Author Topic: Reusability effect on costs  (Read 146684 times)

Online envy887

  • Senior Member
  • *****
  • Posts: 2935
  • Liked: 1367
  • Likes Given: 911
Re: Reusability effect on costs
« Reply #300 on: 05/03/2017 01:16 PM »
Elon Musk has said they spent about a billion dollars developing recovery and reuse. So that needs to be recovered before they are making money with reuse. How long that takes depends on how much they discount the rockets for launch and how much it costs to refurbish them for the next launch. The issue boils down to the question - when do they make more money by reusing rockets than they spent on making them reusable?

An additional facet of this is "how much of your capabilities have you intentionally sacrificed to make your rocket reusable?" which is what ULA has been asking.

Which is a bogus question.

Payload has a fixed mass. You get paid for orbiting this payload. Any extra performance you have over this weight on this flight would not earn you a single extra dollar.
If you can orbit the payload of this fixed mass and land the stage, you "sacrificed" nothing for reusing this state.
If you can orbit the payload of this fixed mass only by expending the stage, you are no worse than your competitors who do not have reuse option at all.

ULA are not stupid, they know this too. They are just not yet resigned to accept the new reality.

1) Extra performance can certainly earn more money on many missions.

2) The extra performance required for reuse means a bigger rocket, which is more expensive than a smaller rocket. However, this is offset to some extent by 1), where more performance can earn more money on an expendable mission.

3) You have to design the recovery systems, which are part of the fixed development cost - even the expendable rockets must bear those. And expending a recoverable rocket is always going to be somewhat more expensive than expending a rocket designed to be expendable.

However, all of the above are offset by the fact that later flights of the same rocket are FAR cheaper than building a new one. Including expendable flights, where you can get all the performance on a rocket that's already paid for itself many times over. THIS is the point of reuse. It's cheaper to build 1 oversized rocket with 10 lives than 10 undersized rockets.

The part I don't get about ULA's response is that SpaceX is beating them on price while throwing away reuseable rockets. How can ULA possibly compete economically now that SpaceX has started reusing them?

Offline Joffan

  • NSF Irregular
  • Full Member
  • ****
  • Posts: 1248
  • Liked: 258
  • Likes Given: 765
Re: Reusability effect on costs
« Reply #301 on: 05/03/2017 04:43 PM »
I think even the billion-dollar budget for reusability is a bit of a red herring. Some of that expenditure has more benefits than just the ability to reuse the lower stage, so that continually improves the value of the SpaceX service.

As a simple example, the ability to review a used stage informs and improves the next increment of design of new stages. As a more subtle example, the continued engagement of capable people in exciting work maintains a high quality of staff (and work) at SpaceX.

Agreed that SpaceX will make more money from reused stages than from continuing the expendable path, so in fact they will become more profitable also. However I think Musk is still holding to his intention to continue lowering the cost of access to space, and trusting that the benefit in gradually expanding the market for launches will allow that to be an on-going process: sales volume feeding efficiency investments, feeding cost reduction, feeding sales volume etc.
When I say "Jump!", you say "To which orbital inclination?"

Offline RyanC

  • Full Member
  • ***
  • Posts: 387
  • SA-506 Launch
  • Liked: 37
  • Likes Given: 5
Re: Reusability effect on costs
« Reply #302 on: 05/03/2017 09:05 PM »
Now for the other item. How long will it take for SpaceX to recover their $1B investment in reuse.

At 25 flights / yr and 70% being used boosters and SpaceX recovering $10M to pay against this charge per reused booster flight it will be 6 years for them to recover this development cost.


What if.... Space X doesn't intend to fully recover their $1B investment?

What if they:

A.) Just charge a good portion of the cost off to the MCT/ITS accounts as a "sunk cost" for development of MCT/ITS reusable stage technology?

B.) Count it as a "sunk cost" to capture more of the marketplace for orbital launches?

