Why haven't we gone back to the moon?

[DruidArmy]

Why haven't we gone back to the moon? Seems like we could save a whole lot of money and time if we were to go back and explore the moon rather than going to mars. A lot of the questions posted here could be answered if we had gone back.

Why aren't you asking this question yourself?

 

[x BlueRobot]

Mars is a more likely candidate for the existence of life.

 

[DruidArmy]

We could build telescopes, radar, place radio reflectors, mine, set up self sustaining biospheres, etc, etc, etc. on the moon. Big waste of time and big money just to find a microbe on mars.

 

[ShayanJ]

We could build telescopes, radar, place radio reflectors, mine, set up self sustaining biospheres, etc, etc, etc. on the moon. Big waste of time and big money just to find a microbe on mars.

You don't talk like someone interested in science!
Actually even laymen understand the importance of discovering extra-terrestrial life!
In fact the applications of those things that you mentioned are only important to scientists but extra-terrestrial life, in addition to being very important to scientists, is important to humanity!

 

[Doug Huffman]

We, US, back to the Moon? Can't afford it due to descent to regression to the mean.

 

[vociferous]

The short answer is, because the Apollo project had one primary goal: that the first man to walk on the moon be an American. When we realized the Soviets had no interest in sending Cosmonauts to the moon or anywhere else beyond low Earth orbit, we stopped going.

When Kennedy committed to going to the moon, it was beyond our current level of technology. We had to commit huge resources into developing the technology to make it possible, and even then, it was still barely within our ability to accomplish. The Apollo program was successful not just because of good engineering, but because of a lot of good luck.

The huge advances in engineering and the modest advances in science that came out of the program were just bonuses for us. The impetus of the space-race was an international pissing contest to prove Capitalism superior to Communism.

 

[phinds]

The impetus of the space-race was an international pissing contest to prove Capitalism superior to Communism.

Exactly, and no one that cares much about what's happening here on Earth would like to see money pissed away on another manned moon mission. It's a pipe dream to think otherwise.

 

[vociferous]

Exactly, and no one that cares much about what's happening here on Earth would like to see money pissed away on another manned moon mission. It's a pipe dream to think otherwise.

I would support a manned moon mission or base as a stepping stone to Mars. I do not think that there is much utility in sending people in the moon just to prove that we can still do it. Any manned mission to Mars, especially one to set up a long-term station or colony might involve a practice run on the moon, or even creating a station there to manufacture fuel or some other useful enterprise.

 

[skeptic2]

... set up self sustaining biospheres, etc, etc, etc. on the moon.

This is the crux of the problem. How would you set up a self sustaining biospheres? Don't forget the moon has a two week long night. Not many plants can survive without light and heat for that long. Artificial light and heat? Powered by what, solar energy? Same problem.

How would you build such a biosphere without heavy equipment and without a vast supply of oxygen and nitrogen? I suspect a base on the moon won't be possible without portable nuclear generators.

 

[phinds]

I would support a manned moon mission or base as a stepping stone to Mars. I do not think that there is much utility in sending people in the moon just to prove that we can still do it. Any manned mission to Mars, especially one to set up a long-term station or colony might involve a practice run on the moon, or even creating a station there to manufacture fuel or some other useful enterprise.

Yes, but all of that is a pipe dream for the next many decades despite what you read in the popular press and what some entrepreneurs would have us believe.

 

[vociferous]

Yes, but all of that is a pipe dream for the next many decades despite what you read in the popular press and what some entrepreneurs would have us believe.

We have the technology. It is all a matter of funding and, at least for the Mars mission, concerns about human health on long-term space-travel and long-term exposure to a planet with no significant atmosphere and no magnetosphere.

 

[phinds]

We have the technology. It is all a matter of funding and, at least for the Mars mission, concerns about human health on long-term space-travel and long-term exposure to a planet with no significant atmosphere and no magnetosphere.

Yes, I agree (although I think you have let's off a lot of other concerns), and my statement stands.

 

[DruidArmy]

Not sure I got a good answer as to why no one has returned to the moon.

There are many scientific reasons to return. Real scientists would have hundreds, thousands of things they could do there.

Funding? Who knows, but this is not a good reason, if we can afford to go to mars, we can afford to go to the moon. Please don't argue this one after we've spent billions and billions on space travel.Simply set up a little moon base and generate your own electricity and oxygen.

My word, think how much more a telescope would reveal if based on the moon.

I can give many reasons to go there and so could you.

Perhaps its political reasons, ie. who would have the rights to anything mined or placed there.

Wouldn't it be nice to explore the dark side of the moon, the side we never see?

Just rocks from the moon, would probably pay for the trip if sold. Ha ha.

Anyway, I want us to return to the moon!

I agree, colonization of the moon or mars, is way off. But it sure would be cheaper and easier to do it on the moon rather than mars. I think the idea of a small moon base is doable with our current technology.

 

[phinds]

Not sure I got a good answer as to why no one has returned to the moon.

The answer is funding. Period.

