MK3 Crew carrier

[Benji13]

Has anyone one been able to make a MK3 SSTO that can carry 20 or so crew to LKO since 1.1 came out? If so, can you please post links? I want to know if its possible. Thanks.

[Jarin]

Certainly possible. Got any other requests? Orbital height? Docking capability/orientation?

Edited September 6, 2016 by Jarin

[Jarin]

Meet the Archon crew transport vehicle. 773m/s dV in orbit with the prototype CTV. Still needs RCS ports and probably airbrakes for re-entry convenience, but the test-flight went without a hitch. Overshot KSC a bit, but had plenty of fuel to fly back. Also determined that the struts were the right decision, as I accidentally pulled back hard on the turnaround and spiked G-forces into the redzone, but the airframe held. 

Craft file and flight profile once the production model is finalized.

Edited September 6, 2016 by Jarin

[Benji13]

57 minutes ago, Jarin said:

Certainly possible. Got any other requests? Orbital height? Docking capability/orientation?

I always thought that it would make most sense to put the shielded docking port on the front of the mk3 cockpit. Are there any other ways that would work that well? Also a 400x400km orbit would be enough for anything I guess. 

[Benji13]

19 minutes ago, Jarin said:

Meet the Archon crew transport vehicle. 773m/s dV in orbit with the prototype CTV. Still needs RCS ports and probably airbrakes for re-entry convenience, but the test-flight went without a hitch. Overshot KSC a bit, but had plenty of fuel to fly back. Also determined that the struts were the right decision, as I accidentally pulled back hard on the turnaround and spiked G-forces into the redzone, but the airframe held. 

Craft file and flight profile once the production model is finalized.

This looks nice! I've never seen the 'upright mk2 tanks in the wing' design before. 

[Jarin]

I think I cribbed the mk2s-in-the-wing from @mk1980 (though his wasn't flipped vertical) but I've grown rather attached to it.

Anyway, here we go! The finalized Archon CTV (kerbalX link).

 

 

Full pictures and instructions below. 

Spoiler

Original instructions suggested flaps (group 1) on takeoff, but they're optional. Start pulling back gently at around 110m/s. Should lift off with little trouble. Gear up/flaps up by 150m/s.

 

Run low and fast over the ocean. Accelerate until comfortably past Mach 1.

 

Once the rapiers are up to speed (400m/s is a good point), nose up into about a 15 degree climb. Warning: even with reinforcement, pulling up too hard can and will rip your wings off. Keep it on fine control (caps lock toggle)

 

Accelerate on your climb. Keep an eye on speed, as the drag profile isn't the greatest. Generally if you keep your navball horizon at about 15 degrees (dropping it a touch as Kerbin curves away) it seems to be fine.

Ride the air intakes as long as you're still getting acceleration out of them. Once your velocity stops rising, close intakes and toggle the engines to closed-cycle mode (group 2). Aiming for over 1200m/s with changeover around 23km.

Keep that 15 degree inclination until you're into the upper atmosphere (40km or so), then set yourself to orbital prograde marker until AP is where you want it. Our example flight runs to 400km.

 

Once clear of the air, open the cargo bay and extend solar panel and radiators (group 3, 4, 5). Radiators aren't strictly necessary, but it's something I've made standard on all my SSTOs. They pick up a LOT of heat from the climb, and if you're only up for an orbit or two (say, to launch a satellite), that heat can hang around long enough to cause trouble on re-entry.

Take care when circularizing. Thrust is almost-but-not-quite perfectly centered behind the CoM (the tail moves it up just a tad), so if you don't have a 3-star pilot to be able to set "hold" on maneuver node, you may want to throw an advanced probe core behind the battery in the cargo bay.

 

400-500m/s left in the tank at our final orbit, depending on ascent profile (and deorbit from here is going to claim at least 200), so this isn't quite the Archon's flight ceiling, but accounting for orbital rendezvous, it's close. Note that RCS is decently balanced, but somewhat underpowered. We've got "overkill" levels of monoprop onboard though, so just take docking slow and steady and it should be fine.

