Impossible Contract?

[Versutia]

Hello everybody,

until now, I thought the contract system is very reasonable and helps me learning the game step by step. But I think this is not ture; especially after investigating about my current "problem".

Does anyone have an idea how to fulfill the following contract?

Test TR-2C stack separator

-Kerbin

-Flying

-Alt: 0m to 4,000m

-Spd: 1,310.0m/s to 1,680.0m/s

 

The best I achieved so far was about 1,100m/s after dashing into Kerbin with 3,000m/s and fireing an additional solid fule thruster on like 10km above ground. But at this point my rocket starts to overheat and explode even with heat protectors.

Edited May 18, 2016 by Versutia

[AlexisBV]

Sounds like a challenge! I'll try that tonight at home.

Also, seems like a job for the Kraken.

[DChurchill]

Yeah looks like a challenge.

[Mister Dilsby]

Welcome to the forums @Versutia! Well, not all contracts are meant to be possible--that's why you have to "read the fine print", and why you have the ability to reject ones that you don't think you can do. If it were me, I'd pack the stack separator in an overpowered and uncrewed spaceplane, fill up a forward cargo bay with radiators, go to full throttle at 3900m and hope for the best  

[Versutia]

23 minutes ago, Kuzzter said:

Well, not all contracts are meant to be possible--

Actually, this would kill the game for me.

I don't want to try the same contract over and over again while there is maybe no way to achieve it. Don't get me wrong. Challenging contracts are fine and I'd try them a 100 times, but they have to be possible.

[Curveball Anders]

The contracts are somewhat random, and some of the parameters for some test contracts are totally bonkers.

The good news is that you can ignore stupid contracts and they'll go away.

Edit:
For reference, google "Kobayashi Maru"

Edited May 18, 2016 by Curveball Anders
Nerdiness

[JoeNapalm]

 

Dunno if it's possible, but I'd try either vertical re-entry with assist and a layered heat solution or a really really fast plane.

That would be exceedingly low to hit those speeds, either way.

Hmmmmmm....

 

-Jn-

Edited May 18, 2016 by JoeNapalm

[suicidejunkie]

You might try looking up some of the rocket designs for the "island express" vehicles.  That should get you the appropriate speeds, and then it would be a matter of surviving the heat (ablative parts?) long enough to trigger the test.

Something like this: https://www.youtube.com/watch?v=gKfHGIMsPco

 

[samstarman5]

I'm not much for the inflight test contracts, but if that came up I think I would honestly be tempted to try it.  Don't give up. Sounds like you are so close that you may need to change but one part to achieve what you need.

[Brian444444]

Here's a video of a rocket doing it. I will let you study what little you can see of the rocket so I don't completely ruin the fun for you.

 

 

[Mjp1050]

2 hours ago, Brian444444 said:

Here's a video of a rocket doing it. I will let you study what little you can see of the rocket so I don't completely ruin the fun for you.

<snip>

You achieved over 1310 m/s for a moment there. What's the problem?

EDIT: I thought you were the original poster. My bad.

Edited May 19, 2016 by Mjp1050
quoted the wrong person

[Snark]

Moving to Gameplay Questions.

[Plusck]

Very cheap option:

Spoiler

And how it got there: first stage

[Versutia]

Thanks a lot for your help!

Finally I did it with the rocket Plusck posted. You guys rescued the game for me  : D

(It looks like you had 3 solid fuel booster. This didn't work for me. At the end I used 4 of them and hardly reached 1310m/s. I have still no idea how you achieved 1400m/s with this rocket.)

Edited May 19, 2016 by Versutia

[Plusck]

15 hours ago, Versutia said:

Thanks a lot for your help!

Finally I did it with the rocket Plusck posted. You guys rescued the game for me  : D

(It looks like you had 3 solid fuel booster. This didn't work for me. At the end I used 4 of them and hardly reached 1310m/s. I have still no idea how you achieved 1400m/s with this rocket.)

I used 3x symmetry because I was worried that the fins would add too much drag.

The Hammers don't really contribute much (or at all...) to the top speed - I found that I needed them to get the Kickback on the right trajectory to start with (if it started at an angle of about 45° it would hit the ground, and if it started at a higher angle it was extremely difficult to get it down to a flat trajectory). The craft file for what you see in the screenshots is here.

I suspect that the speed difference you saw was just due to altitude - I just tried a few tests and got over 1500 m/s at a final altitude of 6000m, but only just 1400 m/s with a final altitude of 3000m. Drag really does change enormously with altitude at these heights.

However I also realised that I was making the craft unnecessarily expensive. The Hammers are essentially there to get the Kickback aligned while waiting for its fuel load to drop and its TWR to get high enough to hit these speeds. So why not just start with less fuel and forget the Hammers? So I pared it down to half the cost with a single Kickback with about 60% fuel. Test craft here. Turn on SAS, fire, wait until reaching an altitude of about 250m and turn SAS off.