Simply set up a little moon base and generate your own electricity and oxygen.

SIMPLY ! Are you serious? I have to conclude that you REALLY haven't looked into this. Who do you think will pay for it and why?

Anyway, I want us to return to the moon!

Good for you. Become a multi-billionaire and try to pay for it.

I agree, colonization of the moon or mars, is way off. But it sure would be cheaper and easier to do it on the moon rather than mars. I think the idea of a small moon base is doable with our current technology.

Sure, but it STILL isn't going to happen. FUNDING !

 

[Chronos]

The moon underscores just how expensive manned space travel is - even to our nearest neighbor. The prestige of being first on the moon simply did not and could not justify the enormous expense. In the past couple decades, the potential of helium 3 as a fuel source has prompted renewed interest in returning to the moon. Assuming the technological issues in unleashing He3 energy are resolved, lunar colonization will become economically viable. The US is not the only nation that recognizes this, or has the ability to act upon it. China is rapidly becoming a serious player in this arena.

 

[SteamKing]

Why haven't we gone back to the moon?

Who's we, Kemosabe?

As part of their muscular presence in the world, the Chinese have apparently established a national goal to put a Chinese astronaut on the moon.

Last year, the Chinese successfully landed a robotic probe on the lunar surface:

http://www.space.com/23968-china-moon-rover-historic-lunar-landing.html

http://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program

Now, the planned date for a manned landing of Chinese astronauts on the lunar surface is at least a decade away, but the goal is there if the Chinese government wishes to attain it. Right now, they don't seem to have any problems funding their space program.

 

[DruidArmy]

We - means Earthlings.

 

[DruidArmy]

How much does it cost? How much does any country have to spend? I doubt , anyone of us can answer these questions?

 

[Drakkith]

We have the technology. It is all a matter of funding and, at least for the Mars mission, concerns about human health on long-term space-travel and long-term exposure to a planet with no significant atmosphere and no magnetosphere.

We do not have the technology or the know-how to create a long-term, self-sustained colony on the Moon or any other body in the solar system. We haven't even been able to build a long-term self-sustaining enclosed environment here on Earth that doesn't rely on the outside world to supply at least some of its resources.

See here: http://en.wikipedia.org/wiki/Biosphere_2#Challenges

Funding? Who knows, but this is not a good reason, if we can afford to go to mars, we can afford to go to the moon. Please don't argue this one after we've spent billions and billions on space travel.

Not only is funding a good reason, it is THE primary reason we haven't been back. The efficiency of a manned program is simply too low in terms of benefits compared to costs when you compare manned and unmanned missions. One of the main things that NASA has done in the last few decades is switch to low-cost missions focused on one single thing instead of much more expensive broad-scope missions such as manned ones.

My word, think how much more a telescope would reveal if based on the moon.

With the advancements in adaptive optics, not much more than telescopes here on Earth reveal. An exception would be those wavelengths which are blocked by the atmosphere. The primary reason we haven't already set up telescopes on the Moon is that it's very difficult and expensive to do so. Telescopes are massive, heavy, and delicate objects that require extraordinary care in transporting, especially ones that use mirrors. Launching one to the Moon is not a trivial matter.

I can give many reasons to go there and so could you.

Anyone can give reasons to go. The problem is that you are hand-waving away the reasons not to go.

I agree, colonization of the moon or mars, is way off. But it sure would be cheaper and easier to do it on the moon rather than mars. I think the idea of a small moon base is doable with our current technology.

It is not doable without some sort of resupply from Earth. In addition, the cost to lift as much material as you would need to build a small colony is staggering.

How much does it cost? How much does any country have to spend? I doubt , anyone of us can answer these questions?

As a comparison, look at the cost of the ISS: http://en.wikipedia.org/wiki/International_Space_Station#Cost

The ISS is arguably the most expensive single item ever constructed.[264] As of 2010 the cost is estimated to be $150 billion. It includes NASA's budget of $58.7 billion for the station from 1985 to 2015 ($72.4 billion in 2010), Russia's $12 billion ISS budget, Europe's $5 billion, Japan's $5 billion, Canada's $2 billion, and the cost of 36 shuttle flights to build the station; estimated at $1.4 billion each, or $50.4 billion total. Assuming 20,000 person-days of use from 2000 to 2015 by two to six-person crews, each person-day would cost $7.5 million, less than half the inflation adjusted $19.6 million ($5.5 million before inflation) per person-day of Skylab.

Approximately 150 billion dollars spread out of 20 years. And that's for a space station in orbit of Earth. The cost to lift an equal amount of material to build a lunar base would be MUCH higher.

 

[vociferous]

We do not have the technology or the know-how to create a long-term, self-sustained colony on the Moon or any other body in the solar system. We haven't even been able to build a long-term self-sustaining enclosed environment here on Earth that doesn't rely on the outside world to supply at least some of its resources.

See here: http://en.wikipedia.org/wiki/Biosphere_2#Challenges

That is a false premise. McMurdo Station has 1258 residents. There are oil rigs and research platforms out at sea. There is the ISS orbiting the Earth They are not self-sustaining (neither are modern cities).

