scientific American wrote a good piece on manned vs unmanned space exploration.

[Mastikator]

This really isn't true, unless you can actually build the thing you're trying to launch on the moon itself. Otherwise you have to spend delta v to launch from Earth, spend delta v to land safely on the Moon, spend delta v to launch from the Moon, and spend delta v to land/orbit your destination. A straight launch from Earth skips those two steps in the middle.

As a result a moonbase only becomes useful if the Moon is a source of supplies, whether materials, propellant, or fuel, and it's not clear if the Moon can effectively serve that purpose. Whether or not the lunar regolith provides access to the sorts of materials we need, and whether or not we can mine anything there effectively remain unknown.

An experimental moonbase to test these questions is a good idea, because until we try it there's really no way to settle such questions.

It's entirely possible that a moon base is not feasible as a launching pad for manned missions to mars, but if that is the case then there are no options at all. It's moon or nothing. Because launching from Earth and putting boots on martian sand is not a thing that will happen. Not on the current trajectory of humanity, not in a potential good future either.

[halfeye]

It's entirely possible that a moon base is not feasible as a launching pad for manned missions to mars, but if that is the case then there are no options at all. It's moon or nothing. Because launching from Earth and putting boots on martian sand is not a thing that will happen. Not on the current trajectory of humanity, not in a potential good future either.

I want to point out that going to Mars is by no means the only use for a moonbase, it's useful for getting to the asteroids, colonising space in general and getting to the orbits of all the other planets too (landing on any planets would probably still be a bad idea, at least without terraforming them first).

[pendell]

Just want to quickly point out that the moon is not a staging point to the rest of the solar system -- *Earth Orbit* is the stepping stone to the rest of the solar system. Getting out of earth's gravity well is the first major challenge. There's no value to then going into another body's gravity well, even if it is only 1/6th that of good old Terra.

Which is why we built the International Space Station. Current tensions are causing trouble with this, but if we ever have an interplanetary civilization within our solar system, so long as Terra is its focal point the 'bright spark at the center of the universe' will be a spaceport, or several spaceports, in orbit. There's no reason to ask ships to waste fuel entering the gravity well -- drop off the materials in orbit, where they can be sent down to earth one-way. Send cargo back up via skyhook or some electromagnetic cannon launcher. Send raw materials into orbit where they can be refined and manufactured into new ships directly in orbit.

If Luna has value, it would be as a source of lunar ice or some other raw material. But I would expect that even those would be used to supply the orbital structures rather than building a great deal of space infrastructure on the moon's surface itself.

Respectfully,

Brian P.

[Mastikator]

I want to point out that going to Mars is by no means the only use for a moonbase, it's useful for getting to the asteroids, colonising space in general and getting to the orbits of all the other planets too (landing on any planets would probably still be a bad idea, at least without terraforming them first).

Fair.
Also a moon base would be pretty cool

[halfeye]

Just want to quickly point out that the moon is not a staging point to the rest of the solar system -- *Earth Orbit* is the stepping stone to the rest of the solar system. Getting out of earth's gravity well is the first major challenge. There's no value to then going into another body's gravity well, even if it is only 1/6th that of good old Terra.

One thing about the moon is that it's not out of Earth's gravity well, it's something like halfway out, from there it is easier to get the rest of the way out. Earth orbital velocity is 18,000 mph, Earth escape velocity is 25,000 mph. The orbit of the moon is very near the plane of the ecliptic, most of the interesting things in the Solar system are also in or near the plane of the ecliptic, so if you can wait a month, the moon is going to be nearer to wherever you want to go than Leo is.

[Mechalich]

One thing about the moon is that it's not out of Earth's gravity well, it's something like halfway out, from there it is easier to get the rest of the way out. Earth orbital velocity is 18,000 mph, Earth escape velocity is 25,000 mph. The orbit of the moon is very near the plane of the ecliptic, most of the interesting things in the Solar system are also in or near the plane of the ecliptic, so if you can wait a month, the moon is going to be nearer to wherever you want to go than Leo is.

The central issue is that going from Earth Orbit to the Lunar surface and then from the Lunar surface to you destination costs more delta v than going straight from Earth Orbit to your destination. Likewise, the Earth-Moon distance is a rounding error compared with the distance between Earth and literally any other location in the solar system.

There are conditions in which the moon may be useful for space exploration. Some of them include:
1. If Lunar gravity is enough gravity to prevent health problems in humans, then Moon has utility as a staging ground for manned operations.
2. If it's possible to produce something useful for further exploration in situ on the Lunar surface, probably fuel/propellant.
3. If the limited gravity well of the moon allows construction of a Lunar space elevator or skyhook while engineering limits prevent one from functioning on Earth.

At present putting together an experimental moonbase would allow a test of the first two conditions. Astronauts living in a moonbase for several months at a time would be a good test of survivability in the environment, and they could conduct experimentation to determine if the Moon harbors useful resources that can actually be accessed in that environment.

