It'snorocketscience

Build a SSTO using tier 4 parts AND lvl 1 facilities

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Posted (edited)

I present you a difficult engineering challenge: Build an SSTO that uses tier 4 parts and below, that can be launched using tier 1 facilities. You'll face juno jets, EC drain (no panels), tight flight envelopes, and toothpick landing wheels. Your only source of EC will be from your engines and those measly batteries. Special flight and re-entry planning is crucial. 

It took me a few hours, but this challenge is possible. If anyone wants proof or needs help, I can PM you my craft and some tips that worked for me. It meets all the requirements (and bonuses, except for the commnet one - that's untested).

Hopefully I'm not the only one who finds engineering challenges thrilling...

Rules:

  1. No refuelling or help from external spacecraft. No EVAs (tourists can't EVA, and crew can't EVA off the ground with a T1 astronaut complex).
  2. The craft should work on normal difficulty (regular reentry heating).
    1. Note: If you really want: You can disable commnet.
  3. Reach a stable orbit of at least 70 km using tier 4 parts and below.
  4. Have a payload of one tourist. This is the hard part!
  5. You can use building/pilot aid mods, but your craft and it's flight should be reproducible in vanilla.
    1. Note: If you really want, you can use SAS (in sandbox) even though the T4 stayputnik doesn't have SAS.
  6. You can build your planes in sandbox, but make sure they fit within the T1 facility restrictions (https://wiki.kerbalspaceprogram.com/wiki/Runway)
    1. Note: If you really want, you can use action groups even though the T1 sph can't do that.
    2. Note: If you really want, you can launch/land from the grass, or use the T3 runway, or ditch in the water next to the KSC.
  7. The craft must take off, fly, and land like a spaceplane.
  8. Land in one piece. This is a reusable SSTO, isn't it?
    1. Note: If you really want, you can jettison parts at/during launch as long as they don't get destroyed. Basically, this means that fancy launch rigs are allowed. (I've decided to edit in this rule because it allows for more design variety).

Hardcore mode (optional challenges):
These are only necessary for the #3/#4 win category (see below):

  • No SAS (stayputnik has no SAS) or pilot aids.
  • Takeoff and land on the T1 runway.
  • No action groups (T1 facilities can't set up action groups)
  • Absolutely no jettisoning of parts, not even launch rigs.
  • Use commnet (normal difficulty)  and set occlusion to max (you can use ground stations around kerbin). No unmanned control during re-entry if you aren't careful!

Who wins?
This isn't really a competition... If you want to compete, here are some milestones to aim for:

  1. Use as few parts as possible to reach orbit (my design uses the max amount of 30).
    1. If there's a tie in part count, the cheaper vessel wins.
  2. Whoever's vessel can achieve the highest orbit apoapsis AND RETURN wins (basically delta v, but piloting and aerodynamics matter).
  3. Whoever fulfills all the bonuses using the least amount of parts.
  4. Whoever fulfills all the bonuses and can achieve the highest orbit apoapsis AND RETURN wins (basically delta v, but piloting and aerodynamics matter).

Use plenty screenshots or record a video to show your design.

Good luck!

Edited by It'snorocketscience
edited for even more clarity
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This is hard !

I had a saved craft called Dolly Bird,  which I had to take a knife to  so as to fit within the limitations.   You can see my solution to not having retractable gear is a "Dolly".  I think it still qualifies as an SSTO so long as the dolly can be re-used (not damaged) on takeoff.  The orbiter can land via parachute (tends to break stuff as it's undersized, but saves the crew)  or it can ditch in the sea next to the space centre.  I think so long as you're just off the beach and you don't damage it..  this should still count.

 

 

In the end, I finally got airborne, spent 10 minutes climbing, then realised i'd left the jet fuel tanks empty and the junos had guzzled much of the vacuum engine fuel.  Great.

