LackLuster. The little chemical SSTO that could...

[Rune]

First of all, an explanation on the name: I kept it from early development, to emphasize how little I expected of the airframe. After all, I already had the Heinlein to perform the VSSTO duty, right? But the more time I spent on it, the more in love I fell with its simplicity and looks... and now? Well, somehow it has managed to earn a place on my first interplanetary stack, and an honourable one at that: primary crew lander for Moho (check the album for a pretty cool pic of the stack breaking orbit). And copies of it are planned to pretty much take over every job the Heinlein had, plus small satellite delivery, and general purpose shuttling. A true workhorse, and awesome-looking to boot!

And the key to its versatility is its main difference with the Heinlein: it has a payload bay! That capsule was really killing that design, because this is lighter, has less thrust, carries one more kerbal if configured to do so (like it is in the file), and if you don't need crew, you can always chuck out the crew module and put up to 2.5mT of payload there and still make orbit. Or exchange modules once on orbit! And due to the relatively small launch mass (~50mT), it is a handy chemical lander to take around the kerbin system. Heck, it can handle Tylo if you have a refueling post there...

Of course, you can't really work miracles, and it is rather small (50 parts!), so really, it is SSTO, but only just, and only if you don't ever, under any circumstance, try to lift more than 2.5mT form Kerbin. Even a perfect launch profile will leave you fumes to perform deorbit/rendezvous. But that is something that it shares with the Heinlein, and if you are not the best pilot out there, or plain lazy, the low TWR at liftoff means a couple of SRB will increase the dV enormously, on account of lower gravity losses. Of course, almost anywhere else, the 4km/s in the tanks will be more than enough, even with larger payloads, but that is another thing...

Anyhow, it really is a '"T","Z","SPACE!"' kind of ship, with almost no action groups and no staging events, so really the user manual is basically "do a perfect gravity turn", so not much to tell you guys about how to fly it... just that the reentry is very easy and stable if you do it with the airbrakes out. Oh, I almost forgot, if you plan on maneuvering during reentry, you want to disable the winglets as control surfaces and enable the airbrakes, in order for them to work the right way on reentry when you are going bottom-first. Squad apparently hasn't figured out yet how to make control surfaces work when placed backwards... Other than that, it will survive an unpowered landing, no need to save fuel for the last second. That's why I spent to much time thinking about the fuel routing and such, so you don't have to pay attention to anything but the navball and the "time to apoapsis" reading during ascent. Oh, and it also floats on water without tipping over... that was totally unintentional, but it is very awesome: water landings on Laythe are nothing to be afraid of!

IMGUR ALBUM:

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DOWNLOAD:

http://www./download/6cgoeaf2uaozz1l/VSSTO+MkXVI+'LackLuster'.craft

Rune. KISS at its finest.

Edited October 30, 2015 by Rune

[Guest]

Very nice! I planned on building a chemical SSTO in the future, too, and I might take inspiration from this.

[Majorjim!]

Hi Rune,

Are those four mk2 fuel tanks full?

[Rune]

Very nice! I planned on building a chemical SSTO in the future, too, and I might take inspiration from this.

Thanks! That's the most I aspire to, to inspire others as I have been inspired myself, countless times.

Hi Rune,

Are those four mk2 fuel tanks full?

Yup, I had to cheat a bit and "increase the density of my propellant" to maintian the small form factor without ruining the lines. Still, really easy to select, they don't Z-fight the lower tank, and maybe more importantly, they actually play an integral part in the fuel routing that keeps it aerodynamically stable during ascent and descent.

Rune. It's the small things.

Edited October 25, 2015 by Rune

[Guest]

Speaking of small things, Mk2 tanks and form factor, I think you could have hidden the edge Mk2 -> Mk3 with a small nosecone or something, and maybe the fuel line inside. But that´s nitpicking, and if it flies...

[Rune]

Speaking of small things, Mk2 tanks and form factor, I think you could have hidden the edge Mk2 -> Mk3 with a small nosecone or something, and maybe the fuel line inside. But that´s nitpicking, and if it flies...

Hehe, it's like being back again in the SPH during development... I asked myself those same questions! But if I did that, one of two things happens: I can no longer run fuel lines from the upper tank (crucial for the fuel routing), or if I put nosecaps they would clip inside the cargo bay. Plus, with 400kgs more in weight, it wouldn't make orbit, even with reduced drag. The way they are right now, you only see the lip in the two with the fuel lines on the side. Which, for the record, I think look cool, which is why I put them visible.

Rune. Deceptively simple!

Edited October 25, 2015 by Rune

[Foxster]

Nice one, Rune.

