Gwynne Shotwell on The Space Show 3/21

[Lobo]

Since Gwynne said she believed Pad 39A would be too small for the BFG doesn't that implicitly confirm that it'll be three cores?

Possibly, and there may be a single core version, too.

You would think that a pad that could launch Saturn V, could handle a single core BFR at least, although if the pad is configured for F9/FH the support equipment would be incompatible, and they would not want to stop launching F9/FH there while they retrofit, so better to build new pad. Maybe 39C?

Another thought, the BFR will probably never be required to launch anything to GTO, so there is less reason to launch eastward from a site nearest the equator.

A 2-stage BFR with a RTLS booster and reusable upper stage could launch large NRO type payloads to GTO, or dual payload launches to GTO like Ariane 5, and have enough margin to allow for total reusability.  Where FH will need to launch at least partially reusable, if not fully reusable, to get those big birds to GTO.

A fully reusable 2-stage BFR could be cheaper to operate than a partially expendable FH.  So I think there could very well be a business case for BFR-R to go to GTO, or other BLEO trajectories for unmanned commercial and government payloads.

[QuantumG]

If anyone is waiting for a transcript of this show, don't. There won't be one from me and The Space Show specifically goes after anyone who makes one. I recommend listening to the show, as many of the short note reports leave a lot of nuance out.

My major takeaway: Falcon 9 / Falcon Heavy / Dragon are SpaceX's product line for the foreseeable future. They're trying to make the launch vehicles reusable and there's a new version of Dragon we haven't seen yet, but otherwise the SpaceX we're looking at now is the SpaceX we'll see for the next decade. After that we should start seeing the Mars vehicle, but that work is not going to change their current product line.

Despite the few comments on this thread and another, I think Gwynne made it clear that SpaceX intends to service the GTO market using LOX/RP-1 vehicles for the foreseeable future.

So yeah, near-term future developments include reusable Falcon, Falcon Heavy, and crew Dragon, but most of us have no trouble imagining that already. The Mars vehicle is a sideline.

[Lobo]

Listening to Ms. Shotwell cleared up a misconception I had about payload capacity v.s. reusability. I had assumed that implementing reusability would reduce payload capacity from those posted on the SpaceX website. It turns out I was wrong. Falcon 9 and Falcon 9 Heavy have approximately 30% more payload capacity than what is posted. She said that all that additional capacity is reserved for recovery and reuse requirements. She said that the posted capacities are for the reusable launch vehicles, not the expendables. She also said that the only thing that would change once reuse becomes standard is a lowering of the prices for launch. Wow.

Before you put that belief on the books I encourage you to run the numbers through the rocket equation and ask yourself what really makes sense.  Even assuming full expendability, the advertised numbers require unprecedented or nearly unprecedented mass ratios.  Squeezing reuse out of that I can't see without payload reduction.

 - Ed Kyle

That was my thoughts to, based on numbers you Ed, and others have run. 

I think 53mt to LEO is going to be fully expendable with cross-feed, 2.5 staging, and maybe some other upgrades. 

Also, fully expendable heavy EELV's like Delta IV with RS-68A, and the conceptual Atlas V-Heavy, are only around 30mt to LEO.  That's with hydrolox and staged combustion kerolox. 
Fully expendable Atlas V Phase 1 Heavy with the larger 5m upper stage was listed at 39mt to LEO on ULA's Atlas growth charts. 
A reusable FH with GG kerolox booster and upper stage will better that by 14mt?  I understand F9 has more thrust per core than Atlas V or Delta IV, but they are of a similar class, and the EELV's won't have the reusability penalty.

I'm no rocket scientist and don't want to pretend to know more than Musk or Shotwell or others at SpaceX, but something doesn't seem to add up there.


Edited:

[CuddlyRocket]

They are loosing performance. The numbers on their website have simply factored that loss in already. So the actual performance of an expendable F9 is 30% higher than given on the website.

Has the thread been trimmed? A little post of mine seems to have disappeared and it's so anodyne I assume it was simply caught up in the wash so I'll restate it.

It has been stated that moving from an expendable stage to a reusable one results in a 30% hit to performance. Conversely, therefore, moving from a reusable stage to an expendable one results in a 43% gain in performance.

The SpaceX site gives 13.15 tonnes to LEO for the F9, which we now know is the reusable figure. A 43% gain gives an expendable performance of 18.8 tonnes to LEO. (Check: 13.15 is indeed 70% of 18.8.)

[DJPledger]

Since Gwynne said she believed Pad 39A would be too small for the BFG doesn't that implicitly confirm that it'll be three cores?

Possibly, and there may be a single core version, too.

You would think that a pad that could launch Saturn V, could handle a single core BFR at least, although if the pad is configured for F9/FH the support equipment would be incompatible, and they would not want to stop launching F9/FH there while they retrofit, so better to build new pad. Maybe 39C?