After flying the complete mission successfully, I reread the challenge notes and realised i'm supposed to do all this with a Tourist on board , meaning  i need  a Stayputnik , an Antenna,  and a bunch of batteries?  Good luck busting mach 1 with all that hanging off the front,  even if you find a way within the part count.    

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Here 's the flight to orbit, anyway.   

 

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Posted (edited)

Managed it once, in this ugly looking thing:

oRTOPub.png

I can't get past Mach 1.01 on Junos no matter what I do. Fortunately that LV-T30 has enough delta-v to get to orbit from 10 km up and Mach 1. Staging is reversed in this picture to show rocket delta-v available.

I haven't mastered landing this thing yet at a slow enough speed. I'll need to do that and then make a video demonstration.

 

Edited by Gordon Fecyk
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Posted (edited)
4 hours ago, AeroGav said:

This is hard !

I had a saved craft called Dolly Bird,  which I had to take a knife to  so as to fit within the limitations.   You can see my solution to not having retractable gear is a "Dolly".  I think it still qualifies as an SSTO so long as the dolly can be re-used (not damaged) on takeoff.  The orbiter can land via parachute (tends to break stuff as it's undersized, but saves the crew)  or it can ditch in the sea next to the space centre.  I think so long as you're just off the beach and you don't damage it..  this should still count.

[video here]

In the end, I finally got airborne, spent 10 minutes climbing, then realised i'd left the jet fuel tanks empty and the junos had guzzled much of the vacuum engine fuel.  Great.

That's a nice design! You got a single measly lv-909 rocket engine to work!

Do you have a .craft file so I can try it out for myself?

I'll accept the dolly. Even though it kinda pushes the definition of an SSTO, (plane needs reassembly before launching again) I'll accept it since it's reusable, jettisoned at launch, isn't a propulsion device, and the craft can still land like a plane in water as you said. Also, that dolly is cool and efficient!

Could you remove the parachute or avoid using it? It doesn't fit the "land like a plane" criteria.

4 hours ago, AeroGav said:

I[...] realised i'm supposed to do all this with a Tourist on board , meaning i need a Stayputnik , an Antenna, and a bunch of batteries?

Don't worry... according to the wiki, the stayputnik's drag coefficient is actually slightly better than the mk1 parachute (smooth round ball). You don't need an antenna either -- pods have one built in. Also, by enabling "hibernate in warp" and hibernating in orbit, you can live off of a surprisingly small amount of power. The stayputnik drains little power and your engines generate power during ascent. You don't need to stay in space for a long time once you achieve orbit.

Edited by It'snorocketscience
edited for clarity and fairness

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Posted (edited)
34 minutes ago, Gordon Fecyk said:

Managed it once, in this ugly looking thing:

[screenshot]

I can't get past Mach 1.01 on Junos no matter what I do. Fortunately that LV-T30 has enough delta-v to get to orbit from 10 km up and Mach 1. Staging is reversed in this picture to show rocket delta-v available.

I haven't mastered landing this thing yet at a slow enough speed. I'll need to do that and then make a video demonstration.

 

Don't worry about the looks too much, but do you think you could make it carry a tourist (#4)? Your design is really close and it won't need big changes to be able to take a tourist.

Edited by It'snorocketscience

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Posted (edited)
1 hour ago, It'snorocketscience said:

Your design is really close and it won't need big changes to be able to take a tourist.

I almost got it. Replaced the Mk1 cockpit with a Mk1 pod and Stayputnik. Managed to make room for the probe by removing one fuel tank and it had 30 m/s left once in orbit. But I still can't stick the landing. Coming in too fast for the rear gear to hold up.

VSLghXC.png

I need to work on fuel flow priority and flaps to reduce the stall speed to something sane. Maybe after some rest.

Edited by Gordon Fecyk
Added updated image
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Posted (edited)
10 hours ago, Gordon Fecyk said:

I almost got it. Replaced the Mk1 cockpit with a Mk1 pod and Stayputnik. Managed to make room for the probe by removing one fuel tank and it had 30 m/s left once in orbit. But I still can't stick the landing. Coming in too fast for the rear gear to hold up.

