Could an Apollo mission be possible if Moon would be Earth like?How would a manned Mars Lander be testedWhat...
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Could an Apollo mission be possible if Moon would be Earth like?
How would a manned Mars Lander be testedWhat would be the effect of increasing the mass of Mars?Would the Moon be a better place than Mars anyways?How plausible are the predictions made by Stephen Petranek at TED?What is stopping us from starting to terraform Mars right now?Are there any major flaws with the Mars Architecture used in the Martian?Venus vs Mars for colonizationHave we considered sending people on no-return missions?Mars “bus” shuttle between Earth and MarsWhich are the reasons for wanting to have a colony in Mars first than in the Moon?
$begingroup$
I suspect that actual technology results in the apparently paradoxical situation that is easier to visit the moon rather than a comfortable planet able to sustain life. I am obviously supposing the crew must return to Earth.
Am I correct thinking that if there would be a copy of Earth at the place of the Moon not manned missions would have been yet possible? This seems obvious but is rarely realised by people in general.
Similar (just similar) considerations apply to manned mission to Mars, which are getting more and more discussed in divulgative TV channels but seems to me almost totally fictional, at the current stage.
(I consider the various energy requirements for getting there, braking, descending, and back, and life sustaining stuff such as food, water and breathable gas. While the design of Apollo did it for the Moon, a two ways trip to a Earth like moon or Mars differ by many points and seems to me currently impossible.
Please note that I am aware that replacing moon with an Earth would change the solar system and perhaps a binary planet system orbiting a star is even physically impossible. I am concerned with distance and escaping speed only).
Edit: I would like to stress that I could have place two earth masses of concrete in my question instead of a couple of earths. Atmosphere is important in the sense that there are different braking mechanisms / dragging etc. There is not much emphasis in my Q about habitability, except that I have mentioned that counter-intuitively is easier to go to the moon than to some kind of a big planet supposed to have a breathable atmosphere. Just to avoid debate not inherent here.
mars
$endgroup$
|
show 1 more comment
$begingroup$
I suspect that actual technology results in the apparently paradoxical situation that is easier to visit the moon rather than a comfortable planet able to sustain life. I am obviously supposing the crew must return to Earth.
Am I correct thinking that if there would be a copy of Earth at the place of the Moon not manned missions would have been yet possible? This seems obvious but is rarely realised by people in general.
Similar (just similar) considerations apply to manned mission to Mars, which are getting more and more discussed in divulgative TV channels but seems to me almost totally fictional, at the current stage.
(I consider the various energy requirements for getting there, braking, descending, and back, and life sustaining stuff such as food, water and breathable gas. While the design of Apollo did it for the Moon, a two ways trip to a Earth like moon or Mars differ by many points and seems to me currently impossible.
Please note that I am aware that replacing moon with an Earth would change the solar system and perhaps a binary planet system orbiting a star is even physically impossible. I am concerned with distance and escaping speed only).
Edit: I would like to stress that I could have place two earth masses of concrete in my question instead of a couple of earths. Atmosphere is important in the sense that there are different braking mechanisms / dragging etc. There is not much emphasis in my Q about habitability, except that I have mentioned that counter-intuitively is easier to go to the moon than to some kind of a big planet supposed to have a breathable atmosphere. Just to avoid debate not inherent here.
mars
$endgroup$
2
$begingroup$
Earth would not be possible if Moon was Earth-like. Or at least it would be vastly different from the Earth as we know it.
$endgroup$
– SF.
7 hours ago
$begingroup$
Yes I was aware of this type of comments. It has not to strictly be a satellite. Or alternatively, the two earth-like object orbit each other. Let us assume that this configuration doesn't prevent atmosphere formation and persistance. Though I am not even sure that binary planets can orbit a star in a stable fashion. Just focus on distance and energetic requirements. @SF
$endgroup$
– Alchimista
7 hours ago
2
$begingroup$
@alchimista Pluto and Charon are doing just fine, in terms of orbital stability.