Establishing a research station or even a colony on Mars and establishing a "self-sustained colony" are not logically equivalent. We most certainly do have the technology to establish a research station or small colony on the Moon and probably on Mars as well.

It is a question of priorities. We live in a society that does not even have the foresight to plan for 50 years down the road (as evidenced by our continued massive dumping of carbon into the atmosphere). Obviously, planning for the need to develop self-sustaining colonies is pretty far from everyone's mind.

We certainly have the resources and technology to create a permanent presence on Luna or Mars. It is simply a question of priorities and myopia. It's why we're still spending trillions of dollars on machines to kill each other with but not on space exploration or colonization. What's important to the average human and what is important to humans of high intelligence, knowledge, and vision are vastly divergent.

 

[Drakkith]

That is a false premise. McMurdo Station has 1258 residents. There are oil rigs and research platforms out at sea. There is the ISS orbiting the Earth They are not self-sustaining (neither are modern cities).

Establishing a research station or even a colony on Mars and establishing a "self-sustained colony" are not logically equivalent. We most certainly do have the technology to establish a research station or small colony on the Moon and probably on Mars as well.

We can establish a small base on the Moon, but not on Mars. We currently don't have any way to land heavy craft on the surface of Mars. The atmosphere is too thin to use parachutes to slow down, and too thick for conventional engines to work. (Or so I've read in a paper. I'm not sure where it's at, but I'll try to find a link if I can)

 

[vociferous]

We can establish a small base on the Moon, but not on Mars. We currently don't have any way to land heavy craft on the surface of Mars. The atmosphere is too thin to use to slow down, and too thick for conventional engines to work. (Or so I've read in a paper. I'm not sure where it's at, but I'll try to find a link if I can)

That really comes down to a money problem rather than a physics or technology problem. Braking a landing craft with a parachute is economical. Having to also use thrust greatly increases the cost because you need fuel, which means you need to add fuel to lift the braking fuel out of Earth's orbit, which means you need to add fuel to lift the fuel you added to lift the braking fuel. . .

Getting people onto Mars and then back to Earth is a daunting logistical challenge, which is why some have suggested it be a one-way trip.

However, it is not significantly technologically different than getting someone to the moon and back other than the scale of the endeavor and the length of time they will be exposed to space-travel.

 

[Drakkith]

That is not correct. From here: http://www.universetoday.com/7024/t...ge-payloads-to-the-surface-of-the-red-planet/

The real problem is the combination of Mars’ atmosphere and the size of spacecraft needed for human missions. So far, our robotic spacecraft have been small enough to enable at least some success in reaching the surface safely. But while the Apollo lunar lander weighed approximately 10 metric tons, a human mission to Mars will require three to six times that mass, given the restraints of staying on the planet for a year. Landing a payload that heavy on Mars is currently impossible, using our existing capabilities. “There’s too much atmosphere on Mars to land heavy vehicles like we do on the moon, using propulsive technology completely,” said Manning, “and there’s too little atmosphere to land like we do on Earth. So, it’s in this ugly, grey zone.”

You can find more details in the article.

 

[davenn]

That is a false premise. McMurdo Station has 1258 residents. There are oil rigs and research platforms out at sea. There is the ISS orbiting the Earth They are not self-sustaining (neither are modern cities).

That's a totally pointless response to Drakkith

you just agreed with him ... NONE of them are self-sustaining
and all because of technological problemscheers
Dave

 

[vociferous]

That is not correct. From here: http://www.universetoday.com/7024/t...ge-payloads-to-the-surface-of-the-red-planet/
You can find more details in the article.

I don't really read that as him saying that it exceeds our current technology, just that we don't currently have technological platforms capable of achieving that.

Like I wrote before, you pack enough fuel into the lander and the reverse thrust will slow you down enough to land. It is simple physics that is certainly not beyond our capabilities (when combined with other technological solutions). It is also simple physics that fuel weighs a lot and is very expensive to accelerate to escape velocity. He mentions this in the article. Basically, it is primarily a problem of having a launch vehicle and having the budget.

When we landed on the moon, we were doing something that was, at the time it was first conceived, technologically impossible, or pretty close to it. Landing on Mars, by contrast, is only technologically very difficult, but certainly possible.

The biggest challenge is the political will. NASA had an effectively unlimited budget for the Apollo program. If congress were to commit NASA to send astronauts to Mars, I don't see any reason why it would be technologically unfeasible, but until someone is ready to actually front the money, NASA has to use its limited resources on projects that are actually likely to come to fruition. Right now, Mars is just a pipe dream.

 

[Drakkith]

Did you read the article? It's pretty clear. From the article (bolding mine):

But using current thruster technology in Mars’ real, existing atmosphere poses aerodynamic problems. “Rocket plumes are notoriously unstable, dynamic, chaotic systems,” said Manning. “Basically flying into the plume at supersonics speeds, the rocket plume is acting like a nose cone; a nose cone that’s moving around in front of you against very high dynamic pressure. Even though the atmospheric density is very low, because the velocity is so high, the forces are really huge.”

