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SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#121

Post by gravypod »

beojan wrote: post #82
gravypod wrote: post #75

Earlier quoted context omitted.

There's gravity and a rock. Ignoring all the differences these still two extremely hard things to solve first before you start thinking of anything else.

There's gravity and a rock on Earth too. Just going up into orbit, then landing back on Earth, is a much better way of testing a Mars landing.

The Earth has a full atmosphere with winds, an expansive array of magnetic and electric fields, and a much much higher gravitational pull then Mars or the moon. About a factor of 10 removed from mars and about a further factor of 10 removed from the moon.

You'd obviously need more fuel, and fuel that can burn in a completely different atmosphere then it's intended to run in. It's an invalid test for the kind of useful metrics that would be obtainable in a "pure" vacume out in space.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#122

Post by ctdonath »

Svezik wrote: post #58
rhcom2 wrote: post #48

Earlier quoted context omitted.

Also the moon is pretty boring and Elon Musk likes exciting things.

Making an automobile that people actually want to buy would be exciting.

There were how many $1000 deposits on Model 3s?

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#123

Post by ctdonath »

nickik wrote: post #96
gravypod wrote: post #75

Earlier quoted context omitted.

There's gravity and a rock. Ignoring all the differences these still two extremely hard things to solve first before you start thinking of anything else.

Sure, if you ignore all the other problems. Why not fly to the Venus and test there? Why not on Saturn? The reason is simple, the cost of doing so outweighs the benefits of doing so. Look, its simply almost as expensive to make such a test on the moon, as it is on mars. If mars is your goal, then testing on the moon makes absolutely no sense. People seem to believe that because the moon is closer, it means its much e…

The difference between a human-cargo test run of days vs months/years is substantial.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#124

Post by jacquesm »

arijun wrote: post #72
ashark wrote: post #64

Earlier quoted context omitted.

Have they said they'll test Martian equipment with Lunar landings? I'd guess it'd make a pretty poor testing ground, considering the cost of getting there.

Lunar landing is harder in many ways than a Martian landing. Without an atmosphere, you cannot aerobrake.

That's a coin with a flipside though: you also don't need much in terms of heatshields so in that sense it is easier than on Mars.

A Mars landing needs both heatshields (because it does have an atmosphere) and retro-rockets to land with (because that atmosphere is not so dense that you can use it for gliding).

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#125

Post by Maultasche »

hackuser wrote: post #113

Note that NASA, I believe at Trump's urging, recently said they would try to place humans on the first flight of the Space Launch System (the new heavy lift rocket) - i.e., no unmanned testing first. https://www.nytimes.com/2017/02/15/science/nasa-looks-to-spe... Is Musk still maintaining a relationship with Trump? When Uber founder Travis Kalanick left Trump's business council, Musk was still on it AFAIK. I wonder i…

NASA agreed to do a study to see if they could place humans on the test flight. That seems to me like the NASA equivalent of saying "Sure, I'll look into that" while trying to not look horrified.

I'm pretty sure that study will conclude that this is a bad idea.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#126

Post by jacquesm »

gigatexal wrote: post #106

Finally the tin-foil hats can be satiated when these tourists see the 50-ish year old flag on the moon.

60-ish? More like 50-ish. I remember those landings and I'm nowhere near 60.

Weirdest thing, I can't delete this comment now that the other comment has been fixed.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#127

Post by jacquesm »

Nokinside wrote: post #93
danmoreno wrote: post #6

zuck and priscilla?

Zuck going around the moon would make sense. He clearly has political ambitions, but he must acquire personality. Being an space-tourist would help.

How on Earth (pun intended) would that help?

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#128

Post by lftl »

jfoutz wrote: post #102
coryfklein wrote: post #98

Earlier quoted context omitted.

Not sure everyone will see it that way. One could look at it as taking the whole "wasteful private jet" to the extreme. Think of the sheer amount of fuel burned in the earth's atmosphere so a rich guy can fly in space. At least, I expect many will spin it that way.

Isn't the exhaust just water?!?

As an interesting bit of trivia: the most prevalent greenhouse gas in the atmosphere? Water vapor.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#129

Post by nickik »

dragonwriter wrote: post #103
nickik wrote: post #96

Earlier quoted context omitted.

Sure, if you ignore all the other problems. Why not fly to the Venus and test there? Why not on Saturn? The reason is simple, the cost of doing so outweighs the benefits of doing so. Look, its simply almost as expensive to make such a test on the moon, as it is on mars. If mars is your goal, then testing on the moon makes absolutely no sense. People seem to believe that because the moon is closer, it means its much e…

OTOH, if you are "rapidly" (insofar as that is possible in space technology) iterating on some aspect of the system that is relatively insensitive to the differences between the Moon and Mars, the Moon being closer shortens your cycle time considerably. Delta-V isn't the only cost you might be concerned with.

True, but nobody has the money to develop something that needs multible moon test mission before it ever gets used productively.

Also, SpaceX has actually thought about the problem quite a bit and until somebody payed them they clearly said they are not going to do anything moon related.

They clearly did the same calculations. Moon is only worth it, if you actually want to go to the moon.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#130

Post by strainer »

ktta wrote: post #12

I wonder if it is going to be only two people who are going to go. Will they add more people if they come forward with significant amount of money too? Seems to me like the cost of taking in another person will be negligible in comparison to the funding they could contribute. This is literally a one-in-a-lifetime experience

Im curious it might be two lovers, with intimate heavenly aspirations.
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