131–140 of 513 posts
Earlier quoted context omitted.
Isn't the exhaust just water?!?
Mostly CO2 and CO, see for instance https://en.wikipedia.org/wiki/RP-1
https://en.m.wikipedia.org/wiki/Kerosene The combustion reaction can be approximated as follows, with the molecular formula C12H26 (dodecane):
2 C12H26(l) + 37 O2(g) → 24 CO2(g) + 26 H2O(g); ∆H˚ = -7513 kJ
Earlier quoted context omitted.
They are going to test the rocket later this year, and the rocket is based on the F9 design, so nothing done from scratch. The crew capsule is also just an enhancement of the capsule which travelled to the ISS and back again several times. It also is going to be tested with flights to the ISS before this planned moon mission. Once you exchange the F9 for the F9 Heavy, going to the moon is not really anyhow more diffi…
Ok, let's put it like this: how much are you willing to bet that they'll be sending two passengers around the Moon on board of Falcon Heavy/ Dragon 2 next year?
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…
The difference between a human-cargo test run of days vs months/years is substantial.
Imagine trying to diagnose a problem that comes up 10 months into the program after the probe is no longer in a direct visual path or while communications via microwaves start taking 10-20 seconds from point to point.
There are too many questions to be answered before we can just say "you know while we're at it lets just risk the lives of 10-20 people, who cares right?"
Earlier quoted context omitted.
The Moon has no atmosphere to use to shed speed. Very different animal than a Mars landing, to the point where it'd need a totally different landing vehicle than Mars. Think heavy, shielded Apollo command modules versus the spidery lunar landers.
There's about .7kPa of atmos on mars. I'd have a hard time seeing how that would meaningfully influence escape or entrance velocity. In fact it should make entry easier because you'll have a higher resistance coming in meaning you'll have to do a lower deceleration burn. Could you provide a source, of someone with experiance in this sort of work, telling me why this is the case? Why does this completely change the ga…
That's why a Dragon 2 can land on Mars, but not on the Moon.
Check out the Scott Manley video on Youtube for lots of details, https://www.youtube.com/watch?v=9zuFdVkVxpM.
So, hmm, we wants to send people around the moon, a year and a half from now, with a rocket he never tested and with a capsule that never flew? I expect half of the directors of SpaceX to resign in the next two days...
Earlier quoted context omitted.
You're right I misread the testing part. I'd very much still like to know who those people are and what their thought process is.
I'd like to know the thought process of people who have this much money and don't want to orbit the moon.
Earlier quoted context omitted.
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.
No one would be willing to fund anything that hasn't gone through at least one viability test on the closest short term analogous scale.
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.
Earlier quoted context omitted.
The difference between a human-cargo test run of days vs months/years is substantial.
Exactly and that's not mentioning the benifit of being able to easily recover a failed prototype or even just analysis of a failed prototype. Imagine trying to diagnose a problem that comes up 10 months into the program after the probe is no longer in a direct visual path or while communications via microwaves start taking 10-20 seconds from point to point. There are too many questions to be answered before we can ju…
Space travel can be dangerous. We will likely lose some crews. Rescue will always be too far away to matter. But I think folks will do it anyway.
SpaceX at its usual :) . By which criteria Energiya is less powerful vehicle to reach orbit than Falcon Heavy?