Gwynne Shotwell on The Space Show 3/21

[WindyCity]

Friday, March 21, 2014, 9:30-11 AM PDT (12:30-2 PM EDT; 11:30 AM-1 PM CDT): We welcome back GWYNNE SHOTWELL, president and chief operating officer of SpaceX. Ms. Shotwell is with us for only the first hour. Please, one question/comment per listener & emails & phone calls must be short.

http://thespaceshow.com

[Blackjax]

I'd like to throw it out to everyone on this forum, if you could ask her one (fairly concise) question, what would it be? 

It may be that some of the questions people propose will get asked by people with the freedom to call in during the show.

[cuddihy]

There's no chance I would catch this live. My question would be: Are you working on a smaller methane Lox engine than the Raptor concept? It seems rather oversized for an upperstage.

[happyflower]

I would like to know if based on the new developments between US and Russia, is SpaceX going to speed up the process of flying a person in the Dragon to free US from dependency on Russian technology?

[Excession]

I would ask if SpaceX is considering propellant depots for future use...

[simonbp]

I would like to know if based on the new developments between US and Russia, is SpaceX going to speed up the process of flying a person in the Dragon to free US from dependency on Russian technology?

I think the answer is that they are already going as fast as they can, Congress is the issue...

[manboy]

I'd like to throw it out to everyone on this forum, if you could ask her one (fairly concise) question, what would it be? 

It may be that some of the questions people propose will get asked by people with the freedom to call in during the show.

When launched on a Falcon 9, is Dragon's max payload to the ISS 3,000 or 6,000 kg? (Note: To anyone asking the question, it doesn't matter that the first number is probably wrong. What matters is figuring out how much mass Dragon can deliver to ISS. If you bring up the rumors about under performance then Shotwell may become defensive and give a half-true or misleading answer to save face.)

When is the cargo version of Dragon planned to be upgraded for terra firma landings?

Musk stated that Dragon's solar arrays are planned to be replaced with batteries, where on the spacecraft will they be kept (in the trunk, inside the capsule, etc)?

[Lars_J]

When launched on a Falcon 9, is Dragon's max payload to the ISS 3,000 or 6,000 kg? (Note: To anyone asking the question, it doesn't matter that the first number is probably wrong. What matters is figuring out how much mass Dragon can deliver to ISS. If you bring up the rumors about under performance then Shotwell may become defensive and give a half-true or misleading answer to save face.)

Ooh, let's plan a sneaky gotcha question in public, where no one can possibly find out.  Are you trying to find out information or prove that you are right? What is this, middle schools debate preparation? 

I'd settle for more information about FH schedule, and if the first flight will use cross-feed or not. And Raptor/MCT nuggets of course.

[DJPledger]

There's no chance I would catch this live. My question would be: Are you working on a smaller methane Lox engine than the Raptor concept? It seems rather oversized for an upperstage.

Also are SpaceX planning a larger version of the Raptor in the ~2-3Mlbf at SL range for a follow on larger BFR for the 100 person MCT after the initial "Raptor 9" BFR? Will the current Raptor get a thrust increase over the initial version several years down the road? These will be my questions to her.

[manboy]

When launched on a Falcon 9, is Dragon's max payload to the ISS 3,000 or 6,000 kg? (Note: To anyone asking the question, it doesn't matter that the first number is probably wrong. What matters is figuring out how much mass Dragon can deliver to ISS. If you bring up the rumors about under performance then Shotwell may become defensive and give a half-true or misleading answer to save face.)

Ooh, let's plan a sneaky gotcha question in public, where no one can possibly find out.  Are you trying to find out information or prove that you are right? What is this, middle schools debate preparation? 

I'm just trying to get the answer to a question that a lot of people want to know. I don't consider it to be a "gotcha question", but to get an accurate answer it's important for her not to think it is. I have no idea what Dragon's actual max payload is, we've seen several conflicting numbers and it would be nice to get some clarification.

[R7]

Current # of employees.

[Halidon]

Asking about things too far off in the future is unlikely to get much more than a vague response if for not other reason than the further out stuff is less likely to be set in stone. Not meaning to shoot anyone down, just cautioning against anyone who's expecting to learn what size the windows will be on an MCT from this interview.

Things I'd like to see asked:
How soon will we see a "real" Crew Dragon in the flesh
How is the Raptor project is coming along
What sort of non-government interest are they seeing in FH
What's the BFR business case

[go4mars]

Relationship (if any) with Hawthorne's Firefly Space systems?
NOFBX opinion/plans?

[Sur Billium]

I would like to ask her about the status of the crewed dragon and what modifications would necessary to allow the crewed dragon to fly a lunar orbital mission as opposed to just delivering crew to ISS. I would then like to follow up with the statement that based on pricing of the FH and crewed dragon, it seems like spacex could run a lunar orbit mission for several crew for less than $500 million, well within the budget of smaller nations like Canada, Brazil or Mexico, especially if they split the cost. Has spacex considered approaching another government space agency other than nasa about crewed missions?

[butters]

When will construction start on LC39A and when is the maiden launch expected from that pad?

[JimP]

I also would like an estimate of when the next gen Dragon will be revealed.  I believe Elon had previously teased us with either a September or 4th quarter 2013 reveal forecast.

[Sur Billium]

Oh, and I would like to ask her what spacex is doing with all the used cargo dragons after recovery.

[MP99]

I would like to know if based on the new developments between US and Russia, is SpaceX going to speed up the process of flying a person in the Dragon to free US from dependency on Russian technology?

I think the answer is that they are already going as fast as they can, Congress is the issue...

This seems to imply they could go faster if Congress assigned more funds??

cheers, Martin

[Adaptation]

I already emailed my question to drspace and it's a secret for now but if I had a second would it would be.

Will the falcon reusable (grasshopper 2) be used for max-q launch abort tests?

[manboy]

I already emailed my question to drspace and it's a secret for now but if I had a second would it would be.

Will the falcon reusable (grasshopper 2) be used for max-q launch abort tests?

It's not.

[2552]

2 questions:

Does SpaceX plan to completely self-fund the Raptor HLV and the MCT, or will they eventually require NASA funding?

If SpaceX's CRS contract is extended past 2015, how likely is it Dragons will be reused from then on?

[JNobles]

Since ISS supposedly can't accept a manned Dragon until the new docking mechanism is installed in 2017 I'm wondering if there is a chance some other _paying_ customer may ride a Dragon into orbit before then.  Or does SpaceX expect the first paying customer(s) to be NASA? I wonder if Ms. Shotwell could answer that.

[WindyCity]

I think it would be great if Ms. Shotwell revealed new information in her hour-long- interview. David Livingston usually makes time for caller questions or write-ins. Based on discussions I've seen in L2 and here, I sent him the following:

When and where will the Raptor engine be tested? Please provide technical details about the rockets that the Raptor will be used in. What would be their intended customers and projected applications? Will the Raptor-powered rockets replace the Falcon Heavy?

If you have questions for Shotwell, you can send them to [email protected] or call in during the program. The latter approach of course allows you to ask follow-ups, which Livingston graciously accepts.

[Adaptation]

Since ISS supposedly can't accept a manned Dragon until the new docking mechanism is installed in 2017 I'm wondering if there is a chance some other _paying_ customer may ride a Dragon into orbit before then.  Or does SpaceX expect the first paying customer(s) to be NASA? I wonder if Ms. Shotwell could answer that.

Why, I know for an escape system they want to be able to shut the doors fast and get the heck out but there is no reason we cant leave spare Soyuz attached and use dragon only for non emergency egress until they get something better figured out. 

When and where will the Raptor engine be tested? Please provide technical details about the rockets that the Raptor will be used in. What would be their intended customers and projected applications? Will the Raptor-powered rockets replace the Falcon Heavy?

I think she is a little better about not leaking details ahead of plan than Musk.  Something like that would probably be best disclosed with a press release but who knows anything can happen with a live interview. 

[manboy]

Since ISS supposedly can't accept a manned Dragon until the new docking mechanism is installed in 2017

You're off by about two years, IDA-1 is scheduled to launch on SpX-7 in April 2015.

[CuddlyRocket]

When launched on a Falcon 9, is Dragon's max payload to the ISS 3,000 or 6,000 kg? (Note: To anyone asking the question, it doesn't matter that the first number is probably wrong. What matters is figuring out how much mass Dragon can deliver to ISS. ...

