Author Topic: We're going to the moon again!  (Read 473 times)

Offline BDL

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We're going to the moon again!
« on: September 17, 2018, 08:58:12 PM »
SpaceX is now announcing the first private passenger to orbit the moon! You know, I think this may be the most excited I've ever been so far! Congratulations, Elon Musk. And all the SpaceX scientists and engineers, too. I hope NASA starts sending astronauts to the moon again. It's been too long.
« Last Edit: September 17, 2018, 10:52:31 PM by BDL »
“One small step for [a] man, one giant leap for mankind.” - Neil Armstrong, 1969

Online bknight

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Re: We're going to the moon again!
« Reply #1 on: September 17, 2018, 10:35:51 PM »
SpaceX is now announcing the first private passenger to orbit the moon!
You know, I think this may be the most excited I've ever been so far!
Congratulations, Elon Musk. And all the SpaceX scientists and engineers, too.
I hope NASA starts sending astronauts to the moon again. It's been too long.


So is the guy or the right the passenger?
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline BDL

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Re: We're going to the moon again!
« Reply #2 on: September 17, 2018, 10:40:45 PM »
SpaceX is now announcing the first private passenger to orbit the moon!
You know, I think this may be the most excited I've ever been so far!
Congratulations, Elon Musk. And all the SpaceX scientists and engineers, too.
I hope NASA starts sending astronauts to the moon again. It's been too long.


So is the guy or the right the passenger?

The Japanese guy is the passenger. His name is Yusaku Maezawa.
He's an artist. And he's planning to bring (6, probably?) other artists with him. I'm not sure at all about how these artists are going to pilot the craft or how they’ll fix any engineering problems that may arise, but nonetheless - there'll be a couple artists going around the moon.
Elon Musk was asked if he was going go with him and he basically answered "I don't know, maybe." in a joking way.
« Last Edit: September 17, 2018, 10:55:10 PM by BDL »
“One small step for [a] man, one giant leap for mankind.” - Neil Armstrong, 1969

Offline Peter B

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Re: We're going to the moon again!
« Reply #3 on: September 17, 2018, 11:10:04 PM »
I skimmed through the broadcast.

What I saw was interesting, but I think they're highly optimistic if they expect that lunar mission to happen when they announced (2023 I think), given how much the first launch of the Falcon Heavy was delayed.

I also hope SpaceX has a good executive structure in place so it doesn't have to rely on Musk himself to achieve results - he's been getting himself into the news for the wrong reasons too often in the last few months: the Thai cave submarine fiasco followed by the paedophile accusation (and now he's being sued over it); the announcement of his intention to make Tesla a private company followed by a reversal a week later; his Trump-like criticism of the media; and some unhelpful criticism of Tesla skeptics...

Offline Peter B

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Re: We're going to the moon again!
« Reply #4 on: September 18, 2018, 12:47:15 AM »
Some further thoughts...

- The spacecraft's landing system is interesting. Two of its three legs are moveable, and it also has a pair of control surfaces near the nose. According to the information, these four control surfaces steer the spacecraft as it dives into an atmosphere at a high angle of attack, while its speed drops to under supersonic. The spacecraft then turns vertical to fire rockets to land. Sure, it all makes sense - at this stage of the mission the spacecraft is going to have a high volume for low mass, so it's going to have a relatively low terminal velocity.

But what interests me is that the one spacecraft design appears to apply for landings on Earth, Moon and Mars, which (obviously) have very different amounts of gravity and atmosphere (unless there was something I missed when I skipped bits). So I assume they have robust maths to demonstrate that this method will work with a Mars landing rather than just an Earth landing, which was all they appeared to demonstrate.

- The spacecraft appears to store some cargo under its base, in the space between the engine bells and the stage skirt. I assume the logic is that the spacecraft's engines fire up only when its up so high there's virtually no atmosphere to conduct or convect heat from the combustion chamber to the adjacent cargo pods. But again maybe that's something I missed as I skipped through the video.

It'll be interesting to read what industry experts have to say about all this.

Offline raven

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Re: We're going to the moon again!
« Reply #5 on: September 18, 2018, 01:30:21 AM »
It's going to be awhile before this happens. Falcon Heavy was a development of an existing, fairly standard (aside from the first stage recovery) design. The Big Fu . . .I mean Falcon Rocket is a whole other kettle of fish. I admire Elon Musk's willingness to put his money where his mouth is and actually work on the things he dreams about and lordy does he dream big, but I worry this might be too big to pull off.
Still, he's pulled off some amazing stuff  before, so I wish him and SpaceX the best of this. Just hope he can get his ego back in check.

Online bknight

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Re: We're going to the moon again!
« Reply #6 on: September 18, 2018, 08:06:30 AM »
This is similar to the direct ascent mode that was eliminated by NASA as it would take far too big a rocket (NOVA) to start.  I haven't seen the video, nor have I studied the mission, but what changed from 1962-63 to 2018?  Is the BFR similar in thrust to the NOVA?  Orbital mechanics haven't changed so what am I missing?


ETA: After some research I find the planning thrust for BFR is 11.8 M lbs versus the NOVA 11.7 M lbs (14.4 m lbs upgrade).
So the rockets do compare favorably.
« Last Edit: September 18, 2018, 09:03:08 AM by bknight »
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Peter B

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Re: We're going to the moon again!
« Reply #7 on: September 22, 2018, 06:50:46 PM »
Some more thoughts coming to mind (including one raised as a YouTube comment by someone else):

- How is this touchdown method going to be used on Mars? Isn't the spacecraft in danger of toppling if one leg comes down on a large rock or soft sand? Doesn't that mean requiring a prepared landing pad?

- The video of the landing sequence - is this coming from Earth orbit or a return from the Moon or Mars? That would make a difference of several thousand km/h on re-entry speeds, wouldn't it?

- What sort of thermal protection system is the spacecraft going to have? After all, coming in from Earth orbit at 27,000 km/h and an altitude of 400 km is quite different from Falcon 9 first stage's 100 kilometres at 7,000 km/h, isn't it?