Klopchuck

The term originates in Tom Logsdon's "Orbital Mechanics: Theory and Applications" (1998); he calls it "Ed Keith's Innovative Asparagus-Stalk Booster"

Hi Bsalis... I'm just getting into SSTO's. Please, do you have any advice on what altitude / intake-conditions that are the critical point for transitioning the Boxkite from the TurboJet Engines to the Aerospikes? I assume LV-N' are space-only. Thank you.

Found some Maths: http://web.mit.edu/16.unified/www/SPRING/propulsion/notes/node70.html This will take me awhile to unpack. I'm not a physicist or engineer, but I spent last night at KSC.

Hello, The attached craft is stock (with mechjeb) and can reach the North Pole in about 30-minutes. It uses and SRB for JATO. I use the smart A.S.S. to keep the heading at 0. The pitch is initially 85-degrees during JATO, then reduced to 45-degrees as I climb to about 14k. I then drop to 25-degrees, and as velocity increases, I decrease the pitch a degree at a time to maintain a zero-vertical speed (i.e., constant altitude just above the "thick atmosphere"). This vehicle can reach 600m/s by the time it reaches the ice shelf. However... I can't really fly, and I am terrible at landing. I'm offering this .craft to any test pilots out there that want to use it for the race, or modify it to go faster. (I think it might have one-too-many fuel tanks). Happy flying!

I see now that my question was incomplete... I've just started to fly aircraft, rather than space launch vehicles. Specifically, I've been playing with some alternate designs for the polar challenge, which seeks to get from KSC to the north pole in the least amount of time using stock parts (and mechjeb) without going ballistic (i.e., fly). In other words, I'm trying to optimize speed, but the amount of fuel is probably a factor too, since it increases weight and affects range. Is this question better? "If two identical Turbojet-powered aircraft were racing, what altitude would be the fastest? Also, would the range be different?") (Here's the reason I can't "help myself": I know where to go to get the maths for space (vis-via equation, etc.) but not flying. Where can I go to get the maths for figuring out thrust, fuel efficiency, and velocity?) What's confusing for me, is when I fly in the 12k-14k range, just above the "thick" atmosphere, I notice the Efficiency of the TurboJet is notably lower, such as 0.62 at 14k. However, I seem to reach much faster speeds. I assume this is due to the thinner atmosphere reducing drag. Is this a a measure of thrust to fuel consumption? Is atmosphere thickness in layers? I recall seeing that in a discussion on an earlier version, so I assume drag is a step-function. "Efficiency" as displayed when you right click the engine seems to be a linear function, so my current theory is the best altitude is probably just above the transition from one thickness to another. (Other factors I assume will help performance in this challenge... I presume you want to arrive at the North Pole with zero fuel, since excess would be dry weight. I've also rigged an SRB for jet-assisted take-off (JATO) that is vectored to the North, so I don't have to waste fuel/time/speed launching east and vectoring my heading to the North)

Please, has anyone determined what is the optimal altitude for the TurboJet engine, when you take into account engine thrust, drag, etc.? I figure it's between 8,000-12,000 based on feel, but I haven't done any math or empirical study. Has anyone else? Thank you.

Is it OK to talk about improving Placeholders In Development? Here is a comparison of Propellant Mass Fraction (Propellant Mass / Total Mass): KSP\'s SRB [li]0.800 RT-10 (1.8/.36)[/li] [li]0.888 RT-B20 (6.75/.75)[/li] In Production [li]0.854 Space Shuttle SRB (503,487/589,670)[/li] [li]0.865 EAP (Ariane 5) (238,000/275,000)[/li] [li]0.881 Gem-46 (Delta II & III) (37,500/42,520)[/li] [li]0.883 Space Shuttle SRB* (503,487/569,893)[/li] [li]0.902 GEM-40 (Delta II) (25,801/28,801)[/li] [li]0.902 Altas V SRB (36,824/40,824)[/li] [li]0.902 GEM-60 (Delta IV) (29,949/33,199)[/li] Looks like Jeb needs to get to work on that RT-10! There should be at least 180 grams of dry mass in that design that could be removed. Has Jeb considered taking off the cup-holder? Hey I just do the maths, not the jokes or snarky moderation. * Post Challenger-disaster design (Sources: KSP 0.16; ESA website; and www.astronautix.com for Atlas, Delta, and Shuttle SRB)

You can probably get much more from the lower stage... ...f you combine fuel-cross-feeding and some complicated staging to minimize dead weight by dropping fuel tanks (and attached engines) as soon as possible. Here are two discussions you might find helpful: http://kerbalspaceprogram.com/forum/index.php?topic=10204.msg154334#msg154334 http://kerbalspaceprogram.com/forum/index.php?topic=16144.msg243459#msg243459 If you post your .craft or send it to me, I\'d be happy to try.

