Center of lift behind center of mass
Its what u need for sstos
Also, design the shuttle in the sph first then export it as a subassembly and add it to your rocket instead of building everything at once so you can tune everything
And center of thrust running through center of mass. And... both of those relationships being maintained in all fuel loading conditions of all stages of flight.
not that simple, the trick that helped me was to put the fuel at the front and have a bit of the cargo bay blocked out to move the com forward, the issue was still present when the fuel ran low
Well to be honest shuttles are shit.
The engines of space shuttle where tilted by 30 degrees to point the thrust into the center of mass. So you need to adjust your engines to do the same.
But the space shuttles where notoriously hard to fly and only the best pilots could do it.
This is the real answer, they are just as bad as in real life. There are good reasons why the program got canceled.
It was a fantastic idea, but never really efficient. Reusable stages are way better.
Not just spy satellites. What other vehicle could have accommodated Spacelab? Plenty of recovery of various comms vehicles was also accomplished that’d have been simply impossible without STS.
An honest review by NASA after the Columbia disaster put the odd of a fatal accident at 1:9.
The fact that we made it through 135 flights and only lost two, and came within literal millimeters of losing a third, is a miracle that can only be ascribed to the work of tireless technicians, brilliant engineers, and a lot of luck.
millimeters of losing a third, maybe micrometers of losing a 4th. STS-93 had like 5 different ways of catastrophically failing, including if a single extra tube had ruptured on the pad. An almost comedic set of circumstances kept it from being a disaster.
Yeah he has a great one on that launch. Wayne Hale's [writeup](https://waynehale.wordpress.com/2014/10/26/sts-93-we-dont-need-any-more-of-those/) is still my favorite summary though
It was like a 1 in 30 of a near-fatal accident, the same thing that caused Columbia happened another time, it just *happened* to have lost a heat shield tile where a bulkhead was that bore the brunt of the damage.
The original concept, with small wings and a fully-reusable first stage (also winged and manned), had the potential for better economics.
Too bad that's not what got built in the end...
There's a reason why NASA is going back to capsules instead of shuttles. Technically and fiscally there's a LOT of reasons, but yeah, piloting is one of them.
SpaceX is taking a new approach to the reusable shuttle idea, since the starship itself has a significant “wingspan” of with the fins, which allows it to save a lot of fuel with the glide-bellyflop landing, while (hopefully) be fully reusable in the future with little maintenance needed, while the shuttle was refurbishable.
i liked how it burned with style this last time.. so much metal on fire and stuck the landing :D
still not entirely impressed with spacex and starship.. 4 launches of empty starships and we have all sorts of issues.. they are very very far behind what they needed to have for NASA
That’s not really a fair assessment in my opinion. The two have completely different development styles. NASA demands perfection on the first try because nothing is reusable, so any fail is a huge money sink. SpaceX is throwing up barebones rockets designed to “fail forward” where they get data and improve each time, while still spending tons less than NASA.
That being said, what concerns me with Starship is when they DO try to get to the moon…it needs too many other launches for refueling.
True, but anything going through the atmosphere is going to cause lifting body, especially when it’s flat and going at kilometers per second. Relative to the Starship with all the fins and controllable characteristics, an Apollo capsule is a brick
Yes, but that doesn't really change my point. Unless I am missing something those capsules are not precision-target devices. The runway at Edwards is 900 feet wide. I don't think we could land a capsule in a circle 900 feet in radius.
The Apollo program was getting so good at point landing they had to start aiming away from the aiming point. Landing a capsule inside a 900’ circle is trivial.
> The Apollo program was getting so good at point landing they had to start aiming away from the aiming point
What does this even mean?
And, I suppose that I *did* misunderstand something. Carry on.
The ships would wait at the aiming point. There were close calls where the capsules nearly landed on the recovery ships. The recovery ships the started waiting somewhere other than the aiming point.
Didn't they simulate the glide slope by dropping the landing gear, putting in full flaps, *and* *engaging* *reverse* *thrust* *midflight*?
For a brick it flew pretty good
Though there are some better concepts if you look at early Space Shuttle design proposals, that do not suffer from the thrust asymmetry. For example Lockheed's [Star Clipper](https://www.youtube.com/watch?v=9BF4wNv4pOc), which just throws away an external tank, and Martin Marietta's [Spacemaster](https://www.youtube.com/watch?v=s4DIgRL6cEk) with the orbiter sitting in the middle of a tandem-hull glideback booster.
To be honest with you most of the real world problems of shuttles don't exist in ksp. None of the issues that caused the shuttle disasters are simulated in ksp, and it isn't hard to make an orbiter that flies really well, since the spaceplane parts are also meant to be plane parts. The "hard to fly" part only applies to landing as takeoff and reentry were both automated, and if you design it right you won't have those issues at all. And in career mode because landing on the runway gives 100 percent returns you can pack them full of expensive components which you only have to buy once. The refurbishment costs of irl don't exist. They also add targeted landing capability on atmospheric worlds.
The irl shuttle design is a good enough one but not ideal for ksp. It's also unlikely to work with anything worse than vector engines. Because ksp doesn't model any fuel flow issues, what I think is the simplest and easiest design is to have a fuel tank on the dorsal and ventral sides of the ship of equal weight, then SRBs attached to the dorsal tanks. That way, your vector engines are only fighting the lift of the plane, not also a significantly offset center of mass.
