Space Launch System Launch System

[sdj64]

Space Launch System Launch System challenge

This is a challenge about efficiency, piloting, and heavy lifting. Your mission, should you choose to accept it, is to make a rocket that can reach orbit... then make a rocket that can reach orbit carrying the first as payload... then make a rocket that can carry that one as payload...

Rules:

First rocket must be manned and your kerbal must be in a pod (no seats).

Second rocket must launch your first into orbit fully fueled (and third must launch second fully fueled, etc.)

Rockets can make use of electric charge and SAS modules on payload rockets and can be controlled by a pod or probe core on the payload, but otherwise can't use resources from payload rockets.

Rockets cannot use engines that are a part of the payload rocket.

Rockets do not need to de-orbit or land.

Your second (third, fourth...) rocket doesn't have to be one piece, for example you can build two side boosters that get your first rocket to orbit, and those two boosters together count as your second rocket.

To make it fair for everyone, use only stock, and mods that don't add parts or change physics. Mechjeb and KER are okay to use in the VAB but not in flight.

There will be two scoring categories: jet engines, and rockets only. In the jet engine category you can use intake air from intakes on the payload.

SCORE = the number of recursive rockets you build.

Here is my entry, a proof of concept that scores 2.

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Jets Leaderboard:

1.

2.

3.

4.

5.

Rockets Leaderboard:

1. zarakon - 5

2. Jouni - 4

3. Bobnova - 3

4.

5.

Edited May 16, 2014 by sdj64

[Endersmens]

-deleted for the reason: stupid question, shouldn't've read so fast-

Edited May 8, 2014 by Endersmens

[zarakon]

I'll see what I can do when I get home later

I predict we'll see a maximum score of 5

Although.. are jet engines allowed?

[sdj64]

yes jets are allowed. If you can get up to 5 using jets, then your part count will probably be more of a problem than your weight.

[Kasuha]

Rocket can't use resources from previous rocket, but can they use their engines, as long as after decoupling the booster the payload is fully fueled?

Reminds me of the Orange tank to orbit to orbit challenge on Reddit.

[Jouni]

Let's see. You can build a 4-part SSTO using a RAPIER an FL-T800 fuel tank, a Mk2 cockpit (or a Mk1 command pod), and a ram intake. The total mass is around 7.5 tonnes, but you can reduce that to 6 tonnes by tweaking the amount of fuel.

A simple jet-boosted rocket with two turbojets can easily launch that into orbit. The total mass should be 15-20 tonnes.

The next rocket would use six turbojets and weight around 50 tonnes. After that, it's better to switch to traditional rockets, as 15-20 turbojets would be hard to handle.

You can reach payload fraction 15% with a low-partcount lifter using SLS engines. The mass of the fourth rocket would be at most 350 tonnes, including payload. The fifth rocket would be 2350 tonnes and the sixth 15700 tonnes. Beyond that, my computer would probably melt.

Maybe I'll try to build this after I have finished my current Eve mission.

[problemecium]

Sooo... they don't have to be able to come back from orbit?

[zarakon]

Rocket can't use resources from previous rocket, but can they use their engines, as long as after decoupling the booster the payload is fully fueled?

I don't think using their engines is allowed, only electrical systems. Clarification on that would be good though

edit: removed a false conclusion

Edited May 8, 2014 by zarakon

[NavalLacrosse]

I'll Give this a try in the near future sounds like a simple enough misson Reserved for my attempt

[sdj64]

Alright, I clarified some rules some more. You cannot use payload rockets' engines. They don't have to come back from orbit, just getting to orbit is enough. But you do need to provide screenshots of each rocket getting to orbit. It would be a totally different challenge if you had to actually land and take off again.

Do you think there should be a separate leaderboard for jets and no jets?

[Kasuha]

Inspired by Seat of Pants industries, this thing can get to orbit at 2.12 t (jet stage has oxidizer tweaked out)

[zarakon]

Yes, I would say jets should be a separate category

[gchristopher]

What about systems that use aerodynamic lift? The design would be a pain, but payload fraction can approach 70% (with preposterous airhogging), and with wings and intakes reused, maybe a little better is possible for a Matryoshka doll lifter.

edit: Huh, guess you don't even need the wings. Wow.

