杨立新解读2018年天津市《政府工作报告》--天津频道--人民网
Current License: CC BY-SA 3.0
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| May 12, 2015 at 14:23 | history | edited | user12 | CC BY-SA 3.0 |
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| May 11, 2015 at 18:42 | comment | added | Russell Borogove | The USSR successfully did unmanned lunar sample return missions in the 1970s. en.wikipedia.org/wiki/Sample_return_mission#First_missions | |
| May 11, 2015 at 15:19 | comment | added | paul23 | You forgot the fact that humans are utterly fragile and weak. The extra weight from safety measures (and pressure chambers, some humans like the breath). Is many times the 80kg a human would be. | |
| Aug 13, 2014 at 8:20 | comment | added | user | In addition to my previous comment, and which appears to not be touched on by this answer: An unmanned mission can afford to take a much longer time in Earth--Moon transfer orbit. With a human, you pretty much have to take the direct route and move quickly; without humans, you can afford to spend perhaps even a few months in transfer orbit to get to the moon, if it means for example a large savings in the amount of propellant needed. | |
| S Apr 1, 2014 at 12:51 | history | suggested | codesparkle | CC BY-SA 3.0 |
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| Apr 1, 2014 at 12:36 | review | Suggested edits | |||
| S Apr 1, 2014 at 12:51 | |||||
| Jan 30, 2014 at 14:41 | comment | added | user | @MarkAdler It's also a lot less risky. With a mission carrying humans, you absolutely have to have large on-board propulsion so that an error in the launch angle can be corrected mid-flight, which alone comes at huge cost even if the capability turns out to not be needed. If you do little more than throw a container, you can basically toss it in the general direction of Earth and call it a day. (Yes, I know in practice it's more involved than that, but for a figure of speech and compared to a human mission, it works.) | |
| Sep 26, 2013 at 2:53 | comment | added | Mark Adler | @john3103: No, that would be much, much easier than sending astronauts back. I would guess about two orders of magnitude down in cost. \$100B vs \$1B. | |
| Sep 25, 2013 at 15:41 | vote | accept | Madeyedexter | ||
| Sep 25, 2013 at 11:54 | comment | added | john3103 | @Madeyedexter - a probe with a robotic limb could scoop-up a sample, toss it into a small re-entry shuttle, and launch it back to earth, just as easily as we could send astronauts back (which is to say, it's incredibly hard). | |
| Sep 25, 2013 at 9:26 | comment | added | gerrit | @Madeyedexter Yes. | |
| Sep 25, 2013 at 6:59 | comment | added | Madeyedexter | The Apollo 17 mission lasted 12 days. And with current technology and Space Collaboration as big as ISS, plans to send Man on Mars, is cost really a factor? | |
| Sep 25, 2013 at 6:54 | comment | added | Madeyedexter | How can the probes bring back the samples on their own? | |
| Sep 24, 2013 at 21:42 | history | answered | john3103 | CC BY-SA 3.0 |