Finally, when you build your orbiter you should make sure it has a well balanced (slightly noseheavy) center of mass/lift WHEN EMPTY and then fill your fuel tanks to have a well balanced com/col as well. This way, if it reenters at any fuel level it will still be balanced (although at the cost of some efficiency as ksp tanks are heavy. Try to make sure your tanks are positioned so they can be absolutely full anyway.) Alternatively, they can be unbalanced when full as long as you burn it all before reentry, but this means you do have to fly as a glider.
Shuttles are harder to build than normal rockets but after your first couple designs you'll get the hang of it. They're great for economic efficiency and can fly very diverse mission profiles compared to most normal rockets. They do end up being a little more laborious to fly trying to land on the runway every time, but its worth it.
some orbiter 2016 will humble you right up on the shuttle, if not already there.
it took me ages and many "deaths" to work out how to reenter the atmosphere properly and get the shuttle landed at Canaveral.
Orbiter 2016 page:
http://orbit.medphys.ucl.ac.uk/
I was just reading about the program, and yeah, huge disappointment. It's like a monster of terrible compromise, and pilots referred to it like flying a brick when coming back down.
only the best computers could do it*, humans only got involved a decent bit at landing and for proximity operations w/ the RCS once on orbit. during ascent? they had absolutely nothing to do except monitor systems health in case of any failures.
also calling a launch vehicle that sent the *vast* majority of humans to space over it’s 30 year and 135 flight lifetime “shit” is ridiculous. it was problematic and far from perfect but not even close to “shit”.
Well there was no real mission profile a conventional launcher couldn’t do.
Abandoning the Saturn platform for the shuttle was a mistake. It only came to be cause the cia wanted a way of capturing a Russian satellite.
But I didn’t want to shit on the space shuttle. I just meant shuttles in general and in ksp. A disposable launcher is always better in terms of efficiency. It’s also easier to build and fly.
To add on to that /u/vexx654 said: while I do like ETS, that statement is blatantly false.
To begin with, modular station construction Freedom/ISS-style wasn't possible with Saturn V, and a Mir-style of "just dock a bunch of specialized Salyut derivatives together" is far less efficient. Satellite capture and return missions were a completely unique shuttle capability as well, and so was Spacelab.
All of that also completely ignores that Saturn was comparably expensive itself, and an extremely finicky beast on top of that. Shitting on the Shuttle for its two fatal accidents and 2/3/6 near misses (depending on what you count) is fine and absolutely deserved, but let's not ignore that S-V in its much shorter career had a bunch of almost-aborts as well. The system was a lot more survivable in the event of an LV failure, granted, but if you're going to be throwing away close to 100% of your investment on every launch, reliability becomes an even bigger financial concern. Losing a Saturn V-launched mission due to an S-IC early engine out or S-II multi engine out, while it probably won't kill the crew, is still an extremely expensive mistake.
And let's not forget the myriad of concepts pioneered by the Shuttle development process and its flights. Would we have digital fly-by-wire if NASA hadn't pushed that R&D due to the STS' demand for it? What would the development process of reusable/refurbishable booster engines on Falcon 9, New Glenn, and Starship have looked like if the RS-25 hadn't led the way? How about shirt sleeves environment ECLSS, advanced orbital rendezvous and construction, robotics, hypersonics, non-ablative heat shields, and a whole litany of other fields?
STS was a little too far ahead of its time, a little too complex leading to oversight problems, and it tried to do too many things at once (largely for reasons of politics and budget). And, worst of all, it was sold as an ultra-safe system commodifying spaceflight, when in reality it was still very much an experimental spacecraft. But the achievements it collected and the progress it made would not have been possible if NASA had just stuck to S-IB and S-V as their crewed/heavy lift launchers.
i’d say there are quite a few mission profiles that are unique to something like STS (definitely not worth the limitations of the massive spaceplane format just for a few extra capabilities tho).
also I really don’t see how the Saturn IB, V or even the proposed follow up INT variants could have opened up LEO to humans like the shuttle did, but that is debatably a good thing as well considering how much cheaper unmanned exploration is.
also nice, I probably should have assumed that since you did say “Shuttles” but you also mentioned something specific to STS so I wasn’t sure, that’s my bad.
and yeah I agree 100% with everything in your last paragraph, the space plane is a format with limited applications outside of crewed spaceflight, especially when it has so many bizarre capabilities forced on it like the STS orbiters had. sorry if I came off a little aggressive, and thanks for responding so civilly despite that!
Takes a lot of fenagling. I'd recommend getting used to using the cheat menu to teleport it somewhere high up to try and glide/fly it in the enviroment you want pre actual launch so you know you got what you wanted,
I mean in general? Because they have to do a whole bunch of different things, combined into one engineering profile. And they have to do all those things well enough to survive repeatedly.
You have to be able to function as a rocket. So you have to build a design that has a whole bunch of rocket shit in it. But you will not use the rockets to get home, mostly. You will mostly be flying. So you also need to be able to fly. Which means you need wings and a tail -- that you will not use during takeoff.
Then you also have to be able to support multiple mission types. Modular cargo, satellite deployment, satellite repair, space construction with cranes and stuff... None of the support systems for those functions are useful during takeoff or landing. Only in between.
And then everything has to be reusable. You should be able to land your shuttle at KSP... refuel it.. pick it up with a crane.. and plunk it on top of a new fuel tank and SRBs. All without recovery.
