capi3101

Myself, I've got an ILS set up - that does take time to do but it pays off in the long run, especially if you intend to spaceplane a lot. Here's what you do: you want to set out a series of ground beacons, one at the ocean end of the runway, one at the other end (the starting end), then further west from that one you put beacons at 1 km, then 5 km from that one, then moar beacons at 5 km intervals to as far out as you're comfortable doing. My own ILS goes out to 30 kilometers. The beacons don't have to be much; a powered probe core will suffice, and rover delivery works well. Then when you want to land, you can use the beacons as a guide. First of all, if you set them up with little variation in north/south, you can use them to help guide your runway alignment. Second, the beacons act as a slope indicator - your distance to the beacon plus its distance to the end of the runway will give you the altitude you want to be at - one hundred times that sum. For example, if you're 20.2 kilometers to the ten kilometer beacon, you want your altimeter to read somewhere around 3,020 meters. (20.2 + 20 = 30.2, 30.2*100 = 3,020). That doesn't work all the way to the ground since the elevation of the runway is at about seventy meters, but it should give you a good feel for whether you're high or low at least, and should get close to a reasonable glideslope. As for getting to the runway itself, from Kerbin orbit you want to set a maneuver node that will put your periapsis onto the ground over on the next continent (not the dinky little peninsula on the same continent, but on the other continent), roughly seventy degrees downrange of KSC. Eyeball it; you'll be okay as long as you've still got gas in the tank. If you find yourself short, you can still fly to KSC if you've got a little gas in the tank (5-10k's when the jets have that 2000+ Isp). If you overshoot, you can double back; your ILS will still be able to help you set up your alignment at least, though you'll just have the ocean beacon to help you with glide slope.

Built a spaceplane I proposed on one of the threads to send three Kerbals to Laythe. To my astonishment, the damn thing actually took off on the first try without careening of to one side or flying straight into the drink. CoL's still too far back so I had to sit there holding the "s" key the entire time, but that's nothing a little tweaking won't mix. I might actually have to send this thing to Laythe at some point... Also tested my parachute disposal system for Eve. Aside from the ejection system taking out the center stack of the whole thing and rendering the test an unqualified failure, it went pretty well...

Going to have to catch up on it I'm afraid; I missed the Waypoint one - I'd been enjoying the series very much so far. Haven't done much today yet; will have to defer the post to tomorrow I think.

General rules of thumb for spaceplane design - *1 turbojet for every nine tonnes of payload (that's everything besides wings, jet fuel tanks, jets and intakes) *200-250 units of liquid fuel per turbojet. That's actually a little more than you need but it's more forgiving of a bad ascent profile. *3 Ram air intakes per turbojet. Since you don't like airhogging, I won't recommend more than that, though I will say the higher the ratio of intakes to jets the more payload you can sustain. *1 pair of swept or delta wings per six total tonnes of craft. Flight profile - Once your design has actually made it off the runway and assuming it climbs (an initial problem with many of my designs), you want to ascend with your prograde vector around 45 degrees or so to 10,000. Then start gradually levelling off your ascent through 15,000 or so - you want your rate of climb to be not much more than 10 m/s (use the gauge to the side of the altimeter) at that point, and especially so once you're up to 20k. Keep it level and continue to ascend. You'll be able to maintain full throttle up until you've got about 0.03-0.04 Intake Air per engine; after that, if you've got more than one jet, you'll want to start throttling back if your plane begins to yaw and you're not telling it to. A few notches will do the trick. Continue throttling back as needed until a) you're no longer accelerating, or you run out of gas. Only then do you fire up your rockets - if you've still got jets, keep them running, though; they might not be outputting a lot of thrust at that point, but they're still offering some. If not, or once you've throttled back almost all the way to zero, kill the jets and throttle up. You shouldn't have to burn the rockets for very long at all if you've done things correctly.