It looks like a better version of what I have been using...

[Legendary Emu]

I'm loving these chemical SSTO's. It seems to me that spaceplane SSTO's are starting to always look the same, so it's really nice to see rocketlike SSTO's.

[Rune]

Nice one, Rune.

It looks like a better version of what I have been using...

http://i.imgur.com/IRPHmgj.jpg

I see the fuel routing, and I approve. Also, you have much more fuel, so I suspect you have a healthier dV margin. But, a couple of points:

-Those airbrakes are backwards! I know they work just the same, but it hurts the eye a bit. Aerodynamic side facing the airstream!

-That main engine is a vacuum engine. At liftoff you get one half its thrust, meaning you could do the same thing with about half the engine mass. Yeah, it's efficient, but SSTOing is all about TWR (as in, keeping it above one while carrying enough fuel and minimizing engine mass). Spikes, or the Mammoth, were built for the job. Even "low isp" boost engines like the Mainsail or Reliant will do better.

-It's kind of impossible to put front facing Vernors showing without them looking horrible. Just give up and sink them inside the fuselage on the nose, it'll work just the same and look 10 times better.

Rune. Actually, yours look like an easier to fly version, to me.... well, that and more expensive.

Edited October 25, 2015 by Rune

[Foxster]

I see the fuel routing, and I approve. Also, you have much more fuel, so I suspect you have a healthier dV margin. But, a couple of points:

-Those airbrakes are backwards! I know they work just the same, but it hurts the eye a bit. Aerodynamic side facing the airstream!

-That main engine is a vacuum engine. At liftoff you get one half its thrust, meaning you could do the same thing with about half the engine mass. Yeah, it's efficient, but SSTOing is all about TWR (as in, keeping it above one while carrying enough fuel and minimizing engine mass). Spikes, or the Mammoth, were built for the job. Even "low isp" boost engines like the Mainsail or Reliant will do better.

-It's kind of impossible to put front facing Vernors showing without them looking horrible. Just give up and sink them inside the fuselage on the nose, it'll work just the same and look 10 times better.

Rune. Actually, yours look like an easier to fly version, to me.... well, that and more expensive.

The airbrakes - It's odd but they feel better my way around for some reason

The thrust of the engine isn't so bad, it's 75% at sea level, which is quite useable. Its nearly at max by 10km.

Yea, the vernors look bad, clipping feels worse though somehow.

Taking a mk2 crew cabin with a crew of 4 as payload leaves the craft with about 1kdv by 100km orbit. Which is enough for a rendezvous and then a de-orbit burn.

Edited October 25, 2015 by Foxster

[turtlebiscut]

This is actually amazing. Great job:wink:

[Cupcake...]

You must spread some Reputation around before giving it to Rune again.

Cupcake...

[CommanderSonic]

Interesting craft, I would like to check her out and maybe fly her.

[ryan234abc]

THAT is cool looking. Rather reminiscent of the MAV from The Martian (great book, great film). I've been working to make my own version, based on the film one. Its an SSTO that can make orbit from Kerbin as it is, but on Duna you can take out the Skipper in the middle, and land it from orbit, take off, make orbit, land it, take off and make orbit again. It is VERY good for Duna, but would definitely need assistance to get to Duna and most likely, to get back again.

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Also, I staged it early to demonstrate the stages, it doesn't actually run outta fuel before it leaves the lower atmosphere.

Also again, I can't +rep you, I've given you too much and need to spread it around. Soz.

Edited October 26, 2015 by ryan234abc

[Rune]

This is actually amazing. Great job:wink:

Thanks!

Cupcake...

Don't sweat it, I honestly enjoy more a comment, even if it is telling me I should have done things differently in some way.

Interesting craft, I would like to check her out and maybe fly her.

Thanks! It is rather easy to try out, let me know if you find it too hard or something, I'm usually able to help.

THAT is cool looking. Rather reminiscent of the MAV from The Martian (great book, great film). I've been working to make my own version, based on the film one. Its an SSTO that can make orbit from Kerbin as it is, but on Duna you can take out the Skipper in the middle, and land it from orbit, take off, make orbit, land it, take off and make orbit again. It is VERY good for Duna, but would definitely need assistance to get to Duna and most likely, to get back again.

http://imgur.com/a/zadaD

Also, I staged it early to demonstrate the stages, it doesn't actually run outta fuel before it leaves the lower atmosphere.

Also again, I can't +rep you, I've given you too much and need to spread it around. Soz.

Yup, it certainly has the looks of a RL rocket. But if I based it off something, that would be the DC-X. Awesome program that got killed as soon as it was put under NASA's wing.