$endgroup$
– Oscar Lanzi
4 hours ago
$begingroup$
@OscarLanzi: Moon is over 5 times heavier than Pluto, and they are tidally locked. Two bodies as massive as Earth in the Earth-Moon distance would most certainly enter a tidal lock, and that means month-long nights and days; enormous sea tides washing over swaths of the continents every two weeks, Massive earthquakes caused by the remaining tidal forces. Such slow spin would quite likely deprive the planets of magnetosphere, and even if not, they would disrupt each other's magnetosphere on regular basis. As a planetary system they could exist. As life-bearing planets - definitely not.
$endgroup$
– SF.
4 hours ago
$begingroup$
@SF agreed. Only the orbital stability is claimed to work on Pluto/Charon. The Earth and an equally massive Moon in this alternate world might even have double-locked before getting 400,000 km apart, amplifying your adverse tidal effects.
$endgroup$
– Oscar Lanzi
3 hours ago
|
show 1 more comment
$begingroup$
I suspect that actual technology results in the apparently paradoxical situation that is easier to visit the moon rather than a comfortable planet able to sustain life. I am obviously supposing the crew must return to Earth.
Am I correct thinking that if there would be a copy of Earth at the place of the Moon not manned missions would have been yet possible? This seems obvious but is rarely realised by people in general.
Similar (just similar) considerations apply to manned mission to Mars, which are getting more and more discussed in divulgative TV channels but seems to me almost totally fictional, at the current stage.
(I consider the various energy requirements for getting there, braking, descending, and back, and life sustaining stuff such as food, water and breathable gas. While the design of Apollo did it for the Moon, a two ways trip to a Earth like moon or Mars differ by many points and seems to me currently impossible.
Please note that I am aware that replacing moon with an Earth would change the solar system and perhaps a binary planet system orbiting a star is even physically impossible. I am concerned with distance and escaping speed only).
Edit: I would like to stress that I could have place two earth masses of concrete in my question instead of a couple of earths. Atmosphere is important in the sense that there are different braking mechanisms / dragging etc. There is not much emphasis in my Q about habitability, except that I have mentioned that counter-intuitively is easier to go to the moon than to some kind of a big planet supposed to have a breathable atmosphere. Just to avoid debate not inherent here.
mars
$endgroup$
I suspect that actual technology results in the apparently paradoxical situation that is easier to visit the moon rather than a comfortable planet able to sustain life. I am obviously supposing the crew must return to Earth.
Am I correct thinking that if there would be a copy of Earth at the place of the Moon not manned missions would have been yet possible? This seems obvious but is rarely realised by people in general.
Similar (just similar) considerations apply to manned mission to Mars, which are getting more and more discussed in divulgative TV channels but seems to me almost totally fictional, at the current stage.
(I consider the various energy requirements for getting there, braking, descending, and back, and life sustaining stuff such as food, water and breathable gas. While the design of Apollo did it for the Moon, a two ways trip to a Earth like moon or Mars differ by many points and seems to me currently impossible.
Please note that I am aware that replacing moon with an Earth would change the solar system and perhaps a binary planet system orbiting a star is even physically impossible. I am concerned with distance and escaping speed only).
Edit: I would like to stress that I could have place two earth masses of concrete in my question instead of a couple of earths. Atmosphere is important in the sense that there are different braking mechanisms / dragging etc. There is not much emphasis in my Q about habitability, except that I have mentioned that counter-intuitively is easier to go to the moon than to some kind of a big planet supposed to have a breathable atmosphere. Just to avoid debate not inherent here.
mars
mars
edited 2 hours ago
Alchimista
asked 7 hours ago
AlchimistaAlchimista
1367
1367
2
$begingroup$
Earth would not be possible if Moon was Earth-like. Or at least it would be vastly different from the Earth as we know it.
$endgroup$
– SF.
7 hours ago
$begingroup$
Yes I was aware of this type of comments. It has not to strictly be a satellite. Or alternatively, the two earth-like object orbit each other. Let us assume that this configuration doesn't prevent atmosphere formation and persistance. Though I am not even sure that binary planets can orbit a star in a stable fashion. Just focus on distance and energetic requirements. @SF
$endgroup$
– Alchimista
7 hours ago
2
$begingroup$
@alchimista Pluto and Charon are doing just fine, in terms of orbital stability.
