Gwynne Shotwell Interview - June 22, 2017 on The Space Show

[guckyfan]

She would have to say that they're "looking into it" because that's what the Air Force paid them to do.

No. Thei Airforce paid for developing an engine. That was done or is being done. Not a word about a stage.

BTW, was there a follow up on that first one year contract? Isn't the whole thing moot without a continuation? Honest question.

[gongora]

She would have to say that they're "looking into it" because that's what the Air Force paid them to do.

No. Thei Airforce paid for developing an engine. That was done or is being done. Not a word about a stage.

BTW, was there a follow up on that first one year contract? Isn't the whole thing moot without a continuation? Honest question.

The contract runs through January 2018, and I'm not sure there would be a public announcement when they commit additional funds under the current contract.

[rakaydos]

the question about the raptor upper stage was totally a leading question.

Something like "So, hows it going on that Raptor upper stage you were contracted to make by the air force?"

[Lobo]

To be fair, everyone's heard of Saturn 5, which was a mixed kerlox/hydrolox rocket. What did apollo do differently that made mixed fuels a good idea?

It was for performance and not cost.

And even for Saturn, or other LV's that use mixed propellants, they were designed from the start for that.  To get back to Jim's point here, Falcon was designed for different propellants.  So are it's pads and infrastructure.  Adding engines that use new fuel and thus new fuel/oxidizer ratios, different fuel denisty, etc is not an easy thing.

No, it is people that don't understand rocket science that are making an issue of the non existent methane upper stage.

This has nothing to do on handling methane.  The issue is adding to the F9 system.  It is disruptive.

However, Shotwell did say this...so they are considering doing something:

"Looking at the utility of it [Raptor] on Falcon"

I speculated about maybe that means using Falcon as a test bed for Raptor, rather than as an upgrade to the production Falcon.

However, if she does mean they are looking at actually upgrading production Falcon to ssRaptor, I would guess they'd only do the upper stage if they have success with a reusable FUS, because it's a complex, expensive engine compared to Merlin.  If it's going to be expended, might as well keep expending the cheaper engine.  Then they get the Raptors back on the booster, as well as (presumably) easier reuse with less soot and coking than kerolox, as well as probably some performance boost. (Better engine efficiency, but less propellant capacity, unless the try to stretch the core more.)

But we're all just guessing to her meaning at this point...

[gongora]

If someone wanted to make an outline of the interview with timestamps for the various topics that would be really great.  I didn't think about it until near the end.

~42:30 Discussion of carbon fiber tanks
~52:30 Discussion of Falcon production rate

Gwynne said she's not really interested in going to Mars but might want to take a Dragon flight around the Moon.

[raketa]

Sound like testing Raptor engine will be best on second stage F9 and F9H. Easier changed this stage and they have to already stretch for F9H. This stretch version maybe is big enough for F9 methane tank.
Second stage flight is less stresfull. SpaceX didn't have any accident of Stage 2.

[gongora]

Sound like testing Raptor engine will be best on second stage F9 and F9H. Easier changed this stage and they have to already stretch for F9H. This stretch version maybe is big enough for F9 methane tank.
Second stage flight is less stresfull. SpaceX didn't have any accident of Stage 2.

Well, not after the second stage engine started.  The CRS-7 flight had stage 2 disintegrate.

[RoboGoofers]

She would have to say that they're "looking into it" because that's what the Air Force paid them to do.

No. The Airforce paid for developing an engine. That was done or is being done. Not a word about a stage.

No? I thought the contract was for an engine, yes, but the qualifier was "to use on a falcon upper stage."

Not that they are planning to, but that at the end of the contract the AF might ask for a document outlining "Here's what it would cost. Here's how long it'd take. Here's what you could expect it to do."

[DOCinCT]

If someone wanted to make an outline of the interview with timestamps for the various topics that would be really great.  I didn't think about it until near the end.

~42:30 Discussion of carbon fiber tanks
~52:30 Discussion of Falcon production rate

Gwynne said she's not really interested in going to Mars but might want to take a Dragon flight around the Moon.

9:00 Falcon Heavy discussion (waiting on pad availability)
12:30 Falcon 9 inventory and reuse customers
14:00 number of reuses, block 5 changes etc.

[DOCinCT]

If someone wanted to make an outline of the interview with timestamps for the various topics that would be really great.  I didn't think about it until near the end.

~42:30 Discussion of carbon fiber tanks
~52:30 Discussion of Falcon production rate

Gwynne said she's not really interested in going to Mars but might want to take a Dragon flight around the Moon.

9:00 Falcon Heavy discussion (waiting on pad availability)
12:30 Falcon 9 inventory and reuse customers
14:00 number of reuses, block 5 changes etc.

15:50 steps for a healtier space program
17:30  Red Dragon vs. some other craft?  2020 date aggressive
19:00 SpaceX vs. NASA astronauts
20:45 private passengers
22:00 Falcon Heavy new vs. pre-flown cores

[Ictogan]

Sound like testing Raptor engine will be best on second stage F9 and F9H. Easier changed this stage and they have to already stretch for F9H. This stretch version maybe is big enough for F9 methane tank.
Second stage flight is less stresfull. SpaceX didn't have any accident of Stage 2.

