Need Help Recovering Boosters Effectively...

[Kardea]

Hokay, so. I have what I hope is a relatively straightforward question:

Let's say I launch a rocket that uses a pair of booster assemblies (one on each side). The boosters are to be used at launch and jettisoned in-atmo when their fuel is spent. With the recent addition of career mode, it'd be nice to safely recover these boosters and get the money back. My question is: is there a way to have a booster deploy a parachute on it's own after separation? I know that I could technically fit each with a probe core and control them that way, but the reality is that there simply isn't enough time to switch to each, pop the chute on each, and then switch back to my mid-flight "main" rocket without chancing a catastrophe. Anyone figured out a way to get the booster assemblies down safely?

Thanks!

[DBT85]

You need to get your main rocket high enough that you can use the probe core to "control" your boosters on the way down before your rocket starts to fall back again.

[Vlk]

You can activate the chutes in the same stage with the separators. But if they are farther than 2.5 km and in the atmosphere, they die.

So yes, you have to drag the reusable boosters up above the atmosphere, detach them, create an orbital, or suborbital path with your vessel, switch back to the boosters, and wait until they descend. But: you dont need a probe, you will get the money. You dont get the report when recovering, but you get the money back.

If you make a suborbital path, you have to know that you have to wait until the boosters fall down in the atmosphere, so, that suborbital path has to be big enough!

[Russoft]

The issue isn't opening a chute. You can stage is that way so that the boosters float down. The issue is that without a probe core, you can't get refunded for the booster, and below about 20 km objects tend to vanish even if they have Kerbals aboard (if you're not focused on the craft). Hence, if you want to recover boosters, detach them at a point where they will rise to a great altitude (300 km for example) before plunging back to Kerbin. Then get your payload into orbit using its engines. Then switch back to your booster(s) and watch them float back to the surface. Keep in mind that boosters aren't worth much to begin with (depending on design) and using this strategy, the boosters will fall far from KSC which means a small refund. My best successes come from a cheap first stage/boosters that can be discarded and a pricey second stage that takes the payload to LKO and still has fuel to be deorbited above KSC for an almost full refund.

[Taki117]

There's a mod for that.

Or this one.

[Th_]

One way of doing it is to set the booster's parachutes to have a Minimum Pressure value of 0.5. It depends on how high you drop your boosters, but this will allow it so that your chutes pre-deploy later, so this will work in some cases, although not all. I strongly suggest the DebRefund or StageRecovery mods, as they allow recovery of spent funds from dropped boosters and stages, and are necessary for reusable space programs in my opinion and should . These mods allow "debris" that goes out of loading range, with parachutes on them deployed, to be recovered. Doing this completely stock is borderline impossible, and the cost of SRBs is dirt cheap, so if you are bent on completely stock, a solid only first stage is a good idea, as nothing else could feasibly be as cheap for the thrust you get.

[cpast]

The issue isn't opening a chute. You can stage is that way so that the boosters float down. The issue is that without a probe core, you can't get refunded for the booster, and below about 20 km objects tend to vanish even if they have Kerbals aboard (if you're not focused on the craft). Hence, if you want to recover boosters, detach them at a point where they will rise to a great altitude (300 km for example) before plunging back to Kerbin. Then get your payload into orbit using its engines. Then switch back to your booster(s) and watch them float back to the surface. Keep in mind that boosters aren't worth much to begin with (depending on design) and using this strategy, the boosters will fall far from KSC which means a small refund. My best successes come from a cheap first stage/boosters that can be discarded and a pricey second stage that takes the payload to LKO and still has fuel to be deorbited above KSC for an almost full refund.

You can absolutely get refunded without a probe core; anyone who says otherwise is wrong. There is no dialog, but the appropriate percentage of funds are restored. Probe cores have zero influence on recovery, except that if you have a LOT of debris, the game starts autoremoving old debris (won't affect any craft with fewer than like 50 dropped things).

[Russoft]

You can absolutely get refunded without a probe core; anyone who says otherwise is wrong. There is no dialog, but the appropriate percentage of funds are restored. Probe cores have zero influence on recovery, except that if you have a LOT of debris, the game starts autoremoving old debris (won't affect any craft with fewer than like 50 dropped things).

Fascinating. I guess I haven't tried, just assumed that was the case based on what I'd heard. I'll have to try this. Thanks!

[Claw]

Yes, it is true that you will be refunded money for RECOVERY of debris even without a probe core.

However, this does not happen automatically. As was posted already, any object that falls outside of physics range (about 2.5km) and is below 0.1 atmospheres (below about 23km on Kerbin) will be deleted, not recovered. That means you will not get funds back in that case.

If you want to activate parachutes on dropped boosters, you can put the parachute activation icon in the same stage as the decouplers. Chutes will auto deploy at the selected altitudes.

Without some fancy designing and flying, you'll need mods like Taki said. There are several that extend physics range and do other things that can help.

If you want to do it all stock, your best bet is to design a booster section that comes down in 1 piece if able. It needs to be able to coast suborbital up to 40-ish km to give you time to get your real ship close enough to orbit that you can switch back and follow your boosters back down.

In stock, you basically must watch them land in order to be able to recover them and get funds back.

[bdito]

The mods Taki mentioned work well.

Recovering boosters on the vanilla game is pretty much pointless IMO. After you separate boosters the game deletes them once they're 2500m from your ship. So they never even reach the ground for recovery.

The only way I know of is to control them like you would a probe. But that creates more difficulties and it's not cost effective. So in the end, just let them crash and burn.

[Geschosskopf]

The only way I know of is to control them like you would a probe. But that creates more difficulties and it's not cost effective. So in the end, just let them crash and burn.

I agree, because I disagree with the whole money refund on salvage anyway. The real world track record for reusable spacecraft is very bad so far, with the shuttle never having been cheaper than 1-shot rockets. SpaceX is giving it a go again and I wish them luck but I really doubt it will work well enough to be commercially viable. Their initial attempts to use parachutes on their boosters worked not better than those on the shuttle's SRBs, so now they're trying to fly the things down. Reserving 30% of their payload capacity for this capability, which seems like economic suicide.

But in the meantime, if I could disable all refunds on recovered parts, I would.

[MarvinKitFox]

SRB's are cheap for a reason.

Use them as disposable boosters in the very low atmosphere.

The second stage/1.5th stage booster, that takes you on your 10km -> 80 boost, but not orbital insertion is the one that is most easily recoverable, and usually masses the most (thus likely cost a lot)

I use one of the SLS engines as primary engine on my booster. Expensive, yes. But very efficient.

I add a probe core, batteries(essential), and several parachutes.

I separate booster from orbital ship at about 45km, with apogee of about 85km.

While the booster is completing its leisurely arc, I have time to circularise my ship's orbit before the booster reenters the atmosphere.

With no other effort, I can land and recover for 85% of booster value. (about 450km downrange)

However, I've recently started doing the SpaceX thing.

Launch more vertically, sep at 40km, and immediately start to circularise my main ship.

When ship and booster pass about 65km, switch back to booster. About here is where your ship normally coasts for a minute, anyways.

Burn 270 degrees, until its trajectory is heading right back at KSC.

Quickly flick back to ship, complete orbital insertion.

Flick back to booster (by now falling at about 45km)

Land it on the runway! Reclaim 100% of booster value!!

Using this approach I lose only about 150m/s of boosted delta-v, and maybe another 120 due to inefficient gravity curve.

Well worth the savings, as my core booster costs 65k

With this approach, my only losses in a launch are fuel (about 18k), and 9 small SRB's.(on 3 decouplers!)

This puts a 25ton ship in orbit.