As to your ship, if it is built for Duna, I will point out that any kerbin SSTO will be able to go up and down Duna at least once, even doing fully powered reentries, and if you can spend less than 300m/s landing due to the atmosphere, it will likely also do it twice. 4km/s is rather "easy" to accomplish with KSP's tankage fractions, if you keep the payload light. My point: staging a Duna lander is a marginal efficiency gain, and it could even end up weighting more than it needs to. Just go for >2.5km/s to have a healthy margin, and put chutes to save fuel on descent. I reckon that upper stage could make the trip to orbit comfortably in a SSTO bay, even if you put twice the fuel, or sit on top of a SRB booster to go up on its own.

Rune. Anyone managed to make orbit on this yet?

[How2FoldSoup]

Hey Rune,

A week or two ago I got inspired by the Heinlein and took it in my own sort of style. I feel your pain in trying to make it work! That capsule is way too heavy and the aerospikes just don't have the Isp needed to make chemical SSTO's kinder.

Anywho, I was able to land on the Mun with mine and figured I'd share it. I went with the bigger and more engines line of thinking that gave me an extra 100-200 m/s that made making orbit a bit easier.

[Threadsinger]

This is one of the most awesome-looking VTOL SSTO's I've seen on KSP. I've been using it for a mission or two now, after some practice, and it is fun and functional. I built it from pictures, not the craft file, so it took me a bit to figure how the engines were built onto clipped fuselages. (I thought there was some part I was missing...). That and the fuel lines.

(The other ones in this thread are awesome too, gives some neat ideas and aesthetics!)

I called mine the "RuneBoat". Also have a heavier lift variant and I'm working on a KSPI fusion engine'd one (RuneBeast) for that extreme delta-v/fast transit time/Eve SSTO goodness.

[Rune]

Hey Rune,

A week or two ago I got inspired by the Heinlein and took it in my own sort of style. I feel your pain in trying to make it work! That capsule is way too heavy and the aerospikes just don't have the Isp needed to make chemical SSTO's kinder.

Anywho, I was able to land on the Mun with mine and figured I'd share it. I went with the bigger and more engines line of thinking that gave me an extra 100-200 m/s that made making orbit a bit easier.

http://i.imgur.com/PD7tPqU.png

Very good-looking one! Just a tiny correction: aerospikes have awesome isp, especially at ground level. The thing they lack (compared with, say, the Mammoth) is TWR, actually. And low TWR in SSTOs means a lot of gravity losses, meaning reaching LEO is more around 4km/s rather than 3,5. Or, a low fuel fraction if you just chuck on a ton of spikes on account of all that engine weight. Just some food for thought, one of those engineering trades that takes some getting used to.

This is one of the most awesome-looking VTOL SSTO's I've seen on KSP. I've been using it for a mission or two now, after some practice, and it is fun and functional. I built it from pictures, not the craft file, so it took me a bit to figure how the engines were built onto clipped fuselages. (I thought there was some part I was missing...). That and the fuel lines.

(The other ones in this thread are awesome too, gives some neat ideas and aesthetics!)

I called mine the "RuneBoat". Also have a heavier lift variant and I'm working on a KSPI fusion engine'd one (RuneBeast) for that extreme delta-v/fast transit time/Eve SSTO goodness.

Sounds good! And thanks for the kind comments, of course. Now, you have me intrigued with that KSPI version... any chance we get a look at it? KSPI engines take a lot of support equipment to put around, and it may give ideas to people!

Rune. It's always great to see derivative designs from my stuff.

[Paranoid Shark]

Hey Rune,

I've been playing with all of your VSSTO's and they are great! I noticed that the Lackluster has no monoprop, is that deliberate or a mistake? Also it is way harder to get to orbit than the Heinlein!

I have had a go at building my own VSSTO's, but to start I have used yours as a base. I'm having a bit of a problem with my VSSTO Mk3 (the one with the full mining kit) (grand plans to land on Tylo, refuel and take off again) I don't think I have the fuel routing quite right, as it goes into a flat spin at the same altitude every test flight, and if you leave it spinning around till it burns off the fuel, the engines shut down in a very weird order! I've tested it coming back in and it will do a perfect unpowered & no electricity landing, and I think it has enough dv to make orbit if it would just stop spinning!

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I'm a bit lost as to what i've done wrong. Could you PM me an email address that I could send the craft files to?

Thanks,

Kit

[Rune]

Hey Rune,

I've been playing with all of your VSSTO's and they are great! I noticed that the Lackluster has no monoprop, is that deliberate or a mistake? Also it is way harder to get to orbit than the Heinlein!

I have had a go at building my own VSSTO's, but to start I have used yours as a base. I'm having a bit of a problem with my VSSTO Mk3 (the one with the full mining kit) (grand plans to land on Tylo, refuel and take off again) I don't think I have the fuel routing quite right, as it goes into a flat spin at the same altitude every test flight, and if you leave it spinning around till it burns off the fuel, the engines shut down in a very weird order! I've tested it coming back in and it will do a perfect unpowered & no electricity landing, and I think it has enough dv to make orbit if it would just stop spinning!

http://imgur.com/a/VmZZt

I'm a bit lost as to what i've done wrong. Could you PM me an email address that I could send the craft files to?

Thanks,

Kit

Yup, not having monoprop is deliberate. It serves little purpose, but hey, no monoprop production needed! Besides, Vernors are cool. The downside is that you can actually run out of RCS with the main engines, the flip side is that whatever fuel you don't use is all RCS, so you don't need to balance it out and you never carry excess monoprop. And yeah, it is very much not forgiving, the little bugger. Just enough to dock to a low orbit station... if you fly it perfect and know how to dock with minimal fuel usage.

As to your designs, as always, glad I inspired.

Let's see if I can figure it out without the file (though I will fix it for you if my pic-fu is not enough). Judging by the pics, you seem to have an odd number of spikes (9) mounted on separate tanks like I did, and I think that is the source of your problems. If you check out the routing in the LackLuster, you will see that fuel is first pumped to two of the engines, then from those to the other two, keeping things nice and symmetrical and the CoM firmly in the longitudinal axis to not create engine torque. With yours, that just can't happen, since they are an odd number. And indeed, in the inflight pic, you can see that four engines have a certain remaining fuel level, and five others a different one. There's your problem! Now let's fix it:

You could instead pump to a central distribution tank inside the lower tank, and then to the rest of the engines, symmetrically. An alternative is to put an even number of engines and mimic the way I did it, first to two of them, then to the rest in symmetrical order. That way some spikes will shut off before the end of the burn (at which point TWR is mostly irrelevant, and it might help to throttle down). Another option would be to put one of them in the middle without routing, and the other eight with a symmetrical fuel routing, I don't think the middle engine draining from the top down would be enough to offset the stability-inducing drain of the others (form the bottom up), and in fact the CoM might wander less.

Also note that the LackLuster is only stable on the way down because of the airbrakes, if yours becomes stable ass-first while it is still inside dense atmosphere, you will have flipping issues. On the Heinlein I just struck a fortuitous config that made it become stable the other way around only by the very end of the climb to orbit, when the front upper tank finally empties.

Rune. Hope that is enough help! It's twice as gratifying if you solve it yourself.

[Azimech]

Love those clean lines!

[CrashTestDanny]

Great ship Rune - I did orbit it when you sent the advance copy... any changes since that one?

Danny

[CrashTestDanny]

Hey Rune - Bill just entered Duna SOI in a trident with 1800 units LF and 1000 units of Ox. Looks like about 600 dv... anything I need to know about aerobraking and landing in Duna's thin atmosphere? Hoping not to kill Bill here!

Danny

[Rune]

Love those clean lines!

Thanks! I also loved it for its misleading simplicity... the form just works out, right? I can assure you it was kind of hell to manage TWR and dV so it could make it to orbit with any payload... If I did a second one, I can assure you it would be bigger and heavier.

Great ship Rune - I did orbit it when you sent the advance copy... any changes since that one?

Danny

Mmmm... not sure, actually. Did yours have vernors? Maybe the electrical system, I think it used to rely on solar panels at some point, but the single fuel cell is actually lighter, and every kg counts....

Hey Rune - Bill just entered Duna SOI in a trident with 1800 units LF and 1000 units of Ox. Looks like about 600 dv... anything I need to know about aerobraking and landing in Duna's thin atmosphere? Hoping not to kill Bill here!

Danny

Hum. I am by no means an expert in interplanetary flight, but my first advice is to F5 before aerobraking, and running a few "simulations". From what I hear, about 20kms for Pe should do the trick... but if you go all belly-first at it, you can probably do it a bit higher and cooler. Don't worry, the design is totally thermal-proofed so it handles quite the thermal abuse.

BTW, this build got me over the three kilorep barrier. Which means I have an average of one rep per post, more or less.

Thanks to all of you guys, I'm really glad you like my stuff so much!!

Rune. Yup, every now and then, there are some previews for daring test pilots that actually bother to report back.

Edited October 30, 2015 by Rune

[CrashTestDanny]

I'll have to double check it after I get Bill landed on or at least in orbit of Duna...

Danny