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Foil. SSTM Crew Trainer.


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No, I didn't make a mistake in the title, this is not your usual SSTO. This is a single stage to Mun. Or Minmus. Or both. Presenting the easiest way to get your crew to lvl 3 in a single flight!

WX5qthB.png

See, there's this mission profile that has been short of my standard for crew training before they step out of Kerbin's vicinity: visit Minmus, plant a flag, pop out of of Kerbin's sphere of influence for the briefest of periods, then reverse and boost back into Kerbin's SOI, getting a Mun encounter on the long way down, to finish with an aerobrake and back to base. It gives you just enough XPs (Flag on Minmus, solar orbit, and Mun flyby) to bring the kerbals cleanly into lvl3, where you unlock pretty much all the abilities worth having (specifically, all the repair abilities). Problem is, the dV Budget to do that is steep. Going to Minmus saves you landing dV, but still, that's like 3-4km/s depending on how long you take to leave Kerbin's SOI and come back, and that is if you aerobrake for full effect and are really good at navigating. And since 1.0, aerobraking at interplanetary speeds is either tricky if you are a very good pilot in a thermal-proofed ship, or downright suicidal if you are not.

yq4cKp6.png

This kind of mission is exactly what my old, pre-1.0 Spatha was built to do, have a crapton of dV and just plunge in the good old souposphere to break at the end of a mission. Some of you might remember that ship... But nowadays that just won't fly with the reentry heating! So I've had to actually improve on the performance, and quite a lot. But fear not! I did, and this is the result: After such a strenuous mission, the new Sabre gets back to Kerbin's atmosphere with 800m/s still in its tanks. More than enough to slow you down to suborbital speeds before the reentry interface, but you also have a huge lifting ratio, and the thing is balanced really nice, so you can also reenter at frightening speeds, completely sideways to the airflow, and brake in the high atmosphere before things start to really heat up (tested at 2,900m/s at entry with a periapsis of 30kms). The thing is so light and "lifty", it is like reentering on a leaf! And, no part has a less than 2000º rating, just to further ease things.

NlWcls2.png

So now, a word or two on the user manual:

First, never mind that orbital proofing pic up there, it says you only have about 2km/s on LKO, but that is because I didn't put any fuel lines there, to save weight and drag: you will have to move fuel manually from the wing tanks into the central rocket body. With that taken care of, your dV is around 3,250m/s.

Second, the thing is a leaf, with a ridiculously low wing loading. That really helps, making it rise like an elevator with minimal drag losses, tearing through the Mach barrier like it wasn't there, and aerobraking incredibly gently if you present all that surface to the atmosphere. But, it can also glide very far, and fast, if you go prograde, and I didn't put any airbrakes, so you can actually get to the runway a bit too fast if you don't take care. If that's the case, just circle around it until you speed goes below 100m/s or so. Turns out, having a lot of wing really cuts on drag, and this is an extreme example. If anything, the thing is a tiny bit unstable in roll, due to the anhedral tail, but hey, it looks awesome, so I'll allow it I guess. :rolleyes: In any case, it is balanced enough so that you can actually maintain the >45º angles of attack required to turn lift into drag, and make full use of a spaceplane's ability to brake much higher, and faster, than any capsule, without bouncing out of atmo.

Oh, and I almost forgot: ther is some oxidizer in there, but it's only for the kick out or Kerbin's atmosphere. It should run out just as you get your apoapsis out of the atmosphere, and afterwards the RAPIERs are pretty much useless until you reenter.

And it think that's everything so, without further due, here you go! The customary album and DL, have fun trying it out.

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http://www./download/d04mcp6pj6f7wvj/SSTO+Mk+LXIX+-+Foil.craft

Rune. I'm not too sure on the name, tough... Foil or Sabre? Which one do you think suits it better?

Edited by Rune
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Hi Rune,

So have you landed it on Mun? Also you say that it can land on Mun or Minmus or both. Can it single stage from Kerbin, land on Minmus take off land on Mun and return to Kerbin without refueling?

Edited by Majorjim
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Hi Rune,

So have you landed it on Mun? Also you say that it can land on Mun or Minmus or both. Can it single stage from Kerbin, land on Minmus take off land on Mun and return to Kerbin without refueling?

The numbers say it should do all those things (although Mun and Minmus landed in the single mission is a bit iffy, and would certainly preclude going into solar orbit and require an efficient intermunar transfer), but, I haven't myself tested anything but the mission I outlined, plus a lot of atmospheric testing. Perhaps someone else can put a few screenies of it landed on Mun before I get around to it? Although I do have a base there full of rookies and a fresh batch of lvl 3's, so it might not be long...