Another thought, the BFR will probably never be required to launch anything to GTO, so there is less reason to launch eastward from a site nearest the equator.

A 2-stage BFR with a RTLS booster and reusable upper stage could launch large NRO type payloads to GTO, or dual payload launches to GTO like Ariane 5, and have enough margin to allow for total reusability.  Where FH will need to launch at least partially reusable, if not fully reusable, to get those big birds to GTO.

A fully reusable 2-stage BFR could be cheaper to operate than a partially expendable FH.  So I think there could very well be a business case for BFR-R to go to GTO, or other BLEO trajectories for unmanned commercial and government payloads.

She said that the SHLV aka. BFR is for Mars missions so don't expect it to be used for anything else. F9 and FH will take care of the satellite markets although FH will likely expend the center core on the heaviest missions.

[su27k]

Since Gwynne said she believed Pad 39A would be too small for the BFG doesn't that implicitly confirm that it'll be three cores?

Possibly, and there may be a single core version, too.

You would think that a pad that could launch Saturn V, could handle a single core BFR at least, although if the pad is configured for F9/FH the support equipment would be incompatible, and they would not want to stop launching F9/FH there while they retrofit, so better to build new pad. Maybe 39C?

Another thought, the BFR will probably never be required to launch anything to GTO, so there is less reason to launch eastward from a site nearest the equator.

A 2-stage BFR with a RTLS booster and reusable upper stage could launch large NRO type payloads to GTO, or dual payload launches to GTO like Ariane 5, and have enough margin to allow for total reusability.  Where FH will need to launch at least partially reusable, if not fully reusable, to get those big birds to GTO.

A fully reusable 2-stage BFR could be cheaper to operate than a partially expendable FH.  So I think there could very well be a business case for BFR-R to go to GTO, or other BLEO trajectories for unmanned commercial and government payloads.

She said that the SHLV aka. BFR is for Mars missions so don't expect it to be used for anything else. F9 and FH will take care of the satellite markets although FH will likely expend the center core on the heaviest missions.

Well it makes perfect sense, I would be surprised if this idea didn't come across her (or Elon's) mind. She didn't say so on the show probably because even FH is still on paper, BFR is not even a paper rocket yet (no name, no specs), so putting this idea on the air is just going to create more confusion and speculation.

[yg1968]

One of the good things that Shotwell said is that SpaceX believes that maintaining competition for the commercial crew program for the next round is important.

[Elmar Moelzer]

They are loosing performance. The numbers on their website have simply factored that loss in already. So the actual performance of an expendable F9 is 30% higher than given on the website.

Has the thread been trimmed? A little post of mine seems to have disappeared and it's so anodyne I assume it was simply caught up in the wash so I'll restate it.

It has been stated that moving from an expendable stage to a reusable one results in a 30% hit to performance. Conversely, therefore, moving from a reusable stage to an expendable one results in a 43% gain in performance.

The SpaceX site gives 13.15 tonnes to LEO for the F9, which we now know is the reusable figure. A 43% gain gives an expendable performance of 18.8 tonnes to LEO. (Check: 13.15 is indeed 70% of 18.8.)

That all may very well be but that is not what Shotwell said. She said "has about 30% more performance than what we put on the web and that extra performance is reserved for us to do our reusability and recoverability demonstrations right now"

[clongton]

They are loosing performance.

Ms. Shotwell specifically said they are not loosing performance.
Do you know something that she does not?

They are most certainly losing performance, they just already have the reduced performance posted on the website. That's exactly what she said.

Perhaps you didn't read my post entirely, or did not actually listen to the interview show. In any case she specifically stated that the 30% is reserved for the RTLS flight. Reserved means that it was never figured into the available performance. She stated that the figures quoted on the website are the available performance and represent what is available for a resuable launch vehicle. Her contention is that the launch vehicle is not loosing performance because it was designed for reusability. That 30% was never alocated for available performance, and because it was never available to the customer in the first place it is not lost performance.

Most cars and pickups will drive 20-30 miles after the gas gage says empty. Only dumb drivers wait until they have burned up that reserve before getting more, because that's not what it's for. This is pretty much the same thing.

[Elmar Moelzer]

Perhaps you didn't read my post entirely, or did not actually listen to the interview show. In any case she specifically stated that the 30% is reserved for the RTLS flight. Reserved means that it was never figured into the available performance. She stated that the figures quoted on the website are the available performance and represent what is available for a resuable launch vehicle. Her contention is that the launch vehicle is not loosing performance because it was designed for reusability. That 30% was never alocated for available performance, and because it was never available to the customer in the first place it is not lost performance.

It is still lost performance compared to an expendable LV and as we can see with the recent SES-10 announcement that performance can be made available for a fully expendable launch to launch payloads heavier than the performance target stated on the website.

[clongton]

It is still lost performance compared to an expendable LV and as we can see with the recent SES-10 announcement that performance can be made available for a fully expendable launch to launch payloads heavier than the performance target stated on the website.

Hmm. You still just don't get it. 
Falcon 9 and Falcon 9 Heavy are not designed to be expendable launch vehicles.
Never mind. We're done here.

[Elmar Moelzer]

Falcon 9 and Falcon 9 Heavy are not designed to be expendable launch vehicles.

They are designed with reusability in mind, but they can still be flown as expendable LVs that have 30% more performance (which is reserved for the breaking, RTLS and landing burns of the first stage). 

[Coastal Ron]

Falcon 9 and Falcon 9 Heavy are not designed to be expendable launch vehicles.

Every statement I've seen from Elon Musk has said that reusability is a goal, not a given, and that Falcon 9 is priced as an expendable launcher.  Things change if they can perfect reusability, but so far they have been careful to say that they are not there yet.

[Robotbeat]

Falcon 9 v1.1 is clearly designed around VTVL reuse for the first stage. With v1.0, reuse did feel almost like an afterthought, but with v1.1 it's clear that reuse is an important design goal. The number of engines, the placement of the central engine (and the inclusion of restart capability for 3 of the first stage engines... that's non-trivial), the attachment points for the legs that are included on ALL v1.1 flights even if the legs aren't there, etc.

[Llian Rhydderch]

It is still lost performance compared to an expendable LV and as we can see with the recent SES-10 announcement that performance can be made available for a fully expendable launch to launch payloads heavier than the performance target stated on the website.

Hmm. You still just don't get it. 
Falcon 9 and Falcon 9 Heavy are not designed to be expendable launch vehicles.
Never mind. We're done here.

I think we all have to be careful with words here, and how we interpret them.

I don't think it is quite right to say F9/FH "are are not designed to be expendable launch vehicles."  It is quite clear that F9 v1.0 was expendable, and F9 v1.1 is expendable (all three flights to date, and the 4th one in the coming days, have all been expendable).  They are just running engineering flight tests on the expendable booster, after they have "accomplished the basic requirement of the first stage: get the second stage and payload on the right orbital trajectory at the right velocity" before they run any flight test on the booster descent.  Other F9 v1.1 flights are planned to do this same thing, until SpaceX completes development of all the requisite systems and control algorithms to get it back to the launch pad.

It is okay to say that the basic hardware of the F9 v1.1 has been designed for reusability.  But not all the pieces are yet there, or yet proven to be "there," and complete yet.  When that basic hardware is completely modified ano/or added to so the first stage is reusable--all the hardware, and control systems, and software is complete and validated--it won't be the same rocket as SpaceX defined as F9v1.1 which they flew in September 2013 and until now.  Once complete, and tested, it will truly be a different rocket:  the F9-R, the Falcon 9-Reusable, or the Reusable Falcon 9.

For example, SpaceX has said they've made changes to the control dynamics and attitude control system for this test flight of the booster (post ss separation), and they have hardware attached for landing legs (for the first time) this time. At some point, if they are successful, they will be done engineering it, and they'll have a reusable booster stage.  But that time has not yet arrived, having been both built and validated. 

So, yes, the F9v1.1 and FH have both been designed to be expendable, as well as have most of the basic "stuff" to be reusable.  But they don't, yet, have all the stuff to be reusable.  So they also have been, quite clearly, designed to be expendable.

I assume that, many of us, look forward to the day when development is complete, and performance (including ground ops performance) is validated, and reusable booster rockets are flying back to the launch pad regularly, just like Buck Rogers.  But that day is not (quite) yet.

[Mader Levap]

Falcon 9 and Falcon 9 Heavy are not designed to be expendable launch vehicles.

Nonsensical statement. Each and every launch of F9 (both versions) so far was expendable.

[JBF]

Falcon 9 and Falcon 9 Heavy are not designed to be expendable launch vehicles.

Nonsensical statement. Each and every launch of F9 (both versions) so far was expendable.

Just because, so far,  they have been used as expendable does not mean they weren't designed to be reusable in the long term.

[Chris Bergin]

What's with the attitudes on here? It was a nice and friendly - straight down the middle - interview. Nothing much was revealed other than current intentions, and yet we've got an eight page assumption-a-thon here.

Have a real good think about your posts from this point onwards, because if I have to come back here because someone's been using the "rolleyes" icon a little too liberally, I'll be deleting that person's post.

I will not - no matter how many people it "upsets" - allow this forum to have its civility and informative nature reduced. You can all go join the "Bergin sucks, coz he banned me for swearing!" morons on Redddit otherwise.

[Elmar Moelzer]

They were designed to be reusable, but if the performance margins reserved for reusability are used to lift a heavier payload, it essentially becomes an expendable rocket. The performance numbers provided on the website are with this reusability in mind. That means that you can get an extra 30% more performance out of the rocket if you are willing to throw it away after the flight. I don't think there is anything more that needs to be said about it.

[AndyX]

Well said Chris! What do you think about Gwynne Shotwell from where you stand?