Grand Tour - most efficient itinerary?

[Oafman]

So, I was thinking that it must be possible to plant a flag on every rock in the Kerbol system with a single launch from KSC. I imagine it's been done, but I couldn't find any challenges or mission reports during a cursory search. There are plenty of grand tours, but they don't all start with one launch, and they don't always visit the surface of every planet/moon.

But it got me thinking about the best order in which to visit everywhere. Eve would have to be the first stop, because the Eve ascent vehicle would be the biggest payload. But then there's a decision to make. Obviously Eve is the best place to access Moho, but the issue there is that you would have to carry everything all the way to Moho (including a lander set up for Tylo, which would be fairly large), slow it down, and then cart everything out to Jool (visiting Eeloo/Duna+Ike/Dres/Mun/Minmus on the way back when you've ditched most of the mass).

A different approach could be to leave most of your ship - including a heavy Tylo lander and something with jets for Laythe - at Eve, and tug a little multipurpose lander to Moho. But the delta v between Eve and Moho is not trivial, and you would have to make the inclination corrections both ways. But at least you have the aerobraking option when you get back to Eve.

How would people approach this? What is the most efficient route? Does anyone think it's not possible?!

Edited July 28, 2014 by Oafman

[metaphor]

I went first to Eve, and then from Eve to Jool to get rid of the heaviest parts. Afterwards it's not that hard to get to the other places, especially if you use gravity assists. I visited Mun and Minmus last when coming back to Kerbin.

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[magnemoe]

http://forum.kerbalspaceprogram.com/threads/48461-Grand-tour-4-new-attempt-at-an-below-100-ton-grand-tour/page2

this is an 100 ton from LKO tour.

I used two steps to save weight, the Eve, Moho and Tylo landers did not have seats to save 40 kg, kerbal jetpac is a 500 m/s upper stage

I used two other tricks, first is an Ion craft from Eve to Moho and back.

second is that I split the ship in two and only one part visited Ike and Dress, the other part went directly to Laythe, then Val and finally Tylo, as second stage had more fuel left I sent it to Bop while I went to Pol first.

Now you could take this further at put up depots and even landers at Duna and Jool.

The new ion engines also give some opportunities.

[Stratzenblitz75]

I made a flow chart to help me plan out an optimal flight plan for my Grand Tours of the Kerbol System (Delta V predictions included for each maneuver). Yeah, as you predicted the best planet to visit first is Eve as you get to dump your heavy Eve lander early on in the mission. Then, Moho because its easiest to get to, ect.

Also, if you are only planning on planting a flag on every planet in the Kerbol System, don't bother using jets on Laythe (Jets are heavy!) or designing specialized landers for any planet other than Eve. Its often a better idea to just have a "universal" lander that can perform many landings.

Here are my two Grand Tours for reference:

The Sigma Mission: 36 tons from LKO, planted a flag on every celestial body, used three landers in total (Eve lander, General Purpose Lander, Ion Powered Lander), one launch, no refueling

The Outer Wilds Mission: 100 tons from LKO, planted a flag on every celestial body (and skimmed into Jool's lower atmosphere), brought science instruments and a MPL, gathered 42,981 science points, one launch, no refueling

Hope this helps!

Edited July 23, 2014 by Stratzenblitz75

[peter1981]

Hi Oafman -- I think that a single launch grand tour is certainly possible but, are you planning a stock only attempt?

If so learn to love the ion and nuke engines.

Are you limiting yourself to not using infingliders and kracken-drives?

I'd suggest not worrying about athetics, or science, or anything that adds mass: Use the command chair, then sit a kerbal in it, then land and finally a plant flag repeat for each rock and then return home.

If your going to use the kerbanauts jet pack as a 600m/s dV final stage you'll have to take a command pod so you can refuel as of 0.24 the monopropellant is not decreased on kerbanaught return; so it is a FREE 600m/s dV! This means you can use the jet pack to land and return to orbit on Gilly, Minmus, Ike, Bop, & Pol.

You can also return to Orbit with just the jet pack from Mun, Dres, & (Eeloo maybe?)

Laythe use the rapier make a space plane ~3200m/s dV each way ideally a plane that can land and take off on water.

Moho ~900m/s dV each way so ~1800m/s dV same as Vall so maybe a refuel?

Eve's highest point is 7540m high, found near (25° S, 158.5° W) and requires ~8,000m/s dV to reach LEvO (95km) (Maximum dV 12000m/s dV)

Duna highest point is 8264m high to reach LDuO (42km) require ~1500-2000m/s dV including some for landing I'm assuming low numbers of paracutes => lean & mean duna lander. Min dV required to reach LDuO from sea level (0m) is 1300m/s dV but you'll need something for the landing the nuclear rocket engine is great in Duna's rarified atmosphere.

Vall ~900m/s dV each way so ~1800m/s dV (see Moho above.)

Tylo has peaks of more than 11290 meters but 0.8g at the surface you'll need a dedicated lander for this but finding a high peak could save alot of propellant and therefore weight. ~2300m/s dV each way so ~4600m/s dV

Eeloo highest points are near the equator and are almost 3.9km high with a gravity similar to the Mun (0.172g vs. 0.166g) it may be possible to jetpack most of the way to LEeO (~620m/s dV)

I'd suggest you look at this map http://i.imgur.com/NKZhU57.png

-> Recieved wisdom is to start with the highest gravity bodies and work backwards.

Good Luck.

EDIT: I think a nuclear powerd interplanetary stage with an Ion powered comand pod shuttle to take down to Low orbit for the planets where your using just the jetpack. For the others, Moho & Vall, Eve, Duna, Laythe, and Tylo; I think you'll get away with refueling the Moho lander and using it on Duna & Vall; a SSTO rapier spaceplane for Laythe, A huge Eve lander and If you can make the upperstage of that reusable as a Tylo lander then just need to plan the route you'll take.

Edited July 23, 2014 by peter1981
EDIT: more ideas

[Oafman]

There are some seriously clever solutions on these tours. I'm in awe at the efficiency of some of these; 36t from LKO?! My Eve ascent vehicles alone tend to mass twice that! Great to see kerbals clinging onto ladders on descents - a very kerbal solution!

It makes me realise just how bad I am at minimising mass. I'm often guilty of just adding more and more rockets, which of course compounds itself into stupidly inefficient ships. This needs to change, so when I finally get around to having a go at a grand tour, I'll try to build as small as I can. I imagine I'll be sending out a lot more than 36t from Kerbin , but I'll do my best.

Thank you all for the examples of successful tours, and for your advice and resources.