Remember, SpX doesn't operate like LockMart/Boeing/ULA/NoGrumman, but more like Amazon, which continually plows profits back into the company to grow it.
« Last Edit: 05/03/2017 09:08 PM by RyanC »

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 9044
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5724
  • Likes Given: 3817
Re: Reusability effect on costs
« Reply #303 on: 05/03/2017 09:12 PM »
I think 2M for refurb costs is high if you're talking 24 hour turnarounds. Airliners are at similar price points (within an order of magnitude) for initial cost of the vehicle and don't spend nearly that much getting ready for their next flight. Maybe when they have scheduled overhauls and have to replace an engine

You may say that SpaceX can't achieve these turnaround times and costs but that's their goal. They may not make it... but I'm thinking a crew of 500 spending 2M in small parts? no.  I could see the average cost being 1M IF you include the once every 10 flights heavy overhaul that might include some engine changeouts if an engine was found to be marginal.... but even that seems high.
For general aviation passenger services the rule of thumb has been that total costs per flight were 3x the fuel costs. Given Musk has said F9 costs about $200K in propellant that would be about about $600-800K. However since unless the US is fully recoverable that will have to be written off and that's around $17m.

Not counting the US, that's totally irrelevant to refurb costs, and you know it.

The topic being discussed was how much refurb costs them. NOT how much the total mission cost is.

I'm interested in people's spitballs on what fairing refurb will cost. I am thinking you don't want to just keep painting over old logos as that increases the weight of the fairing each time.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline ulm_atms

  • Rocket Junky
  • Full Member
  • *
  • Posts: 109
  • To boldly go where no government has gone before.
  • Calhoun, LA
  • Liked: 93
  • Likes Given: 42
Re: Reusability effect on costs
« Reply #304 on: 05/03/2017 09:45 PM »
I'm interested in people's spitballs on what fairing refurb will cost. I am thinking you don't want to just keep painting over old logos as that increases the weight of the fairing each time.

Hopefully the atmosphere will remove some/most of the painting/logos (especially if the painting is ablative tps paint)   ;D

But my guess would be the cost of 1. Getting the fairing back to the "refurb center"  2. Cost of consumables (RCS gasses,parachutes, etc...) 3.  Paint/tps and 4.  Possibly the materials that keep the two halfs together depending on how singed the edges get on return.  If all that is over 1M total I would be surprised.

So my spitball is less then 1M, hopefully closer to $500K

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 9044
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5724
  • Likes Given: 3817
Re: Reusability effect on costs
« Reply #305 on: 05/03/2017 10:13 PM »
I think if we're trying to accurately model costs we need to separate recovery from refurb... S1 recovery may be less (if it's RTLS) or more, if it's ASDS.... The exact amount for recovery varies by mission too, as the ASDS may be farther or closer, and there may be a scrub that adds a day of labor/rental.

Recovery ends and refurb starts when the stage rolls in the facility (you could say "when the stage is loaded on the transporter" I guess)

Similarly depending on the profile flown, the bouncy castle may be closer or farther from shore. But I think the variability there is lower?
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline M.E.T.

  • Full Member
  • ****
  • Posts: 464
  • Liked: 196
  • Likes Given: 13
Re: Reusability effect on costs
« Reply #306 on: 05/04/2017 08:44 AM »
I don't see why the expectation is that SpaceX will substantially reduce prices in accordance with their reusability cost savings. Musk said that they first want to recover the $1B reusability investment. But why stop even there?

I saw the calculations upthread showing 4 years required for recovery of the $1B investment. But what stops SpaceX from dropping their current launch price by just a marginal amount - from $62m to say $55m, and making a $30m gross profit per F9 launch for the foreseeable future?

At $62m they are already cheaper than  any of their competitors. Going down another $7m would undercut everyone else even further, while still giving SpaceX massive profits per launch.

With a 70 launch manifest, at $30m profit per launch they could recover their $1B investment in just over 30 launches - possibly the number of flights they will do in one year in 2018. And still have a massive and growing manifest ahead.

And even after that, why not continue charging say $50m per launch until someone else can do it for $49m? Even at current prices they are charging towards 30 launches per year, so its not like demand isn't there.

30 launches at $30m profit per launch is better than 50 launches at only $10m profit per launch.

