Deploy Multiple Satellites On One Trip?

[Geoclasm]

I have two contracts for equatorial satellites around Minmus (in addition to a flag-planting contract).

Is it possible to do all three in a single shot? (Launch a landing vessel with the two necessary "satellites" attached that can deploy the satellites at their appropriate coordinates, land, and have a Kerbal plant the flag)

[ForScience6686]

You could even complete both sat contracts with the same satellite, they don't have to be left in place once completed.

[Geoclasm]

2 minutes ago, ForScience6686 said:

You could even complete both sat contracts with the same satellite, they don't have to be left in place once completed.

Yeah I'd thought about that but it would mean the complication of putting attitude controls and thrusters on the satellite and I'm lazy. So having the Kerbals on board won't interfere with completing the contracts?

[Reactordrone]

8 minutes ago, Geoclasm said:

Yeah I'd thought about that but it would mean the complication of putting attitude controls and thrusters on the satellite and I'm lazy. So having the Kerbals on board won't interfere with completing the contracts?

Satellite contracts don't care if they're launched manned, they just have to be unmanned when they reach their final orbit. You could even use the manned ship as the satellites and just have the Kerbals step outside for a minute.

[MoonMan22]

1 hour ago, Geoclasm said:

Yeah I'd thought about that but it would mean the complication of putting attitude controls and thrusters on the satellite and I'm lazy. So having the Kerbals on board won't interfere with completing the contracts?

Read the contract carefully, I believe for satellites they require them to be unmanned. If thats the case just take a guidance unit along with all the hardware the contract requires and detach in the correct orbit.

 

Goodluck

[Norcalplanner]

It's very possible.  My favorite way to do it is by stacking satellites on top of each other, joined by small docking ports.  See below:

 

Edited February 3, 2016 by Norcalplanner

[kurja]

5 hours ago, ForScience6686 said:

You could even complete both sat contracts with the same satellite, they don't have to be left in place once completed.

Are you sure? Sat contracts usually require you to launch a new one, can't just move an old one to the required orbit.

[Wemb]

5 hours ago, Geoclasm said:

Yeah I'd thought about that but it would mean the complication of putting attitude controls and thrusters on the satellite and I'm lazy. So having the Kerbals on board won't interfere with completing the contracts?

Well, depending on what probe core you're using they may already have reaction wheels.  A small fuel tank and a very small engine would do the trick without the need for thrusters/RCS, etc.   Having said that, as others have said, you can certainly build a multi-satellite launcher - though don't do what I did and take my entirely capable single payload launcher, double (or triple) it's payload and expect it to work just as before.  I'm not entirely sure it saved me a lot of money, to be honest.

 

Wemb

[Tex_NL]

14 minutes ago, kurja said:

Are you sure? Sat contracts usually require you to launch a new one, can't just move an old one to the required orbit.

You can when you first accept multiple contracts and only then launch.

[kurja]

14 minutes ago, Tex_NL said:

You can when you first accept multiple contracts and only then launch.

And you can launch just 1 satellite to fulfill both contracts? Just to be clear.

[Evanitis]

Yes. These days sat contracts require you to launch a 'new' satellite after accepting them. But any number of active contracts can be completed with the new craft that you build after accepting them.

[RizzoTheRat]

NorcalPlanner's stack approach is the way I usually do it too, so long as you don't want those annoying bloody M700 scanners which are a pain to launch. because they're huge and really have to go on top of the satellite.

The "Launch a new..." contracts are good one's to collect and meet several contracts in one hit.  I recently made a small fortune with contracts to launch a new station in Kerbin orbit, one in Minmus orbit, and one in Kerbol orbit.  A single ship stopping off at Minmus on the way to a Kerbol orbit met all 3 mission criteria, but the crew had to then jettison the lab and other unnecessary weight in to order to make it back to Kerbin before they ran out of sandwiches.

[Tex_NL]

19 minutes ago, Evanitis said:

Yes. These days sat contracts require you to launch a 'new' satellite after accepting them. But any number of active contracts can be completed with the new craft that you build after accepting them.

Exactly.

1. Accept multiple contracts.
2. Launch with enough dV and equipment to reach all targets.
3. After completing one contract change orbit to match another.
4. Rinse and repeat until fuel and/or contracts run out.