Pictured: Lots of happy faces in orbit

 

Finding a simple re-entry profile from 400km turned out to be easier than I thought, A bit over half an orbit away from KSC, burn prograde 'till your PE is around 30km. If you have the trajectories mod, just put your landing point just west of KSC itself. The pictured profile overshot a bit, as you can see below. Bring in the deployables, (groups 5,4,3) toggle engine mode again (group 2) to open up the intakes, and set autopilot hold to Radial Out. This will keep the plane pulling up through re-entry. Your job is now to hold it level and pointing east. This may take a bit of wrestling through the early re-entry, but settles down once your AP drops below about 150km. 

 

Pop the airbrakes at about 35km. Watch their heat, but they should hold okay. Don't worry if you "bounce" the re-entry and start climbing again; just ride it out.

 

If you overshoot, you should have plenty of LF to turn around and fly home.

 

Don't worry about maneuvering on the turnaround. Once you're subsonic, the airframe should be able to handle whatever you care to put it through.

 

Home again, safe and sound. What you can't see here, because the interface is hidden is that the kerbals are overheating from re-entry. Maybe pop the radiators out again after stopping to let them cool off before disembarking.

Disclaimer: Pictures were taken across multiple flights, and there may be a couple design tweaks visible. However, all instructions are accurate for the final design.

Should be a pretty flexible design overall. I don't think anything but a couple RCS ports are attached to the crew cabin, so that should swap out for a cargo bay or whatever you need.

[Benji13]

@Jarin thanks! This looks great and will be perfect. Many reputations to you!

[mk1980]

here's some more images of mk3 crew transports:

this is from a career save. the unusual engine config is also related to the progress in that career (got the whiplash engines through a "test part" contract before i unlocked the tech node properly, so i didn't have the aerospike rocket engines that would normally unlock with the same tech)

i used that bird to bring my kerbals back home after a long "training" trip (getting them all to level 3) through the kerbin SOI. the spaceship had 18 seats (and was not designed to reenter the atmosphere), so the transport that would bring them back to KSC also needed 18 seats:

 

 

this one is a "sandbox" design. made it for the stubby/cute looks. 16 seats, makes it to orbit just fine with some deltaV to spare for a docking maneuver 

 

 

[Val]

160 kerbals.

It was created in KSP 1.0.5, but it still works fine.

SSTO XS-160 Olympus

[Signo]

(nukes are hidden inside the cargo bay)

Imgur album

[Val]

16 minutes ago, Signo said:

(nukes are hidden inside the cargo bay)

Imgur album

That's pretty ingenious. Great solution to keeping CoM near mid craft and a good looking craft, too.

But does it need those pancake wings? It has more wing than my ~300 t craft above.

[Signo]

Thank you, I loved the idea but alas the drawbacks are far more than the advantages.

When the ramp is open drag is huge - wings lift is the best resource this craft has got between 21000 and 25000m. And I wanted it to be able to approach landings at less than 80 m/s - lately I lost a few kerbals due to bouncy gears and a slow approach speed helps my success rate. 

 

[Val]

20 minutes ago, Signo said:

Thank you, I loved the idea but alas the drawbacks are far more than the advantages.

When the ramp is open drag is huge - wings lift is the best resource this craft has got between 21000 and 25000m. And I wanted it to be able to approach landings at less than 80 m/s - lately I lost a few kerbals due to bouncy gears and a slow approach speed helps my success rate. 

 

Still, I like the concept. I'm gonna try making my own interpretation. Maybe with 4 Nukes and 4 RAPIERs to make it lighter and get an oxidizer boost to upper atmosphere... *wanders off towards SPH*

[Jarin]

8 hours ago, Benji13 said:

@Jarin thanks! This looks great and will be perfect. Many reputations to you!

It occurs to me after some sleep that I'm using nothing but Rapiers, so those fuel lines may be superfluous. Try pulling them off and see if the engines drain right in closed-cycle mode. Should get a bit more delta-v on ascent if you ditch that drag. 

