Stagger two boosters' burnout

Cast one pair of solid boosters to run out before another, so the empty cases can be dropped while the rest keep pushing.

Use this when a rocket is carrying more than two boosters and you would rather not haul all of them, spent, up through the thick air. A pair that burns out early can come off early — but only if it actually finishes first, and by default every booster you place is cast the same way.

Before you start

• You have bought the Solid Boosters tech node, and Radial Staging for the decouplers that hold them on.
• Four boosters are on the canvas, strapped to the flanks of a stage on Decouplers, in two mirrored pairs.

1. Tap one booster of the inner pair to select it, then tap it again. Its properties sheet opens at the bottom of the screen with a Length slider and a Burn rate slider on it.
2. Drag its Length slider up. The case grows downward, and the BURN TIME row rises with it: at 128 a Solid Booster burns 60 s, at 288 it burns 135 s. The thrust reading does not move — a longer case is a longer burn, not a harder one.
3. Watch the twin follow. A mirrored booster takes every setting from the one you changed, so the pair stays matched and the rocket stays balanced. Boosters you placed one at a time instead of mirroring do not: set those by hand, or two different burns on opposite flanks will turn the ship as one of them quits.
4. Tap one booster of the outer pair and leave its Length where it is. Drag its Burn rate up towards 150 % instead: the same grain leaves faster, so it pushes harder and finishes sooner — 40 s at 150 %.
5. Read the two BURN TIME rows against each other. The outer pair should now be the shorter of the two by a comfortable margin — twenty seconds or more, so you are not trying to catch two burnouts at once.
6. Give each pair its own stage. Open Stages in the top bar, make a stage holding only the outer pair's two Decouplers, and a later one holding the inner pair's. Put them in the order the boosters will finish in.

What you should see

On the way up, the outer pair's flames go out first. One press of STAGE drops those two cases while the inner pair is still burning, and the rocket carries on lighter. A second press drops the inner pair when their flames go out in turn.