Alrighty...I'ma gonna try to hammer this out real quick-like. The standard guidelines I go off of for any spaceplane are: *1 turbojet per 9-12 tonnes of payload (12-15 total tonnes of craft), depending on how much airhogging I'm willing to commit. In this case, we'll go with strong airhogging for the twelve figure. 1.2 tonnes per jet. *Nine ram intakes per jet. That's 0.09 tonnes, but we'll round up to .1 to make the numbers easier to work with. *200-250 units of liquid fuel per jet. Since we want to do both Kerbin and Laythe takeoffs, we'll double that figure to 400-500 units. I'll recommend a combination FL-T800 and FL-T200 with the oxidizer drained off; that should have a full mass of 2.875 tonnes all told. *Three pairs of swept or delta wings per eighteen total tonnes of craft. Say swept wings for 0.3 total tonnes. That's 4.475 tonnes of flight equipment that will be deadweight in space, let's say. You can have up to fifteen total tonnes of craft on that, so about 10.525 tonnes that's just rocket. Alright. So we want a Mk3 Cockpit (3.5 tonnes), a Large ASAS unit (.2 tonnes), and let's go with two nukes on a Biadapter (4.6 tonnes), so 8.3 tonnes of total paywad. What we can do is up the deadmass for more and more sets of flight equipment, looking for a delta-V target of 5500 at 800 Isp, until we get something that's within the flight tolerances of the flight equipment - like this: 1 set, 12.775 tonnes payload, 5500 delta-V @ 30 FL-T100 equivalents, total mass 29.65 tonnes (too much; you only have enough engine for 15 tonnes) 2 sets, 17.25 tonnes payload, 5500 delta-V @ 41 FL-T100 equivalents, total mass 40.3125 tonnes (too much; you only have enough engine for 30 tonnes) 3 sets, 21.725 tonnes payload, 5500 delta-V @ 51 FL-T100 equivalents, total mass 50.4125 tonnes (too much; you only have enough engine for 45 tonnes) 4 sets, 26.2 tonnes payload, 5500 delta-V @ 61 FL-T100 equivalents, total mass 60.5125 tonnes (close enough for jazz) So you'd need four sets of flight equipment - four turbojets, a total of 36 air intakes, and the fuel. There was some redundancies built into the wing set - twelve wing pairs gives you enough lift for a 72 tonne craft, so if you wanted to you could ditch two pairs or so. The added mass could be applied to things like control surfaces and the like. 61 FL-T100 equivalents? That's three FL-T100s shy of an orange tank in the center, so you could just go with an orange tank, but then whether or not you'd have enough jet thrust would be questionable. It'd be interesting to put this together and see how well it worked; might have to do it myself.

So...when's the final gong on submissions? Two weeks from 15:42 GMT on 2/27 would be 15:42 GMT on 3/13 by my calculations, and that was about fifteen minutes ago (at the time of this post) unless I'm mistaken. EDIT: Maybe not. Maybe not for another 4.75 hours...but I am right in thinking it's today, right?

Hmm...it's not something I've done personally, but I see no reason why it couldn't be done. So...the first thing you need to consider is that once it's in space, your spaceplane is a rocket. So you treat it like any other rocket...to the Delta-V map!! 680 LKO to KSO 180 KSO to Mun 70 Mun to Minmus 20 Minmus to Kerbin Escape 130 Kerbin Escape to Duna 480 Duna to Dres 370 Dres to Jool 270 Plane Change 0 to Laythe (aerobrake at Jool and/or Laythe - muck up a Jool aerobrake and you'll need 1880 to get back out there again) 780 LLO to Laythe Escape 290 Laythe Escape to Laythe 310 Laythe to Vall 220 Vall to Tylo 180 Tylo to Bop 60 Bop to Pol 160 Pol to Jool Escape 160 Jool Escape to Kerbin/Jool Transfer 0 back to Kerbin (aerobrake) So, your plane would need 4,360 m/s of delta-V just for the rocket bit to get to and from Laythe in the optimal case - designing for 5,500 would give you a safety margin. It would also need to be carrying enough fuel for the 4500 launch from Kerbin and the 3200 launch from Laythe; so you want to be carrying around enough jet fuel for about two Kerbin takeoffs. I say that; you might want to get someone with more experience with Laythe flight helping you out there. Anyways, those are the basics.

