Author Topic: SpaceX: General Falcon and Dragon discussion (Thread 4)  (Read 756433 times)

Offline Jason1701

  • Senior Member
  • *****
  • Posts: 2238
  • Liked: 70
  • Likes Given: 39
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #20 on: 06/20/2011 06:37 pm »
FH is end of 2012 delivered to launch site, launch 2013.

Offline SpacexULA

  • Full Member
  • ****
  • Posts: 1756
  • Liked: 46
  • Likes Given: 73
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #21 on: 06/20/2011 06:51 pm »
And it seems that all SpaceX's estimations of dates don't include much margin for issues.

If Falcon 9 or Dragon have any major issues, I wouldn't even hold your breath for another launch in 2012
« Last Edit: 06/20/2011 06:52 pm by SpacexULA »
No Bucks no Buck Rogers, but at least Flexible path gets you Twiki.

Offline Dave G

  • Senior Member
  • *****
  • Posts: 2275
  • Liked: 1065
  • Likes Given: 1232
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #22 on: 06/20/2011 07:14 pm »
SpaceX has stated that the 7th Falcon 9 will use the Merlin 1D engine.
...  At that point, they will have the stable of rockets they have promised.
Exactly.

According to Max Vozoff, the Merlin 1d has a dramatically lower parts count:
http://thespaceshow.wordpress.com/2011/03/05/max-vozoff-friday-3-4-11/
(starting around 57:30 into the interview).

Also, IIRC, Elon said their assembly line should be capable of producing up to 800 Merlin 1d engines per year.

In other words, the Merlin 1d is designed for mass production.

Online ugordan

  • Senior Member
  • *****
  • Posts: 7664
    • My mainly Cassini image gallery
  • Liked: 1885
  • Likes Given: 424
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #23 on: 06/20/2011 07:14 pm »
SpaceX has stated that the 7th Falcon 9 will use the Merlin 1D engine.  That will likely be when they introduce the longer tanks with a strengthened structure.

I'm thinking the engine upgrade will come first, via a derated M1d on the existing tankage. A more incremental approach, would allow for characterizing the engines at a lower thrust setting (lower risk, higher margins) while still not needing a new hangar at SLC-40. Kind of like M1c was first proven out on Falcon 1, but only ran at full thrust on F9.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 28757
  • Minnesota
  • Liked: 8865
  • Likes Given: 5742
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #24 on: 06/20/2011 07:28 pm »
And it seems that all SpaceX's estimations of dates don't include much margin for issues.

If Falcon 9 or Dragon have any major issues, I wouldn't even hold your breath for another launch in 2012
I believe they are NET (No Earlier Than) dates, so doesn't include the SpaceX multiplier.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3567
  • Florida
  • Liked: 1993
  • Likes Given: 239
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #25 on: 06/20/2011 08:44 pm »
SpaceX has stated that the 7th Falcon 9 will use the Merlin 1D engine.  That will likely be when they introduce the longer tanks with a strengthened structure.

I'm thinking the engine upgrade will come first, via a derated M1d on the existing tankage. A more incremental approach, would allow for characterizing the engines at a lower thrust setting (lower risk, higher margins) while still not needing a new hangar at SLC-40. Kind of like M1c was first proven out on Falcon 1, but only ran at full thrust on F9.

The reason for using a derated Merlin 1C on the F1 was because of max acceleration, something that can be managed on the F9 by shutting down a few more engines, 3 or 4 total before MECO instead of the current just 2 to give about the same thrust at MECO ~700klbf. So no derating of Merlin 1D’s would be needed, just shutdown two engines much earlier followed by two more closer to MECO to manage max acceleration. This “hotter” rocket in the slang term used for above normal thrust on a launch would mean engine out capability would exist right at liftoff. In fact two engines could be shutdown and the total thrust would still be more that the current F9 at liftoff.

The hybrid configurations of short tanks and Merlin 1D’s would meet the published 10.5MT LEO capability needed for some of the late 2012 and early 2013 flights. There could be several of this configuration I call “Block IB”, to distinguish them from Block I or Block II, flying from 3 to 5 flights in 2012 and 2013, while the Cape pad is mod to handle the taller full capability F9 Block II.

« Last Edit: 06/20/2011 08:58 pm by oldAtlas_Eguy »

Online ugordan

  • Senior Member
  • *****
  • Posts: 7664
    • My mainly Cassini image gallery
  • Liked: 1885
  • Likes Given: 424
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #26 on: 06/20/2011 09:05 pm »
I would agree, but seems to me running "hot" right from the start would mean running out of juice on the 1st stage much sooner than 3 minutes, even with more engines cut earlier than currently done.

I don't know what that would do to the staging altitude - my gut feeling (which could be wrong) tells me this would make it lower (possibly where aerodynamic forces are still significant - remember F1-02) and that a different flight profile would be needed. More lofted with a sharper turn to horizontal in the end?

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 7144
  • A spaceflight fan
  • London, UK
  • Liked: 663
  • Likes Given: 777
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #27 on: 06/20/2011 09:13 pm »
Will they be able to manifest 3 - 5 flights per year as promised? 

"Our rough ball-park estimate is something on the order of 20 launches a year, of which roughly half are Falcon Heavy and roughly half are Falcon 9, and of those roughly 60%-70% going out of Cape Canaveral."

In other words, a flight rate of 1/month from SLC-40.  A heady ambition indeed.  I'll leave it to those more qualified than I to judge if SpaceX has the wherewithal, as of now, to achieve this.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3567
  • Florida
  • Liked: 1993
  • Likes Given: 239
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #28 on: 06/20/2011 10:08 pm »
I would agree, but seems to me running "hot" right from the start would mean running out of juice on the 1st stage much sooner than 3 minutes, even with more engines cut earlier than currently done.

