FAR + RealChutes, Suborbital Reentry troubles

[westamastaflash]

Just started a hard mode .9 career game with FAR, Deadly Reentry, Realchutes, and a bunch of other stuff.

I launch a suborbital flight to exit the atmosphere. But when I reenter I can't slow down to under 200 m/s before I hit the ground, because my chutes break going faster than that. Even Drogues break. And then I smash into the ground going 300+ m/s. Only way to deal seems to bring along extra fuel and attempt to do a powered descent. Any other ideas on how to slow a reentering capsule that is almost all vertical velocity?

Edited December 22, 2014 by westamastaflash

[stupid_chris]

Well to start with, FAR and RealChute are currently not compatible together. There's a bunch of error throwing going on, and there should b e an update soonish to fix that.

[westamastaflash]

Well to start with, FAR and RealChute are currently not compatible together. There's a bunch of error throwing going on, and there should b e an update soonish to fix that.

Ah! Thank you :-). I installed via CKAN, didn't realize the weren't compatible.

Also, I seem to have solved my reentry suborbital speed troubles by sticking on some high altitude kevlar drogues that deploy at 50km.

Edited December 22, 2014 by westamastaflash

[Yemo]

If it is allmost all vertical velocity, you are going at an angle which is too steep. That was my first mistake using FAR and real chutes, had to radically rethink my descent path.

[westamastaflash]

If it is allmost all vertical velocity, you are going at an angle which is too steep. That was my first mistake using FAR and real chutes, had to radically rethink my descent path.

For a suborbital launch of just 70km straight up and back down again? No angle really to go at. I added some drogues to deploy at 50km and it has done the trick though.

[Yemo]

Havent played modded KSP in a while, testing stock at the moment, but afair the much thinner FAR atmosphere plays a role as well. So even a 70km vertical drop is a problem.

I remember when returning from interplanetary journeys I routinely put in 1-2 Kerbin aerobreaking rounds before the final very shallow descent.

[Bobnova]

They're working just fine together to me, for whatever that's worth.

If your spaceship doesn't slow down enough to put chutes out, you need to redesign it and/or change your reentry angle to slow down further. Trying to do a vertical reentry in real life wouldn't work either

I generally try to reenter at a very shallow angle, something that puts the PE at ~30km.

[Starman4308]

For a suborbital launch of just 70km straight up and back down again? No angle really to go at. I added some drogues to deploy at 50km and it has done the trick though.

Straight up-and-down is going to fry your reentry vehicle. Put some horizontal velocity on it, and you can abuse a combination of orbital mechanics and a lifting reentry to keep your vertical velocity low.

To clarify on the lifting reentry part: if your capsule is pointed above atmospheric retrograde*, FAR will give your capsule a bit of lift. 2-5 degrees usually does a decent job. One way to do it very efficiently is to have an asymmetric capsule. If your center-of-mass is above the midline, atmospheric drag will naturally tend to pull your reentry vehicle to a proper lifting reentry. This is important in the real world, where reaction wheels are very limited, because you can control that with roll, instead of struggling with brute-force pitch.

*Ensure your velocity display is set to surface.

Edited December 22, 2014 by Starman4308

[westamastaflash]

To clarify on the lifting reentry part: if your capsule is pointed above atmospheric retrograde*, FAR will give your capsule a bit of lift. 2-5 degrees usually does a decent job. One way to do it very efficiently is to have an asymmetric capsule. If your center-of-mass is above the midline, atmospheric drag will naturally tend to pull your reentry vehicle to a proper lifting reentry. This is important in the real world, where reaction wheels are very limited, because you can control that with roll, instead of struggling with brute-force pitch.

Thanks - this makes a lot of sense.