I need to work on fuel flow priority and flaps to reduce the stall speed to something sane. Maybe after some rest.

Yeah... the suspension is annoying. I tweaked the suspension and flew mine using trim and used that to gently stall my vessel a meter off the ground.

edit: I just noticed that you are using FAR, which to the best of my knowledge makes things harder. Nice work getting that flying! By any chance could I have the .craft file when you're done?

Edit 2: does the plane make it to orbit in vanilla ksp without FAR?

Edited by It'snorocketscience
FAR may not meet rules, updated to ask about that

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5 hours ago, It'snorocketscience said:

That's a nice design! You got a single measly lv-909 rocket engine to work!

Do you have a .craft file so I can try it out for myself?

I'll accept the dolly. Even though it kinda pushes the definition of an SSTO, (plane needs reassembly before launching again) I'll accept it since it's reusable, jettisoned at launch, isn't a propulsion device, and the craft can still land like a plane in water as you said. Also, that dolly is cool and efficient!

Could you remove the parachute or avoid using it? It doesn't fit the "land like a plane" criteria.

Craft file here.    Getting a Juno supersonic is very hit or miss,   Kerbal Wind Tunnel reveals there's a narrow corridor you must walk down if you want to cross the sound barrier.     If you start from 0.9 Mach,  fuel is extremely tight.   If Val manages to coax Mach 1.6 out of the jets like she did in the video, there's a fair bit left...   i bet we could have gotten some high orbit science...

KrnBqk8.png

My concern with the Stayputnik is battery - how much EC per second does it use?   I managed to fly with no reaction wheel below 65km (and SAS wouldn't be missed really, it's very stable once you get it off the damn ground).  But six and a half minutes elapsed between jet flameout and us passing out of the atmosphere,  and probably twice as long again on re-entry, will the batteries on the stayputnik and command pod last?    The LV-909 has no alternator :-(

https://www.dropbox.com/s/3am0v60cay3xf9k/Dolly Bird2.craft?dl=0

 

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4 hours ago, It'snorocketscience said:

Yeah... the suspension is annoying. I tweaked the suspension and flew mine using trim and used that to gently stall my vessel a meter off the ground.

edit: I just noticed that you are using FAR, which to the best of my knowledge makes things harder. Nice work getting that flying! By any chance could I have the .craft file when you're done?

FAR is a funny one.   Takeoff / Landing speeds double or triple compared to stock, but it is a lot easier to bust mach 1.  On the other hand, above about mach 4,  drag starts to increase above stock again, whereas for stock, lift to drag ratio doesn't change any further once you get past mach 1.7.    

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3 hours ago, AeroGav said:

Craft file here.    Getting a Juno supersonic is very hit or miss,   Kerbal Wind Tunnel reveals there's a narrow corridor you must walk down if you want to cross the sound barrier.     If you start from 0.9 Mach,  fuel is extremely tight.   If Val manages to coax Mach 1.6 out of the jets like she did in the video, there's a fair bit left...   i bet we could have gotten some high orbit science...

KrnBqk8.png

My concern with the Stayputnik is battery - how much EC per second does it use?   I managed to fly with no reaction wheel below 65km (and SAS wouldn't be missed really, it's very stable once you get it off the damn ground).  But six and a half minutes elapsed between jet flameout and us passing out of the atmosphere,  and probably twice as long again on re-entry, will the batteries on the stayputnik and command pod last?    The LV-909 has no alternator :-(

https://www.dropbox.com/s/3am0v60cay3xf9k/Dolly Bird2.craft?dl=0

 

It will last for almost 36 minutes (mk1 pod + staypunik reserves) without EC generation. This doesn't include reaction wheel power drain, but the lv 909 has gimbals and your control surfaces should work.