Very cool, thank you.

@nerdyastronaut - you can toggle engines on and off like the ladders, by right-clicking.

Can we use the Autom8 to get Rendezvous? I might have time to experiment this weekend, but if anyone has figured it out, please share your script.

Coordinates?

Can you show us a picture of a successful re-entry?

One more thing... C7Studios recently mentioned that he found a problem with the textures for parts: http://kerbalspaceprogram.com/forum/index.php?topic=13542.msg231217#msg231217 Does his problem (and his fix) apply to the space scenery?

This topic came up is related to a previous request for a true North Star: http://kerbalspaceprogram.com/forum/index.php?topic=10210.0 A high resolution star field, with constellations, etc., is a valid astrogational aid. You know, for when instruments/mechjeb craps out. Don\'t laugh - real satellites rely on sophisticated instruments to find their location based on the position of stars. From Closette:

Great system. I like the cross-feeding of the fuel; any rocket design without cross-feeding is really leaving delta-v on the table, so to speak. Good job. I think I\'ll add some RCS for kicks, but this is a great starting designs.

I\'m away from the computer for the weekend, but I recall from memory that once an engine is activated via staging, you can right-click on the engine (center of screen, not the icon in the staging diagram) to make appear a small control-window. There is a green rectangle in the window that can be left-clicked to deactivate (or re-activate) the engine. If the engine is part of a group within a stage, this toggle affects all of the same engines. In other words, you only have to do this one one side of the dropship, not both sides. BTW, I forgot where I found this feature documented; I do recall thinking, 'the should do a better job of communicating changes to the interface'.

Well, here is a similar craft, slightly smaller, and all stock. Biggest difference is the landing gear - I need to widen and lower the wheelbase to make landing less forgiving. (Note: activate the second stage after you get rolling down the runway. Don\'t pull too hard on the stick. And save the third stage for landing.)

Wow. My first spaceplane flight. That was fun. Thanks! I haven\'t been using or following spaceplanes. Can you share some of your logic behind the engine choices? I try to design my traditional kerbalkraft (i.e., rockets) to maximize thrust while minimizing (and jettisoning ASAP) dead weight. (e.g., http://kerbalspaceprogram.com/forum/index.php?topic=10204.0). Why do you carry the second stage engines to 5,500 before igniting?

I read that as: Jeb: An awesome person who is not afraid of anything and makes love things explode

Hi. Can I submit the Asparagus design has a medium lifter? It\'s not a heavy-class, but it makes a nice platform for getting to the Mun or the sun: http://kerbalspaceprogram.com/forum/index.php?topic=10204.msg154334#msg154334

Howdy. Hey, is that fuel-routing based on Asparagus? ??? Rocket looks familiar. http://kerbalspaceprogram.com/forum/index.php?topic=10204.msg154334#msg154334

That\'s cool about SpaceX\'s Falcon 9 Heavy. I hope they actually build and successfully test one! Anyone know why ULA/USAF hasn\'t invested in this improvement to the Delta IV Heavy?

Nice video, especially the music. First rate. Hope you don\'t mind... I took the liberty to change your fuel-lines and initial staging, so instead of dropping the first 6 liquid-boosters in two stages of 3, they are dropped in three stages of 2. (I tried extending the logic to drop one at a time, but the craft becomes too unbalanced for control.) For comparison, I used MechJeb to get the craft to an apoapsis of 70km. Not totally scientific, but illustrative. I found the new arrangement ('Mk6-k') to still have ~1.0 FL-T500 in the core booster; Mk6 had ~0.8 FL-T500. (If that seems wrong to you, please let me know. The ascent may not have been optimal; however, I hope with MechJeb that they were equivalent). However, by saving ~0.2 FL-T500, it did take over 10 minutes to get to 70km and circularize, a few more minutes than mk6.

@VincentMcConnell - Charts were created with Excel 2010. I calculated the thrust and mass as functions of time by hand, so it\'s not a very smart spreadsheet. I also assumed instantaneous transitions between stages, which is probably more optimal than possible by hand.