I'm just trying to get the answer to a question that a lot of people want to know. ... I have no idea what Dragon's actual max payload is, we've seen several conflicting numbers and it would be nice to get some clarification.

Important the question clarifies what 'payload' you're talking about. My impression is that the 6,000kg is the maximum payload the Dragon itself can structurally handle. Subject to that, how much cargo any particular Dragon can carry to the ISS obviously depends on the launcher.

[FutureSpaceTourist]

My question would be: what market is there for HLVs larger than Falcon Heavy?

[sugmullun]

  As launches become more routine does SpaceX have any forthcoming strategy(s) for preventing or mitigating the effects of individual launch delays on subsequent launches?

[Dave G]

I'd like to know more details on the BFR, if possible.

[Robotbeat]

My question would be: what market is there for HLVs larger than Falcon Heavy?

Perhaps if they are partially reusable and can capture a majority of the commercial market and some of the US military market.

[Dudely]

When launched on a Falcon 9, is Dragon's max payload to the ISS 3,000 or 6,000 kg? (Note: To anyone asking the question, it doesn't matter that the first number is probably wrong. What matters is figuring out how much mass Dragon can deliver to ISS. ...

I'm just trying to get the answer to a question that a lot of people want to know. ... I have no idea what Dragon's actual max payload is, we've seen several conflicting numbers and it would be nice to get some clarification.

Important the question clarifies what 'payload' you're talking about. My impression is that the 6,000kg is the maximum payload the Dragon itself can structurally handle. Subject to that, how much cargo any particular Dragon can carry to the ISS obviously depends on the launcher.

Don't forget that the more payload you have the more fuel you need to maneuver the spacecraft towards the ISS. This is a very substantial part of the weight.

[Adaptation]

My question would be: what market is there for HLVs larger than Falcon Heavy?

Perhaps if they are partially reusable and can capture a majority of the commercial market and some of the US military market.

The performance hit from reusability will be compounded when they try to do it on second stage.  Maybe a fully reusable BFR wont have that much capacity if the second stage flies all the way to geo and back. 

[WindyCity]

From TheSpaceShow Program Schedule:

3. The Friday March 21, 2014 program from 9:30-11 AM PDT, (12:30-2 PM EDT, 11:30 AM 1 PM CDT): We welcome back MS. GWYNNE SHOTWELL, President & COO of SpaceX. Gwynne will be with us for only the first hour. Listener emails & calls must be very short to make room for as many participants as possible. Please, one question/comment only per listener. AND MAKE IT SHORT, Please!

Mrs. Shotwell was named President of SpaceX in November 2008.  Mrs. Shotwell joined SpaceX in 2002 as Vice President of Business Development to generate and manage SpaceX's customer base and the company's strategic and government relations.   In that role, she built the Falcon vehicle family manifest to 29 launches, representing over $2B in revenue.  Shotwell is responsible for operational activities of SpaceX, including sales, marketing, manufacturing, launch operations, legal, government relations and finance.  Previously, she served for ten years at The Aerospace Corporation and before that, directed business development at Microcosm, Inc. She began her engineering career at Chrysler Motors.  Mrs. Shotwell received, with honors, her Bachelor’s and Master’s Degree from Northwestern University in Mechanical Engineering and Applied Mathematics.  She is active in the Professional Aerospace community, as an elected executive member of the California Space Authority Board of Directors, former officer for both the Space Systems Technical Committee and the LA Section of the AIAA and heads the Frank J. Redd Student scholarship competition raising over $200,000 in scholarships in four years.  Mrs. Shotwell developed curricula and taught courses in Systems engineering at the introductory, management, and team levels. Mrs. Shotwell has authored papers in a wide variety of areas from standardizing spacecraft/payload interfaces to Space Shuttle  integration and reentry vehicle operational risks.

Listeners can talk with Gwynne Shotwell or the host using toll free 1 (866) 687-7223, by sending e-mail during the program using [email protected], [email protected], or [email protected]. To use Skype from your computer with a headset, the I. D. is thespaceshow. Skype is only available if when announced at the beginning of the program. Please note the toll free number is only available during a live Space Show program. At all other times, it is disconnected.

[2552]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

LC-40 to be modded to allow FH launches, 39A will also launch F9 and FH

39A not big enough for SpaceX super HLV, would build new site

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

Raptor super HLV not named yet

When will cargo Dragon make powered landings? powered landing is for Dragon V2 (crew), will retrofit powered landing to cargo version

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

Dragon 2 unveiling later this year

what are markets for super HLV? F9/FH is for commercial sat launches, super HLV is for transport to Mars

what rockets Raptor will be used for, and specs? Raptor is for Mars launches, not releasing specs yet.

only doing a few secondary payloads, not a lot of money in secondary market

commercial crew (not SpaceX specifically) about a year behind where it would be if fully funded, Congress may consider more funding given Crimea

with increased launch rate, will SpX prep 2 launches at 2 pads at once? likely in 2015 (referring to next VAFB launch?)

biggest near term challenges for SpX? make rockets highly producible, increase production rate, no big issues meeting that, current TAKT time 1 core a month, should be 2 a month by end of year.

when will SpX Mars missions happen? Lots of work to do, Elon says 12-13 years, will shoot for that timeframe.

not focused on Phobos or Deimos, but doesn't mean we wouldn't look at them

concern on increasing regulation? not overly concerned, but keep close eye, pretty comfortable with where regs are now

SpX has over 3000 employees, will expand and where focus? yes, will expand at more "sane" pace than in past, in all our locations

almost recovered CASSIOPE 1st stage, what changes to successfully recover? optimize reentry/landing burn, get more stability on stage, add ACS, make iterative progress, hard problem but believe will solve it.

[R7]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

...

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

These comments seem a bit contradictory?

[2552]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

...

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

These comments seem a bit contradictory?

I took it as a general statement that there are no plans for a methane engine for F9/FH, but you never know if plans could change in the future. Basically a no for the forseeable future.

[a_langwich]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

...

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

These comments seem a bit contradictory?

Well, the authoritative answer would be Shotwell's, but she doesn't post on this forum...so, it seems to me she is saying they are only working on the full-size Raptor right now, but she wouldn't rule out a smaller upper stage design in the future.

[DJPledger]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

...

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

These comments seem a bit contradictory?

Perhaps SpaceX will convert MvacD to methane for F9/FH upper stage. Should be easier and lower cost to do than a downscaled Raptor.

[sdsds]

Generalizing on DJPledger's thought, I would reconcile the apparent contradiction in Shotwell's comments by theorizing she implied that if there were to be a methane upper stage engine for FH, it wouldn't be an engine that came out of the "Raptor" development program.

[Llian Rhydderch]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

...

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

These comments seem a bit contradictory?

I took it as a general statement that there are no plans for a methane engine for F9/FH, but you never know if plans could change in the future. Basically a no for the forseeable future.

I think that is exactly right. 

If you listen to her comments in context, it is clear she said their focus is on (only) the full-size Raptor engine.

Much later in the broadcast, she was asked something about using a Raptor on an upper stage of F9/FH; all she said she wouldn't rule it out.  Definitely clear they are not pursuing that.

Also said that the SpaceX focus for NOW is F9/FH/Dragon_v2, higher production and launch ops rates;
THEN...
LATER, when FH & Dv2 flying regularly, and Dv2_crew flying, SpaceX focus would be the Mars-objective missions:  including a "test flight" to Mars, plus early equipment flights, in prep for the (main event) human transport to Mars.  (Raptor on F9/FH upper stage just takes their eye off the main event ball.

[GalacticIntruder]

Seems like you have to look at the marginal cost of Isp. Does it make any sense for SpaceX to spend tens of millions or hundreds of million of dollars for a new vac engine for the current fleet; just to pick up around 20 seconds Isp? I'd say no. SpaceX always leans towards costs over raw performance. The FH does anything it was built for. Their future SHLV is for BLEO, where every second counts.

[Robotbeat]

I don't think it'd necessarily take SpaceX 100s of millions of dollars to modify Merlin Vac to run methane. Falcon 9 could certainly benefit from a higher energy upper stage.

EDIT:I don't mean to give the impression that this is where I think SpaceX either will or should go.

