Nobunaga Interceptor - quick/agile spaceplane

[AnalogAddict]

The Nobunaga Interceptor - a tiny spaceplane.

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Download Link:

Nobunaga Interceptor

Features:

1.3km delta-v after circularization at 80km.

Ability to reach orbit twice

Clamp-o-tron Jr. for interfacing

Balanced flight

Flight Profile:

Full load takeoff @ 135m/s

1. Full throttle @ 45 degrees until 13km.

2. Pitch down to 10~15 degrees (monitor vertical speed indicator), continue 10 degrees beyond 20km.

3. Speed should approach 1600m/s by 21~22km.

4. Set throttle 1/2 and engage nuke @22km (Action group #1 or staging) while pitching up to 30 degrees

5. Work throttle to just below 1/8 by 26km,

6. Disable jets/close intakes anywhere from 26~28km (Action group #2) and throttle back to full.

7. Maintain some distance from apoapsis

8. Begin to pitch towards prograde as apoapsis approaches 50km

9. Circularize at desired altitude.

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The Courier spaceplane is capable of +3.4km/s delta-v after stable 80x80km orbit.

From the runway to anywhere ... and back?

Video available here.

Getting to orbit three times without refueling. ** Note: SAS OFF for final landing

Image Album.

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Download the .craft:

https://dl.dropboxusercontent.com/u/33011069/Ships/SP%20v4a%20stock.craft

As configured:

Designed specifically for the video, this plane is in its bare form. The spacecraft is easily adaptable to hold docking ports, small payloads, RCS, and why not a couple chairs.

47 Parts stock

21 Tons

The Courier can make it from the Runway @ KSC to Laythe, land on Laythe, and return to Laythe orbit to potentially rendezvous with some orbital module... quite a distance she can go.

Flight Plan for stock:

- Stage to initiate Turbo Jets *Note if you use action group (2) to start, the intakes will close.

- Pitch up @ 90m/s, set pitch 45 degrees.

- Maintain 45 degree pitch until 13km, then pitch down to 30 degrees (monitor vertical speed indicator: desired ~50m/s by 17~18km)

- As velocity increases, pitch down in 5 degree increments to massage your vertical speed. Desire speed 1300m/s

- At 21000km, stage or (1) action key to fire the dual LV-Ns, reduce throttle to 33%, pitch up to 45 degrees and using the indicator bring your vertical velocity above 100m/s, slowly reduce throttle to prevent flameout until about 26km the plane should be at 16% throttle.

- Press action group (2) to disable jets and close intakes.

- Burn at 45 degrees until your apoapsis is near 50km and begin pitching down to burn directly prograde. Set desired apoapsis.

- Circularize.

The video shows a more aggressive series approaches, if you aren't afriad of Mech Jeb and its nice flameout prevention, you can perform them as well. That being said, a stock flight is still capable of 3400m/s delta-v after circularization at 80km or even better, I'm not the best pilot.

Edited August 15, 2013 by AnalogAddict
editing Title

[Febin]

Wow. This is very impressive, will be trying this out later tonight.

[AnalogAddict]

Thank you, Febin, its pretty difficult to screw up. Even without SAS on I haven't lost control yet using it.

A friend of mine who doesn't play KSP got this thing to orbit by firing all engines from the runway and literally flying straight up out of the atmosphere. He then turned and circularized after a slight suggestion about how to orbit... amazingly enough, the craft made it to stable orbit.

[zarniw00p]

Thank you very much for this awesome craft. I never thought that its possible to carry that much deltaV into Orbit on an SSTO. I guess when it comes to SSTOs, smaller is better?

[AnalogAddict]

Thank you zarniw00p.

In my experiences I haven't built large SSTOs that had great results while re-entering or landing. Since my view of large SSTOs is they are to be used for payloads, not interplanetary travel, I have not ventured into developing one that had a large reservoir for delta-v post orbit.

I would say there is a diminishing return on smaller and larger SSTOs, medium sized as I have classed this craft seems to have the most success in a variety of tasks.

For instance, this plane: Laythe Nuke-SP SSTO was named due to its ability to be refueled in orbit and travel to Laythe. As a culmination of effort, this spaceplane performs well with empty fuel tanks as well - however the nuke has a tendency to fall off if the plane has more than half fuel. Its smaller than the craft this post is about, and can get to orbit with half this craft's delta-v.

No matter which way you go, it takes a load of work to get a good functional space plane that is versatile.

Edited August 7, 2013 by AnalogAddict

[Clayton]

First off, impressive craft, brother.

Why did you place the center of lift so far behind the center of mass? I watched your vid but I cant figure out the why behind what you did.

Most importantly, I saw your note about the plane landing with asas off while empty (impressive feat man), how are you supposed to know where your center of mass will be at different fuel levels?

Edited August 7, 2013 by Clayton

[AnalogAddict]

First off, impressive craft, brother.

Why did you place the center of lift so far behind the center of mass? I watched your vid but I cant figure out the why behind what you did.

Most importantly, I saw your note about the plane landing with asas off while empty (impressive feat man), how are you supposed to know where your center of mass will be at different fuel levels?

The simple answer is: Its a long game of trial and error, launching the craft, save file editing for half or quarter-full tanks, and multiple flights at various altitudes at each of those fuel levels. If you disable ASAS you will see the nose pitch up or down and that tells me if the CoL is ahead or behind the CoM.

Eventually you'll begin to see where your fuel needs to be in relation to your engines which is where the theory for this craft came about - I wanted to use the nukes to counter balance some of that weight from the turbofans when the fuel tanks were empty.

[Clayton]

Thats kinda vague explanation but thanks! I guess I just need to get my 'hands dirty' so to speak.

[AnalogAddict]

Pm me Clayton. We shall discuss further if you'd like. I find it difficult to articulate what I'd like to say without writing a novel in a forum post. Sorry for the ambiguity.

[AnalogAddict]

I've added the Nobunaga

The Nobunaga Interceptor - a tiny spaceplane.

Download Link:

Nobunaga Interceptor

[Sauron]

Isn't it a touch small to benefit from the DV savings you get from an LV-N? If not, it looks like a very borderline case. (Remember that for light ships, the 909 is more efficient DV-wise than the nukes)

[thufir]

I keep trying your flight plans, but both planes have flameouts below 21k. No idea what's up.

[AnalogAddict]

Its very delicate when it comes to flameouts, monitoring speed I've found is most important. I'll try and re-tool the flight plans for a less aggressive approach, I'm sorry you're having problems.

@ Sauron, perchance I'm investigating multiple solutions for small SSTOs.

[thufir]

No worries dude, probably just me sucking at flying more than anything. Ill keep an eye on the speed more tomorrow, I was watching the intake more. I tried building a slightly bulkier version but it got too big for the nukes. Works great with 45s but consumes more then I'd like. Really love the designs though dude.

[Tankbuster32]

Nobunaga, huh... I like that name!

[Darndello]

I love it's name... It sounds weird. Nobunaga.

[AnalogAddict]

Oda Nobunaga - a great leader and military strategist. I figure he deserves a line of strategic ships.

Thanks for the compliments gents.