Manning likened theses forces to a Category Five hurricane. This would cause extreme stress, with shaking and twisting that would likely destroy the vehicle. Therefore using propulsive technology alone is not an option.

We quite literally don't know how to land a heavy vehicle on Mars. It is not technologically possible at this time.

 

[DruidArmy]

These are great responses. But as far as going back to moon, how about sending unmanned craft such as lunar rovers and other electronic equipment to keep costs to a minimum.

 

[Drakkith]

These are great responses. But as far as going back to moon, how about sending unmanned craft such as lunar rovers and other electronic equipment to keep costs to a minimum.

We have been. See here: http://en.wikipedia.org/wiki/Exploration_of_the_Moon#Timeline_of_Moon_exploration

 

[vociferous]

Did you read the article? It's pretty clear. From the article (bolding mine):



We quite literally don't know how to land a heavy vehicle on Mars. It is not technologically possible at this time.

The article mentions using a combination of heat shields, parachutes, and retro-rockets to land safely, obviously a weighty and expensive option.

It also makes the presumption that a landing would involve a single heavy vehicle rather than multiple missions involving lighter, modular components, similar to how the ISS was assembled.

I have no doubt that engineers are more than capable of accomplishing the task given the resources. Again, I feel that it is simply an question of priorities and funding. Any manned Mars mission would be a tremendous undertaking, and without a clear mandate and budget from congress to get it done, it is never going to get much past the philosophical stage into the actual engineering phase.

 

[Drakkith]

The article mentions using a combination of heat shields, parachutes, and retro-rockets to land safely, obviously a weighty and expensive option.

The article mentions that none of those options will work, by themselves or combined.

It also makes the presumption that a landing would involve a single heavy vehicle rather than multiple missions involving lighter, modular components, similar to how the ISS was assembled.

I don't think you understand. The Mars Science Laboratory (MSL), the rover that landed a year or two ago, weighed approximately 2,000 lbs and required an entirely new way of landing be designed. In comparison, the Apollo Lunar Module, a lightweight craft solely designed to land two people on the moon with minimal equipment, weighed over 32,000 pounds (empty weight). Any manned craft designed to land on Mars, especially carrying materials to build a base, will weigh FAR more.

I have no doubt that engineers are more than capable of accomplishing the task given the resources. Again, I feel that it is simply an question of priorities and funding. Any manned Mars mission would be a tremendous undertaking, and without a clear mandate and budget from congress to get it done, it is never going to get much past the philosophical stage into the actual engineering phase.

I don't see how you're coming to that conclusion. Have you actually done any research into this topic? It appears you're simply arguing in an attempt to avoid being wrong.

 

[vociferous]

“. . .But the problem is that right now the heat shield diameter for a human-capable spacecraft overwhelms any possibility of launching that vehicle from Earth. . . Apollo-type lunar lander with thrusters could be used. . .that would entail a large amount of fuel. . . using thrusters in combination with a heat shield and parachute also poses challenges. . . so now you need the ability to turn the vehicle over sideways to try to get to your landing spot. But this may be an expensive option, adding a large tax in fuel to get to the desired landing rendezvous point.”

-ibid

I do not interpret as him saying that it is impossible with current technology, just expensive. For instance, he points out that current rockets cannot launch a heat shield and rocket fuel is too expensive to launch for the amount needed. He never specifically concludes that a combination of these technologies is not sufficient to land safely or that it is not doable, just that it is challenging, both in terms of needing to develop new launch technologies to get the payload to Mars and in the incredible expense it is likely to incur.

Also, it should be noted that this is reporting on a conference that occurred ten years ago. There has been some actual new funding thrown towards the problem in the meantime, such as AMES work on the Red Dragon spacecraft .

And the basis for my conclusion are the Apollo program. The challenges, at the time it was conceived, were fundamentally greater than the challenges imposed by a manned mission to Mars. The technological hurdles for the Apollo program were much greater than a Mars landing today, but NASA managed to pull it off in only seven years.

Today we have the benefit of advanced computer modeling as well as being able to create automated flight and landing systems. We have experience creating long-term research stations in space. It is still a challenge, but I highly doubt that the level of technological challenge is anything like what the Apollo programs faced.

 

[Drakkith]

I'm sorry but you're not reading the article fully, you're just picking out the pieces that appear to support your opinion. I already linked the part of the article that explains why thrusters can't be used in post #26, so no, it's not just a matter of expense. If you have a reference for a new design to land heavy craft on Mars, please post it.

He never specifically concludes that a combination of these technologies is not sufficient to land safely or that it is not doable, just that it is challenging, both in terms of needing to develop new launch technologies to get the payload to Mars and in the incredible expense it is likely to incur.

Are you serious? The very end of the article says:

Manning explained, “NASA does not yet have the resources to solve this problem and also develop the CEV, complete the International Space Station and do the lunar landing systems development at the same time. But NASA knows that this is on its plate of things to do in the future and is just beginning to get a handle on the needed technology developments.