[Comga]

I am disappointed that someone asked when the "cargo Dragon" would do a powered landing. The word "cargo" lead Ms Shotwell to discuss the different versions of Dragon instead of the timing, which would have been my single question.

This is the kind of overreaching that I often do and regret. KISS

[cuddihy]

2552, great job! Thanks for putting all that down!

[guckyfan]

During the show it was quite clear that Gwynne Shotwell tried not to paint the new vehicle as competition to SLS. The most she said she has her opinion on SLS but that is not relevant.

Also the emphasis that it is for Mars only. 

[Halidon]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

39A not big enough for SpaceX super HLV, would build new site

Yowza. BFR indeed.

[guckyfan]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

39A not big enough for SpaceX super HLV, would build new site

Yowza. BFR indeed.

I take it new site means not in Florida!?

Otherwise she would say new pad.

[Lars_J]

I don't think it'd necessarily take SpaceX 100s of millions of dollars to modify Merlin Vac to run methane. Falcon 9 could certainly benefit from a higher energy upper stage.

What your line of reasoning sounds like:

[Halidon]

I take it new site means not in Florida!?

Otherwise she would say new pad.

No I don't agree at all. A "new site" could just as easily be in Florida, at the Cape, just not on on a current pad.

[FutureSpaceTourist]

Th show is now available on line, eg via iTunes podcast or at http://archive.thespaceshow.com/shows/2212-BWB-2014-03-21.mp3

[cuddihy]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

Raptor question, smaller methane engine than million lb thrust one? no smaller engine, some subscale components being made for testing, focus on full Raptor

...

Raptor methane engine is for super HLV, but wouldn't rule out methane upper stage for F9/FH

These comments seem a bit contradictory?

I took it as a general statement that there are no plans for a methane engine for F9/FH, but you never know if plans could change in the future. Basically a no for the forseeable future.

I think that is exactly right. 

If you listen to her comments in context, it is clear she said their focus is on (only) the full-size Raptor engine.

Much later in the broadcast, she was asked something about using a Raptor on an upper stage of F9/FH; all she said she wouldn't rule it out.  Definitely clear they are not pursuing that.

Also said that the SpaceX focus for NOW is F9/FH/Dragon_v2, higher production and launch ops rates;
THEN...
LATER, when FH & Dv2 flying regularly, and Dv2_crew flying, SpaceX focus would be the Mars-objective missions:  including a "test flight" to Mars, plus early equipment flights, in prep for the (main event) human transport to Mars.  (Raptor on F9/FH upper stage just takes their eye off the main event ball.

Yep, this puts my speculations on a near-term methalox F9 US to bed...

[manboy]

Th show is now available on line, eg via iTunes podcast or at http://archive.thespaceshow.com/shows/2212-BWB-2014-03-21.mp3

10:44 - "I hope we refly a stage next year, we want to land one on land this year. But that's optimistic, we still have a lot of work to do."

11:45 - Falcon Heavy late this year or early next.

16:00 - Talks about the SpX-3 launch delay. (Very interesting)

18:35 - "What is new about this Dragon?" "It looks the same on the outside but it has a completely new avionics system. NASA really wanted the ability to carry more of the glacier and merlin freezers, they needed more power and the cargo racks needed to be redesigned, so in order to accommodate more power for these payloads...we had to redesign the avionics to take power out of the Dragon system to provide additional power for these payloads."

20:40 - Site hasn't been selected for the BFR, "I don't think 39A is big enough for these vehicles. Ya, we'd build a new site."

22:00 - No smaller methane engines are planned, Raptor is the focus.

22:16 - "What name will we be using for the upcoming nine Raptor, 10+ meter diameter rocket?" "We haven't named it yet."

23:50 - "When will the cargo version of Dragon begin making propulsive landings?" "So the current version of Dragon lands in water on parachute descent, we are looking at landing it on land under parachute. As for propulsive landing that is for our new version, we call it V2 for Dragon and that's the primary vehicle, that's the vehicle for crew, and we will retrofit that for cargo."

28:20 - On the unveiling of the Dragon2 "I don't know the specific time frame, it'll be later this year."

33:00 - Came really close to recovering a stage on the Cassiope mission.

38:00 - Q: Using a crewed Dragon for BLEO missions.

39:00 - Q: Using crewed Dragon for tourism and transportation to private stations. "If we're selected to continue the [ISS] crew program then I'm pretty sure we'll be flying Bigelow researchers to their habitats or Bigelow customers to his habitats."

40:30 - "The factory is set up to build 40 cores per year."

[Comga]

Th show is now available on line, eg via iTunes podcast or at http://archive.thespaceshow.com/shows/2212-BWB-2014-03-21.mp3

18:35 - "What is new about this Dragon?" "It looks the same on the outside but it has a completely new avionics system. NASA really wanted the ability to carry more of the glacier and merlin freezers, they needed more power and the cargo racks needed to be redesigned, so in order to accommodate more power for these payloads...we had to redesign the avionics to take power out of the Dragon system to provide additional power for these payloads."

That answers that question.

28:20 - On the unveiling of the Dragon2 "I don't know the specific time frame, it'll be later this year."

That's what Musk said last year.

[Jcc]

She said they are currently working on some some sub scale elements of Raptor, so you might imagine that to mean they build a turbo pump that is sized for a Merlin scale methane engine for the purpose of refining the design, but they don't plan to build a complete sub scale engine.

[Robotbeat]

She said they are currently working on some some sub scale elements of Raptor, so you might imagine that to mean they build a turbo pump that is sized for a Merlin scale methane engine for the purpose of refining the design, but they don't plan to build a complete sub scale engine.

Or, as likely, they may just build a scaled down prototype gas generator and maybe a pressure-fed chamber to test injector design. Turbopumps are a pain unless you're actually going to build an engine around it.

[a_langwich]

Seems like you have to look at the marginal cost of Isp. Does it make any sense for SpaceX to spend tens of millions or hundreds of million of dollars for a new vac engine for the current fleet; just to pick up around 20 seconds Isp? I'd say no. SpaceX always leans towards costs over raw performance. The FH does anything it was built for. Their future SHLV is for BLEO, where every second counts.

NASA science missions do BLEO, could use the performance.  Not sure if Falcon Heavy will come in cheaper than an Atlas 531-541-551.  If not, then maybe SpaceX will just forego that business.   

[Dave G]

Quick notes from Gwynne Shotwell's appearance on The Space Show, if anything here is wrong, feel free to correct:

39A not big enough for SpaceX super HLV, would build new site

Yowza. BFR indeed.

Indeed.

[bocephus419]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

So, using Gwynne's previously stated goal of $7 million per Falcon 9R flight, that comes to $7,000,000 / 28,991 Lbs to LEO = $241/Lb to LEO

[guckyfan]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

We had a lot of argument along that line. However this seems to be the first official confirmation.

Edit: There was also a statement by Elon Musk that they can pretty much fly their whole manifest with the reusable Falcon.

[Owlon]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

That's roughly in line with the old ~16,000-17,000 kg to LEO payload shown in the NLS II vehicle performance plotter and that, if I recall correctly, was briefly on the SpaceX website. I had been hoping that the 13150 kg to LEO number on the website included first stage reuse, so its nice to see confirmation on that.

[guckyfan]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

That's roughly in line with the old ~16,000-17,000 kg to LEO payload shown in the NLS II vehicle performance plotter and that, if I recall correctly, was briefly on the SpaceX website. I had been hoping that the 13150 kg to LEO number on the website included first stage reuse, so its nice to see confirmation on that.

It would also make a LEO capacity of ~10 tons including second stage reuse likely. Dragon space station missions would then become fully reusable flights. But a discussion shoud go into another thread.

[Oli]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

So, using Gwynne's previously stated goal of $7 million per Falcon 9R flight, that comes to $7,000,000 / 28,991 Lbs to LEO = $241/Lb to LEO

Wrt to performance, this

http://www.aviationweek.com/Blogs.aspx?plckBlogId=Blog:04ce340e-4b63-4d23-9695-d49ab661f385&plckPostId=Blog%3A04ce340e-4b63-4d23-9695-d49ab661f385Post%3A41fcfd6c-a6f2-42d5-b20b-52e31a103011

pretty much says it all. I don't know why Musk and co. give conflicting information.

