Elon Musk Royal Aeronautical Society Talk Revelations

[Elmar Moelzer]

I do not think anyone is disagreeing that there are hurdles ahead that must be overcome, but SpaceX (Spacex) is clearly in control of their own destiny now - which is refreshing.

Fully agree with you on that one, Andrew

[bulkmail]

If I'm hearing correctly Musk said that Falcon Heavy will have 60-65% of Saturn V capacity. That's over 70 mT to LEO, right? So, substantially (1/3rd) more than what's announced so far (53 mT).

Quite a news, if correct.

[Elmar Moelzer]

And, that is structure more than 30% cost over a V1.1

So you are saying that the flight envelope of the Grasshopper would not be representative of a real first stage flight? IIRC, they are planning on taking it supersonic next year. So how far off would they really be?
And again lets not forget that the F9 first stage was always meant to have some level of reusability. That means that they should have considered this to some extent already. Also, I am pretty sure that I remember Musk saying somewhere that they would ideally want to reuse the first stage 100 times. That does not mean that they will be able to do more then 20 in the beginning though.

[Elmar Moelzer]

If I'm hearing correctly Musk said that Falcon Heavy will have 60-65% of Saturn V capacity. That's over 70 mT to LEO, right? So, substantially (1/3rd) more than what's announced so far (53 mT).

I think that he meant with cross feeding which I am not sure has been considered yet. The old numbers might also still be for the Merlin 1C.
But dont take my word for that. Just is one explanation. Also I am always confusing metric and english tons...

[johncarpinelli]

Elon explained that the new Raptor engine will use methane and LOX. This is the same propellant proposed by Zubrin for Mars Direct. The methane would be produced on the surface of Mars and used to fuel the return trip.

http://en.wikipedia.org/wiki/Mars_Direct#Mission_Scenario

A demonstration mission to Mars with Raptor engines should be on the SpaceX timeline for the next 5-10 years. After landing on Mars, they could demonstrate in situ production of methane from the Martian atmosphere.

I think the reusable Falcon is not on the critical path for the human mission to Mars. Mars and the RLV are parallel development tracks. If the RLV is not ready in ten years, SpaceX can still go to Mars with expendable vehicles. Elon is currently worth $2.4 billion according to Forbes, and that will most likely grow significantly by 2022. Most likely, he could fund the entire trip from his own wealth.

Mars Oasis was a plan to excite the public about Mars colonization. These talks are just an extension of that original plan. Tesla got people excited about electric cars, and now we have Nissan, GM and Toyota selling plugin cars. It will be interesting to see if Elon can get his competitors to invest in new rockets and space missions. Jeff Bezos must be feeling left behind at this stage.

[Jim]

Elon is currently worth $2.4 billion according to Forbes, and that will most likely grow significantly by 2022. Most likely, he could fund the entire trip from his own wealth.

Huh?  Nonsense.  He could not fund the trip and he has even stated so. Even funding a unmanned Mars mission is not in the cards.

  Net worth doesn't mean it is  all liquid.

[Hyperion5]

If I'm hearing correctly Musk said that Falcon Heavy will have 60-65% of Saturn V capacity. That's over 70 mT to LEO, right? So, substantially (1/3rd) more than what's announced so far (53 mT).

I think that he meant with cross feeding which I am not sure has been considered yet. The old numbers might also still be for the Merlin 1C.
But dont take my word for that. Just is one explanation. Also I am always confusing metric and english tons...

Even if you did confuse the two, there's only one way Musk can lay claim to launching 60-65% of the Saturn V's LEO payload: the Falcon Heavy has more performance than originally announced.  Not sure how that happened or if the original figures were conservative.  Can someone run the figures and tell us if the following numbers are possible with a Falcon Heavy as currently configured? 

60% of Saturn V's 120 mt payload: 72 mt
65% of Saturn V's 120 mt payload: 78 mt

So basically Musk has just claimed his rocket is putting up somewhere between 35.8% and 47.1% more LEO payload than originally claimed, correct?  If there's been no error along the way this would be a huge claim. 