Alright, guys - progress reports from last night. First off, I took a screenshot with the ship as it was, set to Eve and Atmospheric stats: The ship as is gives me 10,273 m/s and an average initial TWR of 1.47. According to the wiki, that would be sufficient for takeoff if I didn't put down any lower than 2,000 meters. My intent is not to land in the sea, obviously, but I'm looking at Kerbal maps and saying to myself "there seems to be an awful lot of this planet that's lower than 2000 meters elevation"... Second shot is the ship adjusted for aerospikes in the core. That gives me 10,375 m/s, the highest delta-V of any of the attempts I made last night, but reduces the average TWR to 1.40. One of y'all harped on me for already having an inefficient ascent, so that didn't seem like something I wanted to keep. So I ditched that configuration - sitting here this morning, it seems to me that I might want to restore central aerospikes in the final configuration. The third shot shows the original ship with the Sepratrons removed and the outer TT-38Ks replaced with TT-70s. The impetus here was to put a little more space between the inner and outer booster ring, to avoid losing engines in seperation events: This configuration gives me essentially the same performance as the original configuration (with a grand total extra delta-V of 1 m/s); the benefit is peace of mind of a clean separation. The last shot kept the outer TT-70s and replaced the Skippers with aerospike quads. Average TWR stayed the same, at 1.47; the benefit here is the increase of delta-V to 10,345. Which is where I left things. I think tonight I'll try different combinations involving aerospikes - though I have to ask, as long as the TWR stays up above...say, 1.2 or so, and the delta-V requirement is there, does it really matter? In any case, I'm still about 1000 m/s short of a craft capable of landing and return from any point on the planet, about 400 shy of being able to take off from 1,000 meters. I experimented around last night with a parachute "pack" that I might utilize for Eve. The basic design is what I indicated in a post yesterday (and I wish I'd taken screenies of its tests) - an upside-down rockomax decoupler with a quad adapter attached to it, with two drogue chutes and two big chutes in each space. I've also attached two radial chutes and four seperatrons to the sides of the decoupler. Seperatrons fire at the same time the decoupler fires, blowing the whole thing clear of the ship. Had pretty good range on Kerbin, though I might've liked a straighter flight path (I suspect the center of thrust of the assembly is too far below the center of mass). The plan is to stick one of these on each of the booster tanks, giving me 24 drogues, 24 radials, and 24 big chutes. I've plugged the craft's mass into the parachute calculator and had it calculate landing velocities for various elevations with that configuration of chutes. Here are the results: 2000 = 7.70 m/s 2500 = 7.98 m/s 3000 = 8.26 m/s 3500 = 8.55 m/s 4000 = 8.86 m/s 4500 = 9.17 m/s 5000 = 9.5 m/s 5500 = 9.84 m/s 6000 = 10.19 m/s 6500 = 10.55 m/s 7000 = 10.93 m/s 7500 = 11.32 m/s It looks like I'll need a quick puff of the engines right on touchdown no matter where I land. The idea is to fire the chutes as soon as I hit atmo and let them "stage" their deployments, that way I get maximum benefit from each chute. Well, that's pretty much been it for last night. Any new suggestions? Comments? Scathing criticisms?

You want Kerbal Engineer Redux. It has three parts - one that will tell you your delta-V in the VAB/SPH, one that will provide you will flight information, and one that will provide you with both. There's a second mod (I forget the name; I have it installed to boot) that will give you KER information without adding the parts.

Farted around with my Eve ship. Built a parachute cluster that I'm happy about; will have to see how well it does on Eve. First thing's first though, I think the stupid thing is still short on delta-V.

^^^ Start with one - building a tanker is tricky enough work as it is. Make sure you test it thoroughly in the VAB for its flight characteristics (notably where the Center of Mass winds up once you empty that tank). My most successful tanker plane, the Auk VIII, can only deliver about 60-70% of its payload per run; the reason is because if I deliver every drop, the CoL goes ahead of the CoM, and I lose control once I start getting deep into the atmo. Mind you that this was a craft that was designed with a ballasting system already.

Okay, both over Moho. Yeah - what you need to do is kick out the Apoapsis of one of the two craft very high (close to escaping Moho's SOI). At the apoapsis, make your plane change burn, then circularize again. That's the most efficient way to do it, but as has been pointed out, it's not exactly easy.

^^^ No, reducing your throttle still works. 0.23 does not do it automatically, though, so you do still have to pay attention. Me, I do it by watching my intake air amount; I really start to give it attention when it gets down to 0.05 IntakeAir per engine. When the plane begins to pull to one side, I throttle back a bit and keep on doing that until A) I'm no longer accelerating or I'm at 1/3 thrust. That's when I fire up the rockets.

http://forum.kerbalspaceprogram.com/showthread.php/33381-0-20-2-Zenith-rocket-family-%28modernised-for-0-20-x-with-perfect-subassembly%29 The Supernova will launch 160 tonnes. The boosters are old, but still work in 0.23 For guidelines on building your own, try http://forum.kerbalspaceprogram.com/showthread.php/28248-Is-asparagus-the-best-staging-system-%28might-contain-science%29?p=346702&viewfull=1#post346702