[Owlon]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

So, using Gwynne's previously stated goal of $7 million per Falcon 9R flight, that comes to $7,000,000 / 28,991 Lbs to LEO = $241/Lb to LEO

Wrt to performance, this

http://www.aviationweek.com/Blogs.aspx?plckBlogId=Blog:04ce340e-4b63-4d23-9695-d49ab661f385&plckPostId=Blog%3A04ce340e-4b63-4d23-9695-d49ab661f385Post%3A41fcfd6c-a6f2-42d5-b20b-52e31a103011

pretty much says it all. I don't know why Musk and co. give conflicting information.

The main discrepancy there, I think, is the 1500 m/s vs 1800 m/s performance. It sounds like Falcon 9 is able to do 3500kg to a 1500 m/s orbit with first stage RTLS and ~5300kg to 1800 m/s fully expendable. The website number of 4850kg may be an 1800 m/s orbit with first stage RTLS.

[Oli]

Beginning at 8:57 she says (paraphrasing here) that while the prices on the spacex site don't account for reusability yet, the performance specs do. She says the actual performance is about 30% higher than quoted on the site.  Was this known already? This is HUGE news to me!

So, using Gwynne's previously stated goal of $7 million per Falcon 9R flight, that comes to $7,000,000 / 28,991 Lbs to LEO = $241/Lb to LEO

Wrt to performance, this

http://www.aviationweek.com/Blogs.aspx?plckBlogId=Blog:04ce340e-4b63-4d23-9695-d49ab661f385&plckPostId=Blog%3A04ce340e-4b63-4d23-9695-d49ab661f385Post%3A41fcfd6c-a6f2-42d5-b20b-52e31a103011

pretty much says it all. I don't know why Musk and co. give conflicting information.

The main discrepancy there, I think, is the 1500 m/s vs 1800 m/s performance. It sounds like Falcon 9 is able to do 3500kg to a 1500 m/s orbit with first stage RTLS and ~5300kg to 1800 m/s fully expendable. The website number of 4850kg may be an 1800 m/s orbit with first stage RTLS.

It says currently Falcon 9 can lift 3.5t to a 1500m/s GTO orbit. I don't know how the 30% higher than 4.85t figure is compatible with this, ok I guess she meant LEO performance.

The other things Musk says, is they're aiming for 3.5t (not sure what GTO, I guess 1800m/s) for the version with reusable booster (with minor improvements to the existing F9).

[Elmar Moelzer]

That's roughly in line with the old ~16,000-17,000 kg to LEO payload shown in the NLS II vehicle performance plotter and that, if I recall correctly, was briefly on the SpaceX website. I had been hoping that the 13150 kg to LEO number on the website included first stage reuse, so its nice to see confirmation on that.

Yeah, I always thought that was the case.

[manboy]

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?

[john smith 19]

At 7:05 she says that NASA requirements add $10m to a standard F9 launch, but USAF launches add more like $20m and security requirements add a further $8-10m

So in principal a DOD launch worst case would be F9 standard launch + USAF costs + security --> F9 cost +$30m

Which sounds like a pretty good deal for any viable payload that can fly on an F9.

That still leaves a pretty broad range of payloads that are not in its range.

And that's won't happen till October 16th 2016 at the earliest.

[EDIT 49:00 3 separate qualification regimes for NASA, USAF and NRO ]

[guckyfan]

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?

It could also be a 18 Raptor 15m single stick. Or 12 Raptor with increased thrust. I think those could also not launch at 39A. Given RTLS constraints with Heavy central cores such a configuration seems to make more sense to me than a Heavy. But what do I know?

[Jcc]

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.

[guckyfan]

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.

Interplanetary trajectories also launch east.

[manboy]

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?

It could also be a 18 Raptor 15m single stick. Or 12 Raptor with increased thrust.

That seems to contradict currently available information.

[guckyfan]

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?

It could also be a 18 Raptor 15m single stick. Or 12 Raptor with increased thrust.

That seems to contradict currently available information.

True, it is only speculation. But this is the next step. The only thing that seems quite set in stone yet is the 9 Raptor first stage as a first step. A 3 core Heavy is much less clear as the upgrade path.

For me the single stick 9 Raptor launcher seems good enough to do anything regarding Mars quite efficiently.

[ugordan]

Interplanetary trajectories also launch east.

That helps launch vehicle performance, but it's not a prerequisite for an interplanetary injection.

[clongton]

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.

[edkyle99]

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

[WindyCity]

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.

Shotwell mentioned that future SpaceX reusable rockets would recover some mass by removing wiring, sensors, etc. that are being used for data-gathering during their R&D. How significant would these gains be? Enough, do you think, to justify her comment that no payload launch capability would be sacrificed?

[guckyfan]

Interplanetary trajectories also launch east.

That helps launch vehicle performance, but it's not a prerequisite for an interplanetary injection.

For interplanetary launches of cargo or humans you will seek best vehicle performance.

[clongton]

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

I'm not taking it to the bank just yet Ed. But what it does tell me is that SpaceX is not planning on loosing performance to LEO because of reusability. We'll see how that works out.

[Lars_J]

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

Did you think that the NASA NLSII 16mt figure to LEO for v1.1 required "unprecedented or nearly unprecedented mass ratio"?

Also remember that When Shotwell was talking reusability, she appears to be only talking about first stage reusability. 2nd stage reuse is a bit down the road.

[john smith 19]

Also remember that When Shotwell was talking reusability, she appears to be only talking about first stage reusability. 2nd stage reuse is a bit down the road.

I'm not sure that's accurate. I got the impression with FH she was talking about full IE all stage recoverability, and that with full resue it could get the biggest GEO comm sats to their orbit and still bring all stages back.

How they will get those upper stages (especially the 3rd stage) will be recovered is of course anyone's guess. 

[hrissan]

Also remember that When Shotwell was talking reusability, she appears to be only talking about first stage reusability. 2nd stage reuse is a bit down the road.

I'm not sure that's accurate. I got the impression with FH she was talking about full IE all stage recoverability, and that with full resue it could get the biggest GEO comm sats to their orbit and still bring all stages back.

How they will get those upper stages (especially the 3rd stage) will be recovered is of course anyone's guess. 

When she was speaking about FH reusability she said "numbers for heavy are with first stages reuse", I assume first stages are 3 FH cores, but not upper stage.

[Hyperion5]

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

It wouldn't take that much effort to get unprecedented or nearly unprecedented mass ratios with all-kerolox rockets, Ed.  It's not like the competition is exactly fierce when it comes to weight-saving designs out there.  There are exactly zero all-kerolox Russian or Chinese LVs with common bulkheads on all stages to the best of my knowledge, and both the Atlas V and Ariane 5 use common bulkheads only on their hydrolox stages.  Add in lithium-aluminum alloy construction (rarer than it should be), friction stir-welding, computer-aided design, a composite PLF, and engines with unprecedented t/w ratios, and you've got a fantastic recipe for great mass ratios.  Spacex can thus achieve "unprecedented" mass ratios simply because the competition has not pushed very hard when it comes to saving weight on all-kerolox rockets.  This is a big part of the reason how Elon Musk can brag about the 30:1 mass ratio on the Falcon Heavy boosters, which he rather unfairly compares with the Delta IV Heavy's boosters' mass ratio. 

[Coastal Ron]

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.

I know she said that about Falcon 9, but I don't remember her stating it for Falcon Heavy.  Falcon Heavy has a lot of variations that they can implement with reusability - and we still have not heard any updates on cross-feed that I know of, so I'm not sure how that still fits in.

[DavidH]

  This is a big part of the reason how Elon Musk can brag about the 30:1 mass ratio on the Falcon Heavy boosters, which he rather unfairly compares with the Delta IV Heavy's boosters' mass ratio.

Can you expand on this? Are you saying the extra size of the H2 tank makes the MR higher?

[Jim]

Add friction stir-welding, computer-aided design, a composite PLF,

Those exist on all US boosters

[Hyperion5]

Add friction stir-welding, computer-aided design, a composite PLF,

Those exist on all US boosters

You know, Jim, I was trying to emphasize the common bulkheads and lithium-aluminum alloy construction, which is why I mentioned "add" in my statement.  The point was that some of the foreign competitors lack even those bits in their design and construction, which is partly why it is not particularly hard to best their mass ratios.  I wasn't just comparing the Falcon 9 to the Antares, Atlas V or the Delta IV family. 