He's saying that we don't know how to land a heavy craft on Mars at this time and that new technology needs to be developed to do so. That's exactly what I've been saying.

 

[vociferous]

I'm sorry but you're not reading the article fully, you're just picking out the pieces that appear to support your opinion. I already linked the part of the article that explains why thrusters can't be used in post #26, so no, it's not just a matter of expense. If you have a reference for a new design to land heavy craft on Mars, please post it.
Are you serious? The very end of the article says:

Manning explained, “NASA does not yet have the resources to solve this problem and also develop the CEV, complete the International Space Station and do the lunar landing systems development at the same time. But NASA knows that this is on its plate of things to do in the future and is just beginning to get a handle on the needed technology developments.

He's saying that we don't know how to land a heavy craft on Mars at this time and that new technology needs to be developed to do so. That's exactly what I've been saying.

I did read the entire article. I simply came to a different conclusion than you did. For instance, I do not interpret the article to imply that he felt it was impossible to use thrusters at all to slow the descent, which would be absurd since the Viking landers used thrusters on Mars. His comment was that the turbulence generated by a landing using nothing but thrusters would be difficult to engineer around. However, I do not interpret the article to imply that the same level of turbulence would be generated using thrusters and a combination of parachutes and heat shields. Furthermore, I am not convinced that the turbulence is an insurmountable engineering program. We've been landing VTOL craft on Earth using nothing but thrust since before we landed men on the moon. With advances in computing power, we have created flyable aircraft which are inherently unstable and impossible for a human to fly due to turbulence. We have also managed to test-fly vertical landing spacecraft here on Earth.

Even if, for the sake of argument, we just agree that it is impossible to land such a single mass on Mars, then we simply use a different engineering paradigm. We figure out what the heaviest craft we can land safely and reliably on Mars is and design the mission to use individual modules that do not exceed this mass.

I think the crux of the difference is between understanding the distinction between us not having a fabrication-ready design for a Mars mission today and a Mars mission simply being beyond our current level of technology.

It is akin to the difference between the Queen of England wanting to build a television in 1820 and 1920. In 1820, there was fundamental ignorance about basic laws of physics and a lack of necessary technology to allow a television to be created. In 1920, we had the technology and science, it just needed R&D funding.

Landing a man on Mars is akin to building a TV in 1920. We have the needed science and technology. It is just a question of resources to develop it into a workable project. Just like the Apollo program, I am confident that we could probably achieve the goal within about a decade given the proper impetus. By contrast, if President Obama ordered NASA to send a man to Alpha Centauri within a decade, I am extremely confident it would have been as hopeless a task as building a TV in 1820.

 

[Drakkith]

I find your argument silly. You're simply arguing semantics, and I will not get drawn into that kind of argument.

 

[vociferous]

I find your argument silly. You're simply arguing semantics, and I will not get drawn into that kind of argument.

Fair enough; I am just stating my opinion as you are stating yours. I am fairly optimistic about the odds of landing a man on Mars in my lifetime (although maybe not so optimistic about it being an American). It will be interesting to see exactly how it ends up being done.

 

[Drakkith]

Fair enough; I am just stating my opinion as you are stating yours. I am fairly optimistic about the odds of landing a man on Mars in my lifetime (although maybe not so optimistic about it being an American). It will be interesting to see exactly how it ends up being done.

Agreed.

 

[D H]

I did read the entire article.

Did you read the part that said "Nobody knows how to do it"?

That is the key sentence in the entire article.

For instance, I do not interpret the article to imply that he felt it was impossible to use thrusters at all to slow the descent, which would be absurd since the Viking landers used thrusters on Mars.

That's a non sequitur. The Viking landers could use thrusters to land precisely because they were small. One of the myriad of nasty facts that confronts putting humans into space is the square-cube law. If you scaled a mouse up to the size of an elephant it would die. The square-cube law dictates that elephant physiology is very, very different from mouse physiology. The same applies to those little Viking landers. Space vehicles don't scale up because of the square-cube law. More mass needs to be added because of structural integrity issues. More thrusters needed to be added because thrust is proportional to throat area. That means even more mass. The end result is that a large vehicle is elephantine compared to the mouselike characteristics of a small vehicle.

Furthermore, I am not convinced that the turbulence is an insurmountable engineering program.

It is a huge issue, one we do not know how to solve.

We've been landing VTOL craft on Earth using nothing but thrust since before we landed men on the moon.

That's another non sequitur. Aircraft don't carry their own oxidizer, and they don't go anywhere close to the speed of a reentering spacecraft . It's more like 1/20th of the speed in the case of a VTOL aircraft vs a reentering spacecraft , and that means 1/400th the energy needs to be dissipated.

Even if, for the sake of argument, we just agree that it is impossible to land such a single mass on Mars, then we simply use a different engineering paradigm.

It's so simple if you simply hand-wave away all the problems!

