Landing rockets

Reusable parts can reduce long-term cost, but landing requires both vehicle hardware and a planned flight sequence.

Capsules generally need parachutes to be recovered. Stages generally need landing legs and enough remaining propellant to survive entry, slow down, and touch down safely.

Screenshot placeholder: returning booster trajectory with landing burn event selected.

Before planning a reusable stage, check that it has:

• Landing legs if the stage is expected to land upright.
• Enough engine thrust for a landing burn.
• Enough propellant reserve after ascent or mission burns.
• A trajectory that returns to the base planet without burning up in the atmosphere.

The reusable hardware adds mass, so it can reduce payload performance. Design the rocket with that tradeoff in mind.

A boostback burn changes the spent stage's downrange path after separation. It is used when the stage needs to return toward the launch site or target a safer landing area.

Place the boostback shortly after staging, while the booster still has control authority and propellant. Tune the direction and duration until the predicted impact or landing point moves where you want it.

During atmospheric return, the simulator uses integrated flight instead of simple on-rails conics. This is where drag, heating risk, and trajectory shape matter.

Use the predicted path to check whether the stage survives re-entry and whether it keeps enough velocity margin for the final burn.

A landing burn cancels the remaining vertical speed close to the ground. A suicide burn is the efficient version: it starts late enough to save propellant but early enough to avoid impact.

Tune:

• Burn start time.
• Throttle.
• Direction, usually close to retrograde.
• Duration.
• Remaining propellant after touchdown.

Small timing changes can have large effects near the surface, so use the timeline carefully and review the final trajectory after every edit.

A part is reusable only if it lands back on the base planet and satisfies its recovery requirements. Recovered parts can then be used by future launches instead of being manufactured again.