$endgroup$
– Oscar Lanzi
4 hours ago
$begingroup$
@OscarLanzi: Moon is over 5 times heavier than Pluto, and they are tidally locked. Two bodies as massive as Earth in the Earth-Moon distance would most certainly enter a tidal lock, and that means month-long nights and days; enormous sea tides washing over swaths of the continents every two weeks, Massive earthquakes caused by the remaining tidal forces. Such slow spin would quite likely deprive the planets of magnetosphere, and even if not, they would disrupt each other's magnetosphere on regular basis. As a planetary system they could exist. As life-bearing planets - definitely not.
$endgroup$
– SF.
4 hours ago
$begingroup$
@SF agreed. Only the orbital stability is claimed to work on Pluto/Charon. The Earth and an equally massive Moon in this alternate world might even have double-locked before getting 400,000 km apart, amplifying your adverse tidal effects.
$endgroup$
– Oscar Lanzi
3 hours ago
|
show 1 more comment
2
$begingroup$
Earth would not be possible if Moon was Earth-like. Or at least it would be vastly different from the Earth as we know it.
$endgroup$
– SF.
7 hours ago
$begingroup$
Yes I was aware of this type of comments. It has not to strictly be a satellite. Or alternatively, the two earth-like object orbit each other. Let us assume that this configuration doesn't prevent atmosphere formation and persistance. Though I am not even sure that binary planets can orbit a star in a stable fashion. Just focus on distance and energetic requirements. @SF
$endgroup$
– Alchimista
7 hours ago
2
$begingroup$
@alchimista Pluto and Charon are doing just fine, in terms of orbital stability.
$endgroup$
– Oscar Lanzi
4 hours ago
$begingroup$
@OscarLanzi: Moon is over 5 times heavier than Pluto, and they are tidally locked. Two bodies as massive as Earth in the Earth-Moon distance would most certainly enter a tidal lock, and that means month-long nights and days; enormous sea tides washing over swaths of the continents every two weeks, Massive earthquakes caused by the remaining tidal forces. Such slow spin would quite likely deprive the planets of magnetosphere, and even if not, they would disrupt each other's magnetosphere on regular basis. As a planetary system they could exist. As life-bearing planets - definitely not.
$endgroup$
– SF.
4 hours ago
$begingroup$
@SF agreed. Only the orbital stability is claimed to work on Pluto/Charon. The Earth and an equally massive Moon in this alternate world might even have double-locked before getting 400,000 km apart, amplifying your adverse tidal effects.
$endgroup$
– Oscar Lanzi
3 hours ago
2
2
$begingroup$
Earth would not be possible if Moon was Earth-like. Or at least it would be vastly different from the Earth as we know it.
$endgroup$
– SF.
7 hours ago
$begingroup$
Earth would not be possible if Moon was Earth-like. Or at least it would be vastly different from the Earth as we know it.
$endgroup$
– SF.
7 hours ago
$begingroup$
Yes I was aware of this type of comments. It has not to strictly be a satellite. Or alternatively, the two earth-like object orbit each other. Let us assume that this configuration doesn't prevent atmosphere formation and persistance. Though I am not even sure that binary planets can orbit a star in a stable fashion. Just focus on distance and energetic requirements. @SF
$endgroup$
– Alchimista
7 hours ago
$begingroup$
Yes I was aware of this type of comments. It has not to strictly be a satellite. Or alternatively, the two earth-like object orbit each other. Let us assume that this configuration doesn't prevent atmosphere formation and persistance. Though I am not even sure that binary planets can orbit a star in a stable fashion. Just focus on distance and energetic requirements. @SF
$endgroup$
– Alchimista
7 hours ago
2
2
$begingroup$
@alchimista Pluto and Charon are doing just fine, in terms of orbital stability.