[Hyperion5]

  This is a big part of the reason how Elon Musk can brag about the 30:1 mass ratio on the Falcon Heavy boosters, which he rather unfairly compares with the Delta IV Heavy's boosters' mass ratio.

Can you expand on this? Are you saying the extra size of the H2 tank makes the MR higher?

David, I believe you meant to say, "Are you saying the extra size of the H2 tank makes the MR lower?" The answer is yes, the extra size makes the mass ratio lower.  There is one other reason, besides tank size, that causes the big difference in mass ratios.  Namely the fact that hydrogen is a "deep cryogen" that likes to be 20 degrees above absolute zero while kerosene can be kept at room temperature.  This difference means that you also have to add a large amount of insulation to hydrogen tanks to keep them from turning into a gas.  This adds mass that you won't find on a kerosene tank, which helps the kerolox rocket achieve a better mass ratio. 

However, when it comes to tank size, there's one thing that really matters: impulse density (or the amount of bang you get out of a given volume of propellants).  Generally speaking, hydrolox rockets have terrible impulse density compared to kerolox rockets like the Falcon 9.  Presuming you were able to design a kerolox and a hydrolox rocket with an identical payload capacity, the kerolox rocket's average propellant density, or bulk density, would be dramatically higher than that of the hydrolox rocket.  Here's a good site for getting a better understanding: http://settlement.arc.nasa.gov/Nowicki/SPBI1LF.HTM. 

While I may not be a rocket scientist like Jim, some basic math makes it easy enough to figure out why a hydrolox rocket has an inferior mass ratio to a kerolox rocket.  In the example on the site provided, the bulk density, or the average density of the propellants, is provided for both a hydrolox rocket and a kerolox rocket.  I've converted down to liters, or 1/1000th of a cubic meter, in order to make the math thereafter easier to follow. 

Hydrolox rocket (6.0 O/F): .358 kg/liter (10 cm^3)
Kerolox rocket(2.5 O/F): 1.026kg/liter (10 cm^3)

So basically, if you were to measure them against one another, the kerolox rocket would mass 2.866X as much per unit of propellant tank volume as the hydrolox rocket of identical capability.  That would be fine for the hydrolox rocket IF it could compensate via increased efficiency.  Here's the relative efficiency of these two rockets' engines (each with identical chamber pressure). 

Hydrolox rocket Specific Impulse: 455.9 seconds
Kerolox rocket Specific Impulse: 354.6 seconds

We multiply Isp by the Earth's gravitational pull to get the exhaust velocity (v_e):
455.9x9.807 m/s=4471 m/s
354.6x9.807 m/s=3477.6 m/s

We then need to multiply these exhaust values by the bulk densities of each engine's propellant mixture to get the impulse density:

Impulse Density Id = v_e(exhaust velocity)*d_p(bulk density)
1600.6 Ns/L = 4471 m/s*.358 kg/L (hydrolox rocket)
3568 Ns/L = 3477.6 m/s *1.026 kg/L (kerolox rocket)

So you see, despite all of the hydrolox rocket's added efficiency, the kerolox rocket will still pack 2.23X as much delta-v into a liter of propellants.  This means your hydrolox rocket must have tanks at least 2.23X as large to compensate, and more if you factor in the added mass of the tanks and their insulation.  This is what I meant about the comparison between the Delta IV Heavy boosters' mass ratio and the FH boosters' MR ratio not being fair.  If you're using hydrogen, then clearly you aren't using it because it will give a good mass ratio.  You're using it because it will let you build a much lighter, more efficient rocket to lift the same amount of payload to orbit.  It should also be noted that due to their greater efficiency, mass ratios are not as critical for hydrolox rockets as they are for kerolox rockets.  The Delta IV Heavy can afford to have boosters with only an MR ratio of 10, while the Falcon Heavy needs an MR ratio of 30 (and a few other tricks) in order to push its full-size payloads to orbit. 

[CuddlyRocket]

Falcon 9 and Falcon 9 Heavy have approximately 30% more payload capacity than what is posted.

43% more! (Reusability is said to reduce payload capacity by 30% from the expendable figure, so if you start from the reusable figure the expendable payload capacity is a 43% increase.)

[john smith 19]

It wouldn't take that much effort to get unprecedented or nearly unprecedented mass ratios with all-kerolox rockets, Ed.  It's not like the competition is exactly fierce when it comes to weight-saving designs out there.  There are exactly zero all-kerolox Russian or Chinese LVs with common bulkheads on all stages to the best of my knowledge, and both the Atlas V and Ariane 5 use common bulkheads only on their hydrolox stages.  Add in lithium-aluminum alloy construction (rarer than it should be), friction stir-welding, computer-aided design, a composite PLF, and engines with unprecedented t/w ratios, and you've got a fantastic recipe for great mass ratios.  Spacex can thus achieve "unprecedented" mass ratios simply because the competition has not pushed very hard when it comes to saving weight on all-kerolox rockets.  This is a big part of the reason how Elon Musk can brag about the 30:1 mass ratio on the Falcon Heavy boosters, which he rather unfairly compares with the Delta IV Heavy's boosters' mass ratio.

It's a subtle point but I think FSW has made the use of AlLi alloys much easier. The issue with welded joints has always been weld "efficiency" IE weld strength /parent metal strength.  This is especially important when you you have to do rework and how thick the plate you have to start with (or if you have to add stiffener plates around the weld areas) in order to ensure you still have a strong enough joint after the second welding attempt (or possibly 3rd  ).

IIRC the Shuttle ET might have 100 inches of rework and NASA expected a welded joint to be 70% efficient OTOH IIRC Spacex have claimed FSW has required no rework. I recall that a recent biz jet design also went from a composite fuselage to an FSW Al alloy and cited no rework as well.

The other benefit is that FSW is claimed to deliver near parent metal strength and as the metal is not actually melted (I've always thought "welding is a bit of a misnomer  ) the crystal structure is much better preserved and (relatively) volatile elements are not vaporized out.

[clongton]

Falcon 9 and Falcon 9 Heavy have approximately 30% more payload capacity than what is posted.

43% more! (Reusability is said to reduce payload capacity by 30% from the expendable figure, so if you start from the reusable figure the expendable payload capacity is a 43% increase.)

I quoted Ms. Shotwell.

[Llian Rhydderch]

It wouldn't take that much effort to get unprecedented or nearly unprecedented mass ratios with all-kerolox rockets, Ed.  It's not like the competition is exactly fierce when it comes to weight-saving designs out there.  There are exactly zero all-kerolox Russian or Chinese LVs with common bulkheads on all stages to the best of my knowledge, and both the Atlas V and Ariane 5 use common bulkheads only on their hydrolox stages.  Add in lithium-aluminum alloy construction (rarer than it should be), friction stir-welding, computer-aided design, a composite PLF, and engines with unprecedented t/w ratios, and you've got a fantastic recipe for great mass ratios.  Spacex can thus achieve "unprecedented" mass ratios simply because the competition has not pushed very hard when it comes to saving weight on all-kerolox rockets.  This is a big part of the reason how Elon Musk can brag about the 30:1 mass ratio on the Falcon Heavy boosters, which he rather unfairly compares with the Delta IV Heavy's boosters' mass ratio.

It's a subtle point but I think FSW has made the use of AlLi alloys much easier. The issue with welded joints has always been weld "efficiency" IE weld strength /parent metal strength.  This is especially important when you you have to do rework and how thick the plate you have to start with (or if you have to add stiffener plates around the weld areas) in order to ensure you still have a strong enough joint after the second welding attempt (or possibly 3rd  ).

IIRC the Shuttle ET might have 100 inches of rework and NASA expected a welded joint to be 70% efficient OTOH IIRC Spacex have claimed FSW has required no rework. I recall that a recent biz jet design also went from a composite fuselage to an FSW Al alloy and cited no rework as well.

The other benefit is that FSW is claimed to deliver near parent metal strength and as the metal is not actually melted (I've always thought "welding is a bit of a misnomer  ) the crystal structure is much better preserved and (relatively) volatile elements are not vaporized out.

John, that was very useful input on the topic of friction stir welding and weld strength, and the economics of rework etc.  I'd like to read more about it.  Might you have any sources or links you could point interested readers to?

