10 Engines Challenge (aka efficient staging design challenge)

[carazvan]

Here's my entry for Speed SRB challenge: 2658m/s Used 1-2-3-4 SRB staging

P.S. Sorry i moved info screen it up ... it would've been nice to see the 25Gs Jeb, Bill and Bob suffered through; Oh well next try ...

[Nao]

Didn't tried 5-3-1-1 that looks like it woud be the best one but I'm a rebel

2856 m/s with 4-3-1-1-1 setup and

2863 m/s with 4-3-2-1 one.

In the first one the kerbals started running around the ship because that would add to the speed of course, results included forcefully decoupled engine and a snack box destroyed. The jury discarded the feeble attempt (no speed gained).

Now onto the main dish of the day, ze asparagus! Although tavert set the bar into geosynchronous orbit .

[carazvan]

Cleaned up and shortened my 1-2-3-4 staged rocket and heres my best attempt with it: 2766 m/s

P.S. If you use this staging and just go vertically (hit T and space to stage when needed) ... you get a nice max of 30G on reentry ... ouch

[sturmstiger]

A few questions that will be settled as new entries come in and push the records:

For the SRB challenge:

1. Are we ready to declare the best configuration yet? The top contenders seemed to be 5-3-1-1 and 4-3-2-1. Anyone tried 5-3-2?

2. Is is possible to do better by "partial" serial staging, e.g., light up a stage before burnout of the previous stage?

For the lifter challenge:

1. What will be the ratio of payload mass for cross-feeding vs non-cross-feeding designs when both types approaches the limit? I would put my bet on something around 1.25. What about you?

[Nao]

A few questions that will be settled as new entries come in and push the records:

For the SRB challenge:

1. Are we ready to declare the best configuration yet? The top contenders seemed to be 5-3-1-1 and 4-3-2-1. Anyone tried 5-3-2?

2. Is is possible to do better by "partial" serial staging, e.g., light up a stage before burnout of the previous stage?

For the lifter challenge:

1. What will be the ratio of payload mass for cross-feeding vs non-cross-feeding designs when both types approaches the limit? I would put my bet on something around 1.25. What about you?

5-3-2, will have too short burn time and will eat up most of its Dv fighting the atmosphere.

I tried partial staging (preburning one engine to half before launch) and the results are very close to the best ones (20-30m/s less). The problem is that it only works for symmetrical thrust setups, it requires 3-1 transition as it does not work on 2-1 (yet ). I tried asymmetrical thrust for last stages and it almost worked.

Also having something similar to 2-1-1 as top stage would be a blessing but there are no efficient 10booster setups that can get that). Maybe ill try that later with control surfaces (are they allowed? I kind off thought they were banned until i saw some recent posts).

I'm betting on 1,28 ratio (i believe in my performance , and there is no way we can beat tavert by more than 0.1-0.2 if it is at all possible).

edit: as i said about 2-1-1 blessing ... 4-2-2-1-1 aaaand 2868m/s , that said it was only one try and without any mods (MJ/KER) so there is definetly room for improvement. Its actually quite surprising that we get that close results for different setups

double edit: just noticed I'm twice on the leaderboards. While it's my fault for posting two entries, I think it would be fair to only use one (probably the most recent one from this post).

Cheers!

Edited July 23, 2013 by Nao

[sturmstiger]

... Maybe ill try that later with control surfaces (are they allowed? I kind off thought they were banned until i saw some recent posts).

You're right they are not allowed per the no low-drag parts rule. I didn't look closely at the entries so I put them on the leaderboard. However because (1) I hate retroactively disqualifying entries, (2) I think the their uses in the entries so far were unintentional and not exploitative, and (3) none of them is currently top ranking, I will not disqualify the existing entries. However I'll enforce the rule closely from now on.

Edited July 23, 2013 by sturmstiger

[numerobis]

If it's not on the payload, it should be kosher, no? The only worry is infiniglide abuse, but good luck getting 35t into orbit off wings.

[tavert]

If it's not on the payload, it should be kosher, no? The only worry is infiniglide abuse, but good luck getting 35t into orbit off wings.

I agree here. If it's not being counted as part of the payload, then it's still adding mass (and a little bit of drag) to the launcher. I didn't bother trying to see if lift from control surfaces on the launch stages could reduce gravity losses enough to be worth it, but it could be interesting.

[Bobnova]

First post!

This is a fun challenge, had to create an account to put my entry in.

The ship:

The data:

2620m/s, manually controlled. I'm going to do some more with mechjeb and see if it helps.

[sturmstiger]

I agree here. If it's not being counted as part of the payload, then it's still adding mass (and a little bit of drag) to the launcher. I didn't bother trying to see if lift from control surfaces on the launch stages could reduce gravity losses enough to be worth it, but it could be interesting.

Point taken. However I'll probably keep that rule as it is for the following reasons:

1. Changing rules (again) mid-challenge is confusing and perhaps unfair.

2. There shouldn't be a need for control surfaces as the 3-man pod or the gimballed LVTs should provide sufficient attitude control.

3. The point of the challenge is efficient rocket staging design. If things like control surfaces are explicitly allowed, some people might waste time thinking about things like "alternative lift sources" whether that would end up helping or not, and thus totally missing the point.

[Rizendell]

Stage 5: 8 x 4 = 32 engine first stage.
Stage 4: Parachute deploys at separation of liquid fuel engines and tanks for recover. 8 x 1 = 8 mainsail second stage continues burning using RCS to aid in vector alignment. (tracking apo at 100km)
Stage 3: 8 x 1 = 8 mainsail second stage continued for 400 m/s while applying counter clockwise roll to induce a barrel roll.
Stage 2: Parachute deploys (for recovery of mainsail engines/tanks in ocean via parachutes) and centrifugal separation occur. 8 Nuclear Engines become active with 4375 delta V (TWR .58)
KETHANE MINING KETHANE MINING KETHANE MINING!!!!

The landing legs work great!!!
The parachutes ensure landing on a planet for reuse)
18000 kethane tank w/ engine and intakes. (just need to hack the K into the file)

+.... I always tend to over achieve.

2x speed to orbit + Haley Reinheart

lots of engines...

and 8 nukes stuck on a jumbo kethane tank and single (large) kethane tanks w a large converter, 24 radiothermal gens, plenty of fuel/thrust for moon landings + 12 parachutes and landing legs. [ no lights, sorry, I forgot ]

The Kintakeair is broken... the part is missing. I used the intakes on the side as a placeholder so that I can hack the save file to convert them. Just need to add a K to the part in the save file to enable the engine once we have mined some sweet kethane in .20 with 2.08 mechjeb to help us out. Edited July 24, 2013 by Rizendell
oopsy url for [video] was messy

[sturmstiger]

First post!

This is a fun challenge, had to create an account to put my entry in.

Welcome to the forum! Glad you liked the challenge!

Stage 5: 8 x 4 = 32 engine first stage

....

Rizendell, you're posting on the wrong thread. Looks cool though.

Edited July 24, 2013 by sturmstiger