There's only so much you can shrink a spacecraft that will safely land humans. The Apollo command modules were 6.5 times as massive as is the Mars Science Laboratory rover. Landing a vehicle that is 6.5 times heavier not just 6.5 times harder. It's harder than we can imagine. We don't know how to do it. The Apollo command modules carried the barest minimum of life support needed to bring humans from separation from the service module down to the Earth, where they would be whisked away via helicopter shortly after splashdown. A Mars lander would need to carry a significant amount of life support (air, water, food, life support equipment, etc.). And a hefty rover. And a launch vehicle.

Why a launch vehicle? Not bringing the astronauts back home is a death sentence. We haven't the foggiest idea of how to grow food away from home. For a little while, and for a few bites of lettuce to augment otherwise boring freeze dried food, yes, we can do that. A fully sustaining farm? We don't know how to do that.

Why a rover? Unless we can land several months worth of life support with that one vehicle, we need to send multiple landing vehicles. Those other landers are likely to land tens of kilometers apart. The Mars Science Laboratory represents the state of the art in precision landing on Mars. It's one sigma landing ellipse was 20 km × 7 km. The probability of landing within that one sigma ellipse is about 39%. Tripling each dimension (60 km × 21 km) yields a probability of 98.9%. Those aren't great odds, but close to the target for human spaceflight activities. We'll need that rover to go pick up the water, food, and equipment that landed tens of kilometers away.

I think the crux of the difference is between understanding the distinction between us not having a fabrication-ready design for a Mars mission today and a Mars mission simply being beyond our current level of technology.

I think the crux of the problem is that you don't know how impossibly hard it is, even using technology that doesn't exist yet. We don't know how to do it. I've mentioned but three of the things we don't know how to do. There are a number more.

 

[phinds]

Fair enough; I am just stating my opinion as you are stating yours .

Well, it does seem that your "opinion" is based on wishful thinking and a very selective reading and interpretation of the information available whereas Drakkith's is based on a pretty straight forward reading of the same information. I don't think anyone here is trying to give you a hard time but it IS frustrating that you don't seem to understand or appreciate the difficulties that have been mentioned to you.

 

[vociferous]

Did you read the part that said "Nobody knows how to do it"?

That is the key sentence in the entire article. That's a non sequitur. The Viking landers could use thrusters to land precisely because they were small. One of the myriad of nasty facts that confronts putting humans into space is the square-cube law. If you scaled a mouse up to the size of an elephant it would die. The square-cube law dictates that elephant physiology is very, very different from mouse physiology. The same applies to those little Viking landers. Space vehicles don't scale up because of the square-cube law. More mass needs to be added because of structural integrity issues. More thrusters needed to be added because thrust is proportional to throat area. That means even more mass. The end result is that a large vehicle is elephantine compared to the mouselike characteristics of a small vehicle.It is a huge issue, one we do not know how to solve.
That's another non sequitur. Aircraft don't carry their own oxidizer, and they don't go anywhere close to the speed of a reentering spacecraft . It's more like 1/20th of the speed in the case of a VTOL aircraft vs a reentering spacecraft , and that means 1/400th the energy needs to be dissipated.
It's so simple if you simply hand-wave away all the problems!

There's only so much you can shrink a spacecraft that will safely land humans. The Apollo command modules were 6.5 times as massive as is the Mars Science Laboratory rover. Landing a vehicle that is 6.5 times heavier not just 6.5 times harder. It's harder than we can imagine. We don't know how to do it. The Apollo command modules carried the barest minimum of life support needed to bring humans from separation from the service module down to the Earth, where they would be whisked away via helicopter shortly after splashdown. A Mars lander would need to carry a significant amount of life support (air, water, food, life support equipment, etc.). And a hefty rover. And a launch vehicle.

Why a launch vehicle? Not bringing the astronauts back home is a death sentence. We haven't the foggiest idea of how to grow food away from home. For a little while, and for a few bites of lettuce to augment otherwise boring freeze dried food, yes, we can do that. A fully sustaining farm? We don't know how to do that.

Why a rover? Unless we can land several months worth of life support with that one vehicle, we need to send multiple landing vehicles. Those other landers are likely to land tens of kilometers apart. The Mars Science Laboratory represents the state of the art in precision landing on Mars. It's one sigma landing ellipse was 20 km × 7 km. The probability of landing within that one sigma ellipse is about 39%. Tripling each dimension (60 km × 21 km) yields a probability of 98.9%. Those aren't great odds, but close to the target for human spaceflight activities. We'll need that rover to go pick up the water, food, and equipment that landed tens of kilometers away.I think the crux of the problem is that you don't know how impossibly hard it is, even using technology that doesn't exist yet. We don't know how to do it. I've mentioned but three of the things we don't know how to do. There are a number more.

I am not trying to downplay the challenges. However, I believe that the challenge of landing people safely on Mars today is very similar to the challenge of landing people safely on the moon in 1960. We have the basic technological know-how, but it is near the edge (although I would argue that we are at a much better starting position for a Mars mission today than we were for a moon landing in 1960).

