A Jool-5 attempt with a single stage spaceplane

[juzeris]

It all started as an ambitious attempt at the fabled Jool-5 mission by the Kerbal Space Center crew. Complete with huge motherships, landers, heroic docking and maybe rovers. However, misunderstandings, misprocurements and misdesigns quickly snowballed, and, as of this moment, astronauts are boarding a single stage monster which is... still supposed to complete the Jool-5.

Simulations (hyperedit) show it should be possible, but the safety margins are very narrow. So the engineering department decided to document the trip just to have evidence in future strategy meetings what happens when the interns are reviewing the designs, and nobody knows who made them in the first place. Bob is saying he saw the KSC cat spend way too much time at the location, but nothing could be conclusively proven.

(The mission will probably be presented mainly as a series of accelerated videos, I'm still trying to figure out how to present everything nicely.)

As an introduction, we are presenting our craft:

Parental advisory: minor clipping, engines firing from within a cargo bay, floating parts (I realize these might disqualify me from the formal challenge, but, eh, this is too much fun not to try it , the only clipping I'm aware of, though, is the partially clipped in landing gear, and the slight clipping of the rapier engines. It is done for the purpose of nicely fitting into a cargo bay however.)

She weighs 60 tonnes dry, 127 fully loaded. The launch weight is 111 tonnes, because getting through the Mach barrier has proven challenging with her fully laden. She has an integrated ISRU system, magnetically suspended nacelles which double as vertical landing gear, 6 rapiers, one nuke, a nose lift system and 8 big wings which make her look a bit like a centipede.

Fun fact - she is made from exactly 100 parts (because I forgot the probe core). 20 of these parts are the monoprop nose lift system, 19 are SAS units. 36% of her launch cost comes from the 4 RTGs which power her. Those RTGs are the only thing providing electricity, except for the nuke engine when it's firing.

Mods: I use MechJeb heavily, however it should not affect the viability of the craft, just compensate a bit for my piloting. I also have Hyperedit installed, which was used for testing but not the actual mission, and Throttle Controlled Avionics, which I am not expecting to use, but, well, the option is there.

As of this posting, I have successfully reached Minmus, so no guarantees how it will turn out. Video of the first part coming up sometime today.

[juzeris]

Well, I've made it as far as Minmus, and the ship is fully refueled, ready to continue the trip. Next stop - Laythe.

The lessons of the day include:

-Ore for mining is not everywhere, and the button to turn on the overlay is a well-kept secret. (Yes, this is my first mission actually using ISRU ) At least I thought to survey the resource beforehand.

-Just because a jet engine does not flame-out, does not mean it's running at full power. I've had my top engine (which is drawing air from the shock cone, surface area 0.9) at almost 50% more thrust than the other ones (which are drawing air from the nacelles, surface area 0.5). Not all the time, though.

I'm not set on the order in which to visit the planets yet, but I guess it will be one of the small ones for easy refueling after Laythe, and then Tylo. Don't want to postpone the scary one too much in case I fail.

[Mister Dilsby]

Ambitious! I hope you make it--Tylo should be the fun one

[Mikki]

Hm looks reasonable, good luck! Me never was to Jool by now, my Jool mission is still in prep, T-130days.

[juzeris]

Thanks!

Coming back to our crew, part 2 of the journey is complete, and the spacebird is now landed at Laythe.

Currently the crew is starting to drill, thinking where to go next (probably Bop), and calculating how much oxidizer to load up on.

Things learned during this part:

-The performance of this craft depends a lot on how much oxidizer is loaded: less oxidizer - more delta-v, less burn-time of the high TWR Rapiers.

-MechJeb delta-V calculations seem to fail to find the fuel in the wings, so it can happen that firing the engines increases the calculated available delta-V.

-Kerbals can climb back in without a ladder (though they mostly need a boost with RCS).

-Also, quicksaves are good, but we knew that already.