[halfeye]

The central issue is that going from Earth Orbit to the Lunar surface and then from the Lunar surface to you destination costs more delta v than going straight from Earth Orbit to your destination. Likewise, the Earth-Moon distance is a rounding error compared with the distance between Earth and literally any other location in the solar system.

People can store stuff at the moon, or at a station in orbit around the moon. People sometimes go up Everest in one go now, but if I remember rightly, back in the day they had something like six camps on the way to the summit, and they would stock each camp so they had enough to live there and carry stocks forward to camps further up, the attempt finally being made when all the camps were fully stocked. For a Mars trip it would be good to have a stockpile of oxygen, food and fuel, yes you'd spend to get the stuff to the moon, but you'd leave from the moon with full tanks, and that is worth quite a lot.

[Anymage]

People can store stuff at the moon, or at a station in orbit around the moon. People sometimes go up Everest in one go now, but if I remember rightly, back in the day they had something like six camps on the way to the summit, and they would stock each camp so they had enough to live there and carry stocks forward to camps further up, the attempt finally being made when all the camps were fully stocked. For a Mars trip it would be good to have a stockpile of oxygen, food and fuel, yes you'd spend to get the stuff to the moon, but you'd leave from the moon with full tanks, and that is worth quite a lot.

If the goal is to make outer space base camps, space stations can do that without having to go down (and consequently have to climb back up out of) a gravity well. Having a base on lunar soil is only a practical plus if the gravity itself proves useful, and/or if something valuable can be taken from the lunar regolith itself. (Which, to be fair, maybe simply being under it to reduce leakage/radiation/micrometeor impacts might prove handy.) But in terms of energy and fuel, your ideal spacefaring civilization would want to spend as little time walking around on massive objects as possible.

[halfeye]

<out of sequence> But in terms of energy and fuel, your ideal spacefaring civilization would want to spend as little time walking around on massive objects as possible.

Absolutely. Totally right.

A station in orbit around the moon is probably ideal. The moon is big and easy to see, you can see it in daylight sometimes, which is some help with navigation.

If the goal is to make outer space base camps, space stations can do that without having to go down (and consequently have to climb back up out of) a gravity well. Having a base on lunar soil is only a practical plus if the gravity itself proves useful, and/or if something valuable can be taken from the lunar regolith itself. (Which, to be fair, maybe simply being under it to reduce leakage/radiation/micrometeor impacts might prove handy.)

I sort of almost agree, I just have a hard time imagining a space station in moon orbit without a base beneath it. The orbital base can be first no doubt.

[Trafalgar]

People sometimes go up Everest in one go now, but if I remember rightly, back in the day they had something like six camps on the way to the summit, and they would stock each camp so they had enough to live there and carry stocks forward to camps further up, the attempt finally being made when all the camps were fully stocked.

Generally people don't go up Everest in one day but that's not just due to logistics. Its also due to acclimatization to the low pressure levels at higher altitudes. Going up too quickly can lead to a pulmonary or cerebral edema which can very easily kill you. So there is usually a plan where you climb to a higher camp and stay for a day and then climb down. You do this several times at higher and higher altitudes until you finally make your summit push.

[Trafalgar]

https://scitechdaily.com/artemis-i-w...at-went-wrong/

It failed a test today. Cryogenic liquids can be tricky to work with. One thing I question about the SLS plan is that there is only one unmanned test launch before we use it to send Astronauts out to lunar orbit. Falcon 9 had t establish its self fully as a platform before NASA would trust it to carry Crew Dragon. I understand that SLS is based on established systems from the shuttle but that doesn't mean the bugs have been worked out. Its still a new vehicle.

[Smoutwortel]

If the goal is to make outer space base camps, space stations can do that without having to go down (and consequently have to climb back up out of) a gravity well. Having a base on lunar soil is only a practical plus if the gravity itself proves useful, and/or if something valuable can be taken from the lunar regolith itself. (Which, to be fair, maybe simply being under it to reduce leakage/radiation/micrometeor impacts might prove handy.) But in terms of energy and fuel, your ideal spacefaring civilization would want to spend as little time walking around on massive objects as possible.

"Having a base on lunar soil is only a practical plus if the gravity itself proves useful, and/or if something valuable can be taken from the lunar regolith itself. " This is the point.
A few things can be pulled from it that can be used:
A. Yes using Luna's crust as radiation shielding is very useful.
B. Luna's big surface area and readily available resources could at least be used to build a big network of solar panels and/or heat dumping panels.
C. Thanks to its lack of magnetic field and atmosphere and abundance age it has a lot of helium 3 which could be used for fusion experiments and other fun stuff.
https://solarsystem.nasa.gov/studies...-distribution/
D. The moon is giant ball full of resources there is no Question we will want to use them in the future. If we have no use for them today we will want to have them the day we go into space.