The Secret to large ship parachutes

[Zaeo]

With the release of .20, comes my "Finally" attempt to make a space program where no one dies.

Aircraft and airless bodies are mastered, however, every time i try to save*intact* ships via parachutes, the velocity is ~80 m/s when chute deploys, effectively ripping the command pod from the rest of the ship, or destroying the command pod in attempt to save the whole ship*by pushing it under the center of mass*

I am trying to *completely unpowered* land the entire craft unscathed on kerbin as a test, and later all atmospheric bodies.

I have tried drogue chutes, and experimented with 20+ designs, all of which are put through their paces.

I'm not trying to land a 600 ton behemouth, I'm trying to land a simple 18-30 part command module without using any fuel, weight MAYBE 7 tons fully fueled.

I'm using 4 radial parachutes, is that too much for 7 tons?

[magnemoe]

Don't add all parachutes to the command pod, try to put most on the main fuel tank, another option is to use struts between command pod and fuel tank.

An picture of the ship would help.

4 parachutes should be enough,

[Klajan]

I usualy don´t have a problem with landing ships this size via chute. If you come down to fast and your chutes rip of, try one of the MK25 Parachutes, these will deploy at 2500m and then slow you down significantly. 4 Radials should be enough for 7 Tons. I found a Setup of 3 Mk25 and 16 radials to be enough for my fully fueled 100t SSTO.

Also mount at least some chutes on the fueltank.

[AnalogAddict]

Usually 4 radial shutes stops my landers of up to 30 tons... But I'm a daredevil and minimalist.

[Landge]

For my extra large ships I add struts to the chutes to reinforce the attachment.

Landing the HMMR. 12 large chutes and 4 drogues plus a bit of powered descent to land back at KSC.

HMMR: Heavy Mobile Mining Rig Mission to Mun...

Edited May 23, 2013 by Landge

[Jason Patterson]

The command module - ASAS connection is extremely weak, if you're using that. Just about any strong jolt will break them apart. I actually use it as a defacto decoupler for my final landing parachutes sometimes.

You can either add struts between the command module and whatever it is connected to (and perhaps from that to the fuel tanks) or simply attach the parachutes to the fuel tanks directly.

[Klajan]

The command module - ASAS connection is extremely weak, if you're using that. Just about any strong jolt will break them apart. I actually use it as a defacto decoupler for my final landing parachutes sometimes.

You can either add struts between the command module and whatever it is connected to (and perhaps from that to the fuel tanks) or simply attach the parachutes to the fuel tanks directly.

I usualy try to avoid the larg ASAS module or reenforce it with duct tape, äh, struts. If you can try to use the small one, as it is lighter and stonger. The large one is quite handy for hiding things within it thought.

[Scrogdog]

While we are on the subject I have a quick question about drogue chutes.

It seems like they should deploy and then get released before the mains deploy. It doesn't seem like there's a lot of room on a basic capsule to get this done. Especially when I've got a docking port on top.

What are you guys doing?

And... holy crap, Landge!

[capi3101]

Temstar's Downmass Tug design incorporates drogues. IIRC, he's got four of them attached to BZ-52s along the sides, so they in effect deploy like radial chutes. It's a pretty solid design; if I had the link I'd post it (help here would be appreciated).

[Klajan]

You have two options with this setup:

1: get something to attach them radial(the Cubic Octagonal Strut)

2: use the same part to attach it unerneath your dockingport

PS: the link for the Downmass Tug. You have to scroll a bit to get there.

Edited May 23, 2013 by Klajan

[Landge]

While we are on the subject I have a quick question about drogue chutes.

It seems like they should deploy and then get released before the mains deploy. It doesn't seem like there's a lot of room on a basic capsule to get this done. Especially when I've got a docking port on top.

What are you guys doing?

And... holy crap, Landge!

I have the drogues and mains deploy together. I figure with the drogues opening at 1500m and 500m for mains, why bother with separate staging for chutes.

It also doesn't make any sense to me to cut drogues it they are helping slow your descent. I keep mine on.

[Scrogdog]

Thanks guys. I have some ideas bubbling now.

Landge, I think historically the reason they got dumped was simply a matter of making room for the mains. I could be wrong on that.

[Landge]

Thanks guys. I have some ideas bubbling now.

Landge, I think historically the reason they got dumped was simply a matter of making room for the mains. I could be wrong on that.

Makes sense in RL because they could tangle up with the main chutes. Would love to see some form of collision detection on chutes in KSP eventually, but not until Squad has finished their other priorities.

Edited May 23, 2013 by Landge

[Zaeo]

Ok, so basically, What I have read here:

Strut up

ASAS bad!

and powered decent.

hrrm...

great, gotta add "fugly clutter" on the sides of my ship

[Kromey]

Two tricks I've used to slow down and safely land big heavy ships unpowered:

1) Drogues. These things are great!

2) Staged chutes. By this I mean that if I have to use a lot of chutes, the shock of them opening is often more than enough to rip the ship apart! Rather than "fix" it by slapping on more duct tape, I've on several occasions split my chutes into multiple stages, so that the first tap of the space bar is e.g. two drogues, the next is two more drogues, the third is 4 regular chutes, and the fourth is another 4 chutes. Doing this reduces the shock that your ship undergoes with each deployment -- just make sure you're opening them in a balanced formation, otherwise you'll start tumbling and probably rip right apart anyway!!

[Shrike42]

As an alternative to massive numbers of stages, you can use command groups for the same purpose. This has the extra advantage of letting you repack the chutes and deploy them again.