$endgroup$
– Oscar Lanzi
4 hours ago
$begingroup$
@alchimista Pluto and Charon are doing just fine, in terms of orbital stability.
$endgroup$
– Oscar Lanzi
4 hours ago
$begingroup$
@OscarLanzi: Moon is over 5 times heavier than Pluto, and they are tidally locked. Two bodies as massive as Earth in the Earth-Moon distance would most certainly enter a tidal lock, and that means month-long nights and days; enormous sea tides washing over swaths of the continents every two weeks, Massive earthquakes caused by the remaining tidal forces. Such slow spin would quite likely deprive the planets of magnetosphere, and even if not, they would disrupt each other's magnetosphere on regular basis. As a planetary system they could exist. As life-bearing planets - definitely not.
$endgroup$
– SF.
4 hours ago
$begingroup$
@OscarLanzi: Moon is over 5 times heavier than Pluto, and they are tidally locked. Two bodies as massive as Earth in the Earth-Moon distance would most certainly enter a tidal lock, and that means month-long nights and days; enormous sea tides washing over swaths of the continents every two weeks, Massive earthquakes caused by the remaining tidal forces. Such slow spin would quite likely deprive the planets of magnetosphere, and even if not, they would disrupt each other's magnetosphere on regular basis. As a planetary system they could exist. As life-bearing planets - definitely not.
$endgroup$
– SF.
4 hours ago
$begingroup$
@SF agreed. Only the orbital stability is claimed to work on Pluto/Charon. The Earth and an equally massive Moon in this alternate world might even have double-locked before getting 400,000 km apart, amplifying your adverse tidal effects.
$endgroup$
– Oscar Lanzi
3 hours ago
$begingroup$
@SF agreed. Only the orbital stability is claimed to work on Pluto/Charon. The Earth and an equally massive Moon in this alternate world might even have double-locked before getting 400,000 km apart, amplifying your adverse tidal effects.
$endgroup$
– Oscar Lanzi
3 hours ago
|
show 1 more comment
1 Answer
1
active
oldest
votes
$begingroup$
Under (very stretched) assumptions that the "Other Earth" would not affect Earth's natural conditions, then an Apollo-like mission would be impossible.
Tyranny of the rocket equation makes the launch mass to scale exponentially with delta-V budget. The enormous Saturn V rocket was capable of lifting and launching towards the Moon the command/service module and the lunar module, and little more than that. Compare scale/size of these - the Apollo spacecraft in upper right corner to the rest of the rocket.
Now instead of the lunar module, you'd need an entire stack of size comparable to Saturn V - additionally, capable of soft landing in the rough terrain of the uninhabited "other Earth". And now you need to add a rocket to bring it to the "Other Earth" - one, that by size, comparing to Saturn V, is as Saturn V is to the Apollo spacecraft. And obviously, by cost too.
The same style mission would be plain impossible. The delta-V to take off from Earth is high enough by itself. Doubling it, scaling the mass ratios exponentially yields an impossibly huge construction.
That is not to say a successful mission including return couldn't be launched. If the other planet was inhabitable, a permanent colony could be established with multiple one-way missions delivering supplies and technology. Utilizing in-situ resources and technology from Earth, the colony could construct rockets capable of entering the "Other Earth's" orbit, where they could rendez-vous with vehicles resembling Apollo CSM and the crew could use it to return to Earth. Thing is the timeline between first landing and first return would be decades, not two weeks.
$endgroup$
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
add a comment |
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$begingroup$
Under (very stretched) assumptions that the "Other Earth" would not affect Earth's natural conditions, then an Apollo-like mission would be impossible.
Tyranny of the rocket equation makes the launch mass to scale exponentially with delta-V budget. The enormous Saturn V rocket was capable of lifting and launching towards the Moon the command/service module and the lunar module, and little more than that. Compare scale/size of these - the Apollo spacecraft in upper right corner to the rest of the rocket.
Now instead of the lunar module, you'd need an entire stack of size comparable to Saturn V - additionally, capable of soft landing in the rough terrain of the uninhabited "other Earth". And now you need to add a rocket to bring it to the "Other Earth" - one, that by size, comparing to Saturn V, is as Saturn V is to the Apollo spacecraft. And obviously, by cost too.