[2552]

I think he said thrust, not payload actually.

[bulkmail]

If I'm hearing correctly Musk said that Falcon Heavy will have 60-65% of Saturn V capacity. That's over 70 mT to LEO, right? So, substantially (1/3rd) more than what's announced so far (53 mT).

I think that he meant with cross feeding which I am not sure has been considered yet. The old numbers might also still be for the Merlin 1C.
But dont take my word for that. Just is one explanation. Also I am always confusing metric and english tons...

Even if you did confuse the two, there's only one way Musk can lay claim to launching 60-65% of the Saturn V's LEO payload: the Falcon Heavy has more performance than originally announced.  Not sure how that happened or if the original figures were conservative.  Can someone run the figures and tell us if the following numbers are possible with a Falcon Heavy as currently configured? 

60% of Saturn V's 120 mt payload: 72 mt
65% of Saturn V's 120 mt payload: 78 mt

So basically Musk has just claimed his rocket is putting up somewhere between 35.8% and 47.1% more LEO payload than originally claimed, correct?  If there's been no error along the way this would be a huge claim.

Exactly. As for the reasons - I think cross feeding is part of the "currently official" 53 mT figure (http://www.spacex.com/falcon_heavy.php "Falcon Heavy will be the first rocket in history to feature propellant cross-feed from the side boosters to the center core") and I think the 53 mT also include Merlin 1D/1Dvacum and the other F9-v1.1 enhancements (but I don't have good source for that).

As for a non-cross feed, 1C, 1.0 version - initial Falcon 9 Heavy initial estimate announced was 32 mT.

Can someone confirm what 2552 says? Did Musk spoke about thrust or payload?

[modemeagle]

I heard thrust as well.  My calculations put it at 57% at lift off.

I have simulated 53 tonnes with cross feed on the falcon heavy and the margins prevent a much higher payload. See the Heavy threads for graphs.

[Elmar Moelzer]

I have heard the 70 tons payload for the FH mentioned before, right when they first announced it, but then the description on the homepage said only 53 or so tons, which is quite a bit less. So I assumed that the 70 was simply a misunderstanding of sorts and that the final payload would be only 53. The whole confision between metric and english tons does not help either (people might be saying one thing and meaning the other). So I just wrote it off. Now that the same number is coming up again, it makes me wonder though. Doing some googling it seems like the 70 tons were based on a later update that would add a LH2 upper stage among other things. My guess is that that number is now based on the assumption of using CH4?

[Elmar Moelzer]

Reading up again, yes the 53 tons are for the cross fed version. My bad. The 70 were for the version with other updates (like LH2 upper stage).

[Mongo62]

Whether it's thrust or payload, it would still be a massive increase over SpaceX's official numbers for the Falcon Heavy.

Their official numbers for 3-core thrust are 3.78 Mlb, which is 49.4% of the Saturn V 1st stage thrust of 7.648 Mlb.  So if Elon is referring to thrust, his figure is still 20%-30% greater than the announced figure.

I suspect that he momentarily forgot the Saturn V / Falcon Heavy ratio during the talk, and simply threw out a ratio on the fly without stopping to calculate the exact numbers.

But if his numbers are accurate, and payload to LEO increases with anything like a linear ratio to thrust, would that not make the cross-feed Falcon Heavy a "Super-Heavy Lift Vehicle"?  The dividing line is generally considered to be 70 mt, isn't it?

[bulkmail]

I think he said thrust, not payload actually.

If it's thrust, then we have "current official" figure at spacex.com "Thrust on liftoff: 17 MN  (3,800,000 lbf)" vs. Saturn V 34,020,000 N (7,648,000 lbf), so the new Musk announcement calculates to 20-22 MN - again above the currently official figure (more than 1/6th).