In any case, the mission I described is like 2,5km/s (~1km/s to reach Minmus, ~0.5 to land and take off, and about another km/s to get to solar orbit quick and then turn back and reverse), and it does that with a 800m/s overhead, consistently, so after the ~2.5km/s of a munar mission, you have still almost another whole km/s to visit Minmus, and energetically, you are halfway there already while on Munar orbit. Also, the ascent would be very crucial, as would be how you use the abundant monoprop. As I said, since I skimped on fuel lines, it's a bit hard to judge until I've tried it myself with 100% certainty.

Rune. But I think it can be done if you know your stuff. Feel challenged enough?

Edited by Rune
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The numbers say it should do all those things (although Mun and Minmus landed in the single mission is a bit iffy, and would certainly preclude going into solar orbit and require an efficient intermunar transfer), but, I haven't myself tested anything but the mission I outlined, plus a lot of atmospheric testing. Perhaps someone else can put a few screenies of it landed on Mun before I get around to it? Although I do have a base there full of rookies and a fresh batch of lvl 3's, so it might not be long...

In any case, the mission I described is like 2,5km/s (~1km/s to reach Minmus, ~0.5 to land and take off, and about another km/s to get to solar orbit quick and then turn back and reverse), and it does that with a 800m/s overhead, consistently, so after the ~2.5km/s of a munar mission, you have still almost another whole km/s to visit Minmus, and energetically, you are halfway there already while on Munar orbit. Also, the ascent would be very crucial, as would be how you use the abundant monoprop. As I said, since I skimped on fuel lines, it's a bit hard to judge until I've tried it myself with 100% certainty.

Rune. But I think it can be done if you know your stuff. Feel challenged enough?

I always get a kind of muscle twitch anytime people say a craft can do something without actually doing it themselves. so do you feel challenged enough?!

LOL, teasing aside my SSTO flying skills are laying withered and shivering unused in a corner so I wont be trying it myself. As we would say here in England, I went to the 'other' place.

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Nice , might have to try this one out. So many ships, so little time. Thanks to you and all who build these wonderful toys to play with. :)

You are welcome! :)

I always get a kind of muscle twitch anytime people say a craft can do something without actually doing it themselves. so do you feel challenged enough?!

LOL, teasing aside my SSTO flying skills are laying withered and shivering unused in a corner so I wont be trying it myself. As we would say here in England, I went to the 'other' place.

Then again, you are always jumping to conclusions a bit... I said it can go to Mun and Minus, but I only talked about the mission I use it for, which involves only landing on Minmus, but visits both satellites, and solar orbit too. So technically, yeah, I've done it myself. ;)

It is unlikely that I will go for a Minmus/Mun tour soon, my career save is neglected enough as it is of late. It's time I visit some planets out there and actually use my stuff! Still, I'm interested to see how much the dV meter reads when on the Munar surface.

Rune. Not much playing time these days.

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If it's stock, where did you get the plant things. And are they going to be in stock at some point. Growing moon food would be a lot of fun. Maybe they should get together with the guys who make "Take on mars" and similar games and put all that type of stuff into planetary items and bases. Could be cool!

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Then again, you are always jumping to conclusions a bit... I said it can go to Mun and Minus, but I only talked about the mission I use it for, which involves only landing on Minmus, but visits both satellites, and solar orbit too. So technically, yeah, I've done it myself. ;)

It is unlikely that I will go for a Minmus/Mun tour soon, my career save is neglected enough as it is of late. It's time I visit some planets out there and actually use my stuff! Still, I'm interested to see how much the dV meter reads when on the Munar surface.

Rune. Not much playing time these days.

I think your description is misleading. Saying you can 'visit' both implies you landed. That's all. I am not jumping to conclusions at all.

I just personally disagree with saying something can do something when even the designer has not done it. It goes against my ethos becuase even if the numbers say so it may be impossible for a human to complete it. And you knew perfectly well what I was referring to when I said have you done it.

And the answer is no. Just for clarity of course. :wink: And, yes, this is just my opinion. And dude, you say you dont have time to play but you flew it to minmus, around Mun and back but, what, didn't have time to land?

Edited by Majorjim
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If it's stock, where did you get the plant things. And are they going to be in stock at some point. Growing moon food would be a lot of fun. Maybe they should get together with the guys who make "Take on mars" and similar games and put all that type of stuff into planetary items and bases. Could be cool!

The plant thing are from USI-LS. The craft itself is stock. It's just landed next to a base that isn't entirely stock.

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Great craft as always. I've learnt to never expect anything bad by now, and I hold to the fact that there never will be. This'll be handy for sure. A question for you though. How do you go about landing plane, SSTO's etc on atmosphericless planets? I'd imagine you just landing it like a rocket and tip forward at the last second, but there has to be a better way to do this. Tylo would prove a challenge to do this on for sure...

Anyway, another great craft. Love the joint tail fin btw.