The same style mission would be plain impossible. The delta-V to take off from Earth is high enough by itself. Doubling it, scaling the mass ratios exponentially yields an impossibly huge construction.
That is not to say a successful mission including return couldn't be launched. If the other planet was inhabitable, a permanent colony could be established with multiple one-way missions delivering supplies and technology. Utilizing in-situ resources and technology from Earth, the colony could construct rockets capable of entering the "Other Earth's" orbit, where they could rendez-vous with vehicles resembling Apollo CSM and the crew could use it to return to Earth. Thing is the timeline between first landing and first return would be decades, not two weeks.
$endgroup$
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
add a comment |
$begingroup$
Under (very stretched) assumptions that the "Other Earth" would not affect Earth's natural conditions, then an Apollo-like mission would be impossible.
Tyranny of the rocket equation makes the launch mass to scale exponentially with delta-V budget. The enormous Saturn V rocket was capable of lifting and launching towards the Moon the command/service module and the lunar module, and little more than that. Compare scale/size of these - the Apollo spacecraft in upper right corner to the rest of the rocket.
Now instead of the lunar module, you'd need an entire stack of size comparable to Saturn V - additionally, capable of soft landing in the rough terrain of the uninhabited "other Earth". And now you need to add a rocket to bring it to the "Other Earth" - one, that by size, comparing to Saturn V, is as Saturn V is to the Apollo spacecraft. And obviously, by cost too.
The same style mission would be plain impossible. The delta-V to take off from Earth is high enough by itself. Doubling it, scaling the mass ratios exponentially yields an impossibly huge construction.
That is not to say a successful mission including return couldn't be launched. If the other planet was inhabitable, a permanent colony could be established with multiple one-way missions delivering supplies and technology. Utilizing in-situ resources and technology from Earth, the colony could construct rockets capable of entering the "Other Earth's" orbit, where they could rendez-vous with vehicles resembling Apollo CSM and the crew could use it to return to Earth. Thing is the timeline between first landing and first return would be decades, not two weeks.
$endgroup$
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
add a comment |
$begingroup$
Under (very stretched) assumptions that the "Other Earth" would not affect Earth's natural conditions, then an Apollo-like mission would be impossible.
Tyranny of the rocket equation makes the launch mass to scale exponentially with delta-V budget. The enormous Saturn V rocket was capable of lifting and launching towards the Moon the command/service module and the lunar module, and little more than that. Compare scale/size of these - the Apollo spacecraft in upper right corner to the rest of the rocket.
Now instead of the lunar module, you'd need an entire stack of size comparable to Saturn V - additionally, capable of soft landing in the rough terrain of the uninhabited "other Earth". And now you need to add a rocket to bring it to the "Other Earth" - one, that by size, comparing to Saturn V, is as Saturn V is to the Apollo spacecraft. And obviously, by cost too.
The same style mission would be plain impossible. The delta-V to take off from Earth is high enough by itself. Doubling it, scaling the mass ratios exponentially yields an impossibly huge construction.
That is not to say a successful mission including return couldn't be launched. If the other planet was inhabitable, a permanent colony could be established with multiple one-way missions delivering supplies and technology. Utilizing in-situ resources and technology from Earth, the colony could construct rockets capable of entering the "Other Earth's" orbit, where they could rendez-vous with vehicles resembling Apollo CSM and the crew could use it to return to Earth. Thing is the timeline between first landing and first return would be decades, not two weeks.
$endgroup$
Under (very stretched) assumptions that the "Other Earth" would not affect Earth's natural conditions, then an Apollo-like mission would be impossible.
Tyranny of the rocket equation makes the launch mass to scale exponentially with delta-V budget. The enormous Saturn V rocket was capable of lifting and launching towards the Moon the command/service module and the lunar module, and little more than that. Compare scale/size of these - the Apollo spacecraft in upper right corner to the rest of the rocket.