Edited May 8, 2014 by gchristopher

[sdj64]

I originally thought something like that would be part-count prohibitive, but with sharing intake air it makes sense. Though the "don't use resources from the payload rocket" could be interpreted by saying intake air is a resource.

Okay, I will make two categories, jets and no jets, and I will rule that you can share wing lift and intake air in the jet category. You still can't re-use jet engines in the payload!

[zarakon]

edit: Huh, guess you don't even need the wings. Wow.

Wings are only helpful if your thrust/weight ratio is low. That little thing has more power than it needs - it's basically just a rocket with extremely high ISP and a slightly different flight profile. KSP's jet engines are drastically overpowered compared to real life

[sdj64]

All this discussion and nobody wants to actually enter?

[zarakon]

I started on it, with the goal of scoring a 4. But then it turned out to be harder than I expected, and I was spending too much time trying to tweak down the weight on the first two, and I started playing a couple of other games so I just never finished

[icantmakemodels]

give this a shot later

edit: i will provide a download, but your computer may not be able to handle the heat

[Jouni]

I have the first three rockets ready, but I still haven't had time to build the fourth. All three are simple two-stage rockets. The first has 11 parts and weigths 8.4 tonnes, the second has 30 parts and weights 64.6 tonnes (including the payload), and the third has 66 parts and weights 418 tonnes. I gave up on using jets, as designing and flying them was too tedious.

Update: Matryoshka-4 flies! At 198 parts and almost 2700 tonnes, it's at the upper limit of my current desing approach. I had to give up on the two-stage model and add some SRBs, because the ARM engines are so weak. I'll make the official flights some other day.

Edited May 11, 2014 by Jouni

[Moar Boosters]

I'm gonna enter this for sure.

Expect something big.

[Jouni]

I built four rockets.

Matryoshka-1:

Matryoshka-2:

Matryoshka-3:

Matryoshka-4:

The orbital information somehow disappears when I take a screenshot. I'm not sure if it's specific to the Mac version, or if I'm doing something wrong.

[problemecium]

My WIP submission. I already had all of these built for use in Career Mode, and thus I've ended up doing Hardcore Mode: have all the rockets be reusable SSTOs and actually able to land. At present I don't have a Kerbal in the top rocket though, so I guess technically it's invalid at this point. And with Stage 3 being based around a Kerbodyne booster with no bottom attachment point, I'm currently at a loss for how to launch it. That, and I have yet to build a launcher that can get 195 tons to orbit.

P.S.: Stage 3 isn't actually able to carry stages 1 and 2 at the same time, but I have them this way for easier tweaking in the VAB.

[sdj64]

Congratulations Jouni for the first challenge entry! I updated the OP with leaderboards.

Parameciumkid, your rocket looks really cool and I hope to see your entry completed. With the SSTO requirement you've set for yourself, that makes it much more difficult, since your payload fraction will be much lower. Even if you can only score 3 I encourage you to enter!

[Whovian]

EDIT: Ignore this; I'm an idiot who can't read.

I'll take a look at this challenge when I get around to it. Is it okay to plagiarize other rockets within certain obvious limits; for instance, could I adapt one of FAR's example crafts into a craft for this challenge? (Of course, directly copying another person's craft would obviously be outside these limits.)

Edited May 13, 2014 by Whovian

[zarakon]

I've gotten mine up to level 3 so far. I think the first one is 4.3 tons, and the level 3 is about 160 tons total, so I'm in pretty good shape for weight. Each level of it just baaaarely reaches orbit.

At this rate, level 4 will be about 976 tons, which is completely do-able, but still quite a bit of work to get it working and optimized. I made one attempt at it, but didn't get close to orbit. I think I need to upgrade my KER or MJ because they aren't giving me good info once I start using the SLS parts.

Level 5 would need to be almost 6000 though. That means it'll need 20+ of the KR-2L or KS-25x4 engines at liftoff. That's also about double the mass and liftoff thrust of the Saturn V. The total craft will also have over 23000 delta v without any nuclear, ion, or jet engines

Edited May 13, 2014 by zarakon