[Elmar Moelzer]

I'm not taking it to the bank just yet Ed. But what it does tell me is that SpaceX is not planning on loosing performance to LEO because of reusability. We'll see how that works out.

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. But I do wonder whether Shotwell means that the numbers include reuse of the first stage only and not the second stage (which would put everything a bit more in line with what we have heard and calculated previously). But it would be quite cool if that was for reuse of first and second stage.

[R7]

Impulse Density Id = v_e(exhaust velocity)*d_p(bulk density)
1600.6 Ns/L = 4471 m/s*.358 kg/L (hydrolox rocket)
3568 Ns/L = 3477.6 m/s *1.026 kg/L (kerolox rocket)

So you see, despite all of the hydrolox rocket's added efficiency, the kerolox rocket will still pack 2.23X as much delta-v into a liter of propellants.  This means your hydrolox rocket must have tanks at least 2.23X as large to compensate, and more if you factor in the added mass of the tanks and their insulation.

It is not that simple. The formulas the your methane F9 family thread apply here too. You can't equate plain impulse density value directly to delta-v. Half of it (density) is inside the logarithm of rocket equation and you'd need more info to calculate actual desired delta-v. Or vice versa, you peg desired delta-v from which you calculate tank volume, or the handy "specific volume" (propellant volume divided by burnout mass)  for different propellants to compare.

For example if there's upper stage needing to do 6000m/s dv then your values give specific volume of 4.496L/kg for kerolox and 7.896L/kg for hydrolox, so volume ratio is 1.756

Lower stages become more complex because reduced upper stage weights need to be taken into account. A first stage doing 3500m/s needs "only" 1.462 times larger tanks using hydrolox with above upper stage example adjusted for its lesser wet mass, assuming it's 80% of first stage burnout mass. Without adjusting the ratio would be 1.961

Yes this is too simple and does not take into account tank mass per volume, insulation, different engine T/Ws etc. just wanted to point out it is not directly proportional to impulse density. Calculated numbers with too-messy-to-upload mathcad sheet.

This is so OT isn'it it 

[clongton]

They are loosing performance.

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

[PerW]

I think It was very interesting, especially that Bigelow is a focus area and not just a client among others. Looking forward to hear more about this.

[Elmar Moelzer]

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

Did you actually read my entire post, or are you just cherry picking parts to criticize later? If you had read the entire post, this would be a lot clearer to you.

[Owlon]

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.

[Robotbeat]

SpaceX's Falcon 9 is the newest clean-sheet launch vehicle with a very, very recent almost complete redo of the rocket. They are using basically the densest propellants available and have the flexibility of building basically everything in-house. They are very well-equipped to get record-breaking mass ratios. And for a boost-back first stage landing on legs, mass ratio is almost the only thing that matters. If you had a 100:1 mass ratio (unrealistic, but throwing that out there) for a first stage, your performance penalty for boost back and landing would be incredibly low. Heck, you'd get better performance out of a first stage with a 100:1 mass ratio that does boost-back than you would out of a first stage with 10:1 mass ratio that is expendable.

SpaceX has publicly mentioned planning on subcooling propellants, too. That's not completely unprecedented (NK-33 does it for oxygen for other technical reasons), but it probably has not been combined with the extremely good mass ratios they're already getting for their Al-Li alloy tanks (with a very, very lightweight thrust structure... especially compared to v1.0's essentially boiler-plate thrust structure)

I'm fairly certain nearly all of Shotwell's statements were about core reuse, not upper stage reuse.

[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?

I'd say so as I don't think they are planning to build another larger core to be there "BFR" after the 10 core.

[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?

It could also be a 18 Raptor 15m single stick. Or 12 Raptor with increased thrust. I think those could also not launch at 39A. Given RTLS constraints with Heavy central cores such a configuration seems to make more sense to me than a Heavy. But what do I know?

Probably tri-core...

http://www.nasaspaceflight.com/2014/03/spacex-advances-drive-mars-rocket-raptor-power/

[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?

[Chris Bergin]

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

Based on what I know, what I'm told and what we've seen, I think Ms. Shotwell is a brilliant person. Probably as important to SpaceX as Elon. I kinda think of Elon as some crazy (in a nice way) visionary, while Ms. Shotwell is the business and engineering brain that facilitates Elon's ambitions.

The ways things are heading, there's a fairly good chance she will have her name etched into history when we see people on Mars.

[clongton]

Allow me to quote the source statements that informed my posts above:

10:25 - Dr. Livingston - "So I guess what I'm hearing is that there really isn't going to be a penalty on the reusable because you've already compensated for that in the existing rocket."

10:35 - Gwynne Shotwell - "That's correct."

There are probably as many ways to spin this as there are posters on this thread, including what I did, which was to not spin it at all and let her statement stand unvarnished without my "I think she meant". Personally I think that without knowing what is actually in her head, that is the only correct approach to understanding what she actually said. However - YMMV 

[Elmar Moelzer]

Allow me to quote the source statements that informed my posts above:

10:25 - Dr. Livingston - "So I guess what I'm hearing is that there really isn't going to be a penalty on the reusable because you've already compensated for that in the existing rocket."

10:35 - Gwynne Shotwell - "That's correct."

There are probably as many ways to spin this as there are posters on this thread, including what I did, which was to not spin it at all and let her statement stand unvarnished. Personally I think that without knowing what is actually in her head, that is the only correct approach to understanding what she said. However - YMMV 
 
Let the spin doctors begin.

What she meant is that there wont be an additional penalty beyond the 30% that they subtracted to get the performance number on the website.

[Dudely]

Just wanted to interject with a salient point.

You can't take a rocket that was designed for reusability- taking a 30% payload hit in the process- then pretend you're going to get 30% more payload into orbit by burning it to empty with no legs on it.

Fuel+legs is not the only aspect of reusability. It's a huge part (legs alone represent hundreds of lost kilos to orbit), but it's not the only part. So why would they ever advertise that they could do that when they are designing a rocket that can't?

None of what she said was very surprising. Though it was encouraging!

[JBF]

Just wanted to interject with a salient point.

You can't take a rocket that was designed for reusability- taking a 30% payload hit in the process- then pretend you're going to get 30% more payload into orbit by burning it to empty with no legs on it.

Fuel+legs is not the only aspect of reusability. It's a huge part (legs alone represent hundreds of lost kilos to orbit), but it's not the only part. So why would they ever advertise that they could do that when they are designing a rocket that can't?

None of what she said was very surprising. Though it was encouraging!

Sure you can, especially when the majority of that 30% hit is the fuel reserves.  What other parts do you think are a major contributor?

[Elmar Moelzer]

Just wanted to interject with a salient point.

You can't take a rocket that was designed for reusability- taking a 30% payload hit in the process- then pretend you're going to get 30% more payload into orbit by burning it to empty with no legs on it.

Fuel+legs is not the only aspect of reusability. It's a huge part (legs alone represent hundreds of lost kilos to orbit), but it's not the only part. So why would they ever advertise that they could do that when they are designing a rocket that can't?

None of what she said was very surprising. Though it was encouraging!

Sure you can, especially when the majority of that 30% hit is the fuel reserves.  What other parts do you think are a major contributor?

Exactly! And SES10 proofs it too.
Besides, how else could Shotwells response be understood?

[Coastal Ron]

Just wanted to interject with a salient point.

You can't take a rocket that was designed for reusability- taking a 30% payload hit in the process...

Maybe you should think about this the other way - that without reusability customers are taking a PRICE hit.  And if SpaceX does succeed in instituting some form of reusability, the customers for other launch providers will be asking why they have to pay a penalty for non-reusability.  That's the day I look forward to seeing, since that will hopefully be the start of a true industry trend towards reducing the cost it takes to access space.

...then pretend you're going to get 30% more payload into orbit by burning it to empty with no legs on it.

Everybody has their own way of pricing things.  It's been pretty clear that SpaceX has been careful to make sure they only promise capabilities that they can deliver on, and so far that has resulted in them periodically upping their specs.  Holding back capabilities is nothing new, as has been pointed out already, so I'm not sure what all the debate is about.

None of what she said was very surprising. Though it was encouraging!

Agreed.

[Hauerg]

...
The ways things are heading, there's a fairly good chance she will have her name etched into history when we see people on Mars.

