How to recover solid rocket boosters in full 1.1 campaign?

[jpinard]

I did Google this but came up empty for how things work now vs. when I played a long time ago.  It used to be I could attach parachutes to the SRB's and have the decoupler and parachute trigger at the same time. SRB's would float nicely back down to Kerbin.  But now I can't seem to find a way to recover them.  I'd especially like to be able to recover the kickback boosters. But when I have the parachutes open just before decoupling the boosters they're always destroyed.

Thanks for the help!

[Jarin]

Aside from a stage recovery mod, I've never figured out how to recover high-velocity boosters. The best I've managed is the smaller boosters that burn out before passing "unsafe parachute speed"

[Alshain]

Unless you are dropping them low to the ground and having their chutes open at an incredibly low altitude, it's pretty hard to do.  They have to be on the ground before you move out of physics range and even with the extended range added a few patches ago, you are just moving way too fast.

I'm not sure you are remembering right, I don't believe you could ever do this properly in stock.

Edited April 21, 2016 by Alshain

[John FX]

I use the stagerecovery mod. It does what I would like a mod to do regarding recovery. If there is a chute on a part does the calculation for your landing speed, checks to see if you would survive and works out a recovered amount. No need to activate the chute.

If there is power, a core, fuel and an engine it will attempt a powered landing (simulated) and you get funds for that too.

As for stock chutes they are only good up to about 260m/s. any faster and they break.

Edited April 21, 2016 by John FX

[LaytheDragon]

In 1.1, debris automatically recover if at KSC (I don't know when, so I would assume after going to the space center scene). This may not help, but it may, depending on when you eject the boosters (though if they survive, you should be able to manually recover them).

 I see debris from my launchers hit the ground in the background all the time, so I wouldn't worry too much about the physics range once the parachute problem is fixed (not that the OP ever mentions physics range problems, anyways).

You may want to use thrust limiters on your boosters so they boost you, but not past parachute-destroying speed. Also, one can try using multiple drogues instead of regular chutes.

Edited April 21, 2016 by LaytheDragon

[Znath]

I guess you could try fitting them with probes and air brakes.  Deploy the airbrakes when you jettison them to buy some time on their way down.  Switch to them when you get out of the atmosphere. Activate parachutes?  Hope?

[fireblade274]

4 minutes ago, Alshain said:

Unless you are dropping them low to the ground and having their chutes open at an incredibly low altitude, it's pretty hard to do.  They have to be on the ground before you move out of physics range and even with the extended range added a few patches ago, you are just moving way too fast.

I'm not sure you are remembering right, I don't believe you could ever do this properly in stock.

I still hope for a day where we can adjust (in my case crank up) the physics range, to make this more feasible. That, along with an ability to drop a stage, forget about it, and have attached parachutes deploy only after the debris are going slow enough.

Actually, is the latter proposition already possible if you place a probe core on the stage your ejecting, then switch to it to deploy the parachutes upon safe speed, then switch back--and hope your main rocket/plane is still doing okay? I'd rather be able to deploy and forget though for the record.

I have a plane that does this and recovers "hammer" SRB's, as long as they land before i'm too far away, which is usually what happens

 

[Alshain]

6 minutes ago, fireblade274 said:

I still hope for a day where we can adjust (in my case crank up) the physics range, to make this more feasible. That, along with an ability to drop a stage, forget about it, and have attached parachutes deploy only after the debris are going slow enough.

Actually, is the latter proposition already possible if you place a probe core on the stage your ejecting, then switch to it to deploy the parachutes upon safe speed, then switch back--and hope your main rocket/plane is still doing okay? I'd rather be able to deploy and forget though for the record.

I have a plane that does this and recovers "hammer" SRB's, as long as they land before i'm too far away, which is usually what happens

 

The latter is possible if you adjust the deployment parameters on the chute.  That is unless you are skimming the ocean surface in that plane, it should be possible.

 

I used to use the Stage Recovery mod, but I've grown much more skilled at building efficient lifters now and using StageRecovery unbalances the game and I end up with way too much funding.