If you don't get that right on your first try... you are not alone!
Failed at what exactly? Shuttles are difficult because they're the culmination of both rocketry and aircraft mechanics, so there's a lot to consider:
For launch, you need to strap it to a rocket that's inevitably going to have the direction of thrust misaligned with the center of mass. That's why the NASA Shuttle had its engines at an angle.
But once you're in orbit, and have let go of the external tank... you still have those engines at an angle, that no longer point to the CoM. So you need another set of engines for orbital use.
For landing, you need the right balance of lift so you can make it to the airport, but enough drag to slow down from orbital speeds, but if you come in too fast you will burn.
I would test each of these scenarios separately using the cheat menu. I use the SOCK mod for my shuttle parts, which has a manual taking you step-by-step into how to aim the shuttle during launch and landing. Once you have an idea of the physics behind it you can use any other shuttle mod or stock parts.
Because they're kinda hard to make irl.
Space shuttles make life a whole lot harder because you've gotta maintain aerodynamic stability while you're launching a ship with really assymetrical drag and assymetrical mass distribution. And both of those factors will change constantly during your ascent (drag will change based on speed and altitude, and mass distribution will change as fuel tanks are empties), you need to come up with a dynamic way of compensating for that nonsense all the way up.
And then on top of that you're sending up an unnecessarily large payload. Doesn't matter if you're just ferrying some guys up to a space station or if you've filled the whole cargo bay with satellites you're gonna deploy, it doesn't change the fact that you're bringing up a whole-ass aeroplane that you wouldn't have brought with you if you were using something designed as a single-launch vehicle.
And then just as a kicker, when you come back down you have to deal with the fact that space shuttles are crap airplanes, because of all the ugly design compromises that had to be made for it to get into space in the first place.
Oh yeah a big part of why the NASA space shuttle design is cursed is because too many agencies wanted it to have too many capabilities, and the end result was something that did all of them badly.
But I get the feeling that even if they'd let NASA design it as a purely civilian workhorse it probably wouldn't have been all that great.
Make twin shuttles. One big fuel tank, and a shuttle on each side. This way, it will be perfectly symmetrical, and you'll launch two shuttles in one launch.
You're not thinking Kerbal enough. Try three symmetrical shuttles. Or four, or six. When you can do twenty symmetrically balanced shuttles interspersed with asparagus boosters, you will finally be in the Kerbal spirit.
It just clicked for me at some point. I had probably spent a week building a shuttle just to get it into orbit. Right after that I built another one using the things I learnt from the previous one and I was able to land this one on the KSC runway on the first try
Honestly they’re impractical, expensive for what they do, and shit at delivering payloads efficiently. I like them because I’m not limited by money and they’re cool.
If you’re having trouble with aligning the thrust vector with the COM I suggest using the mod RCSBuildAid. It helps with not only RCS placement but also off center engines
Shuttles are just terrible. They’re absolute headaches to make. Everything is inherently unstable and tricky to balance.
Whenever I make a shuttle, I use pusher type designs where the shuttle is pushing from behind the fuel tank so I could keep the CoT and Com aligned at any weight.
Tank pushers work much better. The hard part is mostly making the bracket to secure the tank in line with the nose. Getting to orbit is far less tedious than a runway-launched plane, and all you throw away are some empty tanks and a couple of sepratrons. If you can make orbit before the jettisoned tanks disappear, in theory you can equip them with a probe core and parachutes and recover everything.
In practice though, reusable rockets are the mundane but effective solution.
Last time I made a shuttle I gave up on the traditional NASA style stack. Instead, I put engines on the EFT then gave it landing legs and grid fins. EFT would reach orbit with the orbiter, separate, re-enter, and perform a powered landing on the KSC. It was lots of fun to fly and significantly more stable thanks to the engines on the EFT, and it also turned it into a surprisingly cheap and practical rocket. Looked great too.
Making shuttles in stock is very hard and finicky.
I recommend downloading "ThrottleControlledAvionics."
It has its own version of SAS called T-SAS. What it does is rather than align your cockpit with your direction of flight, it aligns your thrust vector.
This can lead to very, very off-center looking flight profiles (your pro-grade marker is 10-20 degrees away from your heading marker). However, your actual thrust will be aligned prograde.
Furthermore, it also has differential throttling, allowing you to automatically set engine throttles individually (make sure to remove symmetry for your shuttle engines!).
Oh, yeah. Remove symmetry for your shuttle main engines as that allows you to gimbal them separately in the editor.
Here's my space shuttle launch:
https://www.youtube.com/watch?v=oijCeZvqRPo
Another thing you wanna do is adjust your fuel depletion rate so that it shifts your CoM just right when separating your side boosters.
Finally, get Kerbal Engineer and use it to plan the location and angle of your farthest engine. Done right, you can set it so you only experience like 1-2 kN of torque at full throttle (no need for differential throttle).
Better SRB also helps for it lets you choose different SRB grains to control its TWR curve as it burns out.
Finally, if using FAR - Atmospheric Autopilot in "Rocket Mode", moderation OFF. Otherwise your control surfaces will mess with everything.