For Moho - try maccollo. http://forum.kerbalspaceprogram.com/threads/61478-Oh-bugger-Injection-burn-at-Moho?p=835667&viewfull=1#post835667 I'm not 100 percent sure I understand the issue. Where exactly is the return vehicle, in orbit of Kerbin, Moho, the Sun, where exactly? If it's in orbit of Kerbin, you could just launch to the west. The extra delta-V you'd need is not that much all told. You'd only be about thirty degrees or so off the inclination of the return vehicle but that's doable; far better than doing the 150. EDIT: I agree. If you've done Duna, I might suggest either Gilly or Dres as a second manned interplanetary destination. Hell, you might even consider Ike. I've had a single success in regards to Moho...the satellite you see down in my salad bar.

What would you say to a quad adapter on top on the boosters, with two drogues and two big chutes each, set in place on top of a large rockomax decoupler and with a pair of seperatrons on the side of the decoupler? The idea being that once the ship was down, the whole assembly could be ejected off. Getting the chutes on the adapter might be a trick but I think I could handle it if I placed them one at a time on a subassembly. I'd definitely test it out on Kerbin before making it operational. Do you think that might do the trick?

Weird thing about that - I could've sworn I took a screenie with the KER window fully open for both atmo and vacuum. I guess I'll have to do that tonight when I get a chance; I haven't really given y'all all of the information. I think it has just short of 11,000 atmospheric if I remember correctly. I'll have to look again. Alright, well, I already know it's less than 12k atmospheric. Going off the craft file this morning, the ship as is breaks down like this - 1 RC-L01 RGU (0.5t) 12x FTX-2 External Fuel Duct (0t) 13x X200-16 (117t) 13x X200-32 (234t) 168x Cubic Octagonal Strut (0t) 175x 48-7S (17.5t) 1x Clamp-O-Tron (0.05t) 1x TR-2V Decoupler (0.015t) 2x Z-1k Batt (0.05t) 36xEAS-4 Strut (0t) 6 TT-38K (0.15t) 6 TT-70 (0.3t) 6x Seperatron (0.435t) 6x Skipper (24t) TOTAL ESTIMATED MASS: 394T I plugged that into the parachute calculator and it's telling me for a parachute landing on Eve to land at about 5 m/s at sea level, I'll need twelve drogue chutes and 73 Mk-16XLs. Based on that it doesn't look like I'll be able to do a landing with just chutes. Now, if I shoot for a higher touchdown speed, it may be more feasible; with a dozen drogues and just 16 Mk-16XLs, I can touch down at 9.78 m/s, but then I'll have to make sure and sturdy up the lander legs. I was considering just going with I-beams anyway I know that if the ladder doesn't go into the ground I'd have a problem; whole reason why I asked that particular question. Yeah, that was those TT-38Ks at work. I added the Seperatrons to try and combat that but they didn't help much. Based on the extra mass of a Seperatron versus the mass difference between a TT-38K and a TT-70, I might just replace the 38Ks with more 70s. They'd add less mass than the Seperatrons. Where would you recommend I attach the drogues given the design as is now? And what would be a generally safe landing speed to aim for? I've already mentioned what the parachute calculator generated for me. The big problem I generally have with ladders is "going over the rim". I think I know how to handle this now, but it's definitely something I intend to test out on Kerbin before heading out. I'll try your suggestion for placement. I do worry about what'll happen when it comes time to ditch the things (don't want them shooting into one of the outer fuel tanks). My original design actually called for an Aerospike in the core stage. The fuel load changed that, but going through my calculator routine this morning, you're right - a quad of aerospikes should produce higher delta-V for a comparable TWR. That might not work for all the stages, but it is something else I could try. I know it'd be more efficient to use the smaller parts, unfortunately part count is an issue. Which then begs the response of "explain that engine cluster to me again", of course... Y'all have given me a lot to think about and I appreciate the responses so far. I'll do some tweaks tonight and report back how it all goes.