« Last Edit: 05/04/2017 09:00 AM by M.E.T. »

Offline JamesH65

  • Full Member
  • ****
  • Posts: 676
  • Liked: 406
  • Likes Given: 8
Re: Reusability effect on costs
« Reply #307 on: 05/04/2017 09:45 AM »
I don't see why the expectation is that SpaceX will substantially reduce prices in accordance with their reusability cost savings. Musk said that they first want to recover the $1B reusability investment. But why stop even there?

I saw the calculations upthread showing 4 years required for recovery of the $1B investment. But what stops SpaceX from dropping their current launch price by just a marginal amount - from $62m to say $55m, and making a $30m gross profit per F9 launch for the foreseeable future?

At $62m they are already cheaper than  any of their competitors. Going down another $7m would undercut everyone else even further, while still giving SpaceX massive profits per launch.

With a 70 launch manifest, at $30m profit per launch they could recover their $1B investment in just over 30 launches - possibly the number of flights they will do in one year in 2018. And still have a massive and growing manifest ahead.

And even after that, why not continue charging say $50m per launch until someone else can do it for $49m? Even at current prices they are charging towards 30 launches per year, so its not like demand isn't there.

30 launches at $30m profit per launch is better than 50 launches at only $10m profit per launch.

Entirely agree. All they have the ensure is that they are cheaper than the competition and at least as reliable. I suspect they are almost there with both of those - still a few reused boosters to try to get some decent reliability figures.

Online AncientU

  • Senior Member
  • *****
  • Posts: 5182
  • Liked: 3102
  • Likes Given: 4421
Re: Reusability effect on costs
« Reply #308 on: 05/04/2017 02:45 PM »
I don't see why the expectation is that SpaceX will substantially reduce prices in accordance with their reusability cost savings. Musk said that they first want to recover the $1B reusability investment. But why stop even there?

I saw the calculations upthread showing 4 years required for recovery of the $1B investment. But what stops SpaceX from dropping their current launch price by just a marginal amount - from $62m to say $55m, and making a $30m gross profit per F9 launch for the foreseeable future?

At $62m they are already cheaper than  any of their competitors. Going down another $7m would undercut everyone else even further, while still giving SpaceX massive profits per launch.

With a 70 launch manifest, at $30m profit per launch they could recover their $1B investment in just over 30 launches - possibly the number of flights they will do in one year in 2018. And still have a massive and growing manifest ahead.

And even after that, why not continue charging say $50m per launch until someone else can do it for $49m? Even at current prices they are charging towards 30 launches per year, so its not like demand isn't there.

30 launches at $30m profit per launch is better than 50 launches at only $10m profit per launch.

Entirely agree. All they have the ensure is that they are cheaper than the competition and at least as reliable. I suspect they are almost there with both of those - still a few reused boosters to try to get some decent reliability figures.

Not so fast... lowering the price is the forcing function for market expansion.
Market expansion is essential for SpaceX to obtain needed revenue -- long term gain vs short term profits.  This is why a private company is necessary for a while.
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Online Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 9044
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5724
  • Likes Given: 3817
Re: Reusability effect on costs
« Reply #309 on: 05/04/2017 03:14 PM »
Yeah I don't see going 50M, then going 48M when someone else goes 49M as fitting the model well.... Musk wants to force this. The West was exploited a LOT better by railroads than wagon trains... because railroad freight rates were so much better.

This might be a bit off topic though.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline WmThomas

  • Full Member
  • *
  • Posts: 119
  • An objective space fan
  • Liked: 49
  • Likes Given: 892
Re: Reusability effect on costs
« Reply #310 on: 05/04/2017 04:00 PM »
Now for the other item. How long will it take for SpaceX to recover their $1B investment in reuse.

I think the $1B number Elon threw out is being misunderstood. I think that was more like the cost of all Falcon 9 development to date.

Elon didn't explain what that estimate meant and I haven't seen any serious attempt to make sense of that number.  SpaceX has spent a lot on launch pads, building rockets, Dragon, etc. Reuse would include the autonomous drone ships, Grasshopper and FR-Dev, Raptor, and lot of R&D. But $1 Billion? I don't buy it.