[Pecan]

13 hours ago, Benji13 said:

Has anyone one been able to make a MK3 SSTO that can carry 20 or so crew to LKO since 1.1 came out? If so, can you please post links? I want to know if its possible. Thanks.

Do you mean SSTO, or do you want a reusable vehicle that can land again after it's been To Orbit?  If the latter, does it have to stay in one piece after it's reached orbit?  Did you specifically want a spaceplane or will any solution do?  (See signature, I'm pedantic).

[KerikBalm]

I've never felt the need to get 20 kerbals to orbit at once, but I'm sure these are up to the challenge:

Spoiler

*that was a pre 1.1 design, as is the following one, the first two are the post 1.1 tweaked designs

 

or this rather unorthodox one:

 

 

[Jarin]

5 hours ago, Pecan said:

Do you mean SSTO, or do you want a reusable vehicle that can land again after it's been To Orbit?  If the latter, does it have to stay in one piece after it's reached orbit?  Did you specifically want a spaceplane or will any solution do?  (See signature, I'm pedantic).

And posting in every thread that mentions the acronym. 

[foamyesque]

26 minutes ago, Jarin said:

And posting in every thread that mentions the acronym. 

 

Well, most people use it wrong.

[Jarin]

59 minutes ago, foamyesque said:

 

Well, most people use it wrong.

Not wrong, just not exhaustively correct. The crafts posted here are SSTO. There are other kinds of SSTO, but from context, it was fairly obvious what was wanted. I could have done something with the same functionality in an SSTO rocket, but I've had little luck with return landing profiles for those.

Being pedantic about "single stage take off and return" like @Pecan is even sillier. Why the heck would you make an SSTO craft for any reason other than the ability to return for cost recovery? If it's not coming back, just save yourself the headache and stage. 

[foamyesque]

I have SSTOs that don't return, multi-stage spaceplanes that do, and SSTOs that stage in order to return. The distinctions are important, and I'm right with Pecan on not liking the sloppy conflation between "SSTO" and "dual-mode fully recoverable plane".

[Jarin]

11 hours ago, foamyesque said:

I have SSTOs that don't return, multi-stage spaceplanes that do, and SSTOs that stage in order to return. The distinctions are important, and I'm right with Pecan on not liking the sloppy conflation between "SSTO" and "dual-mode fully recoverable plane".

Again, those are SSTO craft, so it's not inaccurate. It's like someone saying "rocket" and getting grumpy that they didn't define if it was solid fueled, liquid fueled, or some combination. This would be true even if 95% of the time "rocket" only referred to LF/ox craft. 

I'm curious about what sort of situation you would ever make an SSTO that didn't return for. Other than "just because I can".

[Signo]

@Jarin - I generally agree with you, alas I designed myself a lot of SSTOs that couldn't make it back for "reasons"...

[Jarin]

25 minutes ago, Signo said:

@Jarin - I generally agree with you, alas I designed myself a lot of SSTOs that couldn't make it back for "reasons"...

Ha, fair point. "SSTO not intended to return" then? Design, intent, and actual flight do not align nearly as often as I'm sure we would all like.

[Pecan]

12 minutes ago, Jarin said:

Ha, fair point. "SSTO not intended to return" then? Design, intent, and actual flight do not align nearly as often as I'm sure we would all like.

Why I keep stressing the point:
You are, of course, correct in ridiculing my pedantry, trouble is, so many do say SSTO when they mean spaceplane - and will reject a perfectly workable verticle-launch 'rocket' for the same job.  The more people who should know better misuse the acronym, the more important it is to make sure newbies don't fall into the same bad habit.  And, again, you're right that I post in most topics that misuse the term; it's a tough job but someone's got to do it.  [Alright, I try to rein myself in but gahhhh! haa! the demons! ...]  What's really wrong though, and the reason this annoys me so much, is when people talk about building a 'SSTO' to go from Kerbin launch, land on some other planet/moon and then come back.  What is 'to orbit' about that?  See, it's as pointless building something that does a trip like as building a non-reusable SSTO...