Now instead of the lunar module, you'd need an entire stack of size comparable to Saturn V - additionally, capable of soft landing in the rough terrain of the uninhabited "other Earth". And now you need to add a rocket to bring it to the "Other Earth" - one, that by size, comparing to Saturn V, is as Saturn V is to the Apollo spacecraft. And obviously, by cost too.
The same style mission would be plain impossible. The delta-V to take off from Earth is high enough by itself. Doubling it, scaling the mass ratios exponentially yields an impossibly huge construction.
That is not to say a successful mission including return couldn't be launched. If the other planet was inhabitable, a permanent colony could be established with multiple one-way missions delivering supplies and technology. Utilizing in-situ resources and technology from Earth, the colony could construct rockets capable of entering the "Other Earth's" orbit, where they could rendez-vous with vehicles resembling Apollo CSM and the crew could use it to return to Earth. Thing is the timeline between first landing and first return would be decades, not two weeks.
answered 6 hours ago
SF.SF.
31.8k8103231
31.8k8103231
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
add a comment |
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What would be Mars? Just on braking landing and rejoining an orbiter. It would be possible for a kind of lem leave the planet and rendezvous with an orbiter? Just to see if there is impossibility already at this level or it is arising from the need to carry much more stuff for the long cruuse? Already up voted, by the way.
$endgroup$
– Alchimista
2 hours ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
What you'd probably want to do is launch half a dozen missions to deliver the various stages of the return rocket (as well as an assembly rig) and then essentially construct and fuel the rocket in-situ for a future manned mission. It'd be exorbitantly difficult to accomplish, However, you have the perk of being on a habitable earthlike world, without the complexities of working in space suits or hard-vacuum, you'd have oceans to gather hydrogen/oxygen from, and an atmosphere to aerobrake with. Exploring that other world would be a matter for drone aircraft I think.
$endgroup$
– Ruadhan2300
1 hour ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
$begingroup$
@Alchimista: The mission to Mars considers emptying the tanks during Mars landing, then refueling by producing fuel from the Mars atmosphere to launch back. It's viable because Mars gravity is just 1/3 of Earth, so the escape velocity is much lower, and so a single stage to orbit from Mars surface is viable. Same spaceship that on full tanks can launch from Mars, enter trajectory to Earth and land on Earth, when launching from Earth will need a massive booster it drops halfway up, and arrives into orbit with empty tanks. Six orbital refueling missions follow before departure to Mars.
$endgroup$
– SF.
22 mins ago
add a comment |
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2
$begingroup$
Earth would not be possible if Moon was Earth-like. Or at least it would be vastly different from the Earth as we know it.
$endgroup$
– SF.
7 hours ago
$begingroup$
Yes I was aware of this type of comments. It has not to strictly be a satellite. Or alternatively, the two earth-like object orbit each other. Let us assume that this configuration doesn't prevent atmosphere formation and persistance. Though I am not even sure that binary planets can orbit a star in a stable fashion. Just focus on distance and energetic requirements. @SF
$endgroup$
– Alchimista
7 hours ago
2
$begingroup$
@alchimista Pluto and Charon are doing just fine, in terms of orbital stability.
$endgroup$
– Oscar Lanzi
4 hours ago
$begingroup$
@OscarLanzi: Moon is over 5 times heavier than Pluto, and they are tidally locked. Two bodies as massive as Earth in the Earth-Moon distance would most certainly enter a tidal lock, and that means month-long nights and days; enormous sea tides washing over swaths of the continents every two weeks, Massive earthquakes caused by the remaining tidal forces. Such slow spin would quite likely deprive the planets of magnetosphere, and even if not, they would disrupt each other's magnetosphere on regular basis. As a planetary system they could exist. As life-bearing planets - definitely not.
$endgroup$
– SF.
4 hours ago
$begingroup$
@SF agreed. Only the orbital stability is claimed to work on Pluto/Charon. The Earth and an equally massive Moon in this alternate world might even have double-locked before getting 400,000 km apart, amplifying your adverse tidal effects.
$endgroup$
– Oscar Lanzi
3 hours ago