The cost of the Apollo program was around $100 billion dollars and it would not be surprising to see a Mars mission cost $1 trillion or more. I'm confident if the budget were there, just like the Apollo program, the results would follow.

The only counterpoint to this is a seven year old article about a decade-old conference that took place around the same time that President Bush committed NASA to a manned Mars mission, before any serious planning about how to effect that had occurred.

By contrast, much more recently, a workshop group of more than 60 individuals representing more than 30 government, industry, academic and other organizations has found that a NASA-led manned mission to Mars is feasible if the space agency's budget is restored to pre-sequestration levels. [1]

I am not an engineer, but I'm pretty confident that our current state of technology is commensurate with engineering such a mission in the next decade or two.

REFERENCES:

[1] http://www.space.com/24268-manned-mars-mission-nasa-feasibility.html

 

[D H]

I am not trying to downplay the challenges.

That is exactly what you are trying to do.

However, I believe that the challenge of landing people safely on Mars today is very similar to the challenge of landing people safely on the moon in 1960.

Getting to Mars now is much harder than was getting to the Moon then. The breakthroughs needed in the 1960s to land on and return from the Moon were simple compared to those needed to land on and return from Mars.

Another problem is politics and money. The Apollo mission was uniquely situated in history. There was a perceived threat in the US that Russia was getting ahead of the US technologically. Apollo would never have happened without that perceived threat, or without the perpetual duck and cover exercises (youtube video: ) throughout the 1950s and into the early 1960s. The US was very afraid of what Russia might do (and Russia was very afraid of what the US might do). It was a time of MADness.

By contrast, much more recently, a workshop group of more than 60 individuals representing more than 30 government, industry, academic and other organizations has found that a NASA-led manned mission to Mars is feasible if the space agency's budget is restored to pre-sequestration levels. [1]

Did you read your cited article? It targets a "manned mission to Mars By 2030s" -- in other words, 25 years from now. That is perhaps doable with pre-sequestration funding levels, with some international participation to augment that pre-sequestration level funding. It does not require Apollo-style funding. Apollo-style funding is a pipe dream. That kind of funding will not happen until another major perceived threat appears.

Let's say we do start a long term project to send people to land on and return from Mars. Rhetorical question: What happens after that? The answer is to learn from history. What happens after that is what happened to NASA after they landed a few men on the Moon. What politicians from both sides thought was "Mission accomplished, and now we better clamp down on NASA before they bleed us dry." The end result: NASA went through a rather bleak period from the early 1970s to the late 1980s where they received far less money in inflation-adjusted dollars than they receive now, post-sequestration.

I predict the exact same outcome should NASA focus on sending humans to Mars. We might accomplish that mission, but it will be followed by decades of stagnation. IMHO, a much better objective is for NASA to find a way to show that space is profitable. The asteroid recovery plans are the best thing NASA has come up with for a long time. Show that space is a profit center rather than a cost center and we'll have people in space for a long time to come. Some of them will be doing science, a good deal more science than the meager amount done now. Humanity will be stuck here on Earth with little dribbles of funding for space exploration every now and then if space exploration turns out to be not at all profitable.

I am not an engineer, but I'm pretty confident that our current state of technology is commensurate with engineering such a mission in the next decade or two.

I am an engineer. In fact, I am an aerospace engineer who works with NASA, and I'm pretty confident that this is not the case.

 

[Chronos]

Even with our modern engineering savvy, manned space missions are obscenely expensive. The He3 carrot still dangles in front of us, but, who is willing to gamble vast resources without proven technology to utilize it?

 

[phinds]

I am not trying to downplay the challenges.

I can believe that you BELIEVE you are not but you have made it abundantly clear that you simply don't understand them and you in fact ARE downplaying them to a ridiculous degree.

 

[enorbet]

I am of the considered opinion that it will not only not be mere decades but actually Lifetimes before we land humans on Mars, absent some (and not just a few) fairly extreme technological breakthroughs, not the least of which is propulsion and radiation shielding. I utterly hate concluding this, but "if wishes were horses...".

It seems to me that in a fairly short time, perhaps that decade or two, we could have a Moon Base IF we had the will, which we apparently don't. It is my understanding that despite the apparent fact that such mass conflicts as WWII are a thing of the past, and a more Guerilla/Covert type of conflicts are more likely, the US spends more in a day on Conventional Defense (even though there is no single perceived enemy as during the Cold War) than NASA receives in an entire year.

It is also my understanding that during the height of the Apollo Mission the expenditures reached more than 1% of the National Budget, still a mere fraction of the Defense Budget at that time and even less now.

