Leonon

This thread over here inspired me to try putting cubic octagonal struts on the front of my test high speed air breather to lessen the drag. (click pics to embiggen) The thread I linked stated things that implied that if I put a very small part in front of a larger part it would reduce overall drag. I'm quite pleased with the results.

OK, so I looked at this thread over here and decided to stick a cubic octagonal strut in front of the Pre-Cooler to lessen the drag. 1610m/s with 1567m/s horizontal before structural failure The explosion in the second picture is from the cubic octagonal strut giving out. You can add more cubic octagonal struts in front of the first one and they'll work as ablative drag shielding. Unfortunitely, the Ramjet tends to overheat and explode right after the 3rd strut.

Yep.

Same setup, Rapier replaced with Turbo Ramjet Second picture was after speed started to fall, not sure what the true top air speed was.

1690m/s horizontal speed in atmosphere using only air breathing Rapier (no oxidizer). Click to embiggen pictures. Pic 2 and 3 were different flights.

You have it as [ img]http://imgur.com/a/http://imgur.com/yG5iRsT[/img] When it should be [ img]http://imgur.com/yG5iRsT.jpg[/img] If you want to post the full picture here or [ url=http://imgur.com/yG5iRsT.jpg][ img]http://imgur.com/yG5iRsTs.jpg[/img][/url] If you want to post a thumbnail here that links to the larger picture. Please note that the "[ img]" and "[ url="should not have the space in them when you post, they're just there so it doesn't just post a picture on this post.

I did not consider that the cross section wouldn't matter for drag. After reading your posts I checked the wiki and it says drag is based on total mass, not part count. Whichever it is, it loses part count and total mass more efficiently than asparagus staging. That's why I compared their used dV and not just their total dV and remaining dV. Linear staging starts with more and uses less to get to orbit. Not even close. I saw one guy a while ago who had a craft that consisted entirely of solid boosters. It dropped at least one of its stages by overheating it with a higher stage. Apparently it was more efficient than having to lift a decoupler.

I've come up with a method of increasing efficiency above asparagus staging. This may be old news but since asparagus staging is still most commonly used it probably bears repeating. By placing a cubic octagonal strut below an engine you can have it active and producing thrust while things are below it. It doesn't overheat the parts below it and this configuration allows dropping tanks individually instead of in pairs like asparagus does. This also reduces drag since all parts are in a straight line instead of spread around drag producing parts are dropped sooner. This does reduce stability somewhat and tends to lead to using a very large number of stages, so it's not perfect. It's also very, very unrealistic. I've put examples in an Imgur album but I'll also go over them here. I used the following mods during these examples Mechjeb2 2.0.9.0 Engineer Redux 0.6.1.1 The first example also used RemoteTech 0.5.0.1 Deadly Reentry 2.3 This illustrates the basic concept. The top engine is a LV-909 and the bottom one is a 48-7S. 1385dV of 4689dV remaining, 3304dV used Since the engines were started simultaneously the craft was able to get out of the thick lower atmosphere quickly. As it went up the fuel drained from the bottom tanks upwards and tanks were discarded as they individually emptied. I call it Linear staging. I made a few craft and had Mechjeb get them to orbit to compare dV usage. The first flight limited top speed to terminal velocity, the second limited acceleration to 23m/s squared. All other flight parameters are left the same. Asparagus using LV-909 engine and dropping 4 tanks in groups of 2 4753 dV in hanger Flight 1 1370 dV left, 3383 dV used Flight 2 1378 dV left, 3375 dV used Linear using LV-909 engine and dropping 4 tanks individually 4810 dV in hanger Flight 1 1465 dV left 3345 dV used Flight 2 1472 dV left 3338 dV used Asparagus using Skipper engine and dropping 4 tanks in groups of 2 4986 dV in hanger Flight 1 1228 dV left 3758 dV used Flight 2 1283 dV left 3703 dV used Linear using Skipper engine and dropping 4 tanks iindividually 5022 dV in hanger Flight 1 crashed Flight 2 crashed Asparagus with SAS module using Skipper engine and dropping 4 tanks in groups of 2 4895 dV in hanger Flight 1 1120 dV left 3775 dV used Flight 2 1182 dV left 3713 dV used Linear with SAS module using Skipper engine and dropping 4 tanks individually 4931 dV in hanger Flight 1 1166 dV left 3765 dV used Flight 2 1226 dV left 3705 dV used It's definitely not perfect. I'm pretty sure it's not even as big of a change as asparagus changing is to onion staging, but it's definitely an improvement.

