Boxkite style SSTO Spaceplane

[bsalis]

This is what I call a Boxkite Style SSTO spaceplane.

It's long, with a forward and rear node to attach tanks, engines, lifting surfaces and control surfaces. Why is this good?

* The main reason: it allows you to balance the wet and dry mass around a common center in the middle of the craft.

* Control surfaces can be placed further away from the CoM for better control authority

* Resilient to flat spins from flameouts, because of the length - i have never lost control from a flameout

* Plenty of small tanks allow adequate air intake placement without clipping (16:5 ratio in this case).

Craft is here

Note that pics below of a Duna return mission (with no refueling!) has a radial MJ module attached. The attached craft file has this removed and is all Stock.

Welcome to Duna

Unusual re-entry configuration - oddly stable!

Landed

Back on Kerbin

[Rainbowtrout]

Ooh shiny.

[Colonel_Panic]

I've mentioned this before, but that is damned impressive. I especially like the VTOL capability on Duna. Is that the only way you can land it there, or can you also glide in and take off again normally via rocket propulsion?

These designs of yours are inspiring me to work on some spaceplane challenges of my own.

[bsalis]

I especially like the VTOL capability on Duna. Is that the only way you can land it there, or can you also glide in and take off again normally via rocket propulsion?

I have not really considered it, but it possibly could. I guess I did it this way since all my previous SSTOs did it this way, but they didn't have many lifting surfaces (old habit). Note that the others needed refueling, and didn't use chutes.

edit: here are the others...

Edited May 16, 2013 by bsalis

[Klopchuck]

Hi Bsalis...

I'm just getting into SSTO's. Please, do you have any advice on what altitude / intake-conditions that are the critical point for transitioning the Boxkite from the TurboJet Engines to the Aerospikes? I assume LV-N' are space-only. Thank you.

[bsalis]

Hi Bsalis...

I'm just getting into SSTO's. Please, do you have any advice on what altitude / intake-conditions that are the critical point for transitioning the Boxkite from the TurboJet Engines to the Aerospikes? I assume LV-N' are space-only. Thank you.

Sorry for the late reply.. don't often check my craft threads.

First up check the action mappings in the SPH. You may wish to re-assign them to your preferences. Then to fly...

1. Open the Resources tab. You will need to monitor the IntakeAir.

2. Disable the gimbals on the LT-Ns. You will not need them, and gimbals only work against you when in front of the CoM.

3. Activate all jets and throttle up, accelerate. Pull up and ascend vertically.

4. Start leveling off past 10Km. Start watching the IntakeAir

5. Written down, I have 0.14 units on the resources tab for flameout threshold on 5 engines, so stay under that and pick up speed until you don't seem to gaining much more.

6. Active ALL rocket engines, then shut down 2 jet engines, pitch up

7. Again, written down, I have 0.11 units on the resources tab for flameout threshold on 3 engines. Once you hit that, shut down the other 2 outer engines.

8. Once the center engine flames out... shut that down too, and close all air intakes.

9. Keep climbing on all rockets, then when you are in the higher atmo, and don't think you need all the thrust, shut down the aerospikes, and keep using the more efficient LT-Ns to finish. The rest you should know

You may wish to check the flameout thresholds again in test flights. Also note that I have not used this craft in .20, so it performance may have changed a little since .19.

If you are planning a trip to Duna and back, this craft can do it. However, you have to do it carefully. There margin for error, but it is not big. I suggest getting familiar using it, then launch several to LKO to practice maximising delta-V. Measure this by oxidizer volume. Vent any excess fuel before departing for Duna, and use up the RCS to help with maneuvers too.