Also, note that Raptor development and a good deal of Falcon 9 and Dragon development were paid for by the government, the Air Force and NASA respectively. So SpaceX isn't even out $1B net on the Falcon 9 development, I don't think.

I'd be interested in other people's estimates of what Elon meant and what SpaceX's development expenses have been, and what funded it.

Offline M.E.T.

  • Full Member
  • ****
  • Posts: 464
  • Liked: 196
  • Likes Given: 13
Re: Reusability effect on costs
« Reply #311 on: 05/04/2017 04:15 PM »
I don't see why the expectation is that SpaceX will substantially reduce prices in accordance with their reusability cost savings. Musk said that they first want to recover the $1B reusability investment. But why stop even there?

I saw the calculations upthread showing 4 years required for recovery of the $1B investment. But what stops SpaceX from dropping their current launch price by just a marginal amount - from $62m to say $55m, and making a $30m gross profit per F9 launch for the foreseeable future?

At $62m they are already cheaper than  any of their competitors. Going down another $7m would undercut everyone else even further, while still giving SpaceX massive profits per launch.

With a 70 launch manifest, at $30m profit per launch they could recover their $1B investment in just over 30 launches - possibly the number of flights they will do in one year in 2018. And still have a massive and growing manifest ahead.

And even after that, why not continue charging say $50m per launch until someone else can do it for $49m? Even at current prices they are charging towards 30 launches per year, so its not like demand isn't there.

30 launches at $30m profit per launch is better than 50 launches at only $10m profit per launch.

Entirely agree. All they have the ensure is that they are cheaper than the competition and at least as reliable. I suspect they are almost there with both of those - still a few reused boosters to try to get some decent reliability figures.

Not so fast... lowering the price is the forcing function for market expansion.
Market expansion is essential for SpaceX to obtain needed revenue -- long term gain vs short term profits.  This is why a private company is necessary for a while.

I don't get this argument entirely. What does SpaceX gain by increasing demand to 100 flights instead of 50 from one year to the next if they make half the revenue per flight and thus have no increased gain from it?

What's the point of eventually making $1m profit per flight from 100 flights, if you could have achieved $20m per flight from just 5 fligths? Once ITS is operational, sure, they will benefit from an expanded market. But currently, they can't even service the manifest they do have.

For the foreseaable future they can rake in the cash and still have more demand than they can service. 3 years from now that may change. But until then they need all the cash they can get to invest in their next generation vehicle.

Online envy887

  • Senior Member
  • *****
  • Posts: 2935
  • Liked: 1367
  • Likes Given: 911
Re: Reusability effect on costs
« Reply #312 on: 05/04/2017 04:28 PM »
Now for the other item. How long will it take for SpaceX to recover their $1B investment in reuse.

I think the $1B number Elon threw out is being misunderstood. I think that was more like the cost of all Falcon 9 development to date.

Elon didn't explain what that estimate meant and I haven't seen any serious attempt to make sense of that number.  SpaceX has spent a lot on launch pads, building rockets, Dragon, etc. Reuse would include the autonomous drone ships, Grasshopper and FR-Dev, Raptor, and lot of R&D. But $1 Billion? I don't buy it.

Also, note that Raptor development and a good deal of Falcon 9 and Dragon development were paid for by the government, the Air Force and NASA respectively. So SpaceX isn't even out $1B net on the Falcon 9 development, I don't think.

I'd be interested in other people's estimates of what Elon meant and what SpaceX's development expenses have been, and what funded it.

Here's Elon's quote:
Quote
: I think just a little celebration is in order... If you just say, how much effort has SpaceX put into Falcon reusability, and nobody was paying us for reusability, so it had to be on our own dime, it's probably - at least a billion dollars that we spent developing this, so it'll take a while to pay that off. And then we need to get really efficient with the reuse of boosters and with the fairing. So I would expect the economics to start becoming sensible next year - so it's pretty close - and we expect the boosters to .. I mean, with no refurbishment, be capable of 10 flights, and with moderate refurbishment to be capable of 100 flights. So you can imagine that if the cost of the rocket is say 60 million dollars - really we're not re-using the whole thing, but - with the fairing, assuming fairing reuse works out, and as we optimize the cost of the reuse of the booster, really looking at maybe 3/4 of the rocket cost dropping by an order of magnitude, maybe more.

