[mrec]

One thing I've not seen mentioned in the coverage so far: how much payload is sacrificed by the need to keep fuel in reserve for the return to base?

I'm guessing the sacrifice is roughly equal to the mass of unburnt fuel in the booster at the point of booster separation, but don't much trust my intuition on these things.

[ChuckMcM]

   > how much payload is sacrificed by the need to keep fuel
   > in reserve for the return to base?

Simple answer: None.

A more detailed answer is that building a system which can be reused is an economic proposition. So that the Falcon 9 can lift X Metric tons to orbit for $Y. The way in which they keep the value $Y low is by re-using the first stage. Every satellite project knows the throw weight of all the common launch vehicles and their cost per kilo. And that is how you plan you satellite design.

Now at the moment SpaceX gets 9 merlin engines and the first stage booster back for "free" (which is to say that the cost paid assumed it would be consumed in the launch) but as they learn what they can do they will use that cost savings to offer cheaper launch services (more business) until they have a full launch schedule and then keep any excess value for re-investment.

But an interesting question is this, given that they have a "used" first stage, who would be willing to launch on it? It has no track record and no reliability statistics other than it worked at least once before. To develop that information you need to re-launch them. And I'm hoping that SpaceX will make available some higher risk but lower cost "seats" on those test flights.

[fixermark]

"It worked at least once before" is more track record than any rocket fresh off the assembly line.

[greglindahl]

SES already said that they're willing to be the first customer for a used booster[1].

Before they get that far, it'd be interesting to see if SpaceX flies a used engine, since they've got "one engine out" capability. Which has already been tested twice.

1: http://spacenews.com/spacex-early-adopter-ses-ready-to-reuse...

[ChuckMcM]

That article raises an interesting point I really hadn't considered, who owns the first stage? If you pay "full price" for a launch and SpaceX recovers the first stage to re-use, did the person who paid to launch it own it or does SpaceX? It was presumed lost of course. No doubt there is language in the contracts about that. Would be interesting to see a launch contract.

[Alain-lf]

SpaceX own the first stage.

You pay to get your payload delivered to a specified orbit. You don't actually buy the rocket.

It's like flying, you buy a ticket, not the plane.

[ChuckMcM]

Just for reference, I got an inside look at what it took to get OSCAR16[1] launched and it isn't like flying :-). Now I don't doubt things are more streamlined now but every launch starts with a basic contract and that contract has to cover everything from contingencies to insurance to liability to disposal.

Trying to search for a boilerplate launch contract I found an article[1] where it discusses that Spaceflight Industries bought a Falcon 9 launcher [emphasis mine] which suggests that one buys the entire rocket. That would imply that if they land it, you still own it does it not? Can you then go over to the landing zone pick up your rocket and resell it for parts to offset your original purchase price? :-)

I am really confident that ownership of the first stage is covered in the launch contract if it is returned to the landing field. And the math there would no doubt be really interesting to an insurance company since you have the possibility that the launch is a success and the first stage lands, the launch is a success and the first stage crashes, the launch effectively fails (second stage failure) but the first stage successfully returns, and both stages are lost. That is a number of different outcomes to insure.

Frankly my mind is boggling at the potential legal complexity here.

[1] https://en.wikipedia.org/wiki/AMSAT-OSCAR_16

[2] "SpaceIL has purchased launch services from Spaceflight Industries; an American space company who recently purchased a SpaceX Falcon 9 launcher and will manifest SpaceIL’s spacecraft as a co-lead spot, " -- http://lunar.xprize.org/press-release/israeli-google-lunar-x...

[lmm]

I think the real answer is that there will be a complex contractual relationship that "ownership" is too simple to describe, in either direction. E.g. I say I "own" my flat, but actually I am a shareholder in a company that owns the building and have a lease contract with that company (this is the standard (only?) way of "owning" a flat in the UK, because multiple flats stand on the same piece of land - you can't truly "own" something you don't have the right to destroy, but obviously you don't have the right to destroy a flat with someone else's above it).

