Val

Tried to make a single RAPIER lift a 50 t craft to orbit. Was a bit too ambitious Could get it up to Mach 1, but not past. I think I'm close. Will try something a little lighter next time.

It's harder to make a multistage plane, that is stable after staging? More efficient ascent profiles have been found since. The multistage entries are older than the singlestage.

I don't think staged parts are fraction losses. They wouldn't count as payload anyway, according to the rules. I have a some of guesses, though Because the top multi-stage haven't been beat yet, no one has bothered to put in the effort. Structural/tankage mass is so highly optimized, on these spaceplanes, that staging doesn't give as much benefit as on non-airbreathing.

Looking forward to seeing your entry

Why is the word anec...e (a-n-e-c-d-o-t-e) auto-sensored by the forum? See also my post here.

Thank you. Your praise is much appreciated.Just remember that my way of doing it is not the only way. I have certain preferences for looks, what parts should be used and how the game should be played, and it probably influences the advice I give. You (and others) should definitely also pay attention to GoSlash47. He has many counterpoints and alternatives that are just as good or better than what I come up with.

Not all SSTOs in KSP have air-breathing engines.While it's not very important for KSP game balance, I think it's an interesting anecdote, that some real life Aerospikes were also designed for non-airbreathing SSTOs (X-33 and VentureStar) and were considered for the Space Shuttle.

Seems we agree on all points. For high-TWR flaps can shorten take-off runs. I didn't mention this specifically, though.My experience with flaps was very low-TWR. So low that you need the full runway to gain enough speed for lift and only just able to avoid splashing into the sea. ~30 t per RAPIER or ~50 t per Whiplash. I that scenario, deploying flaps made me lose speed and *splash*.

I still do that.Which reminds me, my instructions above, probably only works for wings that are exactly horizontal or vertical.

Agreed. Adding flaps doesn't really hamper performance, but deploying them does.From my personal experience with low TWR take-off, where flaps are needed the most, they seem to create more drag than lift. So I never use flaps for take-off. But I do find flaps quite useful for bleeding off speed at a steep approach to the runway. And if I have fuel left I may do a powered landing with flaps deployed. It lowers touch down speeds a bit and is especially useful, if landing in terrain.

That is a very not pointless SSTO Looks cool

When attaching elevons to the trailing edges of wings, with angle snap, I use the phrase: "Dammit, Sit Straight" to remind me what keys to press. (D + S) To make it work, make sure you have Angle Snap turned on (C key toggles it), then do the following. Grab a new Elevon from the part list. Move it to the edge you want to attach it to. Press D and S. (This should be sufficient for most elevons on horizontal wings) Press S twice more, if it's a non-symmetric Elevon and you want the ends reversed. [*]Attach the Elevon. On vertical wings it usually enough to just press D and nothing else. Hope that helps.

Heh. That is a cool twist. I love how it lights up in a blue glow, like someone sitting at a monitor. +rep

The link I posted has posts of the type "for x amount of cargo you need this much craft", covering both Mk2 and Mk3 designs.I my opinion, flight profiles are just as important as design. SSTOs are very sensitive to how you fly, especially in the high speed regions above 10 km. Pitching up too hard, ascending too steeply, or going a 100 m/s slower can easily end up costing you a 1000 m/s of dV in orbit, if you reach orbit at all. You really should try it. Angling the wings puts the prograde closer to where it should be. Unless you try to go Mach 2+ at sea-level.Here's the explanation why: The amount of incidence you need depends on mass and wing area. I usually go for 5 degrees Incidence and a wing area 1/8th to 1/6th of the mass in t. (not counting wing area from Mk2 fuselage) - - - Updated - - - I actually firmly believe, my craft ends up going faster, even if it is heavier and has less engine. Yours will undoubtedly get off the runway faster, but mine will probably pass mach 2 first. For SSTOs low drag is King. Canards are a design choice. To convert Canards to Elevators, you just have to move the main wings from slightly behind CoM to slightly in front. Then remove Canards and install Elevators at the back of the plane.I think the reason Canards are so prevalent, is because fuselages are generally heavier in KSP relative to engines. And people tend to over-wing. So CoL often ends up further back and CoM further forward, than for a similar real world design. And because usually the nose is further from CoM than the tail which gives more control authority.

I completely agree, that this is the state of things.But I also think rocket and spaceplane building can be tricky to compare directly for a few reasons. (Some assumptions and generalizations) Most of us have built a lot more rockets than we have spaceplanes. We often start KSP with small suborbital rockets (voluntary or not) and scale-up overtime. With spaceplanes it is quite common to go directly for SSTOs, getting no experience from starting smaller. I kind of think of this as trying to make the first rocket you ever build in KSP a Mun landing and return. How much time and how many attempts would that take to get right? I wonder, if I keep on building just spaceplanes, as I've done since 1.0.4, would I get to a point, where I could throw a design together for any payload in 10 minutes or less? I'm not sure... Spaceplanes are much more dependent on aerodynamics, than rockets. So maybe for that reason rockets will always be faster.

