Ten Tonne Endurance

[sevenperforce]

This is a simple challenge, but I'm very, very curious to see what people do in order to try and beat it.

You're allowed a vessel weighing up to ten tonnes, nothing more. Your sole source of propulsion must be monopropellant or bipropellant rocket fuel; no jet engines, nuclear engines, or ion engines allowed. You can, of course, use the rocket fuel with a fuel cell to power a propeller, but if you do that then you cannot use solar panels or an RTG. No infiniglide or other hacks/cheats; no part mods.

Without ever leaving the atmosphere, how far can you go before you land?

Specifically, on the F3 menu, you want to maximize "Ground Distance Covered" between liftoff and touchdown/splashdown/crashdown/burnup. "Highest Altitude Achieved" on the F3 menu must be below 70,000 meters. You have to be airborne. If you need a takeoff roll on the runway, that's fine, but once you touch down again it's over (no rovers allowed).

Let's see what you've got!

[camacju]

Are aero exploits allowed? If so, electric props will *probably* be the best option.

[sevenperforce]

19 hours ago, camacju said:

Are aero exploits allowed? If so, electric props will *probably* be the best option.

Don’t part-clip ad nauseum but sure, you can mess around with aero exploits if you think that will do the trick. 

[MythicalHeFF]

I’m thinking one could just get to an apoapsis of 69,999m and circularize an “orbit” that’s entirely inside the atmosphere, then just boost the craft back to orbital velocity whenever the orbit starts to decay, repeating this process until it runs out of fuel.

Edited April 20, 2022 by Jack Joseph Kerman

[camacju]

I've cheesed a similar challenge like that before but I suspect that with sufficient aero mechanic (ab)use, a significantly better result is possible.

[swjr-swis]

3 hours ago, camacju said:

I've cheesed a similar challenge like that before but I suspect that with sufficient aero mechanic (ab)use, a significantly better result is possible.

There's zero need for cheesing or aero abuse, just plain spaceplane design with a minimum of drag optimization. More than once I've left to do other things with a regular spaceplane aerobraking because I only had a puff of MP/LFO left to retroburn, and couldn't lower Pe below 55 km. They would circumnavigate multiple times purely on glide, staying in that upper layer of the atmosphere with Pe only marginally lowering every orbit. If it had been the goal at the time, a minimum of reboosting at the right moments would've kept them going round and round for hours.

I suspect most potential participants will be long bored before any cheesing or aero abuse would need to come into play to make a difference in top entries. The first one that enters an under 10 t LFO-only spaceplane will pretty much end this contest, because it will basically become a number-of-circumnavigations challenge and who's willing/able to babysit a craft for longer.

Not contradicting that electric props may end up having more total range than LFO, or that drag optimization tricks would extend even that, but seriously, no need to go for extreme tricks off the bat.

[MythicalHeFF]

I’ve tested the method I described above, and I’m pretty sure I could orbit Kerbin a thousand times in-atmosphere if I actually had the patience.

 

After 30 minutes and orbiting about 5 times without timewarp, I got bored and deorbited. I’m sure with a mod like Better Timewarp I could have gone around thousands of times.

 

Total distance over land: 31,500 km

Not a valid run, however, as I used jet engines on the launcher.

[imcute]

i could just make a craft that uses kal underclocking(fuel) and points its wings to 45 degrees so constant lift is exerted

[Pds314]

Since almost any entry would take a long time to run (be it flying at 69.9 km and periodically boosting the orbit or running through hundreds of thousands of EC with a tiny prop engine on a plane), is it sufficient to merely prove that an entry *would* be able to run for a long time/distance?

 

Also are we trying to maximize actual ground distance covered or what it says on the F3 menu? Those are very different things.

15 hours ago, imcute said:

i could just make a craft that uses kal underclocking(fuel) and points its wings to 45 degrees so constant lift is exerted

KAL abuse is obviously cheating.

 

Edited June 22, 2022 by Pds314

[imcute]

aww man