**Long Post**
should change my name to 'Wafflemaster'
I find it funny that the subreddit has a challenge for it stating that "the math proves it's possible"
That's cos other media outlets are full of nuggets wanting .bps and claiming world records, but still haven't managed to figure out how this delta velocity thing works
Now that's one I hadn't heard before, so I searched the forums. I found something about your KDS, but I'm not quite sure how komodo staging works. Can you explain please?
It comes from the name of the rocket I first seen using it. I use it to solve 2 problems, firstly the issue with SFS staging on ridiculously sized multi staged rockets, second to reduce weight spent on engines overall in a build.
The idea is the entire rocket, every engine on board, fires throughout launch. This gives you the TWR you need to get off the ground with the minimum number of total engines on board, lessening your overall dry weight. Each 'stage' then has carefully timed cut outs as the weight drops and required thrust lessens and is dropped away, getting rid of empty fuel tanks and unneeded engines as required, reducing all up mass and dry weight further in flight.
A simple example would be a 2 stage rocket that needs 10 engines to get a TWR of 1.3 first stage, and 4 in the second stage, so you need 14 engines total. Now your options are to spread the 10 launch engines across the first stage and likely a booster pair (6 in the core, 2 on each booster).
How my lizard launch vehicles (Komodo and Salamander) would do it is they'd have 6 in the first stage and 4 in the second, with more fuel. At launch, all 10 engines would fire, generating your required TWR of 1.3 until the main stage runs out of fuel. It's then dropped, getting rid of the 6 unneeded engines as well, but with the 4 in stage 2 still burning.
Even if you offset the weight of the engines you haven't put on with fuel, your dry mass is much, much less because an engine is all dead weight and a fuel tank is only 1/10th dead weight. Your rocket
may end up heavier at launch, but more of that will be fuel and because delta velocity only cares about the difference between maximum (which you have more of) and minimum weight (which is now lower), you get more of it from the start.
The down side is they're a bawlbag to design, especially if they have more than 2 layers. Mine have 4, sometimes 5 layers with 4-16 build screens in each layer and getting the burn times to run out in sequence from bottom to top requires some crackerjack maths.
The other plus for me is its modular. I've only used it for ridiculous payloads and I used a version on the smallest to jupiter as well, which actually worked out lighter than the one posted because of the stage attachment, but not the engine numbers.
How that helped in the ion case, was that design wanted
z t of fuel,
x ions in the first stage and
y in the second. My idea was a stage one of
x-y ions and sufficient battery power to run just them for the burn time of that stage, but no fuel. Stage 2 would have
y ions, sufficient battery power to run them throughout flight and a 5t fuel tank, partial filled to
z amount.
The pros were less engines, so less weight, less fuel, less batteries at launch. And, I get rid of the dead batteries as well at staging. I only went for one tank rather than 2 through 2 stages because ions let you do that, and it's less dry weight (.5t rather than 1t).
Cons, power also drains evenly like fuel using ions and unlike fuel you can't do power transfer, so I couldn't drain
just the first stage batteries and leave fresh ones on top. Also, even with all this tom-fuckery going on, I
still couldn't get the holy trinity to work sufficiently through to LEO.