Any way to Heavy a Falcon launch?

[Grand Ship Builder]

Does anyone have tips on how to land 2 seperate boosters decoupled at the sametime in the lower atmosphere?

[Jas0n]

You can use FMRS to land one then the other, but landing both at the same time would require some juggling, unless you can get an auto pilot to control one of them, or both.

[Dafni]

I did it before in stock, as have many others. It requires some thought, but it is entirely possible.

First of all, can you do it with one booster, like a Falcon 9 does?? If yes, then you know that everything becomes much easier if the first stage has a Ap of over 70km (ie the game wont delete your booster anymore)

Now with two side boosters you can do something very similar, just do the two boost-back burns slightly different, so that one booster stays airborne a bit longer, giving you time to land the first one.

You could go to the famous twitch stream of @MatoroIgnika, I learned this from him actually. Find an old video of him doing it, or actually ask him on a live stream and I am sure he will show it off and explain you how to do it.

Edited August 21, 2017 by Dafni

[ZooNamedGames]

11 hours ago, Dafni said:

I did it before in stock, as have many others. It requires some thought, but it is entirely possible.

First of all, can you do it with one booster, like a Falcon 9 does?? If yes, then you know that everything becomes much easier if the first stage has a Pe of over 70km (ie the game wont delete your booster anymore)

Now with two side boosters you can do something very similar, just do the two boost-back burns slightly different, so that one booster stays airborne a bit longer, giving you time to land the first one.

This is accurate.

For me and my landable first stages, the best technique is to quicksave while rising to apo.

Also the slowmo mode (can't remember the name) is very useful. As the last 10 seconds of landing are always the most intense. It makes it much easier if you can process what's happening over a longer period of time rather than in the rapid 10 second window.

Also, stock landing legs are weaker than toothpicks for booster landings!

[septemberWaves]

2 minutes ago, ZooNamedGames said:

Also, stock landing legs are weaker than toothpicks for booster landings!

Using wings as landing legs is a nice way around this.

[linuxgurugamer]

Better Burn Time has slomo mode

[ZooNamedGames]

1 minute ago, eloquentJane said:

Using wings as landing legs is a nice way around this.

They are generally just as weak. They have no impact tolerance.

2 minutes ago, linuxgurugamer said:

Better Burn Time has slomo mode

Then that'll do.

[Grand Ship Builder]

4 minutes ago, linuxgurugamer said:

Better Burn Time has slomo mode

So does better time warp.

[linuxgurugamer]

Ooops.  I meant Better Time Warp

[EpicSpaceTroll139]

As mentioned earlier, there are some ways to do this in stock, but they require much juggling, trajectory management, and short time windows.

You could probably do this kind of thing using a kOS script, but it would be quite complicated. I can't even get a single booster to target the launchpad with any accuracy from over 1km altitude.

@ZooNamedGames What size boosters are you trying to land on what size of how many gear gear? I've landed double orange tank boosters on 4 large legs before, and could probably do more on the same gear considering how light tanks are when near empty.

[ZooNamedGames]

1 hour ago, EpicSpaceTroll139 said:

As mentioned earlier, there are some ways to do this in stock, but they require much juggling, trajectory management, and short time windows.

You could probably do this kind of thing using a kOS script, but it would be quite complicated. I can't even get a single booster to target the launchpad with any accuracy from over 1km altitude.

@ZooNamedGames What size boosters are you trying to land on what size of how many gear gear? I've landed double orange tank boosters on 4 large legs before, and could probably do more on the same gear considering how light tanks are when near empty.

2 of the largest white tanks with maybe the fuel tank that's half that on 4 of the heavy legs. It works, it's just that the margin for error is behemoth. Maybe out of 20 attempts one will land successfully.

Now I have tried 4x symmetry with 3 per 1 of the 4 sides and that works moderately well but I feel that it's like dropping an atom bomb to drive a nail in. Bit overkill and past the realism.

[Dafni]

If you are willing to try out a parts mod, the landing legs and grid fins from KRE are very nice for these kind of landings

Usually I am not one for parts mods, but I have some installs where I add just the legs and fins from KRE because I think something like this should be in stock by now.

 

2 hours ago, ZooNamedGames said:

Also the slowmo mode (can't remember the name) is very useful. As the last 10 seconds of landing are always the most intense. It makes it much easier if you can process what's happening over a longer period of time rather than in the rapid 10 second window.

that sounds interesting. I never knew such a thing as a slowmo mod existed. Might have to look into that indeed, maybe raise the success rate on those landings with super tight fuel budget. Altough it has to be said I enjoy the challenge of those intense 10 secs a lot lately.

 

[ZooNamedGames]

22 minutes ago, Dafni said:

If you are willing to try out a parts mod, the landing legs and grid fins from KRE are very nice for these kind of landings

Usually I am not one for parts mods, but I have some installs where I add just the legs and fins from KRE because I think something like this should be in stock by now.

 

that sounds interesting. I never knew such a thing as a slowmo mod existed. Might have to look into that indeed, maybe raise the success rate on those landings with super tight fuel budget. Altough it has to be said I enjoy the challenge of those intense 10 secs a lot lately.

 

I'd love to try the mod but like you, I'll just have to wait until it's stock since I'm a vanilla kinda guy.

[MaxxQ]

There's a mod out there (can't recall the name) that allows you to fly other craft in formation with your main craft.  It just mirrors what you do with your main vehicle.  It may be that this could be adapted to landing multiple boosters at the same time (designate one booster as the "lead" and the second will follow it automatically).  I have no clue how one would do that, or if it's even possible.

