Parachute Destroyed by Air Resistance

[csvolny]

I'm playing version 1.04 in Career mode. I am not using any mods. I have Basic Rocketry, Engineering 101 and Survivability and I'm trying to launch my second rocket. I am only going sub-orbital, never reaching an altitude higher than 24,000 or so, but I have this problem if I go higher as well. I have a basic rocket with a Mk I Module, 3 Science Jr., a Hammer, a parachute on the nose and two on the sides of the top Science Jr, and three Mystery Goo containers on the second Science Jr. I also have two sets of 4 fins at the bottom of the rocket and on the third Science Jr. This is only the latest of several different designs.

When the fuel burns out and I return to the surface, in all cases, I am going too fast to deploy the parachutes, all the way to the ground. I am unable to control the ship in any way to try and slow it down. Even though the SAS light is on, I have never installed it as I don't have the technology yet. I have no idea what I'm doing wrong. From what I've read about similar problems, I'm told to get the speed below 250 m/s. How am I supposed to do this? As you can see from this picture, I still have the "white lines" indicating drag and I'm far too low in altitude to deploy the chutes.

As this specific problem doesn't seem to be mentioned, I'm assuming I'm doing something so fundamentally wrong that none of you experts are even thinking of it as a problem. I am completely new with KSP, having purchased it just last weekend. I do not seem to have any difficulties with the heat, when I leave the atmosphere and return, only with air resistance.

If someone could help me out or point me in the right direction, I would be most appreciative. Thank you very much, in advance.

Edited October 31, 2015 by csvolny

[Claw]

Early career can be difficult for these short sounder type missions. The problem with something like you have there is that it's fairly low drag, and wants to point nose first when coming down. So there's not a lot slowing it down.

Instead of launching straight up, try using a flatter profile, launching and flying at a bit of an angle. That way, when coming back down, the ship is traveling a bit down range also. This lets the rocket travel in thicker air for longer and helps it slow down.

Also consider decoupling that SRB. They add a bit of weight and make it harder to slow down. Funds wise, empty SRBs are quite cheap. You can also keep the decoupler by attaching it upside down, so that it sticks to the Sci Jr and jettisons only the SRB.

I'm sure others have more ideas. Good luck.

Also, welcome to the forums!

Cheers,

-Claw

[mabarry3]

I had this issue for a while, so you're not the only one. I even accidentally killed Jeb while I was still not understanding why I wasn't able to fly (and didn't even know he died! R.I.P. Jeb) or release parachutes.

For me, it was easiest to try to maneuver it while at the highest altitude, or the thinnest possible atmosphere. You want your rocket pointed in the retrograde direction on the way down (you have it in the prograde direction currently), which will give you the least aerodynamic shape. The flat-ish bottom of the Hammer is significantly less aerodynamic than the angular shape of the mk1 pod, and you should slow down a lot more, well beyond the point you can deploy your parachutes.

You can also attempt to turn your rocket on the way up so it's going in a more horizontal direction - the more horizontal you go, the less vertical speed you have which should give you more time to slow down. Just don't go too horizontal or you could flip or not reach the target altitude you want.

Besides that, I'm still a newbie here too so some of the aerodynamic experts around here should show up any time if I'm wrong in my understanding of it.

P.S. Jeb (your current Kerbal) is a pilot, so you do have SAS, and if you didn't you wouldn't be able to activate it. It's a functionality of having a pilot in the command seat.

Edit: Ninja'd by Claw

[AeroGav]

I'm a spaceplane guy, so probably not the best help with regard to rockets. I too found that early game, how fast and how high is limited by what you can bring someone back alive from , not what the rocket itself can do.

SAS is artificial stability system. It makes control inputs to try and counteract any deviation from the straight and narrow your vehicle may do. It's not actually a tech - because your crew contains a Pilot, the option is available. However, it can only correct using the same control surfaces that you yourself have - a sufficiently skilled player flies just as well without it.

And here in lies the rub. You don't have any control surfaces. Those fins are not steerable, nor does the rocket motor have thrust gimballing. The only steering you have is the reaction wheel torque from the crew capsule. I guess you could outfit your vehicle with multiple crew modules for more "steering", but it's not ideal.

