Hacker News Reader

Comment by starbase | Hacker News Reader

If the two stages survive long enough to do a splashdown, will SpaceX attempt to hover them over the water until they run out of fuel?

Will there be splashdown video?

View on HN

According to the flight plan published by SpaceX, the booster is going to attempt a hover in the gulf to simulate a landing, while the Ship isn’t going to slow down at all after reentry and will impact the ocean at a high velocity.

I wonder why they don't plan to execute the flip and landing burn with the ship, just for additional test data. So far it fully worked only once (and _almost_ worked a couple more times), surely it can't hurt to have another go at it, even if the ship is ultimately not being recovered. I guess propellant margins may be a cause, but then they'll likely want to have a "nominal" amount of leftover fuel onboard anyway to have a proper mass distribution for the first re-entry test...

I think the chance that the second stage survives reentry on the first attempt is almost zero anyway.

IIRC Musk said something like that in his second interview with Tim Dodd.

True, but remember he only gave falcon heavy a 50/50 shot of getting high enough before exploding to not damage the launch site on its first launch.

Musk is incredibly optimistic about schedules, and pessimistic about launches.

“We will launch very soon and it will explode very big”

It would be hard for him not to be pessimistic about launches given the early years of SpaceX. Not even their 150-odd successful Falcon 9 launches/landings would erase the scar tissue.

Perhaps the version of the upper stage they're launching is not equipped with whatever the relevant control surface hardware (ailerons / grid fins / etc..) is?

It has everything.

But they're obsolete. S24 uses hydraulic actuators, S27 uses electric actuators.

Mass distribution consistency is important. They can't just lop them off and change the design ad hock.

Just fyi, “ad hoc”. Latin.

> I wonder why they don't plan to execute the flip and landing burn with the ship, just for additional test data

There's been a lot of speculation about this over the last week, and consensus seems to be they decided they were trying to do too much on the first launch, and they should limit the scope down to just the "essentials" and learn from that.

They don't want to over complicate things.

I would also expect them to want to inspect the heatshield.

I remember Elon saying that flight test 1 would attempt to do a soft touchdown in the water.

Reply on news.ycombinator.com