Do you have a source on the second stage being stretched for FH? This is the first time I hear that that could be the case.

[DOCinCT]

If someone wanted to make an outline of the interview with timestamps for the various topics that would be really great.  I didn't think about it until near the end.

~42:30 Discussion of carbon fiber tanks
~52:30 Discussion of Falcon production rate

Gwynne said she's not really interested in going to Mars but might want to take a Dragon flight around the Moon.

9:00 Falcon Heavy discussion (waiting on pad availability)
12:30 Falcon 9 inventory and reuse customers
14:00 number of reuses, block 5 changes etc.

15:50 steps for a healtier space program
17:30  Red Dragon vs. some other craft?  2020 date aggressive
19:00 SpaceX vs. NASA astronauts
20:45 private passengers
22:00 Falcon Heavy new vs. pre-flown cores

22:50 ITAR impacts on foreign inventment in ITS or private passengers
24:30 ITS development progress, strategy
26:00 Upper stage raptor, USAF contract progress
27:30 2nd stage recovery attempts
28:45 satellite program

[DOCinCT]

If someone wanted to make an outline of the interview with timestamps for the various topics that would be really great.  I didn't think about it until near the end.

~42:30 Discussion of carbon fiber tanks
~52:30 Discussion of Falcon production rate

Gwynne said she's not really interested in going to Mars but might want to take a Dragon flight around the Moon.

9:00 Falcon Heavy discussion (waiting on pad availability)
12:30 Falcon 9 inventory and reuse customers
14:00 number of reuses, block 5 changes etc.

15:50 steps for a healtier space program
17:30  Red Dragon vs. some other craft?  2020 date aggressive
19:00 SpaceX vs. NASA astronauts
20:45 private passengers
22:00 Falcon Heavy new vs. pre-flown cores

22:50 ITAR impacts on foreign inventment in ITS or private passengers
24:30 ITS development progress, strategy
26:00 Upper stage raptor, USAF contract progress
27:30 2nd stage recovery attempts
28:45 satellite program

29:50 resource limitations and priorities
31:00 SpaceX hiring;  process by department priorities and needs
33:00 Alignment of companies with goal of Mars
34:33 Merlin tested to 240,000 lbs/thrust
35:00 back to BFR/BFS
added
37:40 Use of carbon fiber components
38:40 Relative cost of F9 stages
40:00 nuclear propulsion
40:55 subscale vs. full scale Raptor engines  current 200k, 600k may be too big
42:20 did test tank have flaws?
45:00 Private vs. NASA crew safety standards
added
48:15 Dragon 2 flight abort test; dates 2018
49:00 Lunar passenger mission - depends on crew missions
50:00 Red Dragon science payloads
51:00  Actual sale of Falcon rockets - model is selling a service
52:15 Rocket production rates  - from 6 to 20 a year
53:35 Introduction of blocks
54:15 Factory production lines - 1 year total time to produce a Falcon9
57:15 General comments by Gwynne
58:15 Reactions to negative press
1:00 Serving on Nations Space Council
1:00:50 Block 3 vs. Block 4 - intermittent step

[Space Ghost 1962]

"Looking at the utility of it [Raptor] on Falcon"

I speculated about maybe that means using Falcon as a test bed for Raptor, rather than as an upgrade to the production Falcon.

Musk has before indicated this, and been coy as to the long term intent with F9. As this comment continues.

Suggest there are three options - test stage (in advance of BFS), performance stage (funded in parallel to ACES?), and fully recoverable stage (follow on to F9US).

If you were to fly as a test stage, perhaps even on top of a F9US as a payload (or with Dragon or RD), the issues would involve prop load/drain & GSE. Most of the cost would be in the pad mods. Keep in mind the upgrades that they did to the E-2 test stand at Stennis. It would be an addition and not interfere with existing F9 flights.

If a performance stage (F9US's Achilles heel is C3 performance), it might be a reformulated F9US that functioned within a redone fairing. It would place a considerable burden on F9 and likely delay BFS as well as increasing F9 launch costs, as maintaining dual US capability would almost certainly be a 30-50% increase in costs, competing with ROI of booster reuse. But the financial impact might be absorbed by some of that, because of lack of competition (if you're the only one actively driving down launch costs, it doesn't help if you are too effective because you can only launch so many). You'd get more flight history this way.

Reminds of the decision to move to subcooled fuels and the additional expanse/AMOS6 incident.

If a reusable stage (arriving at a fully reusable vehicle as intended with the original Shuttle program), you'd phase over to a dual fuel vehicle like Atlas V, while losing the GHe pressurization issues in the US. This would play to Musk's ego and possibly a power play to up the competition with Bezos/Airbus Safran/others. Making it about BFR/BFS level competition that it could stretch too.