[Washell]

5 hours ago, Norcalplanner said:

My favorite way to do it is by stacking satellites on top of each other, joined by small docking ports.

Why docking ports instead of stack separators?

[Rocketthrust]

You could put 2 cube satellites on the sides with radial decoplers, go to one orbit, deploy, go to other orbit, deploy, land, plant flag, fly home.

And remember, add more boosters!

[Norcalplanner]

1 hour ago, Washell said:

Why docking ports instead of stack separators?

Two reasons -

First, no Kessler syndrome. I have a bias against stack separators for this reason.

Second, it gives you flexibility in the future.  You can refuel and/or relocate the satellite, or even attach to an orbital science lab to offload the data for processing.

[Snark]

49 minutes ago, Norcalplanner said:

First, no Kessler syndrome. I have a bias against stack separators for this reason.

Well, technically speaking, Kessler syndrome can't happen in KSP because 1. orbital debris can't fragment, it just goes poof if it hits something, and 2. orbital debris can't collide with each other outside of the physics bubble.

In practice, accidental collisions with debris never happen in KSP.  Space is just too big, and the number of objects too small.  So it's a fine practice if you're just doing it out of a personal sense of "tidiness" because it bugs you, but it's not actually any kind of a practical problem.

49 minutes ago, Norcalplanner said:

Second, it gives you flexibility in the future.  You can refuel and/or relocate the satellite, or even attach to an orbital science lab to offload the data for processing.

This is especially applicable in 1.0.5, which added contracts that ask you to do something with an existing satellite.  Prior to 1.0.5, there was almost never any reason to do anything with the satellite once it was placed, because it was useless for "build a new satellite" contracts that come along after launching it.  Kudos to Squad for adding those contracts-- they filled a hole, there.

(Though the UI around that could use some work; I've seen a lot of puzzled posts here in this forum from people asking "why is there a colored box around my satellite in the tracking station view?")

That said, though, I typically still don't bother with docking ports on such satellites.  Rationale:  Most contract-satisfying satellites have fairly minimal requirements, so they can be very small and light.  Give one of those an Oscar tank with a Spark (or an Ant, or a couple of Spiders) and it will pack a ridiculous amount of dV, just because it's so light.  So even without a docking port, the satellites I place tend to have many hundreds of m/s of dV left, once they're in the designated orbit, which is plenty of reserve to do two or three future orbital adjustments for contracts or whatever.  There's simply no need for the satellite to have a docking port for refueling, because it already has all the fuel it's ever going to need.

Therefore, what I do is, first, try to avoid multiple-satellite launches in the first place (by launching one satellite to satisfy multiple contracts); and, second, when I do use a multi-sat launch, I tend to use stack separators, because they're stiffer than docking ports and it makes the launch easier.

Edited February 3, 2016 by Snark

[moogoob]

I once put a sattellite around Duna, as well as a surface lander in one launch. Launched them just stacked on top of each other and attached to the transfer stage, then separated once I'd done the capture burn. You could easily extend this to 3, 4 etc probes.

Heck, it's been done several times in real life - Cassini/Huygens and that recent comet probe come to mind.

[kurja]

25 minutes ago, moogoob said:

I once put a sattellite around Duna, as well as a surface lander in one launch. Launched them just stacked on top of each other and attached to the transfer stage, then separated once I'd done the capture burn. You could easily extend this to 3, 4 etc probes.

Heck, it's been done several times in real life - Cassini/Huygens and that recent comet probe come to mind.

Jool with it's many moons is a prime candidate for such shotgun approach missions. Probes everywhere! =D

[Norcalplanner]

2 hours ago, Snark said:

Well, technically speaking, Kessler syndrome can't happen in KSP because 1. orbital debris can't fragment, it just goes poof if it hits something, and 2. orbital debris can't collide with each other outside of the physics bubble.

In practice, accidental collisions with debris never happen in KSP.  Space is just too big, and the number of objects too small.  So it's a fine practice if you're just doing it out of a personal sense of "tidiness" because it bugs you, but it's not actually any kind of a practical problem.

This is especially applicable in 1.0.5, which added contracts that ask you to do something with an existing satellite.  Prior to 1.0.5, there was almost never any reason to do anything with the satellite once it was placed, because it was useless for "build a new satellite" contracts that come along after launching it.  Kudos to Squad for adding those contracts-- they filled a hole, there.

(Though the UI around that could use some work; I've seen a lot of puzzled posts here in this forum from people asking "why is there a colored box around my satellite in the tracking station view?")

That said, though, I typically still don't bother with docking ports on such satellites.  Rationale:  Most contract-satisfying satellites have fairly minimal requirements, so they can be very small and light.  Give one of those an Oscar tank with a Spark (or an Ant, or a couple of Spiders) and it will pack a ridiculous amount of dV, just because it's so light.  So even without a docking port, the satellites I place tend to have many hundreds of m/s of dV left, once they're in the designated orbit, which is plenty of reserve to do two or three future orbital adjustments for contracts or whatever.  There's simply no need for the satellite to have a docking port for refueling, because it already has all the fuel it's ever going to need.

Therefore, what I do is, first, try to avoid multiple-satellite launches in the first place (by launching one satellite to satisfy multiple contracts); and, second, when I do use a multi-sat launch, I tend to use stack separators, because they're stiffer than docking ports and it makes the launch easier.

I guess I've just gotten into the habit of putting docking ports on everything. On some of my earlier KSP missions, I would end up with discarded stages in orbit that still had fuel, or probes which had run out of fuel and became useless. Having a docking port on all my unmanned craft has just become a habit at this point, albeit one which allows me to relax a bit more. It's much easier to adapt and change things up mid-mission if docking is am option.

[John FX]

3 hours ago, Snark said:

Well, technically speaking, Kessler syndrome can't happen in KSP because 1. orbital debris can't fragment, it just goes poof if it hits something, and 2. orbital debris can't collide with each other outside of the physics bubble.

I once tried to put enough debris into LKO to hit some. I designed some `kessler bombs` and put loads of debris on orbits all designed to pass through one point in space then had a craft orbit so it also went through that point and while I did have debris whizzing past at a relative speed of up to 4km/s, nothing ever hit me even when there was so much debris the game was running at a crawl.

I don`t believe kessler syndrome is something we can have in KSP.

 

Back to OP I`d say put LOADS of sats in one launch if you need them, manned and unmanned mixed.

[Warzouz]

I do a little bot of every thing.

• For Kerbin SOI, I usually pack more fuel to fulfil several contracts.
• For other SOI, I usually pack several satellites in one launch. I did a quadruple survey scanner deployment around Jool Moon, and I also did a quadruple lander probe Tylo/Laythe (2 for each moon). Quite simple : I use BZ-52 Radial Attachment Point, add a decoupler and fix the probes on it. They only have to be balanced 2 by 2. I usually decouple every thing before entering into Jool SOI, after the correction burn.
• Finally, nearly the same as before, I fix probes radially on bigger ships (space stations). They're also deployed before entering SOI
• I also use carriers with 8 probes, built on the rockamax-sized probe core (you can imagine the size of the bugger... )

I do that mostly because it's easier and cheaper (per ton) to send heavier payloads. Strangely heavier rockets are steadier and forgives a lot on ascent. Light launcher will flip much faster if your design is a bit flawed.

So I feel better to put 400tons to LKO than 4tons. I like big rockets, don't ask me why !

[moogoob]

21 hours ago, kurja said:

Jool with it's many moons is a prime candidate for such shotgun approach missions. Probes everywhere! =D

I totally forgot! My second manned trip to Jool back in 0.23.something had a ring of four probes around it for sprinkling liberally on the Jool system.  

[Snark]

One handy approach for doing a "shotgun" mission where you want to drop multiple probes on another planet, and it's somewhere that you want to aerobrake on arrival (e.g. Jool system, or Duna, or Eve):

Stick a big 3.75m heatshield on the front, then behind that have a skinny 0.625m spindle (octagonal struts work well), with 4 radial decouplers around it, and 1.25m satellites attached to those radial decouplers.  The satellites fit in the "shadow" of the heatshield and are protected.  After aerobraking, ditch the heatshield, then decouple the satellites at your leisure.  You can stack a couple of those clusters-of-4 with no problem, too, for an 8-pack.

[kaptain_kavern]

I saw a video tutorial by Grunfworks, showing that exactly : https://youtu.be/NwDMFoMqcbA

Edited February 6, 2016 by kaptain_kavern