# How does SpaceX decide which half of the Falcon 9 fairing to catch?

Question: How does SpaceX decide which half of the Falcon 9 fairing to catch if they are only going to catch one half? Is one half more expensive and/or well instrumented than the other?

Images from this SpaceX tweet:

Falcon 9 fairing halves deployed their parafoils and splashed down in the Pacific Ocean last week after the launch of Iridium-6/GRACE-FO. Closest half was ~50m from SpaceX’s recovery ship, Mr. Steven. http://instagram.com/p/BjdAcCuFegz

Click images for full size view, or just go to the tweet.

• They could try for both - if they are able to land them at different times (by timing entry angle or parafoil deploy?) then they could try to catch the first one and if they miss, race for the second one (and set landing target coordinates so there is as little as possible maneuvering needed to get from A to B). – jkavalik Jun 1 '18 at 6:34
• Seems like you have the answer in your question: Closest. – SF. Jun 1 '18 at 14:10

The ultimate plan is to catch both of them, on ships like Mr Steven.

Initially they only have one boat, so they have been adding the parachutes to both of them, but only trying to catch one. The theory is that once they figure this out, a second boat is easy to add, built to the final standard. Building two, and then modifying them both is wasteful until they know the proper final standard needed.

On several of the last attempts they have come back with a seemingly complete fairing (sometimes damaged from landing on water visibily, sometimes looking fine) and either pieces or a whole second fairing.

Here is an example from the Iridium 6-Grace mission where Mr Steven returns with both halves, thus both had parachutes to try softish landings.

The two halves are actually different as one is active (has pushers for separation) and the other is passive (it gets pushed). Thus the active half is more valuable if successfully recovered than the passive half, making the choice easy. The ultimate goal is of course, both.

In the mean time, since they float they were still able to recover both halves from the ArabSat Falcon Heavy launch today. Per Space.com's SpaceX Recovered Falcon Heavy Nose Cone, Plans to Re-fly it This Year (Photos) and also ElonMusk Tweet:

Both fairing halves recovered. Will be flown on Starlink 💫 mission later this year.