In 2009, NASA held a symposium on project costs which presented an estimate of the Apollo program costs in 2005 dollars as roughly $170 billion. This included all research and development costs; the procurement of 15 Saturn V rockets, 16 Command/Service Modules, 12 Lunar Modules, plus program support and management costs; construction expenses for facilities and their upgrading, and costs for flight operations. This was based on a Congressional Budget Office report, A Budgetary Analysis of NASA’s New Vision for Space, September 2004.[71] The Space Review estimated in 2010 the cost of Apollo from 1959 to 1973 as $20.4 billion, or $109 billion in 2010 dollars, averaged over the six landings as $18 billion each

Very few people understand the payoff, considering all the advances in so many areas, of those expenditures. Even such mundane things as textiles and fasteners (affecting many kinds or work wear and hazard wear as well as specialized medical condition protective attire, just to name a few) let alone the huge effect on micro-electronics, without which we would not be having this conversation not to mention a complete shift in economic base to Information... none of this and much more would have occurred.

However for the average businessman, politician, man-on-the-street this is all too abstract (read as "nebulous pie-in-the-sky") to actually divert expenditures from the closer to home, sexy new bomber (who cares if they rust away in some hangar? ...just in case, right?)

Many, even those "in the business" thought JFK's challenge was impossible to achieve at even twice the timeframe, but somehow a flame was ignited AND FUNDED and the rest is now History. I think it foolish to dismiss this as "just lucky" and impossible to reproduce.

Maybe it would take 20 years instead of 10. That is uncertain. What is certain is that we will never do it unless we begin to take it seriously and make it common knowledge just how beneficial Apollo really was on a global scale to an inestimable number of people, some of whom are alive today because of it.

 

[Damo ET]

Very few people understand the payoff, considering all the advances in so many areas, of those expenditures. Even such mundane things as textiles and fasteners (affecting many kinds or work wear and hazard wear as well as specialized medical condition protective attire, just to name a few) let alone the huge effect on micro-electronics, without which we would not be having this conversation not to mention a complete shift in economic base to Information... none of this and much more would have occurred.

However for the average businessman, politician, man-on-the-street this is all too abstract (read as "nebulous pie-in-the-sky") to actually divert expenditures from the closer to home, sexy new bomber (who cares if they rust away in some hangar? ...just in case, right?)
Maybe it would take 20 years instead of 10. That is uncertain. What is certain is that we will never do it unless we begin to take it seriously and make it common knowledge just how beneficial Apollo really was on a global scale to an inestimable number of people, some of whom are alive today because of it.

Enorbit, they are words plucked straight from my thoughts!
I believe that this is the fundamental problem that the western world faces, and unfortunately no amount of education, reasoning or even scare tactics will convince the 95% of the population (which enjoy western freedoms) that spending in science of ANY disipline is worth the payoff. Give them the internet with every educational book ever written, every science theory ever postulated, every forum like this, and what do they do, search for boobs!

"I stupid people, they are everywhere, they don't even know they are STUPID!"


Damo

 

[Drakkith]

Just because someone doesn't know much about science and technology, or has different priorities than you, does not make them stupid. Most people are not stupid.

 

[enorbet]

Given the technological difficulties as well as the socio-political environment, I am betting... let's say $10,000 that I will not only be dead but long dead before another single human sets foot on the Moon, forget about Mars. If I'm wrong and you wish to collect I will instruct my lawyer to place the 10K on my headstone in a ziploc baggie (he assures me he is trustworthy). If you think my estimate too long and think you can win this bet and this bet interests you, I also deal in bridges. :P

 

[Damo ET]

Fair point Drakkith, that was a very generalized statement.

It is just so frustrating that our society values such trivial things/people over the genuine contributors to the advancement of our species in becoming more than just consumers and another transient lifeform on this planet.
What happened to the days when 'our' celebrities were people like Einstein?Damo

 

[phinds]

Given the technological difficulties as well as the socio-political environment, I am betting... let's say $10,000 that I will not only be dead but long dead before another single human sets foot on the Moon, forget about Mars. If I'm wrong and you wish to collect I will instruct my lawyer to place the 10K on my headstone in a ziploc baggie (he assures me he is trustworthy). If you think my estimate too long and think you can win this bet and this bet interests you, I also deal in bridges. :P

 

[D H]

Given the technological difficulties as well as the socio-political environment, I am betting... let's say $10,000 that I will not only be dead but long dead before another single human sets foot on the Moon, forget about Mars.

That's a fair bet if you are seventy years old. If you are sixty or less, it's not such a good bet.

NASA is working on plans to send humans to Mars in the 2030s (e.g., 2039 counts, so about 25 years from now) and do so within the constraints of a pre-sequestration budget with only small, inflation-level increases over the course of that 25 years. That 25 year period gives more than enough time to develop solutions to the hard engineering problems outlined earlier in this thread, and it gives time to do so incrementally.

Funding at a pre-sequestration budget level means a bit more than half a percent of the federal budget. That's tiny compared to the unsustainable Apollo-level funding which peaked at 4.4% of the federal budget. This pre-sequestration level funding is arguably sustainable for the long term. An Apollo-style program is not, but this is not an Apollo-style program.

 

[phinds]

NASA is working on plans ...

Have you ever really looked at the outcome vs the plans for ANY major NASA mission? I point you specifically to the costs and timelines for both the Space Shuttle and the International Space Station. The plans are a joke compared to what really happens.