Can a native English speaker confirm the 60-65% figure or even better provide a quote/transcript about the whole phrase/answer?

[bulkmail]

Doing some googling it seems like the 70 tons were based on a later update that would add a LH2 upper stage among other things. My guess is that that number is now based on the assumption of using CH4?

I think the quote was about the current Falcon Heavy (to fly in 2013) - not about future Raptor-equipped rocket.

[MikeAtkinson]

If I'm hearing correctly Musk said that Falcon Heavy will have 60-65% of Saturn V capacity. That's over 70 mT to LEO, right? So, substantially (1/3rd) more than what's announced so far (53 mT).

I think that he meant with cross feeding which I am not sure has been considered yet. The old numbers might also still be for the Merlin 1C.
But dont take my word for that. Just is one explanation. Also I am always confusing metric and english tons...

Even if you did confuse the two, there's only one way Musk can lay claim to launching 60-65% of the Saturn V's LEO payload: the Falcon Heavy has more performance than originally announced.  Not sure how that happened or if the original figures were conservative.  Can someone run the figures and tell us if the following numbers are possible with a Falcon Heavy as currently configured? 

60% of Saturn V's 120 mt payload: 72 mt
65% of Saturn V's 120 mt payload: 78 mt

So basically Musk has just claimed his rocket is putting up somewhere between 35.8% and 47.1% more LEO payload than originally claimed, correct?  If there's been no error along the way this would be a huge claim. 

If you had listened to all the interviews, then you would have heard that the 60% is take off thrust, not payload to orbit.

These SpaceX threads are bad enough without you spreading false information!

[Mongo62]

If you had listened to all the interviews, then you would have heard that the 60% is take off thrust, not payload to orbit.

These SpaceX threads are bad enough without you spreading false information!

Except that the official takeoff thrust for Falcon Heavy is only 50% of the takeoff thrust of the Saturn V, so Musk would be claiming a major increase over the official numbers.

[bulkmail]

I suspect that he momentarily forgot the Saturn V / Falcon Heavy ratio during the talk, and simply threw out a ratio on the fly without stopping to calculate the exact numbers.

Possible, but we if we go with that assumption we can't "use" any of the figures he gives...

would that not make the cross-feed Falcon Heavy a "Super-Heavy Lift Vehicle"?  The dividing line is generally considered to be 70 mt, isn't it?

I don't think there are generally accepted dividing lines for small/medium/intermediate/heavy/super-heavy. http://www.nasa.gov/pdf/500393main_TA01-LaunchPropulsion-DRAFT-Nov2010-A.pdf (page 11) puts super-heavy as above 50 mT.

[bulkmail]

If you had listened to all the interviews, then you would have heard that the 60% is take off thrust, not payload to orbit.

These SpaceX threads are bad enough without you spreading false information!

I don't think more than 20%-30% increase in thrust should be ignored.

[Avron]

Just saw an interview with Musk posted on NewSpaceWatch.

Elon wouldn't confirm what MCT stands for or does when asked directly.
Hopes to unveil details about the Raptor engine next year, mentioned "Perhaps what's more interesting is the spaceship attached to it".

That sir.. is the most exciting thing I got from the talks..   he says " spaceship" and not rocket...  hummm

Oh, reading back I see Raptor  noted as an upper stage engine.. where did that get sourced..  Why is Raptor not a first stage or multi stage engine..

The comment on Dragon 2 and flying saucer ..   hummm and the above comment.. MCT is not Dragon 2.. and  flying saucer is not Dragon2 ( that has legs that pop out or drop out).... pure guess could MCT look like .. a  flying saucer  ..crazy I know.. (thinking shape here)

Musk is a engineer at the core and a good business man with vision.. I would not group him  in with any normal company like LMT.. or BA.. He is special..   something more like "Howard Hughes", but not the same..

Spacex has made errors.. Musk says so many times.. he even notes that they did not know what they where doing with Dragon one development..   

Imagine what can be done when they do know...    I want my shares...