Jeff Findley wrote on Tue, 17 Apr 2018
20:05:43 -0400:

In article ,
says...

https://www.space.com/40313-spacex-r...y-balloon.html

I find this interesting for a couple of reasons.

The approach is interesting and I wonder who much it'll impact the final
payload numbers.

On Falcon 9 the mass of the system would be fairly critical so they
might not be able to recover very many of those stages. But on Falcon
Heavy, the mass penalty wouldn't matter much, so you'd think they could
try to recover many more.

But more so, it seems like both a somewhat low-risk, but also low-reward
approach.

It's low-risk since if it doesn't work, they're already beating folks on
launch costs, so if this fails, they're not out anything. Their business
model doesn't depend on ths.

On the other hand, recovering a single Merlin won't save them that much
money. And if BFR is so close flying, what's the point?

Practice for the upper stage of BFR. More engineering data. Even when
SpaceX doesn't plan to recover a Falcon 9 first stage, they've been
using them for test "landings" in the ocean in order to gather more data
on "hotter" reentry and landings.

I mean I think it's pretty cool, but ultimately, I wonder who much it'll be
worth the trouble. (assuming they do catch the thing somewhere in the
Pacific, they still have to then get it back to the US mainland.)

Though, it suddenly dawns on me, heck, save the engine, forget the tanks and
you can fly the engine home in a air-freighter and still save the most
costly item.

I doubt SpaceX would do that. They'd want the whole stage back for
inspection, even if the engine is the only thing they can actually
reuse. Again, more engineering data.

Build a little, test a little, fly a little. That's how they're gaining
their experience in reuse.


Oh, I didn't mention it before, but if you're using Falcon Heavy for
Moon missions, you're using it in expendable mode because if you try
to recover the cores you have nowhere near enough boost for those
missions.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw