China's Space Program News Thread


Quickie

Major
Do you think the 1,000 ton engine will be as powerful as the F-1 that powered the Saturn V?
500-ton thrust is already quite close to the 680 ton F1. The space shuttle solid booster has a thrust of 12000kN at lift off and that is with a propellant mass of 500t, as opposed to the 150 t engine.

The 1000t engine will have no problem surpassing the F1 and I guess it will probably be designed to be less than 12000 kN, but with longer burning time, because of the use of composite material, and also a multistage rocket is not like a Space Shuttle with its huge external tank where you would need very powerful boosters to bring them to a high enough trajectory for the much smaller Space Shuttle engines to take over.
 

Temstar

Major
Registered Member
Mercury is a huge pain the in ass to get to in terms of delta-V, although time wise it's not so extreme:
AAGJvD1.png

See that 8650m/s delta-V for an intercept after earth escape? Yeah it's way deep in the sun's gravity well. Compared to the "relatively low" delta-V to go to Mars it's a huge trip. There are tricks to getting there cheap though and that's to use multiple slingshots between Venus and Earth for free delta-V, but then the trip would take years which is fine for probes but not for humans.

By the time humans are ready to go to Mercury in a big way you would already have route trips between Earth and Mars and maybe even Venus with NTR galore.
 

FairAndUnbiased

Captain
Registered Member
Mercury is a huge pain the in ass to get to in terms of delta-V, although time wise it's not so extreme:
AAGJvD1.png

See that 8650m/s delta-V for an intercept after earth escape? Yeah it's way deep in the sun's gravity well. Compared to the "relatively low" delta-V to go to Mars it's a huge trip. There are tricks to getting there cheap though and that's to use multiple slingshots between Venus and Earth for free delta-V, but then the trip would take years which is fine for probes but not for humans.

By the time humans are ready to go to Mercury in a big way you would already have route trips between Earth and Mars and maybe even Venus with NTR galore.

I am not saying Mercury is good. But Mars is just shit. DeltaV is only one part of the question.

What about energy after you arrive? A heat engine or solar panels can power a colony on Mercury indefinitely and you don't need any fuel. Mars requires magic to produce sufficient power there because of 40% lower insolation than Earth and a night/day cycle (meaning you only have 50% power due to no power produced at night by panels). Otherwise you have to bring power with you. But if you have to bring power, then what's the difference with reduced payload to Mercury?

What about experience? Any lunar experience is applicable to Mercury, but not Mars

What about chemistry? You can run vacuum smelting to produce pure metal and oxygen in high energy, vacuum environments like Moon and Mercury, you can't do that on Mars.

What about shelter? Mercury has a magnetic field, Mars doesn't. Moon has lava tunnels and is easier to excavate with robots.

There is literally nowhere worse than Mars in the inner solar system.
 

Sincho

Junior Member
Registered Member
I don't think Mercury will ever be an attractive target for human habitation/ exploration. The planet being very close to the sun exists in a very high solar radiation environment. Humans, if they venture there, will have to live in the depths of the craters at the polar region; these depths permanently never see the sunlight and there is ice and hence a water source. The day-exposed side of the planet is searingly hot and the night-side is extremely cold (-180 degree Centigrade) and probably also very dry. By the way, it seems one Mercury day is equal to about 59 earth days, because the planet rotates very slowly its axis.

As for Mars, its temperature range and exposure to solar radiation are not so extreme relative to Mercury. On Mars, solar cells and wind turbines can be used to generate electricity. According to Nasa, solar and wind power can complement each other on Mars especially during the months-long Martian global dust storms which darken the skies. Besides, nuclear power can be developed for use on Mars; l think thorium molten salt reactor might be suitable.

Also, why would you want to go to Mercury when Mars is much more closer to the earth (77 million km versus about 55 million km at closest approach)?

There is a reason why when scientists talk of planetary exploration, Mars is the target and not extremely hostile planets like Mercury and Venus. If there can be a choice, better and more interesting places will be the moons of Jupiter and Saturn such as Europa and Enceladus which could possibly harbor life. But for the moment, they are just too far away.
 
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FairAndUnbiased

Captain
Registered Member
I don't think Mercury will ever be an attractive target for human habitation/ exploration. The planet being very close to the sun exists in a very high solar radiation environment. Humans, if they venture there, will have to live in the depths of the craters at the polar region; these depths permanently never see the sunlight and there is ice and hence a water source. The day-exposed side of the planet is searingly hot and the night-side is extremely cold (-180 degree Centigrade) and probably also very dry. By the way, it seems one Mercury day is equal to about 59 earth days, because the planet rotates very slowly its axis.

As for Mars, its temperature range and exposure to solar radiation are not so extreme relative to Mercury. On Mars, solar cells and wind turbines can be used to generate electricity. According to Nasa, solar and wind power can complement each other on Mars especially during the months-long Martian global dust storms which darken the skies. Besides, nuclear power can be developed for use on Mars; l think thorium molten salt reactor might be suitable.