Incidentally, surely the rocket is going slowly the moment it runs out of upward momentum and stops going up? Or are you well out of the atmosphere at this point ? In which case, you'll just have to earn science with smaller rockets for now.

Or, is your rocket turning over horizontal shortly after launch, and developing a very high horizontal velocity which never goes away till you smack the ground?

There's plenty of science to be had from little rockets anyway. When I got steerable fins, I basically used a combo of winglets and fins to pull the vehicle out of it's vertical dive once re-entry was complete. They'd slow it to 100-150 or so, and a 30 deg dive, wherupon the parachute was safe to deploy.

[Gojira1000]

Ditch one or two of those materials bays, as a capsule, the lil SRB and a single mat bay will descend safely (just) on a single chute, even with a vertical launch. Probably lose the second set of fins as well, just use the ones on the SRB itself.

You'll need a gentler angle of descent, especially once you have bigger boosters. Try pitching over a bit if it'll let you with no control surfaces.

Oh derp that's a Hammer not a Flea, nevermind, one chute won't do the job.

Edited October 30, 2015 by Gojira1000
noted I was full of wrong

[Alshain]

Claw's suggestion is correct though as an alternative mission, spin stabilization is an option depending on the tech tree level. This method would mean switching to an unmanned mission.

Take Stayputnik, put a SRB below it, and put your 4 fins on. Then take the rotation tool and skew them to right like a fan blade. The probe doesn't have SAS but the spin that the fins cause will keep it more or less going up. You can then do what you need to do and go back to the space center and let the probe burn. I do this when I need a quick suborbital part test for cheap. Don't forget to take an antenna to transmit science.

If you don't have that level of tech yet then there is still plenty of science to get closer to the ground. Tier 4 is not that hard to get.

Edited October 30, 2015 by Alshain

[csvolny]

Thank you! You guys have given me some excellent ideas to try out.

Good to know about the SAS. I read in some other post (or forum, I don't remember) that it was a technology.

[MarvinKitFox]

Whack those three science bays of yours side-by-side.

Sure, its a lot more draggy going up, but you can overcome that with engine power.

It will also be a lot more draggy on the way *down*, dropping well below 250m/s, which is more-or-less the safe speed you are looking for.

in short: Your rocket is too...... rocket-like.

[paul23]

Whack those three science bays of yours side-by-side.

Sure, its a lot more draggy going up, but you can overcome that with engine power.

It will also be a lot more draggy on the way *down*, dropping well below 250m/s, which is more-or-less the safe speed you are looking for.

in short: Your rocket is too...... rocket-like.

Actually a "flat surface" would already be enough: either you need enough reaction wheels to stay top up, or just add one of the science modules above the command module (so the falling orientation doesn't matter anymore). Btw that one parachute is never going to slow down enough to prevent breaking of the science labs. - I reckon it'll slow you down to around 8-9 m/s, the science labs have a max impact speed of 6 m/s.

[Reaper98270]

Very early in the tech tree you have to build something wider to be able to get drag if you're going too high. You can try, for example, attaching the command pot on top of the science materials and then strap two of the solid rockets (one you already have) to either side of the materials bay. This will create more drag and slow you down below the 250m/s you need.

The other part is once you get your first inline decoupler, you don't really need to worry about it because you can decouple down to just the pod and then it is easy to keep pointing retrograde to slow down (throwing a heat shield on the bottom of it when you unlock it in the tech tree for less-than-ideal re-entry angles).

The reason your current ship design ends up nose down is because the command pod's weight causes your COM (center of mass) to be towards that end of the rocket. The rocket fuel is drained and that moves the COM up the rocket until it is so high up that all it does is tip it nose down, preventing you from getting any drag. This means another alternative is to leave enough fuel in your tanks to not tip nose-down when you're descending (don't descend on completely empty tanks until you have a decoupler to get down to just the command module).

[csvolny]

Brilliant! I'm coming here for all my Kerbal needs from now on. I sent this up:

Also flew it almost parallel with the ground and it landed nice and soft. Not the prettiest to look at, but that's ok, Jebediah is safe. It never occurred to me to place the Science side-by-side like that. Now I'll send a couple of those to other biomes and accumulate some more science and then open up Tech to get more control over the craft.

Thanks again, I was despairing of ever seeing that sight!