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Posted (edited)
26 minutes ago, It'snorocketscience said:

It will last for almost 36 minutes (mk1 pod + staypunik reserves) without EC generation. This doesn't include reaction wheel power drain, but the lv 909 has gimbals and your control surfaces should work.

Well,  I  swapped the chute for a 'putnik  and also removed the nose cone from the rear attach node of the LV909.   Drag from open nodes has been reduced in 1.4,  and Kerbal Wind Tunnel still thinks we can go supersonic, so I add a battery for my 30th part.Noo4dw2.jpg

Spoiler

 

After half a dozen attempts, i manage to take off without breaking the dolly.

hD2AdZX.png

Patience, padawan - negotiating the transonic corridor with thrust only 3kn higher than drag.

BONBXhN.png

Eventually, we get to mach 1.55 something and stage.  Not a bad view for stock graphics

ezPUyC5.png

Not a bad amount of delta V, ultimately.

84kfIkc.jpg

Five aerobraking passes later, glad i brought the battery.   Verfey Kerman only wanted a sub orbital flight, she's definitely getting her money's worth.

anFRE4C.jpg

Surf's up.  At this point, i realise there may be a flaw in my cunning plan.   Not sure the Stayputnik is designed to survive ditching...

ZULh7d2.jpg

Stall, Stall

Ug6mfYO.jpg

Splosh !  Everything still glued on !

https://www.dropbox.com/s/vuyf9kyyklvny7p/Dolly Bird3.craft?dl=0

 

Edited by AeroGav
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I think I have it! Haven't yet filmed a mission, but I managed to take this crate to orbit, re-enter, and (barely) land.

https://kerbalx.com/gordonf/Space-Plane-7

NdVheVJ.png

My biggest stumbling block was getting a high enough TWR in the lower atmosphere. It occurred to me that I didn't need to get Mach 1, but just get high enough for a LV-909 Terrier to have decent TWR, so I went with two Junos instead of four. It was either two terriers or a single LV-T30 Reliant, and the two Terriers had better ISP. When assisted with the Junos I'd have a TWR greater than one to get out of the lower air. Having a wider body also meant more body lift.

This thing glides remarkably well if I run out of battery power; I had to set Flaps 2 and air brakes and it would glide low enough for the Junos to re-ignite.

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About a year ago I started a Ferram career game.   Everything takes so much longer to design ,  looking it the craft files it appears i lost interest in the middle of designing a two stage to orbit panther/terrier spaceplane (panther gets dumped)

Anyway this appears to be my Juno terrier ssto, i can't remember how it flies because i don't have a ferram install to hand...  can't remember if its supersonic or not on jet power.  If not I assume the highly swept planform was just to lower drag when running on Terrier power.  TWR with the Terrier is only 0.49 to 1, so it needs to have good lift drag ratio in supersonic flight

https://www.dropbox.com/s/fsnx3rcm6ikxcr6/Junovator.craft?dl=0

ynmo3jr.jpg

Obviously, high tech stuff like retracting gears and inline cockpits would disqualify it for the challenge.

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On ‎10‎/‎10‎/‎2018 at 3:56 PM, AeroGav said:

Everything takes so much longer to design [in FAR]

That's part of the challenge of using it. I find I need to think more like an aircraft designer. I do tend to build repeat-use utility vehicles for career mode though, so once I have a working design I'll reuse it many times. I could assemble the Iktomi in three Fat Star launches.

@It'snorocketscience I'll edit this post shortly to add the video of the mission. I've never flown a space plane to orbit without SAS, let alone on Tier 4 parts. I had to re-learn how to fly using flaps. Once I did though, I could send this plane to orbit with little to no control input.

Disqualify me if you must for using Ferram Aerospace, but the accomplishment is its own reward.

Edited by Gordon Fecyk
Updated video link
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On 10/11/2018 at 12:11 AM, Gordon Fecyk said:

That's part of the challenge of using it. I find I need to think more like an aircraft designer. I do tend to build repeat-use utility vehicles for career mode though, so once I have a working design I'll reuse it many times. I could assemble the Iktomi in three Fat Star launches.

