Interplanetary Flotillas

[ruiluth]

Recently I had a Jool Transfer window. Since I had never been to Jool, I sent a flotilla of probes there: two orbiters and two landers for each body to study different conditions, except Tylo had one lander. The upshot of this combined with a very low TWR meant that I had to periapse-kick 19 ships out of LKO at once (don't worry I was using MechJeb and KAC). In retrospect, I am wondering if it would have been significantly cheaper and faster to attach all the probes to a ferry and send them all at once. How do you all do your flotillas, all at once or in lots of separate pieces?

[Geschosskopf]

1 hour ago, ruiluth said:

How do you all do your flotillas, all at once or in lots of separate pieces?

I send everything out separately.  However, over the years I've gotten a bit wiser.  There was a time when I did things like your example and had flotillas of 20+ ships.   That was back before MJ's "Advanced Transfer to Another Planet" so you couldn't space these burns out every hour or 2 over several days, it really did all have to be done at once.  That was a pain.

These days, however, I've revised my mission designs to do things smarter.  For example, invading Jool....  What good are 2 orbiters per moon?  Wouldn't one have been enough?  And why send orbiters to each moon separately?  Why not send just 2 in total with enough dV to move from moon to moon?  Have 1 start at Laythe and work out, the other start at Pol and work in.  Whichever has the most fuel left can do Tylo.  It's really not hard to pack a lot of dV into a probe that's not coming home.  LV-Ns go a long way.  By doing this, you've cut your 19 ships down to 11.

Now as to the landers....  I'm assuming these are all small, 1-way landers.  It's not hard to put 2 of these on 1 rocket.  Thus, you only send 1 lander rocket to each moon and capture it into an inclined or even polar orbit.  That way it will circle over every biome on the moon eventually and you can drop the landers 1 at a time as you pass over the biomes you most want to investigate.  Thus, your 9 lander rockets become 5 and the whole flotilla is reduced from 19 to 7.

Here are some examples of multi-probe carrier rockets.  This one carried 6 commsats, 2 each for the 3 inner Joolian moons.  The carrier had the dV to move from moon to moon and the probes had the dV to go to 60^ inclinations from an equatorial orbit.

 

A stack of 4 prospecting rovers to zero in on the good Ore and find good, flat landing zones for a base on Vall.  I sent a pretty much identical mission to Eeloo in OPM, where Eeloo is a moon of Sarnus.

 

Here's a multi-moon orbital science probe.  This one did a flyby of all 5 of the moons of Sarnus in OPM, getting both high and low orbital science and using gravity assists to go to the next moons.  It had enough fuel left over to capture at Orvok (not a trivial task, actually) and do some rudimentary SCANsat-type stuff there.

 

This flotilla also had a rather similar SCANsat that managed to map all 5 moons of Sarnus, meaning it had to have lots of dV.  Its transfer stage lasted through the 1st couple of moons and it had enough dV of its own to do the rest.  Here the transfer stage is still attached.

 

 

 

 

 

 

[Snark]

lol, I saw the question title ("oh look!  only 1 person responded so far!"), then read the OP, and figured "Well, I don't know anything about doing flotillas, but I should ping @Geschosskopf in the thread because he's all over that and would probably have good advice."

Then I scrolled a little farther down and saw who had already responded... 

Ahem.  To @ruiluth:  Listen to the 'Kopf here, he's basically The Flotilla Guy around here and knows whereof he speaks. 

[ruiluth]

14 minutes ago, Snark said:

Ahem.  To @ruiluth:  Listen to the 'Kopf here, he's basically The Flotilla Guy around here and knows whereof he speaks. 

 

1 hour ago, Geschosskopf said:

I send everything out separately.  However, over the years I've gotten a bit wiser.  There was a time when I did things like your example and had flotillas of 20+ ships.   That was back before MJ's "Advanced Transfer to Another Planet" so you couldn't space these burns out every hour or 2 over several days, it really did all have to be done at once.  That was a pain.

These days, however, I've revised my mission designs to do things smarter.  For example, invading Jool....  What good are 2 orbiters per moon?  Wouldn't one have been enough?  And why send orbiters to each moon separately?  Why not send just 2 in total with enough dV to move from moon to moon?  Have 1 start at Laythe and work out, the other start at Pol and work in.  Whichever has the most fuel left can do Tylo.  It's really not hard to pack a lot of dV into a probe that's not coming home.  LV-Ns go a long way.  By doing this, you've cut your 19 ships down to 11.

Now as to the landers....  I'm assuming these are all small, 1-way landers.  It's not hard to put 2 of these on 1 rocket.  Thus, you only send 1 lander rocket to each moon and capture it into an inclined or even polar orbit.  That way it will circle over every biome on the moon eventually and you can drop the landers 1 at a time as you pass over the biomes you most want to investigate.  Thus, your 9 lander rockets become 5 and the whole flotilla is reduced from 19 to 7.

 

Thanks guys, those are good ideas which I probably should have thought of. Or maybe I did and just decided not to... in any case I'll definitely be reconsidering how I do this in the future!

[Geschosskopf]

9 hours ago, ruiluth said:

Thanks guys, those are good ideas which I probably should have thought of. Or maybe I did and just decided not to... in any case I'll definitely be reconsidering how I do this in the future!

Good luck   I look forward to reading about your endeavors.  Remember, you don't need more than a flyby to get all the orbital science and don't send multiple ships when 1 will do.  When you have a bunch of separate targets (like multiple gas giant), you should end up with a small-ish flotilla of some multi-purpose, free-roaming ships and some mini-motherships.  This keeps things much more manageable.

[Pecan]

10 hours ago, Snark said:

lol, I saw the question title ("oh look!  only 1 person responded so far!"), then read the OP, and figured "Well, I don't know anything about doing flotillas, but I should ping @Geschosskopf  ... he's basically The Flotilla Guy around here and knows whereof he speaks. 

^^ This :-)