As I understand it, you want to learn for yourself how to build spaceplane SSTOs.If you're up for reading your way to knowledge, I can highly recommend the posts from GoSlash27 in this thread, "simple" rule to build spaceplanes? (There're are also some ramblings by me on later pages) If you're more inclined to practical studies or want to supplement Slashy's knowledge, (shameless self-plug) then you can download and study my Mk2 2-RAPIER design. It's a little bit heavier than yours, but it is very powerful and well balanced. If you do decide to download it. Read the Ascent Profile description, take it to orbit, to see how it performs. Maybe land it again. Then go to the SPH and study it closer. Some important features to note: Using only parts with 2000o or higher temperature rating for anything outside the cargo bay, including RCS pods. The only surface attached parts, outside the cargo bay, are wing parts, landing gear, RCS and tanks for mounting engines and intakes. No struts, except to secure cargo in the bay. (This also applies to all of my bigger designs, with a couple of exceptions) CoL position relative to CoM and Dry-CoM (All fuel removed from tanks) to keep it balanced at all fuel levels. Main Landing gear position below CoM to avoid wobbling and veering off the runway during take-off. Pull off the external tanks and Engines. See that the landing gear is mounted to the fuselage, also for increased runway stability. Notice how the wings and canards are mounted with Angle of Incidence. (Leading edge higher than trailing edge) This has several benefits: Reduces drag from fuselage. Decreases cosine thrust losses because the engines are pointing closer to prograde. Allows you to take-off and land with the nose lower, to avoid tail strikes and better view from IVA. [*]All stack-nodes terminated with intakes, engines, nose or tail cones (green attachment nodes), reduced drag. Then try to apply the above to your own design. Hope this is useful.

Whether it was an economical failure or the aerodynamics were atrocious, does not affect the Space Shuttle's status as a spaceplane. According to the official definition of spaceplanes, they do exist. And BTW, IRL unwinged pure rocket SSTOs have never flown successfully, either, unless you count Apollo landers reaching orbit from the surface of the moon. Should rocket SSTOs be scoffed at in KSP, too?

The payload connects the 2 parts, which of course imposes some limitations. Strutting the cargo is needed to stop wobble.The 2 halves, can land and launch as separate crafts or docked together. Been able to lift up to 72 t with it. That limit is imposed solely, by the positioning of the landing gear. If I could get a set of landing gear right underneath CoM, then it should theoretically be able to launch with around 120-140 t cargo. Would need more fuel also. Max take-off weight will be around 400 t. Current version has a max of 300 t.

In my opinion, if it was as easy to launch SSTO spaceplanes from Earth, as it is from Kerbin, then they probably would exist in real life, too. So I see no problem having them on stock Kerbin. BTW, the Space Shuttle was a spaceplane, but not an SSTO. I think, one of the reasons these two statements are true, is because rockets have much larger engines available. With RAPIERs it is not feasible to lift more than 25-30 t per engine. The part count to make a spaceplane capable of lifting 450 t cargo, would be a performance killer, but not impossible.I've made stock SSTO Spaceplanes that lift just over a 100 t with under 100 parts, but I didn't put RCS or external docking ports on it. And I have a WIP one that can take payloads up to 7.5 m in diameter. But you're absolutely right. They take a lot of time to design. But that's the part of KSP I like the most.

I'm not surprised that it flies, but I am surprised it could get off the ground. Impressive.Edit: And even more incredible if it could go supersonic, being that much off prograde to maintain level flight.

Very impressive entry and ship. But I'm wondering, in all the pictures Valentina looks various degrees of happy or excited. Except the last one. She looks really displeased. What happened?

Before 1.0 that was certainly true. But I don't think it is now.Evidence seems to suggest that tail cones reduce drag. And regular nose cones, certainly do: On the particulars of drag in 1.0.4.

You could always mount a probe core that faces in the same direction as the OMS thrust. And use Control from here when transitioning to OMS. I always design my craft so vacuum engines thrust in the same direction as the command pod, but I understand that isn't always feasible when making replica-type crafts.

I agree with, Slashy. The ratios I listed were pulled from succesful designs I had evolved pretty much as he describes. Though, my target was neutral lift at 375 m/s at sea level (or at least below 300 m).

I'm honored to be a source of inspiration - - - Updated - - - When I discovered the benefits of incidence, while doing the Laythe SSTO Challenge, I started with a simple 5o on all wing surfaces. And a wing area a 6th to a 10th of the craft mass at take-off. 20-25t craft per RAPIER. Less wing mass was important to get more dV. But for the very high performance ones I made for Stock Payload Fraction Challenge, I went for 2o and wing area a 4th of mass.