> And the math there would no doubt be really interesting to an insurance company since you have the possibility that the launch is a success and the first stage lands, the launch is a success and the first stage crashes, the launch effectively fails (second stage failure) but the first stage successfully returns, and both stages are lost. That is a number of different outcomes to insure.

The insurance industry already deals with far more complex scenarios. A ship on an ocean voyage will often have the hull and cargo insured separately, different loss layers insured separately (e.g. first 10% of losses, 10-20%, 20-100% all separate), with multiple underwriters on each layer (and sometimes the same underwriter on multiple stamps).

[pbreit]

I think you might be getting hung up on sloppy wording or a one-off situation. Clearly SpaceX owns its rockets and customers pay for the delivery of payloads.

[igravious]

I see what you mean and a literal reading of those words implies ownership but what if the intended meaning was that they were the sole occupant/tenant on that flight? My gut feeling is that the rocket company owns the rocket.

[WalterBright]

The jet engines on the Me-262 jet fighter were only good for 10 hours. (The airframe didn't last much longer, and so the Germans didn't bother with things like corrosion protection.)

Even so, a lot of expensive parts on the rocket likely have much longer service lives.

[rory096]

About 30% returning to landing site, 15% returning to a barge downrange. Note that the rocket's still perfectly capable of running an expendable mission if the payload requires it. The mass figure on their website[1] is for reusable.

[1] http://www.spacex.com/falcon9

[johntb86]

According to http://aviationweek.com/blog/nasa-cnes-warn-spacex-challenge... every 10lbs of recovery hardware loses you 1lb of payload, approximately.

[msandford]

You're right not to trust your intuition! Good call.

It's actually going to be much, much less than that due to the nature of the rocket equation. https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

[msandford]

Given that I'm not wrong as the above link shows (http://aviationweek.com/blog/nasa-cnes-warn-spacex-challenge...) would anyone care to explain to me for a second why I'm getting downvoted?

I'm happy to be less stupid if that's the problem, but I don't know what thing it was that I did that was stupid.

[mannykannot]

I don't think you could allocate all of the landing fuel load to payload as any addition to the payload also requires additional 2nd. stage fuel.

[mikeash]

You can run the first stage longer without any extra second stage fuel. Adding performance to either one (within limits) increases the performance of the system. Using the landing fuel for a launch would allow for a heavier payload without changing the second stage. The first stage would do more of the total work.

[mannykannot]

Ah yes, good point - I was implicitly assuming the liftoff weight was maxed out, by thinking that any upper stage weight increase would have to come from the 1st stage fuel load.

[tcheard]

Except that the longer you run the first stage, the longer you have to carry the weight of the first stage. It eventually becomes much more efficient to jettison the first stage and use a slightly less powerful but much lighter weight second stage, because you no longer need as much power to get through the atmosphere. Which is the whole point behind staging (https://en.wikipedia.org/wiki/Multistage_rocket#Optimal_stag...).

It turns out when you add 10 lbs of weight to the first stage for reuse you lose approximately 1 lbs of weight from the max payload. (http://aviationweek.com/blog/nasa-cnes-warn-spacex-challenge...)

On the second stage every 1 lb of reuse you lose 1 lb of payload, which is one of the big reasons why second stage reuse isn't really feasible on the F9.

[mikeash]

That makes no sense. It's never advantageous to ditch the first stage while it's still producing thrust. At some point when designing a rocket, it's better to add performance to the second stage rather than the first. But when presented with an existing rocket, you'll achieve maximum payload capacity by burning all fuel in the first stage before staging. Every second it burns is more delta-v imparted to the payload. The only reason you'd stage early is if you want to save fuel for e.g. a landing attempt, if the first stage is too powerful and the acceleration or speed would become too great, or if you simply don't need the extra performance to get the payload to where it's supposed to go.