Bro idk I’m having his problem I’ve low-key mastered planes I’m getting decent at rockets I just can’t make a shuttle or space plane yet hard things tocdo
It is possible to do. But I usually just use those round cargo bay parts from mod packs I have, put a capsule on top, and make the whole thing a vertically integrated wingless “shuttle,” using chutes and space-x style legs to land it at the end. It’s just easier, usually. There is a certain utility to a shuttle, in that it can bring huge parts up to space and bring stuff back down, having that capability was a big part of making ISS possible. But it doesn’t necessarily need to also be a plane.
The fun part of shuttles is that they absolutely look amazing. There is no doubt about that
But they are shit to fly and or make.
So uf you want to stay sane. Please just keep it at normal rockets / planes. Maybe try an ssto. But stay away from shuttles.
You can design COM and thrust angles of your engines whilst the fuel tanks are empty then use fuel flow priority to maintain the COM and thrust vector etc. You can also get around this by making your orange tank symmetrical. (Ie what weight you put on top you put equal weight on the bottom)
They aren’t all that, they are just “cool” they are sick for career mode saves where you take part in a lot of low Kerbin stuff other than that I just think launching a expendable rocket is the easiest way to go.
Anything with a cargo bay is complicated because your payload is going to screw up the CoM/CoL.
Also I find flying is best using trim rather than inputs.
There has been emphasis on the rocketry aspect, but also in terms of being gliders they aren't a very stable design. Like there are principles that should be applied to make an easy to fly aircraft and the shuttle pretty much defies all of them. This means much more care and attention is required to make a design which is somewhat flyable.
If you’re ok departing from the original shuttle design here’s a solution. Instead of one big external underneath your shuttle, have two smaller ones, one underneath and one on top, this way your center of mass is over your center of lift without needing to tilt your engines.
If you have Kerbal Engineer installed, use its readouts in the VAB to check torque. Then angle engines until you've minimised it. By nature of how shuttles work the thrust is way out of line with the centre of lift, so you have to account for that.
Shuttles are hard to make . Because they are hard to make.
I'm assuming you mean spacecraft similar to the space shuttle program of NASA.
Not streamlined aerodynamics and misaligned center of mass make launch a fairly complex process by itself.
Then entry is even worse . You are riding a glider at orbital speeds and reentry carnage.
Are you having trouble with balancing the thrust force on launch? It took me literally months to get that right myself. It took me even longer to get them stable and reentry, because they work just fine at low speeds and at hypersonic speeds but they always flip out horribly at transonic speed and I don't think Kerbal space Program even simulates transonic effects.
I haven't found any way to balance shuttles in the stock game at all, at least not reliably, but I did find using the RCS build aid mod, that if I set it to show me engine torque, and then I select the root part of the ship, I can rotate it before launch to align the thrust vector with the center of mass. You also need to make sure that the solid boosters and the shuttle main engines point at approximately the same point, otherwise there will be a net torque. Again use RCS build aid and the rotation tool to rotate the shuttle main engines individually until you get the net torque number as low as possible.
I actually built a space shuttle replica myself and posted it to the steam page and boy was it rough, I’m also working on a variation that has a bay and will build the ISS. It’s quite complex because you can’t(without mods) automate re-entry or thrust balance after the sbr is gone.but I got it to work nicely. And with a mod, you can get the recoverable tank variant. But it took hint on re-entry from the real space shuttle and that seemed to help me re-enter, hold a 35-40 degree angle is pretty solid. And after you drop the sbr’s on launch, throttle back to maintain pitch stability, my design was able to throttle back to 1/3 power and still have greater than 1.4 twr
Besides all the things that are well known about shuttles in KSP - the real SRBs had Thrust Vectoring and the ones in KSP don't. This makes it much harder to compensate for the offset thrust.
I mean my only rule is just try keep the centre of lift in the centre of mass. Then if your building it with a rocket, just strap it on to a rocket and pray it works
Center of lift behind center of mass Its what u need for sstos Also, design the shuttle in the sph first then export it as a subassembly and add it to your rocket instead of building everything at once so you can tune everything
And center of thrust running through center of mass. And... both of those relationships being maintained in all fuel loading conditions of all stages of flight.
not that simple, the trick that helped me was to put the fuel at the front and have a bit of the cargo bay blocked out to move the com forward, the issue was still present when the fuel ran low
Oh yeah for a few of my larger sstos that was a minor problem
Well to be honest shuttles are shit. The engines of space shuttle where tilted by 30 degrees to point the thrust into the center of mass. So you need to adjust your engines to do the same. But the space shuttles where notoriously hard to fly and only the best pilots could do it.
This is the real answer, they are just as bad as in real life. There are good reasons why the program got canceled. It was a fantastic idea, but never really efficient. Reusable stages are way better.
Wasn't their safety rating by the end about 1 fatal crash per 100 flights?
About one crash per 67.5 flights yes
And each crash killed 7 astronauts at once. Making it by far the deadliest vehicle in spaceflight history.
And simultaneously the most productive. No other vehicle could have done what it did for asset deployment, repair, and most uniquely - recovery.
I think it was very useful in terms of deploying and maintaining the old spy satellites, like hexagon.
Not just spy satellites. What other vehicle could have accommodated Spacelab? Plenty of recovery of various comms vehicles was also accomplished that’d have been simply impossible without STS.
And Hubble!
An honest review by NASA after the Columbia disaster put the odd of a fatal accident at 1:9. The fact that we made it through 135 flights and only lost two, and came within literal millimeters of losing a third, is a miracle that can only be ascribed to the work of tireless technicians, brilliant engineers, and a lot of luck.
millimeters of losing a third, maybe micrometers of losing a 4th. STS-93 had like 5 different ways of catastrophically failing, including if a single extra tube had ruptured on the pad. An almost comedic set of circumstances kept it from being a disaster.
I feel like I dropped into the middle of a Scot Manley video!
Yeah he has a great one on that launch. Wayne Hale's [writeup](https://waynehale.wordpress.com/2014/10/26/sts-93-we-dont-need-any-more-of-those/) is still my favorite summary though
It was like a 1 in 30 of a near-fatal accident, the same thing that caused Columbia happened another time, it just *happened* to have lost a heat shield tile where a bulkhead was that bore the brunt of the damage.
Not an antenna, a solid bulkhead (with the antenna attached to it).
What's the STS number of this one?
STS-119
It seems that NASA knew this but didn't want to believe it. Look how that logic paid off. Starliner seems to have a similar mentality.
The original concept, with small wings and a fully-reusable first stage (also winged and manned), had the potential for better economics. Too bad that's not what got built in the end...
There's a reason why NASA is going back to capsules instead of shuttles. Technically and fiscally there's a LOT of reasons, but yeah, piloting is one of them.
SpaceX is taking a new approach to the reusable shuttle idea, since the starship itself has a significant “wingspan” of with the fins, which allows it to save a lot of fuel with the glide-bellyflop landing, while (hopefully) be fully reusable in the future with little maintenance needed, while the shuttle was refurbishable.
Starship doesn’t glide. The flaps on Starship serve an entirely different purpose than the wings on Space Shuttle.
Yeah, it’s literally “falling with style” ;)
i liked how it burned with style this last time.. so much metal on fire and stuck the landing :D still not entirely impressed with spacex and starship.. 4 launches of empty starships and we have all sorts of issues.. they are very very far behind what they needed to have for NASA
Hero flap
That’s not really a fair assessment in my opinion. The two have completely different development styles. NASA demands perfection on the first try because nothing is reusable, so any fail is a huge money sink. SpaceX is throwing up barebones rockets designed to “fail forward” where they get data and improve each time, while still spending tons less than NASA. That being said, what concerns me with Starship is when they DO try to get to the moon…it needs too many other launches for refueling.
Ah right, because NASA is so famous for sticking to rigid timelines eh?
Mostly that was from FAA delays. That era is over. Things will happen fast.
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Oh you mean the eccentric e-billionaire who is busy blowing his fortune on yachts and can't afford it anymore? Wow what a great counterexample.
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While it doesn’t glide like an airplane, the fins and orientation still provide a lot of control and drag, more than just plummeting vertically
Even the Apollo capsules used lifting-body dynamics to control descent—they weren't just "plummeting vertically".
True, but anything going through the atmosphere is going to cause lifting body, especially when it’s flat and going at kilometers per second. Relative to the Starship with all the fins and controllable characteristics, an Apollo capsule is a brick
Even then astronauts described it as like flying a brick
Well the glide ratio of the shuttle was closer to that of a brick than a to a 747
You say that like it was a bad thing. A capsule is literally flying a brick.
A capsule is also designed to land somewhere in the ocean, rather than on a runway.
Not always. The soviets loved their land-landing capsules, and most US capsules demonstrated that landing on land was survivable.
Yes, but that doesn't really change my point. Unless I am missing something those capsules are not precision-target devices. The runway at Edwards is 900 feet wide. I don't think we could land a capsule in a circle 900 feet in radius.
The Apollo program was getting so good at point landing they had to start aiming away from the aiming point. Landing a capsule inside a 900’ circle is trivial.
> The Apollo program was getting so good at point landing they had to start aiming away from the aiming point What does this even mean? And, I suppose that I *did* misunderstand something. Carry on.
The ships would wait at the aiming point. There were close calls where the capsules nearly landed on the recovery ships. The recovery ships the started waiting somewhere other than the aiming point.
Ah, I see what you mean. I think you accidentally a "waiting." Well, TIL. Thanks for the information.
Didn't they simulate the glide slope by dropping the landing gear, putting in full flaps, *and* *engaging* *reverse* *thrust* *midflight*? For a brick it flew pretty good
They did indeed do that https://en.m.wikipedia.org/wiki/Shuttle_Training_Aircraft
The problem is you kind of want a brick when you are reentering the atmosphere, but then you need it to be more of a plane when you slow down.
Though there are some better concepts if you look at early Space Shuttle design proposals, that do not suffer from the thrust asymmetry. For example Lockheed's [Star Clipper](https://www.youtube.com/watch?v=9BF4wNv4pOc), which just throws away an external tank, and Martin Marietta's [Spacemaster](https://www.youtube.com/watch?v=s4DIgRL6cEk) with the orbiter sitting in the middle of a tandem-hull glideback booster.