More intakes and more speed helps. My craft's jet stage has 8 ram intakes on the side attached to cubic octagonal struts. Lowering your throttle makes the engines take less air to run, though very high up it becomes pretty much impossible to manually get the throttle in the tiny sweet spot between "throttle off" and "flame out". Being pointed closer to the direction you're moving also helps.Mechjeb can handle auto throttling to prevent flame outs and I'd suggest using it since it can handle the fine throttle control all the way out of atmosphere. If you're not using MechJeb keep the throttle open all the way until you flame out. After flaming out right click the engine to see its status and lower throttle until it starts back up, then move the throttle up a little. Keep flaming out, restarting, and adding a little throttle until you can't get it to start back up. It's possible to keep raising your orbit with jet engines all the way out of atmosphere with Mechjeb but even without it you can keep your orbit from degrading until you're so high that drag isn't going to slow you down very much. Around 60km is how high you should get before you stop using the jet. If you're using more than one jet engine this method won't work though since you'll end up spinning out when one engine flame outs before another. I just tried launching my craft completely without Mechjeb and managed to get it to orbit using 17.6 more seconds of fuel than my launch above. Also, note that my craft's winglets are set so they hit the ground instead of the engine. If the engine is landed on it tends to break off. You can still recover the broken off engine, but if you land on it hard enough it will explode and be unrecoverable.

The trick is to make the jet stage recoverable every time. Here's how my launches typically go. (Mods Used) Deadly Reentry 2.3 Engineer-Redux-v0.6.1.1 ISA MapSatX4r1 Mechjeb2-2.0.9.0 Mission Controller Extended 0.18.1 ScaledSpaceDumper.dll (fix for ISA MapSat) RemoteTech1 0.5.0.1 RemoteTech Probe Compatibility Mechjeb controls where the craft is pointed, I control everything else. \/Those thumbnails are links. Click them to see my wonderfully cluttered interface with lots of information.\/ There's the whole thing in the VAB. The stack design is slightly more dV efficient than traditional asparagus staging and reduces drag. There's a 48-7S engine with a cubic octagonal strut on it for the rocket stage. More realistically you could use 24-77 engines hooked to the sides. This is the highest temperature any part got on this particular launch. Here it is just after it left the atmosphere. I stuck to 5 degree pitch from about 25km to get the apoapsis up that high. This means the rocket stage loses no dV to drag and gives me plenty of time to control the jet stage after I decouple at apoapsis. After decoupling and getting the rocket stage's periapsis above atmosphere I'm free to controll the jet stage's reentry and landing. On this reentry I burned retrograde to slow sideways movement and get it to land where I wanted. I use ISA MapSat to make sure the jet stage lands instead of splashes down when it's coming down on the night side. It usually has enough fuel left to fly to land if it needs to. After recovering the jet stage this particular launch only cost 13557 Kerbucks. The orbiting rocket stage has enough dV to do just about any mission, though this particular launch is missing some parts required for some missions. Kerbolo II is definitely not balanced properly to match other missions. It should be around 150000 Kerbucks like the Duna mission since they have fairly similar dV and part requirements.

This is correct. Fixing it with a minimum Ap would be much better than my idea of setting a max Ap.I've made a mission package to put ISA MapSats into very specific orbits. It's set up for Dev Build X4-r1 and requires a MapSat dish for each mission. The orbits are taken from This Post and are the fastest or tied for fastest mapping except for Eve which has one mission for fastest mission and one for fastest mission that can detect anomalies. I've only made one mission per planet (except Eve and the planets with no "better" mapsat orbit) so it's not cluttered but doesn't give you as many options as you'd have using just the orbit charts. The missions are numbered by how far they are from the sun. The mission payout is scaled to have about the same pay per dV required as the stock Duna mission except for the Kerbin, Mun, and Minmus missions which give the same payout as the stock missions. Missions also give a 10% bonus for including one of each antenna. There is no time requirement to complete the mission, though the time to properly map is included in mission description. I've only tested Kerbin, Mun, and Minmus so far so there may be some issues with it not mapping properly on smaller bodies using these orbits. ISA MapSat Deployment package

In the included Civilian Space Program mission package the Commercialization of Space missions and Kerbal X missions (15-21) orbit time in their descriptions doesn't match the orbit time they actually require. They also have minimum periapsides but no maximum apoapsides and so don't technically require orbit, only a flyby. Raising the required time to what it says in the description would fix that though. I'd just fix it and upload a copy myself but I don't know if it's supposed to be Kerbin days (6 hours) or IRL days.

I\'m not sure about my screenshot but in my video the engine has 2000 thrust so it should be like getting hit by a standard massed rocket with 2000 thrust that\'s been traveling as long and in the same direction as the cheat rocket has. The cheat rocket was quite a bit tougher than normal though so it may have less give than a standard rocket. Stupiditykills, you must explain how you managed such a ridiculous speed. For Science.

Look at their pictures. Not only are they still alive, Jeb is still smiling.EDIT: I did some more testing and made a showing me breaking light speed in a cheated rocket. The game starts behaving strangely at high speeds.

I tried setting the mass for each part to 0.000001 to see how it compared to the 0 mass version. Results were...interesting. I guess this proves a few things, not entirely sure what though.

I cheated in a perfectly massless and frictionless rocket with infinite fuel, no heat production and 1700 max thrust (slightly over the maximum the unmodded structures can take, didn\'t mod structural integrity) and managed to get to constant 54.4G acceleration or about +1000m/s each second (didn\'t stop watch it). Unless light drives are much sturdier than stock parts it should take a minimum of 3.5 days constant flight to hit light speed.