5 light weight SSTOs (from minimal training to Munar VTOL/Interplanetary)

[katateochi]

I'm pleased to present the fleet of Knat class SSTO's; 5 craft with a range of capabilities from basic (and outrageously cheep) LKO orbiters to Lunar VTOLs with interplanetary capabilities.

• The Equatorial and Elite are the budget or training craft. Very easy to fly and super cheep, send a man to LKO and back for under 2000 (after recovery of craft). Both should reach 100km orbit with some dV spare 350ms and 1000ms respectively (if flown optimally).
  
• The Executive is for when you're late for a meeting on the space station and need to get there quick. It's very OP, fast and fairly easy to fly.
  
• The RangerXL has the greatest range and is able to land, VTOL style on Mun and return. Requires precise piloting but if flown optimally it should reach orbit with 2700ms dV, enough land and return from either moon, or make one way trips to several other planets.
  
• the Ranger (basic) is the hardest one to fly and since the XL it's been pushed to one side a bit. It is able to land and return from Minmus, but not Mun.
  

They all have ejecting cockpits as we all know how treacherous aircraft can be and they all can be flown at 4x physics warps during ascent without problem. Although I'd recommend adding MechJeb and using the SURF to control pitch if you're going to fly at time warp.

I will be adding some vids about how to fly them (especially the Rangers), but I've not had a chance to make them yet.

Download links for each one below,

or you can view them all on KerbalX

(more pics and action group info also on KerbalX)

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Knat Equatorial

mass: 4.85 tons

cost: 21127.1

range: LKO

potential dV available once in 100km LKO: 350ms

cost (after recovery) to reach and return from LKO: 1400

Ultra Cheep and easy to fly, this little craft will get you to a 100km orbit with 350ms dV spare. Has thrusters and a small amount of RCS for docking maneuvers.

This was result of trying to find the cheepest flight to LKO. A trip to LKO and back will only set you back 1400 once the craft has been recovered.

Download from KerbalX

Knat Elite

Only about 300 more costly than the Equatorial, but is able to reach 100km orbit with 1000ms dV spare and has more RCS available. Is able to do a free return flight around Mun and back.

This is the easiest of the range to pilot, good for SSTO training flights.

mass: 6.77 tons

cost: 24798.2

range: LKO - free Mun return

potential dV available once in 100km LKO: 1000ms

cost (after recovery) to reach and return from LKO: 1700

Download from KerbalX

Knat Executive

The Executive is the fastest of the fleet and is really ridiculously OP. It doesn't have much range once in orbit (usually ~500ms dV spare once reaching 100km orbit), but its enough for performing rendezvous. At 4x physics warp and using MJ for control its possible to pilot this to a stable orbit in under 3 (RL) mins.

It's ascent is very simple. pitch to 45 after take off, climb till Ap reaches 10 and then pitch to 20. Then climb till AP reaches 20km and pitch to 10, you can then maintain this pitch until in space. It should flame out around an alt of 35km, by which point the Ap should be nearing 60-70km. A short bust (literally a tap) from the LV-T30 will be all that's needed to raise the Ap to 120km.

mass: 9.24 tons

cost: 33135.28

range: LKO

potential dV available once in 100km LKO: 500ms

cost (after recovery) to reach and return from LKO: 2200

Download from KerbalX

Knat Rangers - Lunar VTOLs

The two rangers are a bit querky and are very hard to fly right. To be both an SSTO and a VTOL, while also keeping the weight down resulted in a design with a single LV-909 set facing down. So it's positioned for VTOL landings on moons but during atmo ascent it means the craft has to flip 90 degs to switch from jet to rocket. This transition has to happen high up (~34km) or it won't work. The two Rangers both need to be flown on the most optimal SSTO ascent path possible, the aim being to maintain airbreathing mode right up to 34km.

The Rangers both lack some of the mod-cons that the others have. They don't have ladders or thrusters to cut down weight. But because the docking port is inline with the VTOL engine they can be docked without thrusters.