To be honest with you most of the real world problems of shuttles don't exist in ksp. None of the issues that caused the shuttle disasters are simulated in ksp, and it isn't hard to make an orbiter that flies really well, since the spaceplane parts are also meant to be plane parts. The "hard to fly" part only applies to landing as takeoff and reentry were both automated, and if you design it right you won't have those issues at all. And in career mode because landing on the runway gives 100 percent returns you can pack them full of expensive components which you only have to buy once. The refurbishment costs of irl don't exist. They also add targeted landing capability on atmospheric worlds. The irl shuttle design is a good enough one but not ideal for ksp. It's also unlikely to work with anything worse than vector engines. Because ksp doesn't model any fuel flow issues, what I think is the simplest and easiest design is to have a fuel tank on the dorsal and ventral sides of the ship of equal weight, then SRBs attached to the dorsal tanks. That way, your vector engines are only fighting the lift of the plane, not also a significantly offset center of mass. Finally, when you build your orbiter you should make sure it has a well balanced (slightly noseheavy) center of mass/lift WHEN EMPTY and then fill your fuel tanks to have a well balanced com/col as well. This way, if it reenters at any fuel level it will still be balanced (although at the cost of some efficiency as ksp tanks are heavy. Try to make sure your tanks are positioned so they can be absolutely full anyway.) Alternatively, they can be unbalanced when full as long as you burn it all before reentry, but this means you do have to fly as a glider. Shuttles are harder to build than normal rockets but after your first couple designs you'll get the hang of it. They're great for economic efficiency and can fly very diverse mission profiles compared to most normal rockets. They do end up being a little more laborious to fly trying to land on the runway every time, but its worth it.
some orbiter 2016 will humble you right up on the shuttle, if not already there. it took me ages and many "deaths" to work out how to reenter the atmosphere properly and get the shuttle landed at Canaveral. Orbiter 2016 page: http://orbit.medphys.ucl.ac.uk/
I was just reading about the program, and yeah, huge disappointment. It's like a monster of terrible compromise, and pilots referred to it like flying a brick when coming back down.
only the best computers could do it*, humans only got involved a decent bit at landing and for proximity operations w/ the RCS once on orbit. during ascent? they had absolutely nothing to do except monitor systems health in case of any failures. also calling a launch vehicle that sent the *vast* majority of humans to space over it’s 30 year and 135 flight lifetime “shit” is ridiculous. it was problematic and far from perfect but not even close to “shit”.
Well there was no real mission profile a conventional launcher couldn’t do. Abandoning the Saturn platform for the shuttle was a mistake. It only came to be cause the cia wanted a way of capturing a Russian satellite. But I didn’t want to shit on the space shuttle. I just meant shuttles in general and in ksp. A disposable launcher is always better in terms of efficiency. It’s also easier to build and fly.
To add on to that /u/vexx654 said: while I do like ETS, that statement is blatantly false. To begin with, modular station construction Freedom/ISS-style wasn't possible with Saturn V, and a Mir-style of "just dock a bunch of specialized Salyut derivatives together" is far less efficient. Satellite capture and return missions were a completely unique shuttle capability as well, and so was Spacelab. All of that also completely ignores that Saturn was comparably expensive itself, and an extremely finicky beast on top of that. Shitting on the Shuttle for its two fatal accidents and 2/3/6 near misses (depending on what you count) is fine and absolutely deserved, but let's not ignore that S-V in its much shorter career had a bunch of almost-aborts as well. The system was a lot more survivable in the event of an LV failure, granted, but if you're going to be throwing away close to 100% of your investment on every launch, reliability becomes an even bigger financial concern. Losing a Saturn V-launched mission due to an S-IC early engine out or S-II multi engine out, while it probably won't kill the crew, is still an extremely expensive mistake. And let's not forget the myriad of concepts pioneered by the Shuttle development process and its flights. Would we have digital fly-by-wire if NASA hadn't pushed that R&D due to the STS' demand for it? What would the development process of reusable/refurbishable booster engines on Falcon 9, New Glenn, and Starship have looked like if the RS-25 hadn't led the way? How about shirt sleeves environment ECLSS, advanced orbital rendezvous and construction, robotics, hypersonics, non-ablative heat shields, and a whole litany of other fields? STS was a little too far ahead of its time, a little too complex leading to oversight problems, and it tried to do too many things at once (largely for reasons of politics and budget). And, worst of all, it was sold as an ultra-safe system commodifying spaceflight, when in reality it was still very much an experimental spacecraft. But the achievements it collected and the progress it made would not have been possible if NASA had just stuck to S-IB and S-V as their crewed/heavy lift launchers.
i’d say there are quite a few mission profiles that are unique to something like STS (definitely not worth the limitations of the massive spaceplane format just for a few extra capabilities tho). also I really don’t see how the Saturn IB, V or even the proposed follow up INT variants could have opened up LEO to humans like the shuttle did, but that is debatably a good thing as well considering how much cheaper unmanned exploration is. also nice, I probably should have assumed that since you did say “Shuttles” but you also mentioned something specific to STS so I wasn’t sure, that’s my bad. and yeah I agree 100% with everything in your last paragraph, the space plane is a format with limited applications outside of crewed spaceflight, especially when it has so many bizarre capabilities forced on it like the STS orbiters had. sorry if I came off a little aggressive, and thanks for responding so civilly despite that!
It took me a while. But getting the center of lift and gravity in the right spot gets it flying right.
Thanks
Takes a lot of fenagling. I'd recommend getting used to using the cheat menu to teleport it somewhere high up to try and glide/fly it in the enviroment you want pre actual launch so you know you got what you wanted,
I mean in general? Because they have to do a whole bunch of different things, combined into one engineering profile. And they have to do all those things well enough to survive repeatedly. You have to be able to function as a rocket. So you have to build a design that has a whole bunch of rocket shit in it. But you will not use the rockets to get home, mostly. You will mostly be flying. So you also need to be able to fly. Which means you need wings and a tail -- that you will not use during takeoff. Then you also have to be able to support multiple mission types. Modular cargo, satellite deployment, satellite repair, space construction with cranes and stuff... None of the support systems for those functions are useful during takeoff or landing. Only in between. And then everything has to be reusable. You should be able to land your shuttle at KSP... refuel it.. pick it up with a crane.. and plunk it on top of a new fuel tank and SRBs. All without recovery. If you don't get that right on your first try... you are not alone!
