Heat shields

[petrichorAM]

Hey, I know that re-entry effects are purely cosmetic at this stage but I like to go for realism with my spacecraft. I am eventually planning to put an unmanned rover on Duna a la Curiosity so want to go for a small sky crane lander with a heat shield below that I can detach once in the atmosphere. Therefore I have two questions:

1) What's the best way to design the crane with stock parts and bring the rover down safely

2)How can I make a heat shield, preferbaly with stock parts but I'm open to mod suggestions, that looks realistic and can be detached without damaging my rover and crane

Thanks in advance!

Edited July 30, 2013 by petrichorAM

[rodion]

All of the fake (stock) heat shields I've seen so far have been either simply relatively flat structural parts like the Rockomax adapter "02" for small payloads, or for large ones they are often made from the M-1x1 or M-2x2 structural panels, eg. here's Brotoro's shield for a rover he landed on Laythe, made from a combo of parts I just mentioned (from this thread):

[espm400]

If you want to go beyond purely cosmetic, you could always install Deadly Re-Entry. Doesn't take as much getting used to as you might think.

[petrichorAM]

Yeah I've seen that mod, do you have to use the add-on heat shields or have the undersides of the manned command pods been tagged as shields?

[ASnogarD]

From what I have 'seen' in videos , it seems you add a disk shaped ablative shield to the underside of your manned capsules (so I would assume the capsule is flagged as unshielded).

[Scorpi15]

The small black capsule (forgot the name) has a heatshield already attached. Ditto for the underside of the spaceplane parts. Be careful though, the plugin will disregard the heatshield entirely if it is coming in at the wrong angle, so keep the heatshield facing prograde.

[espm400]

Not only that, but they're ablative heat shields. Spend too much time in the lower atmosphere slowing down, and you'll burn through it. On top of that, the mod now models the g-forces your kerbals are experiencing, so if you decelerate too quickly certain parts may explode (same goes for positive acceleration during launch, generally anything over 8-g's is too much). If you couple this with FAR, you really have to get your approach angle right because the atmosphere isn't guaranteed to slow you down enough for parachutes (been a couple times I've come screaming in at mach 3 below 10,000m.

[petrichorAM]

Think I'll leave that mod for a while then until I find the re-entry sweet spot, still fully a beginner at KSP! :-) Back to my OP, can anyone offer any suggestions on the 'crane' lander for unmanned rovers and how to incorporate it into a rocket?

[Nephas]

If you want to do it stock, the closest to a sky crane will be a Lander with radial engines and the rover attached below on structural parts and decoupler/docking ports. For more realism you could install the Kerbal Attachment System Mod (KAS) which brings working cables and winches, so you can really do it Nasa style.

Don't get discouraged from the Deadly Reentry mod, it's not that hard, and considering Duna's thin atmosphere, the heating won't be too bad.

Otherwise, i would just recommend the large adapter parts for heatshields.

[petrichorAM]

I'll give the KAS mod a go, sounds good! Prob give the deadly re-entry one a go too (I can remove it of I don't get on with it), how is it with Kerbin's atmosphere? I guess Eve's will be the seriously difficult re-entry with that mod though!

[jbaltus123]

Dont create a flat heat shield thats not goot!

[espm400]

Apparently I completely missed the bit about a skycrane, otherwise I to would have recommended KAS. There was also a mod quite a while back (.19?), that allowed you to use an airbag-style landing system (a la Mars lander style), however I haven't seen it around lately.

A little tip for skycranes though; make sure you keep your CoM above your CoT. For some reason (Unity...) if you have a higher CoT KSP likes to reverse the gimballing on your engines, causing hilarity and frustration. Your two options would be to either, keep your CoT below your CoM, or conversely just not use ASAS after your skycrane has separated from it's transfer craft.

[petrichorAM]

Sorry newbie question, CoT and CoM?

[espm400]

My bad, usually I only abbreviate after spelling it out the first time... Anyways, Cot = Centre of Thrust, CoM = Centre of Mass. You can see these by clicking on the buttons at the bottom left in the VAB/SPH.

[petrichorAM]

Thought it might have been something like that but would rather ask haha How would I keep them in the 'correct' places, i'm guessing it would be to do with placement of engines and how my craft is put together?

[Spaceisbeautifulul]

Yes, always try to keep the engines on the bottom of whatever craft your building.