Space Launch System Launch System

[EdFred]

I've started on this. I expect a score of 6 or 7.

[zarakon]

Good luck with that!

6 may be plausible with the use of jet engines, but 7 is firmly in the realm of absurdity. Even if your first level is only 2 tons and you get a 25% payload mass fraction on each level, you'd be looking at building a 32768-ton monster for level 7.

[EdFred]

I've already done what would be the equivalent of 5.5 at 2100t.

[Rakaydos]

With FAR and Stock Rebalance, I have a rocket that it probably a contender, but I'll have to see how many times it can get to orbit.

[Bobnova]

I made it to three. The fourth one had an issue.

SSTO, launcher for SSTO, launcher for launcher for SSTO.

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The fourth launcher had issues:

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Fun challenge!

[gchristopher]

first level is only 2 tons and you get a 25% payload mass fraction

Even without intake/wing reuse, you can get better than 66% payload fraction on a spaceplane with ridiculous airhogging (~1 intake per ton). Intakes are pretty much the only factor in max lifting ability.

But the time investment would be pretty extreme. That's a lot of time creeping up in altitude while maintaining velocity while keeping your thrust 150 mm/s over atmospheric drag.

Part count might hurt more than tonnage. I've lifted 100 tons payload on a 150-ton spaceplane with 160 ram intakes, but that's one tiny strut per intake, so the air alone was 320 parts.

[sdj64]

Rakaydos, remember that the rules say stock only, FAR makes it easier to get to orbit.

Bobnova, congratulations on getting your SSTO + drop tanks designs to orbit for a score of 3 in the no-jets category!

I would think that with a jets entry, you'd have to switch to rockets after the 3rd or 4th lifter, because of the part count as gchristopher said. Possibly you can use some jets on your later lifters to reduce the weight on the rockets.

[zarakon]

Alright, finally done!

Level 1: 4.3 tons, 60 kN thrust

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Level 2: 30.7 tons, 645 kN thrust

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Level 3: 163.4 tons, 2500 kN thrust

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Level 4: 816 tons, 13900 kN thrust

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Level 5: 4224 tons, 68700 MN thrust

Unmatched in heaven and earth, one machine equal to the gods!

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Total of 23498 delta-v

By far the most I've ever successfully gotten to orbit, largely thanks to the overpowered SLS parts. Without those, this probably would have been twice this size

[Nao]

Where is the whackjob seal of approval when we need one...

Awesome job! SLSLSLSLSLS lol

[problemecium]

I'm working on stage four, the problem is that it seems to be absolutely, unavoidably, entirely impossible to do it hardcore-style. My experiments with Kerbodyne tanks have shown that they LOVE to spontaneously explode in water, even if I land as slowly as 1 m/s. Even if I land the ship SIDEWAYS, they STILL blow up for no reason.

So I can probably cobble together an expendable fourth stage out of piles of boosters, but that's about as far as it goes.

[zarakon]

I'm also trying to do one with just simple vertical staging, 2 stages per level, no droptanks or asparagus nonsense. Currently at level 4

[sdj64]

awesome job zarakon! Not sure we'll see anything better than that in the no-jets category, unless Whackjob decides to enter

With that much dV you can go to Moho, land on it, and come back to LKO... twice.

[zarakon]

Alright, completed my level 5 with only pure vertical staging (no droptanks, no asparagus).

I still need to go back and refly all the levels for screenshots, but here's a peak at the first stage of level 5...

I have to use DynamicWarp to run the first stage at 1/4 speed and the second stage at 1/2 speed

[Whirligig Girl]

I think for the purposes of this challenge, FAR makes it harder because of the complexity of building something so big.

[Whovian]

This is more of a technical question than anything, but is it that we need to make it into orbit without ever using any fuel from the previous stages, or once a stable orbit is reached all previous stages must be full on fuel? That is, do we care if all fuel tanks in the previous stages are full for the entire flight, or just at the end? The nature of the challenge suggests that it's the former, but the whole "if it can't be proven" thing in the rules/guidelines (can't quite figure out which they are) for this forum suggests it's the latter.

It probably doesn't really matter; the only reason I can think of that this would is to keep the mass distribution relatively sane, which is fairly easy to do anyway. Just being sure.

I'll be trying this soon. I like the fact that this is a petite little challenge, but still quite difficult.

[zarakon]

Alright, here's the full gallery for my new one, also level 5. The good pictures are at the end!

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- 2 simple vertical stages per level

- No asparagus, onion, or drop tanks

- Used tweakable fuel tanks to reduce weight of upper levels (and flew them with the reduced fuel, of course)

- Level 5 is about 2.5x the weight of the Saturn V and has 2.8x the first-stage thrust

- I had to use DynamicWarp to slow down the game for level 5

[8MMW]

zarakon, the first stage of the last level somehow reminds me of the hyperdrive ring from Star Wars