5 ms·
https://en.wikipedia.org/wiki/Kosmos_482 https://en.wikipedia.org/wiki/Kosmos_482 > Its landing module, which weighs 495 kilograms (1,091 lb), is highly likely
by eh_why_not 1y ago
https://en.wikipedia.org/wiki/Kosmos_482 https://en.wikipedia.org/wiki/Kosmos_482
> Its landing module, which weighs 495 kilograms (1,091 lb), is highly likely to reach the surface of Earth in one piece as it was designed to withstand 300 G's of acceleration and 100 atmospheres of pressure.
Awesome! I don't know how you can design for 300 G's of acceleration!
- dgrin91 1y agoNitpicking, but wouldn't it be 300 Gs of deceleration? I know the math is basically the same, but technically the words a mean different things
- amoshebb 1y agoI think this is a case where “technically” the words mean the same thing but “generally” they mean different things.
- jbnorth 1y agoWhat is deceleration but acceleration in the opposite direction? /s
- esotericimpl 1y ago[dead]
- JohnKemeny 1y agoThere's no need for the "/s" on the end, there. Deceleration, and especially in this case with a natural frame of reference, deceleration is negative acceleration.
- rightbyte 1y agoMore stringently, deceleration is decreasing the magnitude of the velocity vector, I would say. If acceleration can be negative, so can speed. A negative speed with negative acceleration would not imply deceleration?
- mongol 1y agoSpeed is not a vector, it is a scalar. You are thinking of velocity.
- DiogenesKynikos 1y agoThe magnitude of the velocity vector is dependent on the frame of reference. If you measure the same object's velocity from a spaceship traveling through the solar system, you'll get a different answer from what we measure from Earth. That's why physics doesn't distinguish between acceleration and deceleration. What looks like acceleration in one frame looks like deceleration in a different frame.
- crazydoggers 1y agoAcceleration is a vector. So if you apply the “deceleration” long enough you’ll eventually be accelerating in the opposite direction. Without a frame of reference it’s all the same. Even with a frame of reference you’re still accelerating just that it’s in he opposite direction of the current velocity.
- Eduard 1y agoI fly through trams in completely different directions depending on whether it accelerates or decelerates. So for sure a system's design must consider more than just the magnitude of acceleration.
- FredPret 1y agoThey tend to do this with spacecraft by turning the whole craft so acceleration always comes through the floor
- crazydoggers 1y agoWithout looking out the window how would you tell the difference between acceleration or deceleration? You can’t. And if you say “well one way I fly to the back of the tram and the other the front” You’re arbitrarily associating “front” with decelerate and “back” with accelerate. 300gs is 300gs regardless of the direction vector of the component. > So for sure a system's design must consider more than just the magnitude of acceleration. What else would you need to consider? Acceleration up? Down? Left? 20%x,30%y,40%z? There’s an infinite number of directions.
- ryandrake 1y ago“The enemy's gate is down.”
- anyfoo 1y agoWell to be fair, the person you reply to has a point. There’s a continuous range of directions, but even though I’m no spaceship engineer, I suspect they’re probably engineered to withstand acceleration better in some directions than others, given that pretty much only their thrust method, as well as gravity at source and destination, will actually be able to apply any acceleration.
- anyfoo 1y agoAcceleration, deceleration, point is: Something is going to apply 300 gs in a certain direction to design for. It's not like you can tell whether you're going slow or fast, in one direction, the other direction, or even just standing still, if you close your eyes.
- stickfigure 1y agoSure you can. You just need a luminiferous aether detector.
- anyfoo 1y agoOf course, my bad. Otherwise the speed of light would have to be constant in any reference frame, and that would just be ridiculous.
- exabrial 1y agoFlip your phone upside brah
- Rover222 1y agoThis is wrong when talking about the physics of something. Deceleration is acceleration. Acceleration is just a change in velocity.
- drob518 1y agoIt’s just a minus sign.
- os2warpman 1y agoThere are electronics and gyroscopes designed for >9,000 G loads, in guided artillery shells. Aerospace is awesome.
- nandomrumber 1y ago88.2 m/s^2 For well under a second though, typically artillery muzzle velocity is, what, two to three thousand feet a second? Still, it’s wild that guidance electronics and control mechanisms can survive that sort of acceleration.
- Baeocystin 1y agoThat vacuum tubes(!) were part of that package, and were able to be that robust, still floors me every time I think about it.
- MathMonkeyMan 1y ago> 88.2 m/s^2 Isn't that more like 9g?
- nandomrumber 1y agoYes, thanks, I meant to write 88.2 kilometres / second squared.
- af78 1y agoAccording to https://en.wikipedia.org/wiki/M777_howitzer https://en.wikipedia.org/wiki/M777_howitzer (typical howitzer): - barrel length (x): 5.08 meters - muzzle velocity (v): 827 m/s Assuming a constant acceleration γ, x = γ * t² / 2 and v = γ * t Hence: - t = 2 * x / v = 12.29 ms - γ = v / t = 67316 m / s² = 7000 G A bit lower than 9000 G, but in the same ballpark. Certain rounds, like Excalibur (https://en.wikipedia.org/wiki/M982_Excalibur https://en.wikipedia.org/wiki/M982_Excalibur) or BONUS (https://en.wikipedia.org/wiki/Bofors/Nexter_Bonus https://en.wikipedia.org/wiki/Bofors/Nexter_Bonus), are sophisticated and are able to cope with such accelerations.
- WJW 1y agoOverbuild everything. For things that might be fragile-ish like surface mounted electronics, cast the whole thing in resin. As a sibling poster has mentioned, we shoot things out of artillery tubes these days that have way harsher accelerations than 300g.
- MarkMarine 1y ago300g is nuts. Electronics in a shell is one thing, this is a landing craft. In a prior life my designs had to survive 12g aerial drop loads and we had to make things pretty robust.
- deleted 1y ago[deleted]
- consumer451 1y agoIt also blew my mind that a human being, John Stapp, survived >40g acceleration and 26g deceleration, in a rocket sled. I believe it was the deceleration that hurt him the most.
- numpad0 1y agoGun scopes are minimum 500G rated. Apparently that's the ballpark for recoils(the reaction force from the barrel becoming a rocket engine, and/or the bolt/carrier bottoming out)
- aaron695 1y ago[dead]
- casylum 1y agoIf anyone wants to try and see it the orbit is listed. https://www.n2yo.com/passes/?s=6073 https://www.n2yo.com/passes/?s=6073