@It'snorocketscience I'll edit this post shortly to add the video of the mission. I've never flown a space plane to orbit without SAS, let alone on Tier 4 parts. I had to re-learn how to fly using flaps. Once I did though, I could send this plane to orbit with little to no control input.

[video]

Disqualify me if you must for using Ferram Aerospace, but the accomplishment is its own reward.

I think I might need to disqualify that plane... I can't get it to work in stock... maybe I'm doing something wrong but the aerodynamics overlay (stock ksp) tell me that those angled tanks create a crap ton of drag (since they're radially attached instead of attached to the mk1 pod node)... Maybe FAR fixes that or something... sorry

I'll try flying it again since I forgot to use any of the flaps the first time around... I didn't know stock ksp wings had fancy flaps and spoilers...

Edited by It'snorocketscience
clarity
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16 hours ago, It'snorocketscience said:

the aerodynamics overlay (stock ksp) tell me that those angled tanks create a crap ton of drag

When I put it together, I figured stock KSP would not like it at all. It would only work in FAR because of the otherwise-open ends of those tanks. So don't worry about trying to fly it in Stock and I'll accept the [Rejected] stamp. This is why whenever someone puts together a space plane-related challenge, someone else always asks if FAR can be used.

Stock KSP doesn't have flaps as-such like FAR introduces. What it does have is an Extended / Retracted toggle for control surfaces that may be used as flaps or spoilers.

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Yeah a lot of work goes into making something in FAR.     A high speed airplane that can land at speeds the small retractable gears can survive ends up looking like my plane,  lots and lots of wing parts, and sophisticated high lift systems.   No way in hell of getting it under 30 parts nor of getting landing speed below 60m/s ,  which the fixed landing spats probably cant handle

 

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32 minutes ago, AeroGav said:

Yeah a lot of work goes into making something in FAR.     A high speed airplane that can land at speeds the small retractable gears can survive ends up looking like my plane,  lots and lots of wing parts, and sophisticated high lift systems.   No way in hell of getting it under 30 parts nor of getting landing speed below 60m/s ,  which the fixed landing spats probably cant handle

 

Do you think I should make a separate category for FAR SSTOs then?

 

On a side note, I actually managed to get to LKO with these requirements with ~900 m/s of dV left, believe it or not. That means my design can do a mun flyby, but I have to do some more testing if it can return, let alone meet all those bonuses (tier 1 tracking station is such a pain!).

Basically the plane resembles a fuel tank more than a plane... this thing has a takeoff speed of 70-80 m/s in stock ksp, but trust me; it launches, flies, and lands like a plane. :) It comes in at 17.9 tons and exactly 30 parts.

 I'll post a video in a bit... you might find the runway braking mechanism (or lack thereof) a bit interesting. :)

Edited by It'snorocketscience
editted for clarity
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Inspiring challenge, but I (sadly) find my solution looking more and more like AeroGav's.  30 parts <L4 is very constraining!

How do people prevent the wheels from burning off on the way back in?

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2 hours ago, antbin said:

Inspiring challenge, but I (sadly) find my solution looking more and more like AeroGav's.  30 parts <L4 is very constraining!

How do people prevent the wheels from burning off on the way back in?

I have a working T4 SSTO plane that uses the "reliant" rocket and it can land back on it's wheels. It can comfortably reach orbit.

Those landing wheels are a pain, but if you balance the dry CoM and CoL correctly and use your command pod torque, you can point your wheels retrograde which protects them during reentry. If that's not possible then you can at least tilt them away from prograde and use your plane's body to shield them. Shallow re-entry trajectories are important.

I will get a video (or at least some screenshots) of my craft soon... I got 2 school tests on one day this week! sorry

Edited by It'snorocketscience
edited for clarity

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