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Artemis II Launch Day Updates
711–720 of 1001 posts
Re: Artemis II Launch Day Updates
#712Earlier quoted context omitted.
It’s absolute in the sense that you can determine your acceleration without any external reference. You feel a certain force (like what you feel in an elevator). That’s your acceleration. You don’t accelerate relative to Earth, or relative to anything else. You accelerate relative to when you wouldn’t be accelerating (your inertial rest frame, a state of free fall). If you are in space accelerating and the Earth woul…
I am in a gravitational field. I have no idea what my acceleration is, I just know that I feel 1G (I could be falling in a stronger gravity and only feel 1G, or I could be climbing in a weaker gravity and feel 1G). The only way of determining it is to see if I'm moving relative to the stuff around me. Even then, that's not definite - I could be in an elevator and everything around me is also accelerating. I'm not dis…
You can always hold an accelerometer in your hand. If you did so now, assuming you're on Earth's surface, it'd register approximately 9.8m/s/s pointing in the upward direction.
You could also perform one of many historical experiments, such as dropping an object from an elevated height with careful timing, or rolling a round ball down a gently sloped track, and so on.
Re: Artemis II Launch Day Updates
#713Earlier quoted context omitted.
~450 square feet, with how many feet in the third dimension? You probably had an order of magnitude more volume than 330 cubic feet there.
> You probably had an order of magnitude more volume than 330 cubic feet there I’m 6’, so that’s the usable volume. (I’m not claustrophobic heighwise.) I honestly don’t see an issue spending a couple days with folks I respect and admire in close quarters for ten days.
You don't get it. Your 400sqft apartment needs to be shrunk by a factor of 6 to have the same area as the Orion. Try living in an 8x8 foot square for a couple weeks.
Re: Artemis II Launch Day Updates
#714[deleted]
Re: Artemis II Launch Day Updates
#715Earlier quoted context omitted.
It’s absolute in the sense that you can determine your acceleration without any external reference. You feel a certain force (like what you feel in an elevator). That’s your acceleration. You don’t accelerate relative to Earth, or relative to anything else. You accelerate relative to when you wouldn’t be accelerating (your inertial rest frame, a state of free fall). If you are in space accelerating and the Earth woul…
I am in a gravitational field. I have no idea what my acceleration is, I just know that I feel 1G (I could be falling in a stronger gravity and only feel 1G, or I could be climbing in a weaker gravity and feel 1G). The only way of determining it is to see if I'm moving relative to the stuff around me. Even then, that's not definite - I could be in an elevator and everything around me is also accelerating. I'm not dis…
According to general relativity, you (and the ground) are accelerating at 1g, and feel weight because your inertia resists that acceleration. If you jump off a cliff, you'll stop accelerating for a bit, until the ground hits you.
Edit to reply:
> I am standing on the ground. I feel 1G acceleration. My speed is not changing. How much am I accelerating?
You are accelerating at 1g through curved spacetime. Newtonian "speed" behaves strangely in curved spacetime.
Re: Artemis II Launch Day Updates
#716Earlier quoted context omitted.
Do you prefer that we not even try to spread beyond our one planet, when an entire galaxy, or maybe even the neighboring ones, might be in reach if we try? What if someday at the very end of the lifetime of our sun and similar stars, we look back, and regret not trying?
Exactly what I mean. People who obsess over space are so egotistical they can’t imagine someone not thinking it’s “the best”. It’s interesting, but no more important than any other science or field of study. And no, I’d prefer we take care of our home planet and make it a sustainable place to live first. It’s ludicrous to think we have any chance of surviving elsewhere if we can’t stop ourselves from making our natur…
I too wish we would all hold hands and sing kumbaya and collectively decide to simply make things better here on Earth but sadly it seems far off.
The best alternative demonstrated so far seems to be for some of us to push the limits of what is possible and watch all boats rise with the tide. Better this than slinging Tomahawks at school children.
Re: Artemis II Launch Day Updates
#717Minutes after launch they reached "ten thousand miles per hour". That's 2.78 miles per second. Nuts. No doubt the speeds go even higher later too. I'm sure people here are already familiar with the speeds these things go, but that's the first time I've confronted a fact like that and it blew me away.
ICBMs also have a similar speed at the terminal warhead stage — only the direction is different.
I’d prefer to cheer for something that’s primary objective isn’t killing people. So there’s that, too.
Re: Artemis II Launch Day Updates
#718Earlier quoted context omitted.
The scale really is unfathomable for the human brain.
That's what I thought standing at the rim of the Grand Canyon. Pictures just do not do it justice. Same thing with Starship. My brain knows it's massive, yet feels underwhelmed looking at it on video. Musk should let his ego build replica Saturn V and a Shuttle next the Starship launch pad so there will be proper perspective available
Have you been to the rocket garden at KSC? The Saturn V isn't vertical, but they've got almost everything from the Redstone and later vertical. I was in Florida in 2018 and I think they were getting ready to display a pair of SRBs. They did have Atlantis inside, too. And of course a horizontal Saturn V.
I saw that Saturn V as a child once, too. I think that the Saturn V really made me the person that I am today. Seeing something so huge, that is literally engineered down to every last tenth of a millimeter - that was profound for a young child. I could not believe how detailed that rocket was, yet so huge. There should be an engineering term for the size of a machine divided by the smallest critical engineered component of the machine. I don't think any machine would have beat that in the Saturn V's day - maybe some ocean liners?
Re: Artemis II Launch Day Updates
#719Minutes after launch they reached "ten thousand miles per hour". That's 2.78 miles per second. Nuts. No doubt the speeds go even higher later too. I'm sure people here are already familiar with the speeds these things go, but that's the first time I've confronted a fact like that and it blew me away.
A Dodge Challenger SRT Demon can also reach 10,000mph in 4 minutes if it held its 0-60 acceleration over the whole span.
So yes, you can buy a car today that'll let you feel the G's like you're a space pilot.
Re: Artemis II Launch Day Updates
#720If the crew were to be lost into deep space or something, is there a protocol for self euthanization?
They will be in a free return orbit so that can’t happen - just other bad things.
What’s the margin of error on a free return orbit burn though? Isn’t there a scenario of being pointed slightly in the wrong direction or burning for too long throwing them off?