Interstellar shield or aerobraking shield?

[tstein]

On 11/2/2022 at 3:25 AM, intelliCom said:

Like dropping into water. Normally you can pass through it with some effort, but with enough speed it can cause a lot of damage to a human body just hitting it.

Out of curiosity, what would an atmosphere like Duna's do to interstellar speeds? Or an atmosphere even 1% of Duna's?

For the sake of argument, lets assume "interstellar speeds" is 10% the speed of light, maybe less.

Terminal ballistics depends  on several factors (and this is a sub case of terminal ballistics) the speed of the event, the density of the actors, their shape, their mass  and angle. THe density of the actors is crutial, not only the atmosphere but of the ship. Energy transfer happen proportional to the capability of the material to transfer and that is mostly related to their cross section, density and mass. So if you hit  a  fluid it also matters how big that "pool of fluid is"   the cloud of water around of an asteroid will have a very  different energy transfer potential to the same density of fluid in a large atmosphere (one will weight a dew thousand tons the other is a gogol scale number).

Any  speed useful for interstellar travel is far far above than the capability of any material to transfer or absorb energy, so  they  will fracture. That is why  you cannot  make a projectile just for faster and faster to get larger penetration. When you go faster than the material capacity to transfer energy, it collapses.  You would  get dusted space ship.

 

That lead to a question.. will we have to protect our ships from  interstellar dust?

[magnemoe]

3 hours ago, tstein said:

Terminal ballistics depends  on several factors (and this is a sub case of terminal ballistics) the speed of the event, the density of the actors, their shape, their mass  and angle. THe density of the actors is crutial, not only the atmosphere but of the ship. Energy transfer happen proportional to the capability of the material to transfer and that is mostly related to their cross section, density and mass. So if you hit  a  fluid it also matters how big that "pool of fluid is"   the cloud of water around of an asteroid will have a very  different energy transfer potential to the same density of fluid in a large atmosphere (one will weight a dew thousand tons the other is a gogol scale number).

Any  speed useful for interstellar travel is far far above than the capability of any material to transfer or absorb energy, so  they  will fracture. That is why  you cannot  make a projectile just for faster and faster to get larger penetration. When you go faster than the material capacity to transfer energy, it collapses.  You would  get dusted space ship.

 

That lead to a question.. will we have to protect our ships from  interstellar dust?

I say unlikely, more likely its just there for the look. I say at so relativistic velocity the  atmosphere will act as radiation, think cosmic radiation at your velocity. 

[Bej Kerman]

Just now, magnemoe said:

I say unlikely, more likely its just there for the look. I say at so relativistic velocity the  atmosphere will act as radiation, think cosmic radiation at your velocity. 

At relativistic velocity, the atmosphere will act as a brick wall. Just the interplanetary medium would probably damage your shielding.

[magnemoe]

59 minutes ago, Bej Kerman said:

At relativistic velocity, the atmosphere will act as a brick wall. Just the interplanetary medium would probably damage your shielding.

Well getting nuked would be closer, just a bit lower intensity but damage over an bit much longer time than an nuke direct hit. 

And shielding would be an problem even atoms as in cosmic rays, but the big issue is dust or you are getting bombed. 

[tstein]

Anything  in the realms of a fluid (like air) instead of a disperse system (like interstellar dust)  will  behave as something far worse than an average  brick wall for the ship. Obviously  terminal ballistics formulas will nto work  very well at those speeds, the result is probably even worse, but  even not counting that the chance of any material to handle it is nil.

[GoldForest]

5 minutes ago, tstein said:

Anything  in the realms of a fluid (like air) instead of a disperse system (like interstellar dust)  will  behave as something far worse than an average  brick wall for the ship. Obviously  terminal ballistics formulas will nto work  very well at those speeds, the result is probably even worse, but  even not counting that the chance of any material to handle it is nil.

I wonder if the time warp bug will still exist. The one where you can time warp through an atmosphere so quick that the game doesn't have time to detect the atmosphere and drop to physics warp or normal speed. I imagine it will still exist. If it does, you could save your interstellar ship from becoming explodium central by just warping through the atmo. Problem solved. 

[Bej Kerman]

1 hour ago, GoldForest said:

I imagine it will still exist

The devs came up with a way to simulate vessel collisions at speeds where the physics step would otherwise cause them to phase through each other, so I doubt that.

[tstein]

18 minutes ago, Bej Kerman said:

The devs came up with a way to simulate vessel collisions at speeds where the physics step would otherwise cause them to phase through each other, so I doubt that.

Well that technique is in fact nothing new. it existed for every game with simulated projectiles (as  most combat fligth sims).  It is more a case of  KSP1   history of development prevented its proper usage, or maybe Unity did not support it directly.

[magnemoe]

23 hours ago, GoldForest said:

I wonder if the time warp bug will still exist. The one where you can time warp through an atmosphere so quick that the game doesn't have time to detect the atmosphere and drop to physics warp or normal speed. I imagine it will still exist. If it does, you could save your interstellar ship from becoming explodium central by just warping through the atmo. Problem solved. 

I once managed to warp trough Eve, messed up the launch and had to do two penalty orbits before an encounter with an correction burn. It was a impact  trajectory but would anyway need to modify inclination once I was closer. 
wanted to reduce warp for this but instead got to max warp and was past Eve SOI before I could stop it. 

Its many ways to solve this, simplest is probably an internal version of the alarm clock who tell game to reduce warp at the time. 
My flock of probes on a free return trajectory who ended with most returned to Kerbin had an fun effect, i was watching an probe in the atmosphere who slowed down, trailing probes went faster as they was not slowed by drag until inside physic distance.