"Welcome to Shotwell City Space Port" 

[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.

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.

I am referring to the 10m single core LV, not the tri-core SHLV, which I'm sure is intended for sending the final version of MCT to Mars for colonization.  As there's little else such a beast would be used for.

[QuantumG]

I am referring to the 10m single core LV, not the tri-core SHLV, which I'm sure is intended for sending the final version of MCT to Mars for colonization.  As there's little else such a beast would be used for.

Any vehicle with a Raptor engine is a decade away and will only be used for Mars launches. I don't know how Gwynne could have made this more clear. If you haven't already listened to the show, please do.

[Lobo]

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.

I've not had a chance to listen to the interview, just read the summaries on here.

So a question.  Does "30% reserved for RTLS flight" mean there's 30% of the booster fuel left in the booster for boost back and landing?  Or that Falcon would have 30% more payload to LEO or GTO if the booster was expended and not reused?

[JBF]

30% more payload.

[llanitedave]

A 747 designed for reuse can be used in expendable mode as well.  That doesn't normally mean that you're losing performance when you use it as designed.

[Jim]

A 747 designed for reuse can be used in expendable mode as well.  That doesn't normally mean that you're losing performance when you use it as designed.

Yes, it does. .  A 747 with a 10k mile range can only go 5k if it has to return to the takeoff site on using only one load of fuel.

[Ludus]

A 747 designed for reuse can be used in expendable mode as well.  That doesn't normally mean that you're losing performance when you use it as designed.

A 747 can fly more cargo considerably further if you give up any planning for refueling or taking off again.

[llanitedave]

Have you ever heard anyone say that reusable 747s were losing performance compared to expendable 747s?  Has anyone ever included that in an analysis of the 747s capability?  Was expending 747s ever discussed during their design phase?

[beancounter]

I can't see any of these posts as adding to the discussion.  Unless someone has something useful to add then I vote to close the thread.

[Jim]

Have you ever heard anyone say that reusable 747s were losing performance compared to expendable 747s?  Has anyone ever included that in an analysis of the 747s capability?  Was expending 747s ever discussed during their design phase?

Yes, an expendable 747 would be lighter since its structure would not have to endure thousands of cycles and flight hours.  Since it would be lighter, it would fly higher and further.

[Jim]

Have you ever heard anyone say that reusable 747s were losing performance compared to expendable 747s? 
Has anyone ever included that in an analysis of the 747s capability?
 Was expending 747s ever discussed during their design phase?

Yes to all three  questions for F9 v1.1
F9 V1.1 is assumed to be expendable for NASA missions

[Hyperion5]

Impulse Density Id = v_e(exhaust velocity)*d_p(bulk density)
1600.6 Ns/L = 4471 m/s*.358 kg/L (hydrolox rocket)
3568 Ns/L = 3477.6 m/s *1.026 kg/L (kerolox rocket)

So you see, despite all of the hydrolox rocket's added efficiency, the kerolox rocket will still pack 2.23X as much delta-v into a liter of propellants.  This means your hydrolox rocket must have tanks at least 2.23X as large to compensate, and more if you factor in the added mass of the tanks and their insulation.

It is not that simple. The formulas the your methane F9 family thread apply here too. You can't equate plain impulse density value directly to delta-v. Half of it (density) is inside the logarithm of rocket equation and you'd need more info to calculate actual desired delta-v. Or vice versa, you peg desired delta-v from which you calculate tank volume, or the handy "specific volume" (propellant volume divided by burnout mass)  for different propellants to compare.

For example if there's upper stage needing to do 6000m/s dv then your values give specific volume of 4.496L/kg for kerolox and 7.896L/kg for hydrolox, so volume ratio is 1.756

Lower stages become more complex because reduced upper stage weights need to be taken into account. A first stage doing 3500m/s needs "only" 1.462 times larger tanks using hydrolox with above upper stage example adjusted for its lesser wet mass, assuming it's 80% of first stage burnout mass. Without adjusting the ratio would be 1.961

Yes this is too simple and does not take into account tank mass per volume, insulation, different engine T/Ws etc. just wanted to point out it is not directly proportional to impulse density. Calculated numbers with too-messy-to-upload mathcad sheet.

This is so OT isn'it it 

I didn't want to confuse David by jumping into "the deep end" too soon.  Impulse density is a good way to introduce people to rocket science because the math is so straightforward.  So yes, I could have gone in more detail, and yes, it isn't that simple, but the point was not to overwhelm David with all the gory details.  David, if you have more questions regarding this matter of mass ratios, I would suggest starting on thread on the subject or sending R7 and me a PM.

 

I am referring to the 10m single core LV, not the tri-core SHLV, which I'm sure is intended for sending the final version of MCT to Mars for colonization.  As there's little else such a beast would be used for.

Any vehicle with a Raptor engine is a decade away and will only be used for Mars launches. I don't know how Gwynne could have made this more clear. If you haven't already listened to the show, please do.

Oh I wouldn't be so limited in your forecast, Lobo.  When Sir Tim Berners-Lee was asked about something people use the internet for he (the inventor of the modern internet) did not anticipate, he had a ready answer:

In responding to the question, "What was one of the things you never thought the internet would be used for, but has actually become one of the main reasons people use the internet?" he replied, "Kittens".

Spacex says the rocket is exclusively for Mars, but does anyone here really think they'd say no to Bigelow wanting to use the MCT to send 100 people to a mega space station?  There are all sorts of missions that don't involve Mars that are possible, from large commercial payloads, DoD missions, NASA exploration missions, asteroid mining and so on.  Who knows?  Perhaps the Kate Upton weightless photo shoot was a harbinger of the future.  I can see it now:

"I'm Chris Bergin"
"And I'm Alejandro Belluscio."
"We're reporting live here in orbit from the Etihad Airlines Space Station."
"That's right Chris, and in just a few minutes, the first ever Victoria Secrets Space Show will begin.  I'm told a few of the models have been kept out of the show due to space sickness, but the rest are faring well.  The press for this show has been incredible, and I'm told that more people are expected to tune in to this show during the Super Bowl Halftime than the Halftime Show itself."
...
Now while I doubt this would happen anytime soon, provided the price was low enough, you have to admit a vehicle the size of the MCT would start enabling things Spacex never even dreamed could happen. 

[QuantumG]

Spacex says the rocket is exclusively for Mars, but does anyone here really think they'd say no to Bigelow wanting to use the MCT to send 100 people to a mega space station?  There are all sorts of missions that don't involve Mars that are possible,

That's irrelevant. Lobo's comments contradicted Gwynne. That's the only reason I suggested he go listen to the interview before commenting.

[luinil]

For me she is saying that the raptor rocket will be designed and produced with the focus on Mars only, and nothing more. They do not want (but she said that they would think of it if an offer was done) to focus out to adapt it to other purposes.

She did not said that if someone wanted to use the rocket as it is for another purpose, they would not allow them.

i.e. : they will build a Mars rocket, if you can use the Mars rocket to do other things, you can, but they will not use time and money to change the design to other goals.
The rocket will not be used only for Mars launches, it will be designed only for Mars launches, that's different.

[NovaSilisko]

For me she is saying that the raptor rocket will be designed and produced with the focus on Mars only, and nothing more. They do not want (but she said that they would think of it if an offer was done) to focus out to adapt it to other purposes.

She did not said that if someone wanted to use the rocket as it is for another purpose, they would not allow them.

i.e. : they will build a Mars rocket, if you can use the Mars rocket to do other things, you can, but they will not use time and money to change the design to other goals.
The rocket will not be used only for Mars launches, it will be designed only for Mars launches, that's different.

Would a good analogy for this be the Saturn V being later repurposed to launch Skylab? I can't remember at what point in the development of the Saturn that Skylab first arose. The dry workshop variant, anyway.

[QuantumG]

She did not said that if someone wanted to use the rocket as it is for another purpose, they would not allow them.

Actually, she did say they wouldn't redirect SpaceX onto a path that wasn't to Mars. Listen to the interview.

The rocket will not be used only for Mars launches, it will be designed only for Mars launches, that's different.

Lobo seems to be of the belief that SpaceX intends to use a Raptor-based vehicle for launching satellites to GTO, and that this is SpaceX's plan. I have no idea where he gets this stuff from, but Gwynne has specifically said that's not the case.

