Gunstar AP - 3 passenger, 10 ton capacity autonomous SSTO

[Overgoats]

GUNSTAR AP

As I was developing this design, it began to look more and more like Gunstar One from The Last Starfighter. In the end I just went with it, and tried to make it as close to identical as possible.

Launched empty, it can achieve LKO with enough delta-v left to exit the Kerbin SOI. It can also carry ten tons on the nose docking port, as long as the payload includes winglets -- the craft is already a bit nose-heavy. A 10t drop tank is enough to take this ship to Duna and back. If refuelled in space, it can easily reach Jool or Moho, even without external fuel.

The first time I tried to lift a 10t payload, I got a little hung up on the acceleration stage, and didn't have enough fuel left to circularize. I'm pretty sure I can get it up there with a little practice, though.

-c.

Edited July 9, 2015 by Overgoats

[quasarrgames]

NOICE!

Finally, another tower SSTO'er! I thought the rest of them died in 1.0.4. So, friend, how dids ya do it? What's the best apporach to jet rockets now? A high thrust -to-weight ration, or a low one with more rocket fuel? Are nukes good for getting payloads to LKO, or should high-twr chem rockets be used? I'd love to discuss it with ya!

[Overgoats]

NOICE!

Finally, another tower SSTO'er! I thought the rest of them died in 1.0.4. So, friend, how dids ya do it? What's the best apporach to jet rockets now? A high thrust -to-weight ration, or a low one with more rocket fuel? Are nukes good for getting payloads to LKO, or should high-twr chem rockets be used? I'd love to discuss it with ya!

Well, as you can see from my rather convoluted stage management process, I could only pull it off with a combination of all three.

The jets are great for the acceleration stage, but they don't generate enough power before Mach 1, so I run the Mainsail for about 30 seconds to get the ship up to speed. The LV-Ns don't even contribute before about 10 km up, but after 18 km they're outperforming the jets, so I run both at once. Finally, when the jets flame out at about 22 km, I go back to the Mainsail to grab a fistful of apoapsis. The Mainsail runs out of fuel, the LV-Ns keep pushing, and before you know it you're in space!

-c.

[Nothalogh]

So, how does this thing land?

[Overgoats]

So, how does this thing land?

Vertically, on parachutes and landing legs. Assuming it's landing on Kerbin or Laythe, the jets will be on to soften the landing a bit. My initial tests showed that the chutes slow the craft enough for the **landing legs** to survive, but for all that I've strutted the bejeezus out of the engines, I don't know if that would extend to every linkage. I've always soft-landed.

I *think* it can soft-land on Duna using the LV-Ns alone, but I haven't gotten ISRU in place to send it there yet.

-c.

[Overgoats]

The Gunstar had its first rescue/salvage mission today. Outfitted with a grappling claw, the Gunstar linked up with a fuel tank in orbit (not pictured). Incidentally, I learned that grappling counts as docking, and you can suck fuel out through the punctures. I made a Space Vampire!

Re-entry was kind of a bear, because the craft was both nose-heavy and aerodynamically unstable.

It took four tries to deploy the chutes - they really wanted to spin the craft around *hard*, to the point that they tore it apart! I finally figured out that I could deploy one *specific* chute at 5 km, and rotate the ship manageably, if not gently.

In the end, ten chutes plus some retro thrust from the jets was enough to set the craft down, saving the research module for post-incident analysis.

-c.