Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why haven't we gone back to the moon?

  1. Sep 1, 2014 #1
    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?
  2. jcsd
  3. Sep 1, 2014 #2
    Mars is a more likely candidate for the existence of life.
  4. Sep 1, 2014 #3
    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.
  5. Sep 1, 2014 #4


    User Avatar
    Gold Member

    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!
    Last edited: Sep 1, 2014
  6. Sep 1, 2014 #5

    Doug Huffman

    User Avatar
    Gold Member

    We, US, back to the Moon? Can't afford it due to descent to regression to the mean.
  7. Sep 1, 2014 #6
    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.
  8. Sep 1, 2014 #7


    User Avatar
    Gold Member

    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.
  9. Sep 1, 2014 #8
    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.
  10. Sep 1, 2014 #9
    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.
  11. Sep 1, 2014 #10


    User Avatar
    Gold Member

    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.
  12. Sep 1, 2014 #11
    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.
  13. Sep 1, 2014 #12


    User Avatar
    Gold Member

    Yes, I agree (although I think you have lets off a lot of other concerns), and my statement stands.
  14. Sep 1, 2014 #13
    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 dont 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.
  15. Sep 1, 2014 #14


    User Avatar
    Gold Member

    The answer is funding. Period.

    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?

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

    Sure, but it STILL isn't going to happen. FUNDING !!!
  16. Sep 1, 2014 #15


    User Avatar
    Science Advisor
    Gold Member

    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.
  17. Sep 1, 2014 #16


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    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:



    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.
  18. Sep 1, 2014 #17
    We - means Earthlings.
  19. Sep 1, 2014 #18
    How much does it cost? How much does any country have to spend? I doubt , anyone of us can answer these questions?
  20. Sep 1, 2014 #19


    User Avatar
    Staff Emeritus
    Science Advisor

    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

    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.

    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.

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

    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.

    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.
  21. Sep 2, 2014 #20
    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.
  22. Sep 2, 2014 #21


    User Avatar
    Staff Emeritus
    Science Advisor

    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)
    Last edited: Sep 2, 2014
  23. Sep 2, 2014 #22
    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.
  24. Sep 2, 2014 #23


    User Avatar
    Staff Emeritus
    Science Advisor

    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.
  25. Sep 2, 2014 #24


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    That's a totally pointless response to Drakkith

    you just agreed with him ... NONE of them are self-sustaining :smile:
    and all because of technological problems

    Last edited: Sep 2, 2014
  26. Sep 2, 2014 #25
    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook