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1.0.2 - Any hope left for SSTOs?


panzer1b

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SSTOs aren't supposed to be the logical choice for more than Low orbits. Think of an SSTO like a small boat. You bring the large vessel near shore and the small boat carries passengers and cargo back and forth. That's the most efficient way to do things with current technology or near future, forseeable, tchnology ( actually, current tech does not allows for SSTO's, but that's because Earth is a "little" bigger than Kerbin :P) The fun in this game is to achieve great things using the real laws of physics, if we are to break them (too much) this wouldn't be Kerbal Space Program, it would be more like a shoot'em up... Not funny at all :P

Still, you do have a point in one thing, a "turn it all off" buttom is always appreciated, whenever possible let the player costumize the game for the level of realism he/ she wants...

Note: I always designed and flew my planes in 0.9 as they should in real life. When 1.0 came only a minor tweak in my SSTOs and they were back in business, doing what they always did, carry people, fuel and small cargo between Kerbin and LKO. As for my aircraft, they even fly better in 1.0.x than previously :)

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I agree, it was never sensible. But when has KSP ever been about being sensible?

The best part of KSP is that you can play it however you want. The second best part is the large number of opportunities to not be sensible :D

SSTOs aren't supposed to be the logical choice for more than Low orbits.... The fun in this game is to achieve great things using the real laws of physics, if we are to break them (too much) this wouldn't be Kerbal Space Program

I don't think anyone builds long-range SSTOs because they're logical, but because they're an interesting challenge. Pushing real physics to its limit is essential in exploring space in the real world. The way I play KSP is to push the game's physics to its limit!

EDIT: And really, there are only small differences between a cargo SSTO and a distance SSTO. I'm pretty sure I can haul a 33%+ payload fraction to orbit with my 4,200dV-in-orbit design by switching out the nuke and replacing a bunch of fuel with cargo.

Edited by Sattorin
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^ Quoted for truthiness. This is why I haven't bothered chasing the single-stage-to-Laythe problem. I'm just building mine with high payload fraction, around 300 m/sec DV in orbit, and enough reserve fuel to cruise home.

I will need to get a shuttle in service on Laythe at some point. My plan is to piggyback a fuel tank onto it in orbit and send it on it's way.

Best,

-Slashy

Thanks! That is why I've started to put a rear-facing docking port on some on my winged SSTO designs, centred over the CoM: some of them are going to be transported (probably by payload they themselves lifted up) to Laythe, when I get enough of the tree unlocked to build them that is (right now I'm in the "mine Mun and Minmus for science" part).

The best part of KSP is that you can play it however you want. The second best part is the large number of opportunities to not be sensible :D

I don't think anyone builds long-range SSTOs because they're logical, but because they're an interesting challenge. Pushing real physics to its limit is essential in exploring space in the real world. The way I play KSP is to push the game's physics to its limit!

EDIT: And really, there are only small differences between a cargo SSTO and a distance SSTO. I'm pretty sure I can haul a 33%+ payload fraction to orbit with my 4,200dV-in-orbit design by switching out the nuke and replacing a bunch of fuel with cargo.

Yup, same designs will get the same payload fraction on LKO, be it nukes and fuel tanks, or a lander for an interplanetary stack. And as always, whatever you do in KSP is alright! It is a sandbox after all. Actually, while we are at it, let's put my money where my mouth is. This are the two things I am talking about, one thing is to be really efficient the easiest way possible:

WK1Or0a.png

While another is to look good while doing your thing:

w5tr5iT.png

The first one is an actual ship I'm using a lot in my career save. A reusable SSTO chemical 10mT payload booster that is dirt simple to fly, lofting a single stage lander with enough dV to get several biomes worth of science back. All reused except the cheap LFO, low tech, and simple. But eventually, when I have science out of my ears, the big beautiful plane is how I plan to loft big bulky payloads up to 20mT, and get the last few % out of a proper runway recovery:

Rune. KER gets weirded out by RAPIERs, BTW, but you can run temp fuel lines to get rocket dV readings.

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You can't discount just Rapiers either, 4 engines, 31t, 70km orbit with quite a bit of fuel to spare. It can get so fast it is in danger of exploding on ascent so I found keeping it just above mach 1 until you are above 10,000 leaves it with enough oomph for the dash to apoapsis. With the 4 Rapiers I don't see the pre-mach 1 slouch.

3y0eKOs.png

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Thanks! That is why I've started to put a rear-facing docking port on some on my winged SSTO designs, centred over the CoM: some of them are going to be transported (probably by payload they themselves lifted up) to Laythe, when I get enough of the tree unlocked to build them that is (right now I'm in the "mine Mun and Minmus for science" part).

