# If we had to get man back to the Moon, how soon could we do it? **URL:** \ **Category:** Factual Questions\ **Created:** [November 30, 2012, 8:50pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608 "2012-11-30T20:50:47Z")\ **Posts on this page:** 12\ **Page:** 2
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 1, 2012, 7:36pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/21 "2012-12-01T19:36:51Z")
> [@Enochian](#): > > Here are a few questions… Would people inside a space craft hear the roar of the engines on the way to the moon? Secondly, why did one astronaut who went to the moon report that the engines were roaring loud… Third, why would another astronaut who also went to the moon say he didn’t hear the engines because you can’t hear sound in the vacuum of space? The first astronaut’s answer is more believable… So why the conflict? I never believed that we didn’t go to the moon, but a few data points have introduced some doubt in my mind. > > Also, if it’s not dangerous to pass through the Van Allen Radiation belt, why is NASA and other scientists working on solutions to destroy the Van Allen Radiation belt? > > “HiVOLT (High Voltage Orbiting Long Tether) is a concept proposed by Russian physicist V.V. Danilov and further refined by Robert P. Hoyt and Robert L. Forward for removing the radiation fields of the Van Allen radiation belts[1] that surround the Earth. A proposed configuration consists of a system of five 100 km long conducting tethers deployed from satellites, and charged to a large voltage. This would cause charged particles that encounter the tethers to have their pitch angle changed, thus over time dissolving the Van Allen belts. Hoyt and Forward’s company, Tethers Unlimited, performed a preliminary analysis simulation, and produced a chart depicting a theoretical radiation flux reduction,[2] to less than 1% of current levels within two months[3] using the HiVOLT System.” **Moderating** **Enochian** , I fail to see how any of this is relevant to the question in the first post. If you wish to raise questions about the original moon missions, start a new thread in Great Debates. Don’t hijack this one. Colibri General Questions Moderator ---
**Author:** ![Santos\_L\_Halper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/santos_l_halper/32/1_2.png) [@Santos\_L\_Halper](https://boards.straightdope.com/u/Santos_L_Halper)\ **Post date:** [December 1, 2012, 7:39pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/22 "2012-12-01T19:39:36Z")
> [@HardlySanguine](#): > > I don’t understand this. Why couldn’t we do it in a couple weeks, if this were the case? Just re-use plans from the 60s, with multiple groups, locales around the country. If a few missions fail, oh well. Hmm, you seem to think Apollo took, say, ten people ten years to accomplish, so lets have a thousand people work on it and it’ll get done in a fraction the time. 🙂 Not all problems can be solved that way. Funnily enough, Wernher Von Braun had a quote that exactly fit that situation: > [@](#): > > You can’t have a baby in one month by getting nine women pregnant. Anyway, Apollo did use multiple groups around the country. At its peak, the Apollo program employed 400,000 people and required the support of over 20,000 industrial firms and universities. ---
**Author:** ![Santos\_L\_Halper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/santos_l_halper/32/1_2.png) [@Santos\_L\_Halper](https://boards.straightdope.com/u/Santos_L_Halper)\ **Post date:** [December 1, 2012, 7:51pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/23 "2012-12-01T19:51:51Z")
> [@TriPolar](#): > > Suppose we wanted to send a couple of robots to the moon and back instead of men? How much of the difficulty is simply due to the danger of the mission? They could use a much smaller rocket because there’s no need for life support, and the entire rover would not need to be the size or complexity of the Apollo lunar module and command/service modules. You could presumably use something on the scale of the rovers we’ve sent to Mars, depending on what mission they needed to accomplish. > [@](#): > > There have been many technology advances since the Apollo project. The spacecraft should be smaller, lighter and use more efficient rockets. Computer and materials technology has advanced tremendously since the sixties, so there is a fair amount of weight savings there, but the vast majority of the weight of any rocket is in the fuel, which we can’t really use much more efficiently than the old days. Much as with cars and gasoline, a gallon of rocket fuel only contains so much energy and no technological improvements will change that. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [December 1, 2012, 8:04pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/24 "2012-12-01T20:04:22Z")
