GoSlash27

Darn it! My new entry is ready and Photobucket's down for maintenance I'll just share the craft file for now and upload the pics when I can. http://wikisend.com/download/420034/GenII20.craft This is the Gen II "Cheep 20". Total cost at launch $31,060 minus payload $17,710 = $13,350 expended. Payload in 82x5 orbit 19.7 tonnes, which yields $677.66 per tonne. *edit* This is an entry for the new 2.0 challenge. *edit* Pics are up. http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/CnCRocketFactoryII Best, -Slashy

Norcalplanner, Looks good from my house! Best, -Slashy

Thinking about what the payload should or should not provide in this challenge... Guidance: I'm okay with that. The end- user would have guidance in the payload. Electricity: I'm kinda torn on this. I usually have enough batteries in the payload to keep the lifter alive, but I could picture a situation where it wouldn't be enough. Reaction wheels: I'd say no reaction wheels in the payload. It's unrealistic to expect the end user to put enough torque in the payload to control the whole lifter. Thrust: Definitely not. We know that the payload will circularize itself. Simulating that does nothing to develop the lifter. Just my $0.02, -Slashy

Nich, Yeah, they're too heavy and the Isp sucks. SRBs are a great "bang for the buck" solution so long as you don't have to actually pick them up. When used as a second stage, their inefficiency cascades and you wind up with a more expensive stack overall. At least... that's been my experience so far. Best, -Slashy

Yeah, I'd agree with Temstar. 100% inert payload, but 80km x 1m minimum. This would put the focus squarely on the lifter itself with the emphasis on "practical". This is how lifters are actually used in- game; the payload circularizes itself while the preceding stages deorbit. Best, -Slashy

Yeah, I'm inclined to agree with this. A practical launcher wouldn't make such heavy use of the payload to help it get to orbit. Best, -Slashy

Meithan, Thus far, no LF&O engine can hope to compete with solid fuel for cost- effectiveness. There may be a true asparagus design that can keep up in terms of "bang for the buck", but if so it's likely to be a very large lifter. Best, -Slashy

Outstanding! You hit on the same concept I was looking at last night; semi- asparagus staging. You use SRBs for propulsion while lifting drop tanks to feed the central core. I couldn't make it work, but it looks like you've got it wired. Congrats! -Slashy

Norcalplanner, Here it comes! The Cheep 18 lifter stack. 3 Kickbacks for the booster and a Poodle for the transstage. Cost on the pad is $29,050 Cost of the payload is $17,300. This leaves $11,750 as the cost of the disposable stages. Mass at the start of circularization is 20.09 tonnes. Mass at end of circularization is 18.05 tonnes. Isp of payload engine is 340s. DV expended by payload is 340*9.81*ln(20.09/18.05) = 357 m/sec. Expended cost is $11,750/ 18.05t = $650.97 per tonne. I seriously think this is about the best I am capable of doing. I relied heavily on "gaming" this entry. A more realistic insertion stack based on this design would be more expensive, but still under $800 per tonne. Best, -Slashy

Norcalplanner, FWIW, I'd recommend a change to the rules where the apoapsis must be at least 80km, the periapsis must be at least 1m, and the payload may not provide any DV. This would remove the problem with "gaming" the payload. As it stands, I believe i have a design that can break the $700 barrier within the current rules. Best, -Slashy

Warzouz, Had. This was from back when infinigliders and kraken drives were still a thing, so fuel wasn't necessary. Best, -Slashy

Mr. KrakBadger goes to Eve. http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/KrakBadger Best, -Slashy

I made a couple minor adjustments to the Cheep 38 and had another go at it. I removed the fins and added a reaction wheel to the payload. Got a slightly more efficient launch profile. The entire vehicle is $51,900 on the pad and $20,850 in orbit, which leaves $31,050 expended. Payload on orbit is 37.83 tonnes, for a final cost of $820.78 per tonne. I think that's about all I'm gonna get out of this design, short of gaming it. I'm going to try something different for the next one. Best, -Slashy

^ Quoted for truthiness. Best, -Slashy

I'm cool with both, but I can't have either because I'm allergic. I'm a big fan of doges. Especially whippets and weimaraners.

True. No point in not being precise I'm talking about an air breathing SSTO spaceplane. It's the ultimate in cost efficiency. Best, -Slashy

mrmcp1, I mean take that fuel and put it in a series Mk.2 tank so it's not hanging out in the breeze. Drag is your enemy in spaceplanes, and tucking those tanks in where they currently are doesn't shield them from creating additional drag. Yessir. Angle them up a little bit so your nose is pointed where you're going. That helps with drag tremendously. Best, -Slashy

Norcalplanner, This is one that you've already seen before. It wasn't really intended to put a payload into an 80x80 orbit, so I just used some of the payload to circularize. It's just a basic no- frills medium lifter. The entire lifter is $52,200 at launch. Less the $18,750 that will be left in orbit leaves $33,450 expended. It took a tonne of MP to circularize, so final payload is 37.13 tonnes. That works out to $900.89/ tonne. Entire slideshow is here (probably jumbled because Photobucket sucks). http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/CnCRocketFactory Best, -Slashy

Nefrums, You should probably divvy up the leaderboard into different weight classes. There's a definite economy of scale in KSP that favors larger launchers. Best, -Slashy

Yes, absolutely. Local surface gravity, not Kerbin. Best, -Slashy

The Thud is underappreciated as an early career booster, but not very good as a vacuum engine. KSP makes or breaks an engine by the tech level where it becomes available. The LV-T30 maximizes your payload to orbit within an 18t pad limit, but has no thrust vectoring. The LV-T45 limits your payload, but simplifies control. The Thud makes a nice compromise between the two, but becomes eclipsed by the Skipper once you upgrade the pad. For vacuum engines, the Terrier is unlocked very early and the Thud can't compete with it in that role. Best, -Slashy

Lights for the cupola, hitchhiker can, and MPL. propellers, either electric or LF&O. Hydrogen gas bags would be cool too. A biome scanner for survey sats. I'm sure there's a bunch of other goodies I'm missing. Best, -Slashy

Yeah, you're being stingy to the point of harming your program. The World's First awards actually pay much better than contracts. If you just go places, collect science, and unlock tech, money will not be an issue. Once you've got all the parts unlocked, you can set up a strategy to sell your science, thus keeping you in cash. Best, -Slashy

I play single missions when first operating in the Kerbin system and unlocking the tech. This is both because mission durations are short and I want to get all of my roster trained up as quickly as possible. Once I'm ready to go interplanetary, I start running multiple parallel missions. No sense in wasting all of that transit time. Best, -Slashy

mrmcp1, I have had success with the RAPIER at weight loadings over 40t/ engine. I'm sure the weight isn't a problem. Your problems look to be insufficient intake area/ wrong intake type and excessive drag. I'd recommend switching to 3 structural intakes to take care of that issue. After that, I'd try to stack those side fuel sponsons into a Mk.2 tank in series and give the wings some static incidence so that your nose is pointed prograde at Mach 1. Best, -Slashy