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Great craft as always. I've learnt to never expect anything bad by now, and I hold to the fact that there never will be. This'll be handy for sure. A question for you though. How do you go about landing plane, SSTO's etc on atmosphericless planets? I'd imagine you just landing it like a rocket and tip forward at the last second, but there has to be a better way to do this. Tylo would prove a challenge to do this on for sure...

Anyway, another great craft. Love the joint tail fin btw.

Thanks! But I'm sure I can be less than inspired every now and then... I just have set myself a good standard on R-SUV to measure against, and see if something is release-worthy. And yeah, I land them just like rockets, tipping over at the last second. It's one of the reasons of the tail, actually, it'll tend to drop you on your landing gear and protects the nuke from rough landings. WWhich, incidentally, I totally stole from someone else when I saw it on the SSTO thread, but I can't remember who to thank right now. ^^'

On other models, like the Javelin, I have added vertical landing gear, it's not hard if you are willing to take a slight drag hit and make the whole thing easier. Besides, the tipping maneuver, as you say, only work on the lower gravities... you have to take off afterwards!

The plant thing are from USI-LS. The craft itself is stock. It's just landed next to a base that isn't entirely stock.

Yup, exactly that. And just to clarify, no fuel was exchanged there, I just docked to refresh the TAC clock with a prototype that didn't have backup drone control for when the kerbals go on strike.

I think your description is misleading. Saying you can 'visit' both implies you landed. That's all. I am not jumping to conclusions at all.

I just personally disagree with saying something can do something when even the designer has not done it. It goes against my ethos becuase even if the numbers say so it may be impossible for a human to complete it. And you knew perfectly well what I was referring to when I said have you done it.

And the answer is no. Just for clarity of course. :wink: And, yes, this is just my opinion. And dude, you say you dont have time to play but you flew it to minmus, around Mun and back but, what, didn't have time to land?

Visiting can mean many things. For example, a SSTM could perfectly well be something that does a free return. Or get there one-way. Or you wouldn't say Apollo 8 visited the Moon? In any case, semantics.

As to playing time... well, this was built at the beginning of September. Only now did I finish the two inaugural missions, both of which were made to ever so slowly advance my save towards interplanetary flight. Total amount of time spent outside career since then? Zero. So, yeah, it should be clear from my releasing tempo lately that I don't have the time to build and test exhaustively. :( And during my limited playtime, anyhow, I will only do the stuff that I enjoy doing, really, I think that is the sensible thing, or I would burn out very quickly if I took it as an obligation or something.

Rune. In any case, I think it is very clearly stated in the OP, what the reference mission is.

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Thanks! But I'm sure I can be less than inspired every now and then... I just have set myself a good standard on R-SUV to measure against, and see if something is release-worthy. And yeah, I land them just like rockets, tipping over at the last second. It's one of the reasons of the tail, actually, it'll tend to drop you on your landing gear and protects the nuke from rough landings. WWhich, incidentally, I totally stole from someone else when I saw it on the SSTO thread, but I can't remember who to thank right now. ^^'

On other models, like the Javelin, I have added vertical landing gear, it's not hard if you are willing to take a slight drag hit and make the whole thing easier. Besides, the tipping maneuver, as you say, only work on the lower gravities... you have to take off afterwards!

Yup, exactly that. And just to clarify, no fuel was exchanged there, I just docked to refresh the TAC clock with a prototype that didn't have backup drone control for when the kerbals go on strike.

Visiting can mean many things. For example, a SSTM could perfectly well be something that does a free return. Or get there one-way. Or you wouldn't say Apollo 8 visited the Moon? In any case, semantics.

As to playing time... well, this was built at the beginning of September. Only now did I finish the two inaugural missions, both of which were made to ever so slowly advance my save towards interplanetary flight. Total amount of time spent outside career since then? Zero. So, yeah, it should be clear from my releasing tempo lately that I don't have the time to build and test exhaustively. :( And during my limited playtime, anyhow, I will only do the stuff that I enjoy doing, really, I think that is the sensible thing, or I would burn out very quickly if I took it as an obligation or something.

Rune. In any case, I think it is very clearly stated in the OP, what the reference mission is.

Ok Rune, I just wanted to say what I said. We have to agree to disagree. See ya.

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That's my official Flight Test report: Wow.

That's what I'm looking for in a spaceplane!!

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4894 delta-V on LKO. Headed for Min now...

Danny

- - - Updated - - -

Oh neet. I think I'll tear it apart and build a giant one :D

Seems to be my thing. Something works. Let's scale it up until it doesn't!

LOL! Love it!

Danny

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Beautiful and functional! I will have to try this one.

Glad you like it! I hope it serves our needs well.

- - - Updated - - -

Make up your mind on the intakes! lol

What do you mean?

- - - Updated - - -

Oh neet. I think I'll tear it apart and build a giant one :D

Seems to be my thing. Something works. Let's scale it up until it doesn't!