> [@Santos\_L\_Halper](#): > > They could use a much smaller rocket because there’s no need for life support, and the entire rover would not need to be the size or complexity of the Apollo lunar module and command/service modules. You could presumably use something on the scale of the rovers we’ve sent to Mars, depending on what mission they needed to accomplish. I was presuming the mission required the same mass of material to be taken and was just eliminating the danger to human life. So in the circumstances you mention, it could be much lighter and require much less fuel. If we were talking just robots you wouldn’t even have to return them to earth, they could just put some moon rocks back in the module to return to earth. > [@](#): > > Computer and materials technology has advanced tremendously since the sixties, so there is a fair amount of weight savings there, but the vast majority of the weight of any rocket is in the fuel, which we can’t really use much more efficiently than the old days. Much as with cars and gasoline, a gallon of rocket fuel only contains so much energy and no technological improvements will change that. Rockets are somewhat more efficient, and weight savings compound to reduce the fuel requirements. But you’re right, overall rockets are big heavy flying fuel tanks and technology hasn’t given us a new means to get to space yet. It’s a different problem to consider how fast we could make flight to orbit technology to work. ---
**Author:** ![Cheshire\_Human](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Cheshire\_Human](https://boards.straightdope.com/u/Cheshire_Human)\ **Post date:** [December 1, 2012, 8:14pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/25 "2012-12-01T20:14:49Z")
> [@kanicbird](#): > > Would it be needed to be a manned mission? Perhaps a up and coming mars rover can be repurposed. This would lower the thrust requirements as the rover can take longer then what is reasonable for human travel, and should be able to use existing rockets used to launch probes to Mar, Jupiter and Saturn. We would not have to reconstruct the Saturn V. It took 3 days for Apollo to get to the Moon, because that’s how long it takes to get there in a minimum-energy transfer orbit. If you want to take longer to get there, it’ll cost you more energy, not less. The Apollo life support system was designed for the length of the trip, not vice verse. ---
**Author:** ![Santos\_L\_Halper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/santos_l_halper/32/1_2.png) [@Santos\_L\_Halper](https://boards.straightdope.com/u/Santos_L_Halper)\ **Post date:** [December 1, 2012, 8:23pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/26 "2012-12-01T20:23:08Z")
> [@Cheshire\_Human](#): > > It took 3 days for Apollo to get to the Moon, because that’s how long it takes to get there in a minimum-energy transfer orbit. If you want to take longer to get there, it’ll cost you more energy, not less. The Apollo life support system was designed for the length of the trip, not vice verse. The European [SMART-1](http://en.wikipedia.org/wiki/SMART-1) satellite used an ion engine to get it to the moon. The low thrust but highly efficient engine propelled it on an orbit that gradually spiraled out farther and farther from Earth over thirteen months until it reached Lunar orbit. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [December 1, 2012, 8:24pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/27 "2012-12-01T20:24:05Z")
> [@Santos\_L\_Halper](#): > > Anyway, Apollo did use multiple groups around the country. At its peak, the Apollo program employed 400,000 people and required the support of over 20,000 industrial firms and universities. The other problem is that the plans from the sixties don’t exist any more. Except for a few drawings people kept for souvenirs, the plans for the Saturn V were deliberately destroyed decades ago. I don’t imagine the LM, CM, and SM drawings fared any better. Any jigs and tooling are gone as well. ---
**Author:** ![AtomicDog](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@AtomicDog](https://boards.straightdope.com/u/AtomicDog)\ **Post date:** [December 1, 2012, 8:47pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/28 "2012-12-01T20:47:47Z")
“Deliberately destroyed” in the sense that aerospace contractors didn’t see the need of keeping railroad boxcars full of plans around for obsolete vehicles and got rid of them. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [December 1, 2012, 8:54pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/29 "2012-12-01T20:54:37Z")