It doesn't sound like the $1 billion or more estimate specifically includes initial F9 development or anything that NASA or DOD paid for, although there is almost certainly a lot of overlap.

And I'm curious what "the economics to start becoming sensible next year" means. Does that mean the $1B investment will be paid off?

From Elon's answer, Falcon 9 costs $60 million, the booster costs $45 million, and the cost of the booster over it's lifetime is $4.5 million (or less) per flight, so the booster reuse cost savings is $40.5M per flight. If SpaceX is saving $40.5M in costs per reuse and only giving up 10% ($6.22M) in price that's a net profit of $32.3M per reuse, and they need 30 reuse flights to get $1B in savings. 30 reflights seems pretty aggressive by "next year".

Online AncientU

  • Senior Member
  • *****
  • Posts: 5182
  • Liked: 3102
  • Likes Given: 4421
Re: Reusability effect on costs
« Reply #313 on: 05/04/2017 04:37 PM »
Six reflights this year, 24 next -- if 3/4ths of flights are reused, that is 32 flights next year (about what they are planning).  If fraction reused takes longer to build up, maybe another year. 

Then they start launching the constellation, and the reusable launchers will repay the investment or more every year thereafter in the form of profit or reduced capital expenditure.  Sounds like a no-brainer to me.

By the way, NASA/DoD did not pay for the F9/FH.
« Last Edit: 05/04/2017 04:38 PM by AncientU »
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Online envy887

  • Senior Member
  • *****
  • Posts: 2935
  • Liked: 1367
  • Likes Given: 911
Re: Reusability effect on costs
« Reply #314 on: 05/04/2017 05:01 PM »
Six reflights this year, 24 next -- if 3/4ths of flights are reused, that is 32 flights next year (about what they are planning).  If fraction reused takes longer to build up, maybe another year. 

Then they start launching the constellation, and the reusable launchers will repay the investment or more every year thereafter in the form of profit or reduced capital expenditure.  Sounds like a no-brainer to me.

By the way, NASA/DoD did not pay for the F9/FH.

It's pretty optimistic to see it happen by next year, though I have no doubts that they can eventually get 30 reflights out of F9. If that's all it takes to repay for reuse development I'd say they are doing great; a 2-3 year 100% return on investment is just fine.

Offline Mongo62

  • Full Member
  • ****
  • Posts: 919
  • Liked: 557
  • Likes Given: 123
Re: Reusability effect on costs
« Reply #315 on: 05/04/2017 06:11 PM »
I don't understand this $1B figure. Isn't most of this simply the cost of developing the Merlin engine and the F9 system, through its various iterations? The incremental cost of developing reusability, given the initial version of the F9, does not seem anything like a billion dollars to me. The flight tests were essentially free, since they were added to commercial and government flights paid for by commercial and government customers, and the extra hardware needed was minimal. The grid fins and upgraded 'non-sticky' servos, as far as I know. The rest was already designed and built for the expendable version of F9. Add the cost of Grasshopper, the 'drone ships', landing zones, etc., and it still does not seem close to a billion dollars.

Online Space Ghost 1962

  • Senior Member
  • *****
  • Posts: 2551
  • Whatcha gonna do when the Ghost zaps you?
  • Liked: 2526
  • Likes Given: 1898
Re: Reusability effect on costs
« Reply #316 on: 05/04/2017 07:15 PM »
I don't understand this $1B figure. Isn't most of this simply the cost of developing the Merlin engine and the F9 system, through its various iterations? The incremental cost of developing reusability, given the initial version of the F9, does not seem anything like a billion dollars to me. The flight tests were essentially free, since they were added to commercial and government flights paid for by commercial and government customers, and the extra hardware needed was minimal. The grid fins and upgraded 'non-sticky' servos, as far as I know. The rest was already designed and built for the expendable version of F9. Add the cost of Grasshopper, the 'drone ships', landing zones, etc., and it still does not seem close to a billion dollars.