Edit: Found it.  The mod is called Burn Together Continued.

Edit 2:  There doesn't appear to be a page on the forums for the mod, but you can download it here: 

Burn Together
Releases link: https://github.com/PapaJoesSoup/BurnTogether/releases
Issues link: https://github.com/PapaJoesSoup/BurnTogether/issues

Edited August 15, 2017 by MaxxQ

[septemberWaves]

On 8/15/2017 at 6:53 PM, ZooNamedGames said:

They are generally just as weak. They have no impact tolerance.

Impact tolerance mostly seems to be based on landing speed. Are you really trying to land boosters at more than about 12m/s? I usually save a bit of fuel if I'm planning on landing a booster, and use that to slow it almost to a halt right before landing even if I'm using parachutes too.

[ZooNamedGames]

1 hour ago, eloquentJane said:

Impact tolerance mostly seems to be based on landing speed. Are you really trying to land boosters at more than about 12m/s? I usually save a bit of fuel if I'm planning on landing a booster, and use that to slow it almost to a halt right before landing even if I'm using parachutes too.

I try to aim for under 10m/s. I usually save one of the smallest fuel tanks in the diameter I am using for landing alone.

[KerikBalm]

On 8/15/2017 at 8:29 AM, Dafni said:

... if the first stage has a Pe of over 70km (ie the game wont delete your booster anymore)...

Ummm... then its just a SSTO rocket that decouples its payload. That's not a booster, its the entire launch vehicle.

Also I believe that the PE limit for no deletion is more like 23 km (even then, you're mostly to orbit anyway).

With strictly suborbital decouplings, you can still recover spent stages, 100% stock, but its fairly difficult.

You need to get your main craft's Ap over 70km to switch back to the booster(s). Ideally you get the upper stage to orbit and then switch back to the boosters before they go below 23km.

This doesn't recover the SRBs because they burn out too fast:

But the main tank gets recovered just short of the coast on the far side of the ocean east of KSC, the orbiter has enough fuel to circularize.

This was an attempt at a flyback booster, closer to the falcon system:

Here I got both the booster and the orbiter over 70 km Ap, 70km so that I can switch to a vessel outside the physics bubble (it won't allow you to switch otherwise, even if it won't delete stuff until 23km)

So I switched to the booster which still had some fuel:

and reversed its direction (keep in mind the rotation of kerbin, and its ability to glide):

Switched back to the orbiter and did the orbital insertion burn:

Switched back to the booster before it got under 23km, and flew it back to the runway:

(I may have had to quickload, it doesn't look like that's going to pull up fast enough)

I'm sure with some tweaking and drogue chutes/airbrakes, I could make it do a vertical landing somewhere in the vicinity of KSC

[Dafni]

On 18.8.2017 at 3:56 PM, KerikBalm said:

Ummm... then its just a SSTO rocket that decouples its payload. That's not a booster, its the entire launch vehicle.

 

You are right of course. I wrote Pe instead of Ap. Sorry for the confusion. I corrected it in my post. Was just a brainfart typo, the rest is correct and how me and many others do it on a regular basis. (for example the famous streamers EJ_SA or MatoroIgnika)

[samstarman5]

The real trick here is not only landing the boosters, but to take it even further. Refueling them after landing and then using them again for another launch and not just salvaging.  That is, of course, if you really want to emulate the full Falcon experience.  Whether you do liftoff horizontal or vertical is up to you, but it should certainly feel more legit if the second launch was the same attitude as the first launch.

[dvp]

If you were lazy and sufficiently Kerbal enough, couldn't you just make a booster with a bunch of parachutes, stage them, and let them fall back? Assuming they didn't burn up on reentry, anyway?

 

Or is that one of those "outside physics range" issues?

[KerikBalm]

Quote

Or is that one of those "outside physics range" issues?

Basically yes.

The only way for this to work is if the boosters land before moving outside the physics bubble*, or focusing on the booster and following it down to the ground... but then your main craft needs to be going high enough with a high enough TWR, that you can switch back to it -before it gets too far past Ap- and complete orbital insertion.

*I actually have made some designs that do this, but the burn time of the boosters is extremely short. I even used the escape towers as boosters because they have a great TWR (those on top of the flea SRBs with barely any fuel in them, and a set of parachutes).

With very high TWR , short burn time boosters, I can get the craft to >100 m/s before decoupling, and have the boosters land under parachute before leaving the physics range.

Its not just  just the >100 m/s, but reduced gravity losses on ascent because of that.

Its not a massive help, but it helps and is 100% recoverable. (you can also do this with RATO boosters for horizontal launch spaceplanes)

[Tyko]

For those of you open to mods, StageRecovery enables you to set up stages to recover by parachute even outside physics range. I believe it basically shortcuts the landing process by asking "does this booster have enough parachutes to land safely?". If 'Yes' then the stage counts as recovered. Not nearly as cool as landing them yourself, but another option.

 

 

[DAL59]

Use flight pause mod to pause one booster.  

 

[Vanamonde]

This question about how to play the game has been moved to Gameplay Questions. 

[Helmetman]

Another trick I used for landing 2 boosters is to use docking ports on the boosters that connect them rather then decouplers.

This way you can undock both boosters @ 70km or anywhere you might detach them and land it as one. Obviously you need some skill in docking to manage it since you have about a minute window (depending on your ascent profile obviously)

Or, you do the same but you put a 3rd stage beneath the center engine of the 2nd stage.
Then you attach side boosters/tanks/engines to the sides and when you decouple they detach as one. You might need some crash obsorbing parts in between the center tank and the outer tanks (boosters) or they might hit against one another during staging.