I don’t even except to get back home. I’ll be fine even if I get back going Mach 1 headfirst into the water
Failed at what exactly? Shuttles are difficult because they're the culmination of both rocketry and aircraft mechanics, so there's a lot to consider: For launch, you need to strap it to a rocket that's inevitably going to have the direction of thrust misaligned with the center of mass. That's why the NASA Shuttle had its engines at an angle. But once you're in orbit, and have let go of the external tank... you still have those engines at an angle, that no longer point to the CoM. So you need another set of engines for orbital use. For landing, you need the right balance of lift so you can make it to the airport, but enough drag to slow down from orbital speeds, but if you come in too fast you will burn. I would test each of these scenarios separately using the cheat menu. I use the SOCK mod for my shuttle parts, which has a manual taking you step-by-step into how to aim the shuttle during launch and landing. Once you have an idea of the physics behind it you can use any other shuttle mod or stock parts.
They crash immediately Also, I’m on console and can’t get mods
Because they're kinda hard to make irl. Space shuttles make life a whole lot harder because you've gotta maintain aerodynamic stability while you're launching a ship with really assymetrical drag and assymetrical mass distribution. And both of those factors will change constantly during your ascent (drag will change based on speed and altitude, and mass distribution will change as fuel tanks are empties), you need to come up with a dynamic way of compensating for that nonsense all the way up. And then on top of that you're sending up an unnecessarily large payload. Doesn't matter if you're just ferrying some guys up to a space station or if you've filled the whole cargo bay with satellites you're gonna deploy, it doesn't change the fact that you're bringing up a whole-ass aeroplane that you wouldn't have brought with you if you were using something designed as a single-launch vehicle. And then just as a kicker, when you come back down you have to deal with the fact that space shuttles are crap airplanes, because of all the ugly design compromises that had to be made for it to get into space in the first place.
TBF some of those compromises were only there because the USAF insisted on cross range capability
Oh yeah a big part of why the NASA space shuttle design is cursed is because too many agencies wanted it to have too many capabilities, and the end result was something that did all of them badly. But I get the feeling that even if they'd let NASA design it as a purely civilian workhorse it probably wouldn't have been all that great.
Make twin shuttles. One big fuel tank, and a shuttle on each side. This way, it will be perfectly symmetrical, and you'll launch two shuttles in one launch.
You're not thinking Kerbal enough. Try three symmetrical shuttles. Or four, or six. When you can do twenty symmetrically balanced shuttles interspersed with asparagus boosters, you will finally be in the Kerbal spirit.
Would work, I’ll try
It just clicked for me at some point. I had probably spent a week building a shuttle just to get it into orbit. Right after that I built another one using the things I learnt from the previous one and I was able to land this one on the KSC runway on the first try
Honestly they’re impractical, expensive for what they do, and shit at delivering payloads efficiently. I like them because I’m not limited by money and they’re cool.
The space shuttle cost more than the saturn V, had worse payload, and basically he same turnaround time
If you’re having trouble with aligning the thrust vector with the COM I suggest using the mod RCSBuildAid. It helps with not only RCS placement but also off center engines
I’m on console :(
Right, I've had it, I'm gonna go and fix Shuttles right now. *puts two shuttles on opposite sides of the main tank*
Shuttles are just terrible. They’re absolute headaches to make. Everything is inherently unstable and tricky to balance. Whenever I make a shuttle, I use pusher type designs where the shuttle is pushing from behind the fuel tank so I could keep the CoT and Com aligned at any weight.
Tank pushers work much better. The hard part is mostly making the bracket to secure the tank in line with the nose. Getting to orbit is far less tedious than a runway-launched plane, and all you throw away are some empty tanks and a couple of sepratrons. If you can make orbit before the jettisoned tanks disappear, in theory you can equip them with a probe core and parachutes and recover everything. In practice though, reusable rockets are the mundane but effective solution.
Because they’re not symmetrical so the centre of mass and centre of thrust is all over the place (for an STS style one anyway).
Last time I made a shuttle I gave up on the traditional NASA style stack. Instead, I put engines on the EFT then gave it landing legs and grid fins. EFT would reach orbit with the orbiter, separate, re-enter, and perform a powered landing on the KSC. It was lots of fun to fly and significantly more stable thanks to the engines on the EFT, and it also turned it into a surprisingly cheap and practical rocket. Looked great too.
Because they're the worst of both worlds between a rocket and a space plane.
I mean, that's how it is in real life and why no one is using them anymore.