Why make a non-reusable SSTO that stages:
Worse, in fact, since a non-reusable, vertical-launch SSTO is sometimes the most cost-effective, or only, way to do it.  Career or science tech 1, for instance.  Once you unlock Basic Rocketry and have the liquid-fuel tank you can SSTO, the swivel makes it easier (command pod with parachute, stack of fuel tanks, engine - simple].  It doesn't land too well though until you unlock the other tech 1 node, Engineering 101, for the decoupler.  Then you can separate the pod+parachute from the rest of the vehicle after your de-orbit burn.  Gentle touch-down and 100% survivability (if you don't burn up ^^).  Oooh, but, it's two stages!  Indeed - it is a Single Stage To Orbit and another back down again.  A very good reason to build a non-reusable SSTO that separates after it has got to orbit (and started back down).

Why 'SSTO to Mun', etc. makes no sense:
The crux of the matter is that people who like spaceplanes can make spaceplanes, it's their game.  It makes absolutely no sense to drag big, heavy wings and oxygen-atmosphere-only engines around the system, however.  Saying "it's a SSTO" adds nothing to its value - by all means launch to orbit with a single stage, then stage and leave the atmospheric bit behind!  I have no idea why anyone would insist on a single vehicle for such different operating environments as Kerbin launch-to-orbit and space-only vacuum.  SSTOs, spaceplanes or rockets, are not good at space-work.  They have too much thrust and too much structural mass.  It makes sense to design re-usable SSTOs for launching things that then operate in and beyond orbit, so stage those things once you get to orbit.  If you have some reason to bring those space-vehicles, as oppossed to the SSTO launch vehicles, back down - parachute them down.  Does this configuration seem familiar?  Oh yeah, it's just the way you built your first SSTOs in career/science (and probably sandbox).  Now though, you've added the re-usable to SSTO.  For tutorials and newbies it's important to make that distinction.  For effective design it's also important; what do we need to recover, what do we intend to re-use, etc. etc.  If it reaches orbit in a single stage and all it's stages can be reused it's a re-usable SSTO, I don't care how many pieces it comes down it.  In fact, what is special about SSTO?  If it goes up and all comes back down, in however many stages, and can be re-used, it's a reusable vehicle.  KSP's physics makes it hard to make a reusable multi-stage to orbit vehicle but, in principle if not practice, they are a better approach for all the reasons that staging exists in the first place.  Another reason to stop this mindset of "spaceplance is good" without thinking what it's good for.  Once people get-over thinking that spaceplanes are automatically good they can start thinking about the missions again i) launch, in a purpose-designed recoverable vehicle, ii) stage a purpose-built vehicle to perform the mission in space, iii) repeat as needed (stage landers, rovers, etc.), iv) recover all the pieces that need to be recovered but v) leave the stages designed for vacuum up there so you don't have to make a whole round trip with them again next time.

End of hijack:
Re-usable SSTOs are good.  Spaceplanes make good re-usable SSTOs.  Specifically; jets make very efficient re-usable SSTOs, so don't forget the alternatives to spaceplanes.
For missions beyond orbit re-usable SSTOs make good launch vehicles.  Separate the stage(s) that are to perform missions in space.  There's usually little reason to bring them back down, but if you do the whole thing's still re-usable, even if it isn't a single stage, so don't forget the advantages of staging.  If you are taking stuff up just to bring in down again, you've probably misunderstood the mission requirements [statement by the chief medical officer: this does not apply to tourist or astronauts]

[Jarin]

4 minutes ago, Pecan said:

Why make a non-reusable SSTO that stages:

Good info post overall, just wanted to comment on this section. Isn't it still better to do your example multistage rather than just stacking a bunch of tanks on a single engine? I've always done my first career orbit with a sold-fuel kicker to get off the pad, then a second LF stage to orbit. Since recovery is still a major pain at the early tech levels, that minimizes your cost to orbit since you're getting more of your dV from the high cost-efficiency solid fuel at the start.