On that theme, you mght get some useful ideas from this one...

Javascript is disabled. View full album

Pre-1.0 FAR design, but the idea translates to stock.

http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1809058&viewfull=1#post1809058

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The first one is an actual ship I'm using a lot in my career save. A reusable SSTO chemical 10mT payload booster that is dirt simple to fly, lofting a single stage lander with enough dV to get several biomes worth of science back. All reused except the cheap LFO, low tech, and simple.

That is one [very attractive] simple ship.

On that theme, you mght get some useful ideas from this one...

I've always liked making my big interplanetary ships into space trains. Dropping tanks off the back feels somehow more satisfying than radial decoupling.

Edited by Sattorin
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I can go both ways here, I found that most of my SSTO craft needed fine tuning when the update came out.

The R.A.I.P.E.R Is now almost required for SSTO craft which is good and bad for me, good because i can burn using the same engine without a manual switch. Although its Bad because it makes balancing LF+O much harder, not to mention engines now have thrust for when in vac and atmo. Fear not my friend, SSTO's are still alive, not as well as they used to be, but still alive.

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I'm not home till late Sunday but Monday I'll post up my craft for people to try out.

Weighs 61t

Can carry 5.8t to LKO with 3600dv remaining.

Has 2 rapiers, 4 turbojets and 2 nervas.

Easy climb off the runway using jets and rapiers, 18 degrees all the way. At 6km I light the nukes for extra oomph to get speed up and then turn off the nukes. Once I hit 17km I light the nukes again, and when the rapiers hit 170 kn I switch to closed cycle and close all the intakes, and at this point I'm going over 1300m/s. Burn until all o2 is gone, from then just the nukes are needed to circularize.

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Here's an attempt for a LF-only SSTO. 4 rapiers, 4 nukes (doh - with 2 I never made it to orbit)

~2k dV left in LKO, which should be at least enough to visit Mun or Minmus.

No payload yet. And the 4 nukes got REALLY hot on the burn to orbit - the precoolers did a great job with absorbing the heat, otherwise it would be SSTO BBQ.

AXCGcCR.png

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It definitely is! I just got a medium-size SSTO into LKO with 4,200 dV available. Going to fly it some place and post the pics after work!

That's pretty impressive! Can you tell us how you made it to orbit? Or is it something special with design? I think that you can easily make Single Stage to Laythe and back + cargo (5-8% of the start mass to Laythe surface) using Galileo style trajectory like Kerbin-Eve-Kerbin-Kerbin-Jool.

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Galileo style trajectory like Kerbin-Eve-Kerbin-Kerbin-Jool.

just wanted to jump in here to ask, how do you plan that? does it just work or would it take certain planetary alignments, how do you do it?

Edit:I semi understand gravity assists, but I dont get how to do multi planet ones in game.

Edited by r4pt0r
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just wanted to jump in here to ask, how do you plan that? does it just work or would it take certain planetary alignments, how do you do it?

Edit:I semi understand gravity assists, but I dont get how to do multi planet ones in game.

The planning for the launch window must be murder. I would be really interested if someone shows an easy way to do it!

Rune. It is pretty much the only maneuver I have yet to do in KSP, a planned double gravity assist.

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@r4pt0r I'm not sure if my english is enough good to explain it, but ok :wink:

First you should know is that Kerbin orbital period is 106 days 12h 30min (Earth time), so if you set first Kerbin flyby to increase your orbital period to 213days, 1hour (2x 106d, 12h, 30min) you will arrive at Kerbin in the same place, exactly 2 years later. After first flyby you should end up with ~11mln km Pe and ~30mln km Ap. It's very easy to calculate if your orbital period is exactly 2x Kerbin orbital period: Time to Ap less Time to Pe should equal 213d, 1h. You can make 1 hour error. Second flyby will be enough to raise your Ap to Jool orbit. Of course you will need some tweaking between two flybys: first to set your flyby on the proper position of Kerbin (dark side, bright side) to increase your velocity instead of decreasing, second to set proper Kerbin Periapsis: 500-600km should be enough, litle less and you will set your Aphelium too high.

Obviosuly the arrival time of your first Kerbin flyby have to be exactly 213 days before the middle of launch window from Kerbin to Jool. So your second arrival will be during the launch window.

Its very helpful to go to settings.cfg and set CONIC_PATCH_LIMIT TO 5 (default is 3). It will show you your next encounters, orbit parameters after encounters etc.

Ok, now you need to know how to perform first Kerbin flyby. To do this job you will employ Eve. I know a guy who can calculate this on his own (Von Ziegendorf, he has an account on this forum) but I'm using Flyby Finder. It's pretty useful tool to plan single flyby like Kerbin-Eve-Kerbin but unfortunately it has no abilities to calculate double flybys and deep space maneuvers (Cassini, Juno). Also there is no possibility to go efficiently to Jool/Jupiter using single Eve/Venus or Duna/Mars flyby.