Perhaps because you have a narrow view of what its about. Like perhaps direct/fixed costs.

There's  lots of other costs, including opportunity costs. Can easily see ways to find more than $2B in costs, so was surprised when he said just $1B. Think it is too low. Keep in mind the added cost of LOM's/RTF's brought on by the reuse agenda, as well as failed landings. If you don't use these as costs, you're cherry picking your numbers.

The more you invest in your business strategically, the less obvious the costs become. Which is why a lot of "hand to mouth" firms don't dare it.

Suggest that he's decided on a near term means of assessing SX by means of two timelines - one where they went all in on ELV, and the other where they did what they have done, i.e. this timeline.

That could get you easily $1B. And any accountant would accept this as reasonable guidance.

Now, he recovers that $1B to bring the two timelines back into synch. One way you could do that is to have the incremental cost savings and flight frequency increases "happen", such that as you use the benefits in a gradually increasing way, the delta between the timelines shrinks.

When it's shrunk to nothing, then all you have is the lost time it took to get there.

When it goes positive, you then have a means of valuing it as an competitive advantage over rivals. Which you could use to a)predict market share gains/dominance if unopposed, b)a measure of lead time ahead of rivals, or c) a lever on the market to drive demand where you'd like it to go to.

Online envy887

  • Senior Member
  • *****
  • Posts: 2935
  • Liked: 1367
  • Likes Given: 911
Re: Reusability effect on costs
« Reply #317 on: 05/04/2017 08:39 PM »
Perhaps because you have a narrow view of what its about. Like perhaps direct/fixed costs.

There's  lots of other costs, including opportunity costs. Can easily see ways to find more than $2B in costs, so was surprised when he said just $1B. Think it is too low. Keep in mind the added cost of LOM's/RTF's brought on by the reuse agenda, as well as failed landings. If you don't use these as costs, you're cherry picking your numbers.
...

This gets tricky really fast. Developing an expendable vehicle has it's own set of opportunity costs. And there is no way to know that the same failures, or new ones, wouldn't have occurred while developing a ELV. Certainly the CRS-7 failure or a similar one was just waiting to happen.

Offline docmordrid

  • Senior Member
  • *****
  • Posts: 4381
  • Michigan
  • Liked: 1504
  • Likes Given: 1
Re: Reusability effect on costs
« Reply #318 on: 05/04/2017 11:23 PM »
Of course the maximum benefit from reuse will be gained by who will be SpaceX's biggest customer: SpaceX, via the Internet constellation. Lowered implementation and  operating costs (replacements) for "CommX" also has to be figured in.
DM

Offline Joffan

  • NSF Irregular
  • Full Member
  • ****
  • Posts: 1248
  • Liked: 258
  • Likes Given: 765
Re: Reusability effect on costs
« Reply #319 on: 05/04/2017 11:28 PM »
There's  lots of other costs, including opportunity costs.
Hmm. Has reuse really slowed their launch cadence ramp-up? Or were you thinking they'd be further ahead with some other project? Not Dragon 2 - that's been paced by NASA's budget. Falcon Heavy, perhaps? except that's actually being helped towards an affordable demonstration flight by reuse. So I don't know what opportunities you mean, specifically.

Keep in mind the added cost of LOM's/RTF's brought on by the reuse agenda
Citation required. I see no evidence that Falcon 9's failures were a product of the drive for resuability. Their startup launch failure rate has not been at a level that would suggest that the attempt to re-use has played into more failures than expected. As I mentioned above, recovery of intact stages is more likely to play in to better reliability and fewer future failures.

as well as failed landings.
What, the cost of the legs? the damage to the ASDS? - peanuts. Certainly you can't possibly mean the cost of the rocket bodies, since in the expendable scenario, they would be lost anyway.
When I say "Jump!", you say "To which orbital inclination?"

Tags: