It was spectacular. Go to 46:00 for the launch.
OT: Artemis Launch
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Love this stuff. A few things I learned about the dynamics of liftoff and flight generally. The water is poured below the rocket not to cool the cement, but to diffuse the sonic booms created by the fuel, which is supersonic when released from the main tanks. The rocket is traveling over 100mph as it clears the 300' tower, which is ludicrous given the weight and upward trajectory of the rocket. In order for a rocket, which has continuous thrust, to escape earth's gravitational pull and head into space, it must achieve a speed of somewhere in the neighborhood of 14,500mph.
@RUScrew85 Might be able to verify my nerddom, as he took the same physics classes I did.
@RUScrew85 Might be able to verify my nerddom, as he took the same physics classes I did.
Very cool. The one camera angle on the liftoff reminded me of the old MTV start.
I think you're being unclear a bit with "head into space". Low Earth orbit requires give or take 25K fps which fits with what you are saying. But with enough fuel and thrust you can hover in space at "zero velocity" as long as you intend to hover back down or free fall. This of course never has happened - but I'm pretty sure it's possible. Escape Velocity - the velo required to leave the Earth's gravitational influence (Like being shot out of a giant cannon straight to "outer space") is like 37K fps. Of course all of this has a lot of assumptions built in because this crap is really complicated in real life. As always I am not a Rocket Scientist.
Want to get an easy headache? Try learning orbital dynamics.
By the way. That was like $5B of your tax dollars being 98% thrown away. Sigh. Just let SpaceX do it. They're maybe a year from fully reusable and maybe as soon as next month.
watched it live on Nasa TV. Amazing how fast it accelerated. Thx for the explanation of the water. I've watched tests of that system but never noticed it during a launch.
Mission tracker
https://www.nasa.gov/specials/trackartemis/
only 3914mph now and slowing. Return speed pretty amazing @ 20,000mph.
Mission tracker
https://www.nasa.gov/specials/trackartemis/
only 3914mph now and slowing. Return speed pretty amazing @ 20,000mph.
If you really want a headache, consider that velocity is only velocity when it's relative TO something. When you say "hover in space" are you taking relative to the center of the Earth? Or a point on the surface?
Here's an interesting semi-factoid. It's widely believed the first thing to leave Earth's gravitational field was a metal cover on a borehole that "contained" an early underground nuclear test. The containment/lid failed and is believed to have been shot off the damn planet. LOL
Actually I've seen elsewhere it will hit the Earth's atmo at 25K MPH which is just about the same speed as Apollo IIRC. Which sorta makes sense as they are doing the same basic mission. Earth to Moon and back.
That's, as they say, "Hauling the mail." ; )
I've read about a thought experiment. If you are floating in perfectly empty space you can't tell if you are moving or stationary. Now for the crazy part, imagine being in the same place floating in space but spinning. Can you tell? Does it matter? And here's the real mind bender - do your arms feel forced outward if your spinning while floating in empty space. Or something like that. IIRC no one's absolutely sure about the correct answer for the arm's raising or not while spinning. At least that's how I remember it. Now go smoke a joint and think on it. LOL
I didn't qualify the hovering option because, as you pointed out, it's never happened so I played the odds. As for the difference between the 25k/fps and 37k/fps, the latter applies to objects without constant thrust (as in your nuclear-explosion-propelled borehole, since it's literally a one-shot deal. The former applies to rockets because constant thrust changes the impact of gravity, which IIRC would be measured by a rate of increasing deceleration/second.
Don't worry I think all the engines are H2 - O2 and they burn to make only water vapor - now the hypergolic thrusters...
Nope sorry - the SRBs are very polluting too.
I'd not heard this thought experiment before, but it sounds like the question is whether you would know if you were spinning or if the stars were spinning. My initial guess would be that, over time, you'd figure out that it is you who is spinning because your increasing awareness of and sensitivity to of your internal organs would inform you of your motion.
The second part seems like the dilemma is whether you would know if your arms were being pulled toward something or if they were being pushed outward due to centrifugal force. I have no guess on whether I could figure it out. After a while, though, I'd be so bored that every time I saw a nuke go off on planet earth I'd be hoping to be blasted with a borehole.
I don't smoke so much but you're just perfectly described the feeling of being stoned. At least my experiences.
That's probably what they said. it was late. They went on to talk about how this is the first attempt of a skip maneuver - the capsule will enter the atmosphere, then exit again before returning. Lots of benefits if they pull it off - increased 5,524 range to target splashdown, lower g's on astronauts, and reduced heat.
https://www.nasa.gov/feature/orion-spacecraft-to-test-new-entry-technique-on-artemis-i-mission
1) You'll know you're spinning if you have a reference point...stars, planets, or spacecraft.
2) I don't think that centripetal force (not centrifugal) would be affected by gravity so my guess is that your arms will feel the outward force. You know like in the artificial gravity of a spinning spaceship in those old movies.
NASA isn't what it used to be but I'm still sentimental about it
NASA could launch a lot of rockets for the billions sent to the lunatic in Ukraine launching misiles into Poland
There are no stars. Just blackness with you floating in it. Or spinning? or moving?
That's why you don't know about being in constant motion. The freaky part is the spinning. How would you know? Nausea? Arms feeling pulled? But what are you spinning in reference to in the empty weightless blackness? And would you really feel the arms and nausea and other stuff?
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I don't think you would need to have reference points to know you are spinning. The difference between the initial example of not know if you are moving or not in space is because your velocity is constant, therefore there is no acceleration. In the spinning example, there is acceleration, specifically centripetal acceleration as you note, so you would be aware of the movement and the tendency for your arms to want to pull away from your body. Centripetal acceleration is indeed not impacted by lack of gravity, and is expected to be leveraged in the big "hamster wheel" space ships you mentioned to generate a false sense of gravity.
I'm sentimental for the work they did. Those hundreds of thousand folks that accomplished so much are gone. These modern guys - I'm not so sure I'm in awe of them. I AM very impressed with SpaceX and that autistic genius nut Elon.
Ash clearly left his footprint all over that experiment.
I guess I wasn't clear. When I said empty space, I meant E M P T Y. Nothing there but you and empty. No starts, gravity, atoms, radiation. Nothing.
The point is that if you have no frame of reference are you really spinning? It's a corollary to the constant velocity question. As much as you expect that you'd experience centripetal force, that presupposes you can spin in a universe with no frame of reference. The question is, can you if you are spinning there are you really spinning? Can you spin?
That was my question for 1984 and being stoned.
Anyway I'm getting out of my zone here. I just thought it was an interesting step up for 1984's comment.
Doing a quick re-verify and it's now believe it was going so fast it vaporized when it tried to go through the atmo on its way to space.
So it could have but the atmo got in the way. LOL
https://en.wikipedia.org/wiki/Operation_Plumbbob
I'm always worried that we are being studied by aliens lol. Our planet is so unique in this part of the galaxy. Seeing that blue gem from space makes one realize how beautiful it is, and all of us won the lottery to be here, and to get to learn about its history.
Not to mention all the other planets have nothing to do and the weather sucks.
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