Minimal mass craft to go to the Island Airfield

[bitzoid]

What is the lightest vessel that can hop to the airfield in one piece?

Rules:

• Build a stock ship in the SPH (with or without kerbonauts).
• Launch it from the runway.
• Use no mods or cheats.
• Never touch water.
• Reach the Island Airfield off the shore of the KSP.
• Land (in one piece) on its landing strip.

The goal is to build a ship with a minimal wet mass. On a tie, lowest dry mass wins.

My current best is 0.490t (wet mass) but I believe at least 40kg can still be stripped off that design, I'm just terrible at landing.

Submissions:

• With lifting surfaces:
  • 0.220t propeller design w/o engine (4x4cheesecake)
  • 0.490t twitch (bitzoid)
• Without lifting surfaces:
  • 0.483t juno (bitzoid)
  • 0.525t spark (HebaruSan)

Edited January 2, 2019 by bitzoid
That was just a ridiculously brilliant design!

[HebaruSan]

39 minutes ago, bitzoid said:

What is the lightest vessel that can hop to the airfield in one piece?

Well this isn't it, but that was fun anyway! Lifting bodies are super OP.

[bitzoid]

I tinkered with crafts that have no lifting surface inspired by your statement that they are over powerered.

 

A jet with 0.483t wet mass is the lightest I could come up with. The Juno engine with its whopping 250kg being the worst contributor to mass. But to balance it, this thing only needs 4 units of liquid fuel. I think the parachute can be replaced with a single landing leg, which would remove 85kg from the vessel (falling below the 0.4t mark). But it would require a lot of patience and experience with throtteling the sluggish jet engines to actually land it.

[4x4cheesecake]

I've build this little craft with lifting surfaces and a total mass of 0.220t

Spoiler

By 'rolling' to the left, this craft will lift-off

After flying 5km straight up, I stop rolling

Pointing the wings in one direction will cause the craft to glide in this direction

After falling below 1km altitude, I point radial out again and start rolling to gain hight. Took me 4 cycles to reach the Airfield:

Landing is tricky

Done!

It is possible to bring down the mass to 0.190t by using the Basic Fin instead of the Structural Wing Type D but the smaller lifting surface will make this flight a pain^^

[Ultimate Steve]

EDIT ignore this

Edited January 1, 2019 by Ultimate Steve

[bitzoid]

17 hours ago, 4x4cheesecake said:

It is possible to bring down the mass to 0.190t by using the Basic Fin instead of the Structural Wing Type D but the smaller lifting surface will make this flight a pain^^

I love your propeller idea so I tried to improve on it. You can get down to 0.115t by using two basic fins and a single STAT solar panel instead of a NUK. At high noon it can power the small reaction wheel with amps to spare (angling the craft can only be done for so long, though). It takes patience to fly larger distances but it can be done. As I didn't want to steal your record, I only proof-of-concept landed it on the VAB. In an earlier test I got a few kilometers off the shore, so one could get to the island.

Btw. if you plant the okto2 on the bottom it gives you the greatest margin of error when landing as it has a greater tolerance than the small reaction wheel.

Spoiler

 

[4x4cheesecake]

1 hour ago, bitzoid said:

You can get down to 0.115t by using two basic fins and a single STAT solar panel instead of a NUK

Nice, haven't thought about using a solar panel^^

1 hour ago, bitzoid said:

As I didn't want to steal your record, I only proof-of-concept landed it on the VAB. In an earlier test I got a few kilometers off the shore, so one could get to the island.

It's fine for me It will take a lot of patience to do this flight (maybe a bit easier since you got the mass down) and I don't want to improve it any further. So if you want to try it, feel free to do it

1 hour ago, bitzoid said:

Btw. if you plant the okto2 on the bottom it gives you the greatest margin of error when landing as it has a greater tolerance than the small reaction wheel.

I had no issues with the crash tolerance of the 'core' parts but with the wings hitting the ground while rotating too fast. Keeping the descent rate < 6m/s requires a few tries but it is not too difficult. But if your wings are placed low on the core, they will probably break (I'm curious though why it happend to me during the landing but not while launching)^^

[bitzoid]

20 minutes ago, 4x4cheesecake said:

I had no issues with the crash tolerance of the 'core' parts but with the wings hitting the ground while rotating too fast. Keeping the descent rate < 6m/s requires a few tries but it is not too difficult. But if your wings are placed low on the core, they will probably break (I'm curious though why it happend to me during the landing but not while launching)^^

First of all, I think placing them higher makes for a more stable flight, anyway. I suppose the COL should be slightly above the COM. Second, I don't think the game engine was intended for propellers. In my runs, the wings were pulled out of the core all the time. Perhaps they also wobble in other directions. Physical time warp does some really wonky things.

[4x4cheesecake]

29 minutes ago, bitzoid said:

First of all, I think placing them higher makes for a more stable flight, anyway. I suppose the COL should be slightly above the COM.

I haven't researched this stuff, but I would actually expect a more stable glide if you place the CoL below the CoM because as soon as you tip over, the CoL will be slightly behind the CoM, like you want it for every plane:

It is probably not very import for a light craft which can be controlled by a single reaction wheel^^

32 minutes ago, bitzoid said:

Second, I don't think the game engine was intended for propellers. In my runs, the wings were pulled out of the core all the time. Perhaps they also wobble in other directions. Physical time warp does some really wonky things.

Yep I like to rotate my rocket during long flights just to see the radial attached parts beeing pulled apart and flipping back as soon as the rotation stops Well, a quicksave is always a good idea before doing this ^^

[MaverickSawyer]

Hmmm... May have to do the paramotor, just for giggles (and to demonstrate a more "conventional" solution)