MechMars 3 and Deep Space 1

[CobraA1]

Hey, so wanted to share a couple designs that I may attempt to use in 0.17 with the new planets.

The first is MechMars 3, which is designed to go to a Mars-like planet (now confirmed to be Duna). Right now, the top stage is MechJeb, but I should be able to modify it to use a lander for a crew when 0.17 comes out. Took quite a few iterations to get something that won't blow up on stage separation, and my solution was to simply use the smaller parts for most of the craft, with the larger parts acting as a booster through the lower atmosphere. It's the first craft I've really designed for interplanetary missions.

Not much to say about it, hopefully it will get me there. Designed mostly to be a one way trip, although I think it has enough delta v to swing by and return to Kerbin if needed. I may end up doing what most people are recommending and sending two craft: One with the lander, and one with a return capsule. A future iteration will need a lander capable of taking off again in an atmosphere.

The second craft is Deep Space 1. It's the result of asking the question "Let's say I want to use only a single aerospike engine. How much fuel can I send into orbit with it?"

The reason being, well, it seems that navigating space is all about delta v. How much you can change velocity. And since it's space, it doesn't really matter how much thrust you have, only how efficient the rocket is. Basically, you want your ship to be a flying gas tank.

So, I designed a big gas tank to go with my engine. This thing should be able to make it to any planet in 0.17. It's not really designed to land (although I chose the MechJeb lander as the payload), but should be able to get me basic info about all of the planets and moons in the system.

The original design was two large gas tanks attached to a thinner, inner stage. After a lot of experimentation, I figured it would be boosted into orbit with large rockets, each two tanks high.

Well, the launcher got to four tanks long and two tanks wide, and that was getting me into the upper atmosphere, but not into orbit. It was, however, getting me there fast, so I knew that I had more than enough power, just not enough fuel to get into orbit. So, I decided to add another stage to the bottom of the existing rockets.

That proved to be way more than enough - indeed, I had a lot of fuel left! Once in orbit, my launcher had four large tanks that were completely full, with four more tanks containing some leftover fuel. I had to incorporate those tanks into the final spacecraft - so I did, adding the ability to drop the four powerful rockets of the final liftoff stage, and allowing fuel to go back into the interplanetary craft itself.

The result once in orbit? Over six large fuel tanks, filled to the brim, feeding a single aerospike engine. Plus some fuel left over in four more large tanks, and the four small centerline tanks.

And it turns out to have great endurance, even being able to make the 8 km/s delta v for a sundive. Never imagined I'd ever want to create such a craft, but once I decided I wanted a deep space craft, I figured I might as well test the sundive.

It does take nearly the entire craft to do the dive, though. I was down to the inner tanks, having ejected all of the outer tanks. And it is annoying fighting the kracken on the way down.

Screenshots taken are basically launching and in orbit. I didn't take any screenshots during the missions, will have to remember to do that in the future :/.

NOTES:

-MechMars has a higher thrust/weight ratio of the two, and should be able to make it to the inner planets.

-When you break off the last four large rockets, Deep Space 1 will have a really low thrust/weight ratio. Be prepared for some really long burns. If you don't mind wasting a bit of fuel, you can keep the last four large rockets attached for a while longer.

-Be careful about launching the last two large tanks on Deep Space 1, as they can snap off the rest of the vehicle. Best to do it with the engine off and wait for them to float off.

-MechJeb is required for these two rockets. No other mods were used. Both rockets should be safe for a MechJeb launch.

MechMars 3:

https://www.dropbox.com/sh/hiiam0iqixpppq9/IViYWR-36h

Deep Space 1:

https://www.dropbox.com/sh/rbt9zvylrxdav0a/oPPFAyLZoi

Edited September 1, 2012 by CobraA1
Duna, not Eve . . .

[iZINC]

pictures would be nice...

[BlueSubstance]

Can you add some pics please?

[CobraA1]

Ok, I'll go put some pics in the post itself soon, although the dropbox links had pics.

[CobraA1]

NOTE: These aren't the most beautiful ships, but I build to be functional.

So here's the deep space launcher and Deep Space 1. Eight large rocket motors makes for a lot ot thrust for the lower atmosphere, and two large tanks per motor per stage is plenty of fuel.

Here it is, just made orbit. Six large tanks and four small tanks worth of fuel left for deep space missions.

Droppping the lowest engines from the last launcher stage saves me about 30 tons, and switches thrust to the aerospike.

This is the original concept I had, and is what you get once you release the outer tanks. Truth be known, it probably wouldn't have a whole lot of delta v compared to my final design.

Here's the "Mars" (Duna) spacecraft. Not as much delta v as Deep Space 1, but should be able to do a trip to Duna or Eve. It was actually the first of the two designs.

Here it is, just made orbit. Plenty of fuel for inner plant missions.

Here's what the final stages look like.

Edited September 3, 2012 by CobraA1