Also, why would you want to go to Mercury when Mars is much more closer to the earth (77 million km versus about 55 million km at closest approach)?

There is a reason why when scientists talk of planetary exploration, Mars is the target and not extremely hostile planets like Mercury and Venus. If there can be a choice, better and more interesting places will be the moons of Jupiter and Saturn such as Europa and Enceladus which could possibly harbor life. But for the moment, they are just too far away.
Thorium reactors don't exist yet except as experimental testbeds. More importantly, nobody has ever launched a heat engine reactor into space much less landed one again. They've only launched thermoelectric reactors which are far less efficient.

On the other hand a gas turbine is proven technology and turbines have actually been launched and landed before (see every single liquid fueled reusable rocket). Solar is proven technology.

You know how silly wind power on Mars is? Mars atmospheric pressure is 0.1% of Earth's. If wind power on Earth is hard, it is literally 1000x harder on Mars.

Do you also realize that Mercury has a magnetic field which Mars does not have?

And do you realize that not spinning fast is a plus because that means you can harvest energy 24/7?
 

Sincho

Junior Member
Registered Member
China is now trying out a thorium reactor in in the Gansu desert. If the thing works, it could be adapted for Mars.
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The atmosphere in Mars might be thin but it is still strong enough to whip up dust storms. Wind turbines that work in Mars can be designed. Afterall, Nasa has build a helicopter that can fly in the thin Martian atmosphere. Besides, the part about the wind turbines I read from the nasa.gov site. You tell me that it is all BS?

Fat good the magnetic field on Mars do if you imply that it sets up a protective magnetosphere. Its strength is only 1/100 that of the earth.

Mercury is just too near the sun. The solar radiation is too harsh and the surface temperatures are just too extreme for human habitation.

Mars is more like earth. The length of a Martian day is just slightly longer than earth, about 25 hours.

You can harvest solar energy 24/7 on one side only for Mercury. While on Earth and on Mars, both sides of the planet can harvest their share within the 24 hours cycle.

And earlier, were you not saying China should better focus on Venus also than on Mars - Venus the perpetually hot planet?

Truth is the focus should be on planets which has conditions more suitable for human habitation or which can be more easily adapted for human habitation. It is nonsensical to advocate human landing or inhabiting planets like Venus and Mercury which are veritable super ovens. Besides, in flying to Mercury, the spacecraft will get hotter and hotter as it gets nearer the sun. I am not sure even with a super heat shield you can control or prevent fatal heat buildup (for humans) in the spacecraft in the 10 months to a year that it takes to reach Mercury.
 
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FairAndUnbiased

Captain
Registered Member
China is now trying out a thorium reactor in in the Gansu desert. If the thing works, it could be adapted for Mars.
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The atmosphere in Mars might be thin but it is still strong enough to whip up dust storms. Wind turbines that work in Mars can be designed. Afterall, Nasa has build a helicopter that can fly in the thin Martian atmosphere. Besides, the part about the wind turbines I read from the nasa.gov site. You tell me that it is all BS?

Fat good the magnetic field on Mars do if you imply that it sets up a protective magnetosphere. Its strength is only 1/100 that of the earth.

Mercury is just too near the sun. The solar radiation is too harsh and the surface temperatures are just too extreme for human habitation.

Mars is more like earth. The length of a Martian day is just slightly longer than earth, about 25 hours.

You can harvest solar energy 24/7 on one side only for Mercury. While on Earth and on Mars, both sides of the planet can harvest their share within the 24 hours cycle.

And earlier, were you not saying China should better focus on Venus also than on Mars - Venus the perpetually hot planet?

Truth is the focus should be on planets which has conditions more suitable for human habitation or which can be more easily adapted for human habitation. It is nonsensical to advocate human landing or inhabiting planets like Venus and Mercury which are veritable super ovens. Besides, in flying to Mercury, the spacecraft will get hotter and hotter as it gets nearer the sun. I am not sure even with a super heat shield you can control or prevent fatal heat buildup (for humans) in the spacecraft in the 10 months to a year that it takes to reach Mercury.

You have no idea what you are talking about. You don't understand the numbers, the energy argument or the technology required. You do not understand technological readiness, launch requirements or how roadmaps are defined.You don't know what is hard and what isn't hard and what are solvable problems and what are unsolvable problems.

A helicopter on Mars... Ok... You realize that it has power of 350 watts and can only loft 1.8 kg for a few minutes? And that's spinning at 2800 rpm, 100x faster than the 20 rpm of commercial wind turbines?

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NASA does outreach to the public where it promotes highly aspirational ideas.

When it's time to put money into working mission, they are far more prudent with their resources.
 

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