Edited April 21, 2016 by Alshain

[fireblade274]

9 minutes ago, Alshain said:

The latter is possible if you adjust the deployment parameters on the chute.  That is unless you are skimming the ocean surface in that plane, it should be possible.

 

I know that you can set a deployment altitude by right clicking on the part, but you cant set the semi-deployment altitude, which happens when you release the stage. So, if you want to eject and forget a stage that you want recovered, you can't do this unless you can allow an ejected debris to delay semi-deployment parachutes until below a certain speed/altitude, correct?

Edited April 22, 2016 by fireblade274

[Alshain]

Just now, fireblade274 said:

I know that you can set a deployment altitude by right clicking on the part, but you cant set the semi-deployment altitude, which happens when you release the stage. So, if you want to eject and forget a stage that you want recovered, you can't do this unless you can allow an ejected debris to delay semi-deploying parachutes until below a certain speed/altitude, correct?

If you set the minimum pressure to deploy high enough, it won't pre-deploy.  I've landed craft on Eve with no input from me this way.

[fireblade274]

Just now, Alshain said:

If you set the minimum pressure to deploy high enough, it won't pre-deploy.  I've landed craft on Eve with no input from me this way.

By God your right. Brilliant.

[Alshain]

2 minutes ago, fireblade274 said:

By God your right. Brilliant.

Lol, glad I could help.  When you play with RemoteTech, learning to land a probe with no communications signal is a must.

[bewing]

2 hours ago, jpinard said:

I did Google this but came up empty for how things work now vs. when I played a long time ago.  It used to be I could attach parachutes to the SRB's and have the decoupler and parachute trigger at the same time. SRB's would float nicely back down to Kerbin.  But now I can't seem to find a way to recover them.  I'd especially like to be able to recover the kickback boosters. But when I have the parachutes open just before decoupling the boosters they're always destroyed.

Thanks for the help!

For most of my launches, I recover my first stages (usually a triplet of kickbacks). How to do it:

You have to understand that if you are not watching a stage as it falls through the atmosphere, then when it falls to about 25km altitude, it gets automatically deleted.

So you have to switch to it, and watch the stage as it descends all the way to the ground and stops. As long as it is moving in the atmosphere, once you start watching it you are unable to switch away from it.

So the problem is that this can take a few minutes, and during those minutes the upper stage of your craft is uncontrolled.

The basics: So, you launch. You do whatever you have to do to get your upper stage into a trajectory where you can ignore it for several minutes. You make sure you switch back to watching your stage 1 before it falls too low and gets deleted. You watch it touch down. Then maybe you switch back to your upper stage and finish putting it in the proper orbit. This method is often a little inefficient with upper stage fuel, but you can save 10 thousand kerbucks per launch by recovering your boosters -- which buys a lot of fuel.

The details: You can either have a probe core attached to your stage 1, so that you can control aerodynamic surfaces and deploy chutes at a moment of your choice. Or you activate the parachutes on your stage 1 during ascent -- and then use the tweakables to control auto-partial deployment and auto-full deployment on drogues and main chutes. You can also use action groups to prepare your stage 1 boosters for landing, just before you decouple them.

If you would like an example craft and launch instructions, say so.

 

Edited April 22, 2016 by bewing

[wumpus]

I figured out how to do this for 1.0.x a ways back and gave up as I didn't feel it was worth it.  As mentioned:

You have to get your SRBs back to the ground before the main ship exceeds 25km (technically, you *could* drop them on the mountains behind KSC, but I've never been interested).  This means using Thumpers and Hammers, not Kickers.

You need to reverse the course of your SRBs fast:  probably the best way is to put flea/hammers on top of them (hopefully your main rocket is long enough so that the combined thumper+flea can have fins on top).  So now your "drop SRB stage":

• drops the SRB
• fires the "retro SRB flea stage"
• release the drogue chute [optional: drogue chutes are only recommended if the flea isn't working right.  Also they are pretty late on the tech tree for this type of silliness.]
• releases the parachute (with pressure adjusted to not release until the flea is done).  Note, for best effect the chute should open just late enough to stop the booster before landing.  You can hit 25km pretty fast while an SRB is slowly wafting down.