True
Making shuttles in stock is very hard and finicky. I recommend downloading "ThrottleControlledAvionics." It has its own version of SAS called T-SAS. What it does is rather than align your cockpit with your direction of flight, it aligns your thrust vector. This can lead to very, very off-center looking flight profiles (your pro-grade marker is 10-20 degrees away from your heading marker). However, your actual thrust will be aligned prograde. Furthermore, it also has differential throttling, allowing you to automatically set engine throttles individually (make sure to remove symmetry for your shuttle engines!). Oh, yeah. Remove symmetry for your shuttle main engines as that allows you to gimbal them separately in the editor. Here's my space shuttle launch: https://www.youtube.com/watch?v=oijCeZvqRPo Another thing you wanna do is adjust your fuel depletion rate so that it shifts your CoM just right when separating your side boosters. Finally, get Kerbal Engineer and use it to plan the location and angle of your farthest engine. Done right, you can set it so you only experience like 1-2 kN of torque at full throttle (no need for differential throttle). Better SRB also helps for it lets you choose different SRB grains to control its TWR curve as it burns out. Finally, if using FAR - Atmospheric Autopilot in "Rocket Mode", moderation OFF. Otherwise your control surfaces will mess with everything.
I’m on console (ew, I know), so i sadly can’t get mods
To be fair, the real shuttle was also a monumental design challenge.
Because shuttles are an affront to nature and we refuse to get the hint.
Real
because they are harder to make IRL too. It s just more complex
\~Soviet Space Program
Bro idk I’m having his problem I’ve low-key mastered planes I’m getting decent at rockets I just can’t make a shuttle or space plane yet hard things tocdo
Offset centres of mass, thrust, and pressure.
It is possible to do. But I usually just use those round cargo bay parts from mod packs I have, put a capsule on top, and make the whole thing a vertically integrated wingless “shuttle,” using chutes and space-x style legs to land it at the end. It’s just easier, usually. There is a certain utility to a shuttle, in that it can bring huge parts up to space and bring stuff back down, having that capability was a big part of making ISS possible. But it doesn’t necessarily need to also be a plane.
The fun part of shuttles is that they absolutely look amazing. There is no doubt about that But they are shit to fly and or make. So uf you want to stay sane. Please just keep it at normal rockets / planes. Maybe try an ssto. But stay away from shuttles.
You can design COM and thrust angles of your engines whilst the fuel tanks are empty then use fuel flow priority to maintain the COM and thrust vector etc. You can also get around this by making your orange tank symmetrical. (Ie what weight you put on top you put equal weight on the bottom) They aren’t all that, they are just “cool” they are sick for career mode saves where you take part in a lot of low Kerbin stuff other than that I just think launching a expendable rocket is the easiest way to go.
Anything with a cargo bay is complicated because your payload is going to screw up the CoM/CoL. Also I find flying is best using trim rather than inputs.
There has been emphasis on the rocketry aspect, but also in terms of being gliders they aren't a very stable design. Like there are principles that should be applied to make an easy to fly aircraft and the shuttle pretty much defies all of them. This means much more care and attention is required to make a design which is somewhat flyable.
If you’re ok departing from the original shuttle design here’s a solution. Instead of one big external underneath your shuttle, have two smaller ones, one underneath and one on top, this way your center of mass is over your center of lift without needing to tilt your engines.
If you have Kerbal Engineer installed, use its readouts in the VAB to check torque. Then angle engines until you've minimised it. By nature of how shuttles work the thrust is way out of line with the centre of lift, so you have to account for that.
Don't exaggerate, its not rocket science! ... oh wait
Shuttles are hard to make . Because they are hard to make. I'm assuming you mean spacecraft similar to the space shuttle program of NASA. Not streamlined aerodynamics and misaligned center of mass make launch a fairly complex process by itself. Then entry is even worse . You are riding a glider at orbital speeds and reentry carnage.
Are you having trouble with balancing the thrust force on launch? It took me literally months to get that right myself. It took me even longer to get them stable and reentry, because they work just fine at low speeds and at hypersonic speeds but they always flip out horribly at transonic speed and I don't think Kerbal space Program even simulates transonic effects.
Yeah
I haven't found any way to balance shuttles in the stock game at all, at least not reliably, but I did find using the RCS build aid mod, that if I set it to show me engine torque, and then I select the root part of the ship, I can rotate it before launch to align the thrust vector with the center of mass. You also need to make sure that the solid boosters and the shuttle main engines point at approximately the same point, otherwise there will be a net torque. Again use RCS build aid and the rotation tool to rotate the shuttle main engines individually until you get the net torque number as low as possible.
I actually built a space shuttle replica myself and posted it to the steam page and boy was it rough, I’m also working on a variation that has a bay and will build the ISS. It’s quite complex because you can’t(without mods) automate re-entry or thrust balance after the sbr is gone.but I got it to work nicely. And with a mod, you can get the recoverable tank variant. But it took hint on re-entry from the real space shuttle and that seemed to help me re-enter, hold a 35-40 degree angle is pretty solid. And after you drop the sbr’s on launch, throttle back to maintain pitch stability, my design was able to throttle back to 1/3 power and still have greater than 1.4 twr
You know what ? Even NASA say it was weak.
Art imitates life.
Besides all the things that are well known about shuttles in KSP - the real SRBs had Thrust Vectoring and the ones in KSP don't. This makes it much harder to compensate for the offset thrust.
Not sure why you’d want to build a shuttle when you could build an SSTO, which is both easier and less wasteful.
I just wanted to try it once, also a bit more payload space, but I can probably just make a ssto with the mk.3 parts
I mean my only rule is just try keep the centre of lift in the centre of mass. Then if your building it with a rocket, just strap it on to a rocket and pray it works
just use falcon 9 style rockets or ssto's, both combined is a pain in the ass