There is full instruction how to use it: http://forum.kerbalspaceprogram.com/threads/80978-Flyby-Finder-for-KSP-V0-60

So let's assume that 512 day is good launch window to Jool. 512d - 213d, 1hour = 299d It means that your first Kerbin flyby have to be on 299 day. So go to the Flyby Finder and find Kerbin-Eve-Kerbin trajectory with Kerbin arrival on the 299 day. FF will show you Kerbin departure date, inclination of your parking orbit (yes, you will go into inclined orbit), prograde delta V of your transfer burn, Eve arrival date and closest encounter, then Kerbin arrival (it should be on 299 day)

look, here is good example:

pDaFoij.jpg

High Vz mean that you will start from highly inclined orbit (18 degrees in this case)

As you can see the second arrival is 299,01 day, you need to perform flyby to get orbital period 213d after it. So your second Kerbin flyby will be 299+213 = 512 day. And the 512 day is launch window to Jool!

That's how the full trajectory should look:

http://i.imgur.com/C6e34Wu.png

http://i.imgur.com/PTq3fj8.png

Obviously your first burn will be never 100% accurate, so you need little tweaking to get accurate Eve encounter date and Eve Periapsis. It's best to set up the radial and prograde velocities while 180 degrees from the target and normal velocities while 90 degrees from your destination. See the picture below:

fFLVv7r.jpg

I can go to Jool using only 1220m/s with this while the record is 1011m/s (Mun gravity assists and lots of crazy things), so it could be quite useful.

BTW how to make thumbnails?

Edited by winged
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  • 2 weeks later...

77569918972bd40733abc1577e899e510eb30999.jpg

This is my best shot of a 1.02 SSTO insofar. About 4850 DV left after achieving orbit. Seriously, this amount of DV could get us somewhere. I am not talking about a round trip though.:sticktongue:

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  • 4 weeks later...
Well as the title says, it appears that SSTOs are now completely dead. Im not saying it is impossible to actually SSTO, heck i have a working craft right now, but it feels that 1.0 has truly killed any viability in SSTOs, with the new drag increases. I know that its most likely more realistic, but common, i think even FAR is easier to work with now.

i think ssto's with the NERVA engine will be easier, because all you need now is liquid fuel (liquid hydrogen in real life). The NERVA actually works by a nuclear reactor, and liwuid hydrogen is used to cool down the engine, while being shooted out the back to give more thrust.

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Try to download and install this (it's totally free) simulator. There's a winged-SSTO in this program called the "DeltaGlider". If you can reach LEO with it, you'd have no trouble at all bringing almost any winged-SSTO in KSP v1.x.x to LKO.

This only means everything you knew about pre-1.0 aerodynamics, you have to throw out of the window, and learn a new one, that might not be so forgiving, but is actually closer to real-world aerodynamics.

http://orbit.medphys.ucl.ac.uk/

Well.... The DG runs on Handwavium. The thrust and ISP are completely unrealistic. You'd want to use a reconfigured XR2 for this demo.

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  • 2 weeks later...
Someone doesn't know what SSTO means.

SSTOs can be rockets.

It's Single Stage To Orbit, not single stage to mun and back.

And no they are not impossible. Far from it. A single Rapier with a fuel tank and some wings tacked on can do the job easily.

who cares about wings? i saw 4 parts ssto for 1.x

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Well as the title says, it appears that SSTOs are now completely dead. Im not saying it is impossible to actually SSTO, heck i have a working craft right now, but it feels that 1.0 has truly killed any viability in SSTOs, with the new drag increases.

I am using SSTO for almost all my LKO flight, just launching stations and sats frm the launchpad, any supply or kerbin transfer are done in SSTO. You just have to be more careful when building your SSTOs.

DC53DA3A0FDAFF4559DECFF511E557E3627C9D88

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  • 10 months later...

I made two SSTOs when I first downloaded 1.0.5 in December. One is a two-jet, single-rocket, the other is an overkill 4-jet, 2-rocket. Here's a link:

 

https://www.youtube.com/watch?v=upiil3LCwkQ

Yeah. It will get a suborbital trajectory and be on rockets in four minutes from starting the jets.

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2 hours ago, Vanamonde said:

This is a fairly old thread, and we're not on the same game version anymore. The thread will be closed now to avoid confusing folks with old information. 

@TheKosanianMethod, I suggest you make your own thread in the craft-sharing subforum

Oh, and, congrats on your successful plane. :)

Off to the subforum! Thanks, by the way. :)

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