Jool: 5 moons or bust

[Foxster]

I decided to tackle the Jool 5 Challenge - visit all the Jool moon surfaces in one mission. Not done it before, so why not, eh?

A couple of self-imposed wrinkles to how I'm doing it though:

Only the one lander for all the moons. No adding or removing bits for the different moons.

Two Kerbals will visit the moons. Don't want anyone getting space madness!

Here's the lander:

It's a pretty simple lander, though it has to be clever too to cope with, particularly, Laythe and Tylo.

I'm then going to use a nuclear tug to ferry the lander to and from orbit of the different moons (no, I don't know why I didn't use one big LF tank):

Then we will need a mother ship with loads of fuel parked somewhere in the Jool system for the tug to bring the lander back to for re-fuelling each time. Plus some more fuel and engines to get the whole lot to Jool:

Anyway, I've completed the first part of the mission. The ship was assembled in orbit, sent off across the abyss of space to Jool, gravity-assisted around Laythe and parked in an orbit between Laythe and Tylo. Here's the record of this bit :

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Highlights of the mission so far:

Not taking enough crew and so having to fly someone else up to orbit.

Docking the massive parts was totally awful. Took ages and burned up most of the RCS fuel I really needed for the mission.

Ending up with a very heavy and wobbly rocket. All the mass meant that it took ages and ages to align for burns. The wobbliness meant it was hard to keep it on course without starting to wobble out of control.

A long, long burn to Jool. I under-estimated the fuel I'd need for this drastically. I had to enable crossfeed and use up 2/3 of the LF that was meant for refuelling the lander.

I don't know now whether I am going to have the fuel to finish all the moons. I might need to send at least some more LF and possible O and monopropellant too.

Part 2 will be visiting the moons. Watch this space...

Edited September 30, 2015 by Foxster

[Foxster]

Part 2 is going to cover just Tylo and Laythe. These are The Big Two.

Tylo has high gravity and no atmosphere so is greedy on dV. Laythe has an atmosphere to help with braking but has to be fought with a not-very-flightworthy craft back to orbit.

Fuel is not looking great. The mothership re-supplies are getting low. Will I need to send a refuel mission to the Jool system? Check out the pictures to find out...

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So, I'm pretty sure I can't do the last three moons on the remaining fuel. Even if I tried I wouldn't have the fuel to make it back to Kerbin. So, it looks like I am doing a re-supply run to the Jool system. Ah well, at least that's within the challenge's rule, it's just a pain to have to fly another fat ship all the way out to Jool. Part 3 will be the resupply mission, but that will have to be tomorrow, I'm tired!

Edited September 27, 2015 by Foxster

[Foxster]

That's part 3 done. I have now delivered my resupply craft to Jool.

Once again I messed-up the fuel I needed to drag a massive craft across to Jool. I had to steal 10k LF from the resupply tanks to get there. I really, really hope I still have enough fuel to finish this mission!

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[Foxster]

Part 5 - Where I do the last moons using the resupply fuel and have a decision to make...

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It turned out that my resupply run had more than enough fuel to finish the last three moons. They are all low-gravity moons and so didn't need much fuel to visit.

After the last moon, Pol, the lander+tug has plenty of fuel left so I could just head off home from Pol orbit. Or to be really sure I could go refuel again at the resupply ship. Decisions, decisions.

I'll sleep on it and decide tomorrow.

[Starhawk]

Nice mission so far, Foxster.

Happy landings!

[Foxster]

Nice mission so far, Foxster.

Happy landings!

Thanks, dude! I didn't imagine anyone was going to check this out.

[Foxster]

The last leg:

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I was getting really punchy at the end of this mission. My original plan was to refuel again before heading back, but I skipped that. Then I was going to ease into an orbit around Kerbin and send a rescue mission to bring the Kerbals from orbit, but I skipped that too and went for a landing.

I never tried putting this lander down on Kerbin before so I had no idea what it would do. It was a pig to land on Laythe, so I wasn't hopeful.

It did make it down though - just! It was wobbling all over the sky and I handed it over to MJ to try and it was only a bit helpful. Came in for a water landing and hit at about 10m/s but nothing much broke off.

All the guys are back safely, so all's well that ends well!

What did I learn from this mammoth mission?

1. Don't take a single heavy lander and try to do all the moons with it. It's a dumb idea. Much better with two or three small, clever landers, probably using command seats. Throw them away when used.

2. Don't cart the huge amounts of fuel a heavy lander needs to Jool. The craft needed is unwieldy. It turns poorly and uses stupid amounts of fuel.

3. If you do need more fuel at Jool then take an ISRU.

4. Take days or weeks to do this so you don't get bored and give up.

(A final confession: I did use Hyperedit! Gasp. I used it to delete a spent fuel section because it was confusing having it and the mothership so close together in orbit. So sue me!)