# Could we put humans on Mercury? **URL:** \ **Category:** Factual Questions\ **Created:** [July 8, 2021, 12:22am UTC](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937 "2021-07-08T00:22:42Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [July 13, 2021, 2:22pm UTC](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937/42 "2021-07-13T14:22:07Z")
> [@Elmer\_J.Fudd](#): > > I know NASA funding has been declared off topic, but isn’t it fair to say that the resources necessary for such a feat are far more daunting than any technical obstacles? Not to mention the will necessary to do something so costly with so little foreseeable return on the investment. If we had basic orbital infrastructure, which we will likely have before the end of the century, it isn’t such a daunting task. These lasers would require a lot of energy, but nothing a large solar array or small nuclear reactor couldn’t handle. Sending 3 or 4 of these lasers into orbit around the sun is probably easier than building a solar sail big enough to move a spaceship that can sustain a crew for years. Although both would be huge tasks. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [July 13, 2021, 2:24pm UTC](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937/43 "2021-07-13T14:24:59Z")
> [@Machine\_Elf](#): > > AIUI, solar sails are useful for propelling things _away_ from the sun. Mercury is closer to the sun than Earth, so how would a solar sail help a vehicle get from here to there? Am I misunderstanding how solar sails work, or how they would be used for this mission? Similar to how a sailboat can sail into the wind, a solar sail can use the sun’s light to slow its orbital velocity, lowering periapsis. It isn’t used only to push directly away from the sun- that wouldn’t be very useful at all. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [July 13, 2021, 2:40pm UTC](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937/44 "2021-07-13T14:40:23Z")
I think what you are describing is more or less identical to the Hohmann transfer, or more precisely a patched-conic trajectory, as already described by @Stranger_On_A_Train . Things are even worse, though, than that first-order calculation describes because the orbit of Mercury is inclined, as in by a lot, even compared to planets like Mars where orbital inclination is already an issue. In any case, the Venus flyby saves you a huge amount of fuel. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 13, 2021, 4:05pm UTC](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937/45 "2021-07-13T16:05:31Z")
Hohmann orbits are only optimum if you ignore all other objects. In the real Solar System, though, where you do have other objects, you only ever need slightly more than the energy needed to reach the next closest object (in our case, the Moon). Though depending on how much more your “slightly more” is, and when you want to depart, you might end up with an extremely long and complicated path to get there. One thing about sending humans to Mercury is, the trip has relatively few unknowns. To land anything (manned or unmanned) on Mars, say, you have to go through an atmosphere, and atmospheres can do all sorts of crazy unpredictable things. Mercury doesn’t, though, so you don’t have to worry about that unpredictability. ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [July 17, 2021, 2:15pm UTC](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937/46 "2021-07-17T14:15:46Z")
> [@Stranger\_On\_A\_Train](#): > > which still is about the same amount of acceleration as staring at someone really hard across the room. Ha!!! [Previous page](https://boards.straightdope.com/t/could-we-put-humans-on-mercury/945937.md?page=2)