[luinil]

My understanding of it is that they will develop a Mars rocket, not a GTO rocket, and that they do not want to use time and money on developing a GTO rocket.

But I did not get the impression that they would forbid the use of the Mars rocket for other purposes. ie if you have a GTO payload that can use the Mars rocket, you might be able to use it.

I tried to listen again to the show, and when she is asked about Moon questions she says that they would consider it, points being how much modifications are needed, is the goal interesting enough to divert the teams focus, and cost. I think this part is more about the falcon 9 and Heavy, but the same kind of thinking might apply to the mars vehicles (I don't remember of a part forbidding it, but maybe that's only me).

[QuantumG]

Lobo seems to be of the belief that SpaceX intends to use a Raptor-based vehicle for launching satellites to GTO, and that this is SpaceX's plan. I have no idea where he gets this stuff from, but Gwynne has specifically said that's not the case.

Now *you* are the one putting words in her mouth. She said it would be designed for getting to Mars, but she did not explicitly say that it would never be used for anything else.

I never said she did. What I said is that Lobo's theory that SpaceX plan to use the Mars rocket for GTO launches is so obviously wrong and that no-one could possibly come away with that impression by listening to the interview so he should go listen to the damn interview.

[luinil]

Any vehicle with a Raptor engine is a decade away and will only be used for Mars launches. I don't know how Gwynne could have made this more clear. If you haven't already listened to the show, please do.

You said that the mars rocket will be used only for mars launches. It's the point where I'm not following you.

Yes the vehicle will not be designed with GTO launches in mind, but that do not equals that it will never be used for GTO launches.

[neilh]

Any vehicle with a Raptor engine is a decade away and will only be used for Mars launches. I don't know how Gwynne could have made this more clear. If you haven't already listened to the show, please do.

You said that the mars rocket will be used only for mars launches. It's the point where I'm not following you.

Yes the vehicle will not be designed with GTO launches in mind, but that do not equals that it will never be used for GTO launches.

It's called context!

Oh my god. The irony is killing me. Why should we listen to the interview and not just read people's comments about it? So you get the context. Why should you read the entire thread instead of just reading individual comments? So you can get the context.

Here's the actual quote from Shotwell. The context was whether SpaceX would be open to working with another company to create a variant of their rockets optimized for lunar exploration:

"We're pretty focused on the path that we've set up, and that is Falcon 9 and Falcon Heavy, both LOX/RP vehicles, flying regularly for NASA, for the DOD, and for our commercial customers, while we're working on a much larger LOX/methane system to facilitate settlement to Mars."

[LouScheffer]

A 747 designed for reuse can be used in expendable mode as well.  That doesn't normally mean that you're losing performance when you use it as designed.

A 747 can fly more cargo considerably further if you give up any planning for refueling or taking off again.

This exact capability was used for the Doolittle raid in World War II.

Basically, for a plane or a rocket, you can plan to return it or not.  Each has a cost, each has a capability, and each has customers who may prefer it.

[su27k]

Any vehicle with a Raptor engine is a decade away and will only be used for Mars launches. I don't know how Gwynne could have made this more clear. If you haven't already listened to the show, please do.

You said that the mars rocket will be used only for mars launches. It's the point where I'm not following you.

Yes the vehicle will not be designed with GTO launches in mind, but that do not equals that it will never be used for GTO launches.

It's called context!

Oh my god. The irony is killing me. Why should we listen to the interview and not just read people's comments about it? So you get the context. Why should you read the entire thread instead of just reading individual comments? So you can get the context.

Here's the actual quote from Shotwell. The context was whether SpaceX would be open to working with another company to create a variant of their rockets optimized for lunar exploration:

"We're pretty focused on the path that we've set up, and that is Falcon 9 and Falcon Heavy, both LOX/RP vehicles, flying regularly for NASA, for the DOD, and for our commercial customers, while we're working on a much larger LOX/methane system to facilitate settlement to Mars."

There was another question about BFR's market (and later a question about BFR's use or something), she said human colonization of Mars. But yeah, no mention of exclusivity.

And the BFR is "a decade" or "12 to 13 years" from now is also a misquote, she said SpaceX is aiming for 12 to 13 years for the start of Mars mission, but right now they're doing their other things so need to wait 2 years before they can focus on Mars and get a schedule.

[clongton]

The impression I got was that Falcon 9 and Falcon Heavy are the vehicles for the commercial market.
The Raptor-powered MCT is not intended for the commercial market at all, although that does not preclude a commercial customer purchasing a ride uphill on one, provided it does not distract from or divert the Mars effort.

[Lar]

I'm not clear what additional value this thread is generating at this point, I am seeing good folks getting increasingly heated about smaller and smaller points. Don't do that, ok?

Trimmed a few posts.

[Robotbeat]

Except the return flight is without a payload. On a first stage with a really good mass fraction, this can make a huge difference.

[Lobo]

Lobo seems to be of the belief that SpaceX intends to use a Raptor-based vehicle for launching satellites to GTO, and that this is SpaceX's plan. I have no idea where he gets this stuff from, but Gwynne has specifically said that's not the case.

Now *you* are the one putting words in her mouth. She said it would be designed for getting to Mars, but she did not explicitly say that it would never be used for anything else.

I never said she did. What I said is that Lobo's theory that SpaceX plan to use the Mars rocket for GTO launches is so obviously wrong and that no-one could possibly come away with that impression by listening to the interview so he should go listen to the damn interview.

Quantum.  You've mischaracterized what I've said several times on this thread now.  Almost seems like you are doing it...intentionally...?

Let's go back to the whole quote and see why you are.

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.

I am referring to the 10m single core LV, not the tri-core SHLV, which I'm sure is intended for sending the final version of MCT to Mars for colonization.  As there's little else such a beast would be used for.

To which you said:

Any vehicle with a Raptor engine is a decade away and will only be used for Mars launches. I don't know how Gwynne could have made this more clear. If you haven't already listened to the show, please do.

To which Robotbeat and I said a couple of things about L2 that we shouldn't have, and they were removed by mods (our bad).
I'll just suggest you get an L2 subscription if you don't already have one, and go do some reading there.

But -when- a 10m single core Raptor powered HLV will be flying is immaterial to your later mischaracterization of my comments.  You seem to keep implying repeatedly something that I wasn't saying.  I was replying to JCC's comment that a BFR will likely never be required to send anything to GTO.  To which I -speculated- there could be a business case for that, if such a 2 stage, fully reusable 10m core LV were cheaper to launch than an FH with only partial reusability as I don't think (but I could be wrong) that a fully reusable FH can get some of the largest NRO type satellites to GTO, if it existed.  Simple logic dictates that, if that were the situation.

But, at no time, did I say that I -know- that the main reason SpaceX is building "FXX-R" is for flying GTO payloads, and I don't give a flying rip what Shotwell said in her interview.  So why do you keep saying that I did?

Additionally, I find it interesting you seem to think that a comment by Gwen Shotwell on a radio station interview in 2014 will forever bind SpaceX's future decision making in regards to their future LV's.  With all due respect to Ms. Shotwell, I think that's putting a little too much gravity to her words.

[QuantumG]

Lobo, I have L2.. post an L2 link and I might have a chance to figure out what you're talking about.

But, at no time, did I say that I -know- that the main reason SpaceX is building "FXX-R" is for flying GTO payloads, and I don't give a flying rip what Shotwell said in her interview.  So why do you keep saying that I did?

Then why are you commenting on this thread at all?

Ya know, I appreciate the wild speculation on this forum as much as anyone else, but that's not what this thread is for. We're trying to discuss what Gywnne said. Imagined scenarios belong elsewhere.

[Lobo]

Lobo, I have L2.. post an L2 link and I might have a chance to figure out what you're talking about.

http://forum.nasaspaceflight.com/index.php?topic=33488.msg1167982#msg1167982

Then why are you commenting on this thread at all?

Ya know, I appreciate the wild speculation on this forum as much as anyone else, but that's not what this thread is for. We're trying to discuss what Gywnne said. Imagined scenarios belong elsewhere.

Don't change the subject.  If that was what you wanted to say, then just say -that-, instead of mischaracterizing what I said.  Why did you repeatedly do that?

[Chris Bergin]

Locking this thread before any one else has a fit.