However, if she does mean they are looking at actually upgrading production Falcon to ssRaptor, I would guess they'd only do the upper stage if they have success with a reusable FUS, because it's a complex, expensive engine compared to Merlin.  If it's going to be expended, might as well keep expending the cheaper engine.  Then they get the Raptors back on the booster, as well as (presumably) easier reuse with less soot and coking than kerolox, as well as probably some performance boost. (Better engine efficiency, but less propellant capacity, unless the try to stretch the core more.)

Yes.

Could it be that in confronting BFS as the next vehicle, they've desired ... an interim step?

[Kabloona]

When stating "the utility of Raptors for Falcon is being investigated", are we sure Shotwell was referring to the Upper Stage only? Not having heard the broadcast itself, the cryptic notes seem to leave her exact meaning slightly open to interpretation. Maybe someone can clarify.

For the record, this is what she said about Raptor/Falcon, close as I can get it:

"The original idea for it (the Raptor engine) was to serve as propulsion for the big Mars system, but we are looking at the utility of it on the Falcon program." (Gwynne Shotwell)

It's interesting to me that she stresses the word "original." Suggesting that not just, oh by the way, we may try it out on F9 as a testbed before we move it onto BFR/ITS, but that this is potentially a whole new purpose for Raptor, ie possibly switching either the upper stage or the entire vehicle over to Raptors.

I realize it's shaky at best to infer great meaning from one stressed word in one general sentence, but since the one sentence is all we have to go on, that's how I read the tea leaves. FWIW.

And to quote envy887, no doubt this is on their mind:

If they hit Raptor's performance goals or anything close it will blow Merlin and every other engine away. They won't need kerolox.

[MikeAtkinson]

I think SpaceX's aim for about 2027 is to have 3 launchers:

small: 20 tonnes to LEO for the constellation - also used for GEO satellites (replacement for Dragon 2 as well?)

medium: 80-100 tonnes to LEO - refueled in LEO for other destinations, mainly used for cis-lunar, but also the few LEO and GTO payloads too big the for small launcher.

large: 300-400 tonnes to LEO - the Mars system.

All fully reusable with Raptor (small uses the sub-scale (1MN) Raptor, medium 3MN raptor for 1st stage and 1MN for upper stage, large similar to IAC presentation).

With these three launchers SpaceX can efficiently cover the entire payload market from about 5 tonnes to LEO through to 300-400 tonnes to Mars.


Which order they create those stages in depends on priorities. But it seems to me that F9 will eventually be replaced by an all-Raptor launcher and that FH will be dropped sooner rather than later (except possibly for some NSS missions).

[rsdavis9]

By 2027 I think SpaceX to orbit will be analogous to trucks. Would you send anything less than a full tractor trailer to orbit? With daily flights just fill her up with stuff.

EDIT:
 To elaborate. the 5000km truck ride with the tractor trailer is from earth surface to LEO. The step vans can take the parcels from there to the various home addresses. Think UPS.

You always load your biggest truck and fill it for the cross country ride.
 

[Roy_H]

Ok so I'm trying to wrap my head around these numbers, 1.9m lbf of thrust is more than the 1.71m listed for block 5 on the website yes? Which is 50k lbs to LEO, if 240k lbs thrust is doable and stable with margin, that would be what? 2.2m lbs thrust? If the Merlin 1D Vac is capable of increased thrust also, what is the theoretical payload ability for the FULLEST thrust Falcon 9 to LEO and GTO?


Sent from my iPhone using Tapatalk

Shotwell did not say that the 240k lb thrust was "stable with margin". In order to be able to state what margin there is, you have to test to extreme. That extreme is 240k. Thrust is 190k with a 50k margin or 25%.

[IntoTheVoid]

Ok so I'm trying to wrap my head around these numbers, 1.9m lbf of thrust is more than the 1.71m listed for block 5 on the website yes?

No, you're mixing units here (as has been done in other threads, but I didn't see it corrected here.)
1 Merlin B5 = 190k lbf -> 1 Falcon B5 = 9 Merlins B5 = 1.71m lbf

The numbers still agree, just need to watch Merlin v Falcon and police your units.

[Lobo]

Ok so I'm trying to wrap my head around these numbers, 1.9m lbf of thrust is more than the 1.71m listed for block 5 on the website yes? Which is 50k lbs to LEO, if 240k lbs thrust is doable and stable with margin, that would be what? 2.2m lbs thrust? If the Merlin 1D Vac is capable of increased thrust also, what is the theoretical payload ability for the FULLEST thrust Falcon 9 to LEO and GTO?


Sent from my iPhone using Tapatalk

Shotwell did not say that the 240k lb thrust was "stable with margin". In order to be able to state what margin there is, you have to test to extreme. That extreme is 240k. Thrust is 190k with a 50k margin or 25%.

With a 190klb Merlin, that would put F9 booster with more thrust than Saturn 1B.  Pretty impressive!

I thought this last Merlin was at its max thrust already though?  Where do they keep finding addition margin?