Greetings, fellow Kerbonauts. For the last few days I've been toying once again with the notion of attempting to build an Eve ascent vehicle, with the goal of delivering one Kerbal to the surface of Eve and returning him to orbit safely. I haven't actually thought seriously about an Eve attempt since 0.19, but I remember the basic delta-V requirement being about 12,000 or so and the trick being to have sufficient TWR all the way up. Lately there's been some talk about Eve ascents on the forums, and one thing I kept hearing over and over is "don't take along unnecessary mass", "don't take along unnecessary mass", "don't take along unnecessary mass"... Today I calculated a craft that could potentially do the job - except for one little snag, that being the fact that the first stage (dependent on a pair of Skipper engines) had a TWR of 0.99. Frustrated to be so close and yet so far, I thought "I wonder if I could replace the Skippers with an engine cluster that would give me slightly better performance". An hour later, I had written down the basic idea for what I called the Skipjack Cluster (names are really not my thing): using an X200-16 as a structural base (because my calculations called for an X200-32 and X200-16 in each stage), I attached a total of 25 48-7S engines onto the bottom. The end result - 2.5 tonnes of engines, 750 kN of thrust and the same specific impulse characteristics as a Skipper, a lighter and more powerful substitute; only downside is a vastly increased part count. Tonight I built the booster craft I calcuated. Here's the end result: Based on the results of the test flight and the information KER is giving me, I'm fairly confident that the craft as is could make an Eve ascent, but I wanted to get the opinions of any Eve veterans out there. Questions then: 1) Can the craft make a successful ascent as I've designed it, or am I still a little short on delta-V? 2) What do I need to add to it to get it down onto the surface? I know both large chutes and drogues (on decouplers) will be necessary along with lander legs (again, on decouplers); any idea how many? 3) How would you handle a ladder system for the craft? What's there now is a proofing payload; the ultimate idea is to replace the large probe core and battery banks with a Mk1 Lander Can.

Tonight I flagrantly clipped some parts together and built this: Ignoring the mass of the tank, this engine cluster has a mass of 2.5 tonnes, outputs 750 kN of thrust and has the same specific impulse characteristics as a Skipper engine. The downside between it and a Skipper is the part count only - 50 parts. Used the cluster to build a craft that may potentially be an Eve ascent vehicle; going to solicit some more advice on that momentarily.

Glad to have been of assistance.

You'd probably need to look up the source material to get a full description of the equations. Fortunate for you that I work at a research library. Gimme a sec and let's see what we can do here...expect edits. EDIT 1814Z: We do have electronic access to that particular book - Go to libraries.ou.edu Type in "Introduction to Space Dynamics" in the Discover box. It should be the first thing that comes up. Question becomes whether or not you can access it based on your location. I'm assuming not and will continue searching for the equations in question. EDIT 1819z: The equations are on Chapter 8, page 257. Z is the tangent of 1/2 the angle of the rocket's acceleration trajectory from the vertical. The equations give you that angle in terms of t (time) and C (initial conditions of velocity and Z angle), so yes you should be able to use them to get a perfect gravity turn. That's if I'm understanding the equation's correctly; it mostly looks Greek to me... Anyways, I hope you have luck accessing the materials yourself. There's some good stuff in there.

How has the Auk been handling for most of y'all, BTW? I know it has that annoying tendency to tip up on its wheels before you fire up the jet; anything else you guys would improve with it?

The advice folks are giving you so far is for getting into stable orbit around Eve from an Eve launch - you need anywhere from 7.5k-15k of delta-V in your Eve booster just to make orbit, depending on where you land and what ascent profile you're using. The delta-V requirement is why most folks haven't successfully performed an Eve launch. Been working through this myself now for close to a year; might've come up with a solution just this morning, but I'll need to test it out before I can definitively call success. But yeah, get rid of unnecessary weight - for the ascent, that's everything that brought you down (chutes and lander legs, and even ladders), and an asparagus booster design is almost a must. I'd definitely send a boilerplate probe first before committing a Kerbal to making the ascent attempt.

Completed my Ike landing and re-rendezvous with the transfer stage to take Jeb home. Ran out of gas during the ascent; RCS saved the day again. Was a bit hairy to perform the rendezvous solely on RCS; good thing I had a lot of practice with that. Transfer stage still has 1600 m/s of delta-V, more than enough to make it back to Kerbin; the bit that might get me problems now is that the lander attached to the transfer stage is now a tad on the wobbly side. Plan is to head to Gilly sometime in the near future, will probably send this mission back before the Gilly mission returns.

Launched my Ike mission for science. Made it there no sweat; was even able to pick up an encounter with Ike without having to circularize around Duna after aerobraking. Game went glitchy on me after I decoupled the stack seperator holding the lander to the rest of the ship, otherwise I would've landed already. Delta-V looks good for Kerbin return. Tonight, I will land, take my science and get back into space. Then comes the waiting...during which I intend to head to Gilly.