Hehehe, that's a funny one. Tell us how it goes!

- - - Updated - - -

That's my official Flight Test report: Wow.

That's what I'm looking for in a spaceplane!!

http://imgur.com/a/oPhYA

4894 delta-V on LKO. Headed for Min now...

Danny

- - - Updated - - -

LOL! Love it!

Danny

So Mechjeb can make the calculation right. I didn't think it had quite so much dV! Thanks for the thorough testing, as always.

Rune. Damn posting from a phone is crappy.

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So Mechjeb can make the calculation right. I didn't think it had quite so much dV! Thanks for the thorough testing, as always.

That's not actually something I would bank on in a spaceplane. The number changes without any fuel usage and I haven't quite figured that out. Yet... Especially since it went up after moving fuel around and locking the tanks that the Rapiers are directly attached to... Let's calculate it ourselves and see...

BRu1mbC.png

ln(Mstart/Mend) * Isp * 9.81 ought to be simple enough, right?

Mstart looks like 23.258. Mend looks like 17.050. (current mass, dry mass from the readout).

Isp of the Nerv is 800 and there's only one of them...

so ln(23.258/17.050) works out to... ln(1.36410557...) = 0.310498955...

that * 800 is 248.4 and multiplied by 9.81 is 2436.8... I must have missed something... I'll try to figure it out later... lol...

Danny

- - - Updated - - -

Ok - I think I partially understand what MechJeb is doing here. First, if we add in the Isp from the Rapiers, we get a whole lot closer to MechJeb's numbers (4200ish), which is clearly wrong since the Rapiers are paperweights until we return to an atmosphere. The 2400 I calculated is still a little high because some of the fuel is reserved for the Rapiers during said return flight. It seems that neither MechJeb (reports false numbers) nor KER (refuses to report) understand which fuel is going to go where, which probably means that the crossfeed and/or fuel pump mods and/or KSP are not reporting something correctly... but analyzing code is too much like work for me - I'm just gonna fly it and see what happens. :cool:

I think my delta-V budget for landing on Min, then escaping Kerbin and coming back via the Mun should be under 2k anyhow, right? Let's see... Insertion 160, landing 180, ascent 180, escape (Min) 160, escape (Kerbin) 20, return 90... that's 790 - I have 2400... I can do it with three or four little mistakes and still be able to glide in... :cool:

Sounds like a plan, right?

Danny

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That's not actually something I would bank on in a spaceplane. The number changes without any fuel usage and I haven't quite figured that out. Yet... Especially since it went up after moving fuel around and locking the tanks that the Rapiers are directly attached to... Let's calculate it ourselves and see...

http://i.imgur.com/BRu1mbC.png

ln(Mstart/Mend) * Isp * 9.81 ought to be simple enough, right?

Mstart looks like 23.258. Mend looks like 17.050. (current mass, dry mass from the readout).

Isp of the Nerv is 800 and there's only one of them...

so ln(23.258/17.050) works out to... ln(1.36410557...) = 0.310498955...

that * 800 is 248.4 and multiplied by 9.81 is 2436.8... I must have missed something... I'll try to figure it out later... lol...

Danny

- - - Updated - - -

Ok - I think I partially understand what MechJeb is doing here. First, if we add in the Isp from the Rapiers, we get a whole lot closer to MechJeb's numbers (4200ish), which is clearly wrong since the Rapiers are paperweights until we return to an atmosphere. The 2400 I calculated is still a little high because some of the fuel is reserved for the Rapiers during said return flight. It seems that neither MechJeb (reports false numbers) nor KER (refuses to report) understand which fuel is going to go where, which probably means that the crossfeed and/or fuel pump mods and/or KSP are not reporting something correctly... but analyzing code is too much like work for me - I'm just gonna fly it and see what happens. :cool:

I think my delta-V budget for landing on Min, then escaping Kerbin and coming back via the Mun should be under 2k anyhow, right? Let's see... Insertion 160, landing 180, ascent 180, escape (Min) 160, escape (Kerbin) 20, return 90... that's 790 - I have 2400... I can do it with three or four little mistakes and still be able to glide in... :cool:

Sounds like a plan, right?

Danny

Oh, so Mechjeb is also confused. Move all the fuel towards the center tanks, it's the best plaace for it. I really tought long and hard about piping it up... But honestly, you only need to move it once, and at leisure once in space. The RAPIERs can draw it wherever it is if you ever re-light them, so don't worry about that. All in all, you should have quite a bit more than those 2km/s, at least one more.

Rune. You might have some fuel still in the wings, too

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It's enough challenge building an SSTO and you made one to do this, definitely deserves REP but I can't rep you again yet and I am ok with that its a good thing to spread the love around, I'll catch you later on that rep

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