Knat Ranger

Lunar VTOL - extremely hard to fly

mass: 11.60 tons

cost: 25109.3

range: Minmus Landing and Return | one way trips to Mun, Eve, Duna, Ike.

potential dV available once in 100km LKO: 2500ms

This craft is able to reach a 100km orbit with 2500ms dV spare, but it takes very careful flying. 2500 is annoyingly just short of being able to return from a Mun landing, but it is able to land and return from Minmus.

The Jet engine is only just powerful enough to accelerate the craft to orbital speeds, you must hit the air-breathing sweet spot around 30km or you'll burn too much oxidizer on the ascent.

After take off pitch to 45 and climb till Ap is at 14km and pitch to 30, climb till ap is at 22km and pitch to 12 degrees (or a pitch around there which enables you to maintain a vertical acceleration of 100ms. From 20km to 30km you should be climbing at 100ms and still accelerating, as you reach 30km pitch up by a couple more degrees to increase the rate of climb. When then engines flame out, hit action group 1, then select control from here on the top docking port, then set a pitch of 30 and a roll of 180 and hit action group 2 to bring rockets online. That switch over needs to happen as fast as possible.

Download from KerbalX

This craft failed its original design goal of being able to land on Mun and return. On paper it is about 60ms dV short, in reality it needs another 200ms to make it back from Mun. Many attempts where made to add the additional fuel needed but even a few more liters and it becomes too heavy for the single jet to cope. Which is why the XL was built.

Knat RangerXL

Lunar VTOL - hard to fly

mass: 14.142 tons

cost: 34608.36

range: Mun or Minmus landing and return | one way trips to Eve, Duna, Ike, Jool (orbit)

potential dV available once in 100km LKO: 2700ms

The design if this craft took longer than all the other Kant's combined. But finally I've got a small SSTO that is capable of making a VTOL Mun landing and return.

Like the smaller Ranger the key is hitting the air breathing sweet spot and staying on air breathing up to 34-35km before switching over.

pitch to 45 after take off. climb till Ap is at 12km, pitch to 25 deg, climb till Ap reaches 20km, pitch to 10-15 (to maintain a vertical speed of 100ms). You should reach ~34km before flame out. When then engines flame out, hit action group 1, then select control from here on the top docking port, then set a pitch of 30 and a roll of 180 and hit action group 2 to bring rockets online. That switch over needs to happen as fast as possible.

Download from KerbalX

(yes, I am trying to push KerbalX a bit here, can you blame me?! Also, kinda tried, so sorry if this is riddled with typos!)

Edited October 27, 2014 by katateochi

[LvL]

Whoa. These look perfect for my career mode as soon as I unlock all of the parts. awesome looking! rep for you!

[Redshift OTF]

Nice! Keep up the hard work. Trying to keep spaceplanes small, nice looking and functional in all ways is a very hard art but worthy of the best builders imo. Have you tried clipping LV-N engines into your craft?

[katateochi]

Thanks for the Rep guys!

Whoa. These look perfect for my career mode as soon as I unlock all of the parts. awesome looking! rep for you!

Yeah from a career mode point of view these do require some of the latter parts (ie the new intake is use on 3 of them), so not so helpful for an early career, I think the Elite will get unlocked first.

The RangerXL is what is all about for career missions. I'm about to do a mission to Duna with it, won't be able to return but I'll get my flag and science contracts done.

Nice! Keep up the hard work. Trying to keep spaceplanes small, nice looking and functional in all ways is a very hard art but worthy of the best builders imo. Have you tried clipping LV-N engines into your craft?

I have used LV-N's on SSTO's before but only on much larger ones, the Equatorial is not much heavier than an LV-N! My fav engine is the 909, ok only half the ISP of the LV-N but still better efficiency than any other stock engine and its light. I want to make a larger SSTO that can carry some cargo to interplanetary orbits, I might use an LV-N for that.