> [@HardlySanguine](#): > > I don’t understand this. Why couldn’t we do it in a couple weeks, if this were the case? Just re-use plans from the 60s, with multiple groups, locales around the country. If a few missions fail, oh well. Rockets are systems and systems are holistic. Start with those plans from the 60s. They call for thousands and thousands of parts, all of which were farmed out to contractors and subcontractors. The vast majority of those firms no longer exist. You can’t get the parts off the shelf because nobody makes them anymore. Could you just tell firms to go ahead and start anyway? Not likely. The parts depended entirely on 60s technology. That is, the technology was the technology of the day, the machine tools to make the part were the technology of the day, and the engineering and design were the technology of the day. All of that would have to be replicated. So then, why use old technology? Why not use current technology? That creates problems of its own. You can’t simply swap out a 1960s compressor for a 2012 compressor. All the fittings and connections and interactions have to be redesigned to make it work. That holds true for every single part. To make everything work you need to redesign the entire system to modern standards and then create a whole supplier network from scratch. Neither approach is conceivably possible to do in a few weeks. A year would be amazingly quick and that is leaving all the bureaucracy out of the picture. ---
**Author:** ![jonesj2205](https://avatars.discourse-cdn.com/v4/letter/j/ecc23a/32.png) [@jonesj2205](https://boards.straightdope.com/u/jonesj2205)\ **Post date:** [December 1, 2012, 9:02pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/30 "2012-12-01T21:02:40Z")
Plans aside, the forms, tools, supply chains are all changed or gone. It’s starting from scratch no matter how you look at it. ---
**Author:** ![Santos\_L\_Halper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/santos_l_halper/32/1_2.png) [@Santos\_L\_Halper](https://boards.straightdope.com/u/Santos_L_Halper)\ **Post date:** [December 1, 2012, 9:21pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/31 "2012-12-01T21:21:45Z")
> [@DesertDog](#): > > The other problem is that the plans from the sixties don’t exist any more. Except for a few drawings people kept for souvenirs, the plans for the Saturn V were deliberately destroyed decades ago. I don’t imagine the LM, CM, and SM drawings fared any better. Any jigs and tooling are gone as well. > [@](#): > > The aren’t all destroyed. Many of the detailed plans for the Apollo hardware are on microfilm at the United States National Archives. > > Unfortunately the design documentation for something as complicated as a space ship or the lunar rover is not something that just comfortably fits in a file cabinet. It typically occupies several hundred thousand cubic feet. Grumman engineers were, at one point, producing more than 4,000 drawings per week. In addition, each unit produced requires installation, service, and modification documentation for each individual part on the unit. > > Congress provided no funding for the storage and archive of the detailed design documentation. The private companies who had custody of it did not have the funds nor the desire to archive materials that required an inconveniently large building in which to house it. They are for-profit companies, not museums. Thus the detailed documentation was regretfully discarded while the basic documentation was preserved. > **[Clavius: Bibliography - cosmic dave's 32 questions](https://www.clavius.org/bibdave32.html)** As you indicated, all the jigs and toolings are long gone. And the engineers and technicians that had the specialized skills to build what were practically hand built, one of a kind machines are all long since retired or dead. There are a lot of complicated little details in how to build these things that can’t be conveyed in a bunch of blueprints. Stuff that would pretty much need to be re-learned if they tried to create new copies of a fifty year old space vehicle. It’d make more sense to study how it was done then and learn from the engineers who are still alive what kind of problems they faced and solutions they came up with, then use that as a starting point to build new vehicles that take advantage of the much more advanced technology that is available today. ---
**Author:** ![Cheshire\_Human](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Cheshire\_Human](https://boards.straightdope.com/u/Cheshire_Human)\ **Post date:** [December 2, 2012, 3:39pm UTC](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608/32 "2012-12-02T15:39:00Z")
> [@Santos\_L\_Halper](#): > > The European [SMART-1](http://en.wikipedia.org/wiki/SMART-1) satellite used an ion engine to get it to the moon. The low thrust but highly efficient engine propelled it on an orbit that gradually spiraled out farther and farther from Earth over thirteen months until it reached Lunar orbit. They made a trade-off. More total energy per kg at the moon, in exchange for far fewer kgs wasted in a much less efficient engine. [Previous page](https://boards.straightdope.com/t/if-we-had-to-get-man-back-to-the-moon-how-soon-could-we-do-it/642608.md?page=1)