At this point I just grab a mod (typically flight manager [the SVN-style one] or stage recovery [the one that recovers for you]).

[klesh]

16 hours ago, LaytheDragon said:

In 1.1, debris automatically recover if at KSC.

Thats a setting in the main menu, the default is to clean clutter, but it can be turned off.  

[jpinard]

OK I have to say I'm curious.  This game is a lot easier than real life, but it appears the Space Shuttle's SRB's did this with ease.  What is different in real life vs. this?  Were they going at a much lower relative speed and didn't have to worry about heat?

I have to say I am super confused because the kickback boosters specifically mention recovery as a leading principle of their use.

[mrclucks]

Stage recovery mod will attempt to recover anything with a parachute, regardless if you deploy it or not.  You can also adjust the pressure where the parachutes will predeploy, but you'll probably have to play around with it to get it in an area where it's not too low and not too fast

[Loren Pechtel]

On 4/21/2016 at 4:57 PM, Alshain said:

I used to use the Stage Recovery mod, but I've grown much more skilled at building efficient lifters now and using StageRecovery unbalances the game and I end up with way too much funding.

They should make some better way for us to bring things down so we don't need Stage Recovery.  It's just providing something that should be in the game anyway.

[Alshain]

13 minutes ago, Loren Pechtel said:

They should make some better way for us to bring things down so we don't need Stage Recovery.  It's just providing something that should be in the game anyway.

They could do that, they would just have to rebalance the game so you make less money.

[Jarin]

 

1 minute ago, Alshain said:

They could do that, they would just have to rebalance the game so you make less money.

It fits my balance just fine, honestly. I never liked grinding, and this frees me up to do biger rockets earlier. Facility upgrades still eat the lion's share of my budget

[Alshain]

12 minutes ago, Jarin said:

 

It fits my balance just fine, honestly. I never liked grinding, and this frees me up to do biger rockets earlier. Facility upgrades still eat the lion's share of my budget

Well it doesn't fit my balance, so either rebalance or leave it like it is with no recovery.

[Loren Pechtel]

23 minutes ago, Alshain said:

They could do that, they would just have to rebalance the game so you make less money.

True, but I think it would be fair, it would reward good design.

I've even figured out how they could do it without too much pain:

If "debris" consists of multiple parts and it's on a path that intersects the atmosphere then don't delete it.  Let it fly until it's either destroyed or touches down and if it touches down recover it.

[Alshain]

40 minutes ago, Loren Pechtel said:

True, but I think it would be fair, it would reward good design.

I've even figured out how they could do it without too much pain:

If "debris" consists of multiple parts and it's on a path that intersects the atmosphere then don't delete it.  Let it fly until it's either destroyed or touches down and if it touches down recover it.

Depends on how you look at it.  Rewarding good design by removing all the challenge from the game, feels more like a punishment.

They can't leave the debris when it is in the atmosphere because they can't calculate physics for it.  They don't know that it will touch down at all, unless it's periapsis is below 0, but what if it isn't?  What if it has a 10km Pe?  It clearly should crash or touch down due to aerodynamics, but since you aren't calculating physics, you would never know that.

Edited April 25, 2016 by Alshain

[Dafni]

On 22.4.2016 at 3:48 AM, bewing said:

You have to understand that if you are not watching a stage as it falls through the atmosphere, then when it falls to about 25km altitude, it gets automatically deleted.

Now how stupid is that? I wish the game would not do this.

[Harry Rhodan]

2 hours ago, Alshain said:

They could do that, they would just have to rebalance the game so you make less money.

SRBs already are dirt cheap and and you can only recover 40% of their value. Heck, parachutes on a Thumper are worth more than the burnt out SRB they are meant to recover.