I don't know what that would do to the staging altitude - my gut feeling (which could be wrong) tells me this would make it lower (possibly where aerodynamic forces are still significant - remember F1-02) and that a different flight profile would be needed. More lofted with a sharper turn to horizontal in the end?

The staging altitude can be managed by when the extra shutdowns occur so that total burn time gets you to the altitude you want. Velocity at MECO is what will be different. It will be much higher than the current, even with more payload mass. I am thinking that the first shutdowns would occur as little as 30 seconds after liftoff to reduce the max Q which is a function of altitude and velocity. Even with two engines shutdown that early max Q will be higher and at a lower altitude.

Flight 7 is the 3rd CRS flight. It could have a single Merlin 1D in the center position. This would enable gathering flight data on the Merlin 1D performance without posing significant mission risk. There could be as many as 3 flights of F9 prior to FH with 1D’s. It is also possible that the stretched tank version may not even fly on the first FH. This would still give FH a 32-38MT capability even with short tanks and active propellant cross-feed. I believe that from a business standpoint of managing yearly outlays and trying out one thing at a time to manage risks it is a possible scenario. With the longer tanks being done post 2013 when a increase in capability of both F9 and FH would be a feature to keep SpaceX ahead of the pack in $/kg to LEO and the ever slowly increasing weight of payloads.

Online ugordan

  • Senior Member
  • *****
  • Posts: 7664
    • My mainly Cassini image gallery
  • Liked: 1885
  • Likes Given: 424
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #29 on: 06/20/2011 10:18 pm »
It is also possible that the stretched tank version may not even fly on the first FH.

This would make sense to me too, especially since there's really no requirement for 50 mT to LEO in the near term or 15-ish tons to GTO. However, Gwynne Shotwell is on record saying the first FH will be the full capability vehicle so take that FWIW. I'm still skeptical myself.

Online oldAtlas_Eguy

  • Senior Member
  • *****
  • Posts: 3567
  • Florida
  • Liked: 1993
  • Likes Given: 239
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #30 on: 06/20/2011 10:26 pm »
It is also possible that the stretched tank version may not even fly on the first FH.

This would make sense to me too, especially since there's really no requirement for 50 mT to LEO in the near term or 15-ish tons to GTO. However, Gwynne Shotwell is on record saying the first FH will be the full capability vehicle so take that FWIW. I'm still skeptical myself.

I do expect them to tryout cross-feed on the first FH flight. It is a significant flight risk in the managing of fuel usage in the boosters and the boosters staging event disconnecting cryo piping even though this has been done since 1956 with Atlas. Too much fuel and lox escaping and igniting can damage the rocket as well as a fuel line being ripped off the remaining core when the disconnect fails.
« Last Edit: 06/20/2011 10:27 pm by oldAtlas_Eguy »

Offline HMXHMX

  • Full Member
  • ****
  • Posts: 1587
  • Liked: 1569
  • Likes Given: 415
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #31 on: 06/20/2011 11:34 pm »
It is also possible that the stretched tank version may not even fly on the first FH.

This would make sense to me too, especially since there's really no requirement for 50 mT to LEO in the near term or 15-ish tons to GTO. However, Gwynne Shotwell is on record saying the first FH will be the full capability vehicle so take that FWIW. I'm still skeptical myself.

I do expect them to tryout cross-feed on the first FH flight. It is a significant flight risk in the managing of fuel usage in the boosters and the boosters staging event disconnecting cryo piping even though this has been done since 1956 with Atlas. Too much fuel and lox escaping and igniting can damage the rocket as well as a fuel line being ripped off the remaining core when the disconnect fails.


Gwynne actually equivocated while discussing if cross-feed would be on the first FH flight.  At the time (this was at the Space Access 2011 Conference in early April) she may have been expressing a personal rather than "official" opinion, since this presentation took place a day or two after the press conference.  But I think upon reflection that SpaceX has realized if they fly w/o cross-feed on the first flight, they'd basically have to fly another test with, doubling their costs and taking an extra few months to a year to get to where they want to be.  So it really makes no sense to test w/o it.

Offline Jorge

  • Senior Member
  • *****
  • Posts: 6184
  • Liked: 37
  • Likes Given: 0
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #32 on: 06/21/2011 12:06 am »
It is also possible that the stretched tank version may not even fly on the first FH.

This would make sense to me too, especially since there's really no requirement for 50 mT to LEO in the near term or 15-ish tons to GTO. However, Gwynne Shotwell is on record saying the first FH will be the full capability vehicle so take that FWIW. I'm still skeptical myself.

I do expect them to tryout cross-feed on the first FH flight. It is a significant flight risk in the managing of fuel usage in the boosters and the boosters staging event disconnecting cryo piping even though this has been done since 1956 with Atlas. Too much fuel and lox escaping and igniting can damage the rocket as well as a fuel line being ripped off the remaining core when the disconnect fails.


Gwynne actually equivocated while discussing if cross-feed would be on the first FH flight.  At the time (this was at the Space Access 2011 Conference in early April) she may have been expressing a personal rather than "official" opinion, since this presentation took place a day or two after the press conference.  But I think upon reflection that SpaceX has realized if they fly w/o cross-feed on the first flight, they'd basically have to fly another test with, doubling their costs and taking an extra few months to a year to get to where they want to be.  So it really makes no sense to test w/o it.

The flip side of that is that even without crossfeed, FH has enough capacity to carry all existing payloads at a price no existing launcher can match. There are no payloads, existing or planned, that are too heavy for a FH without crossfeed that could be lifted by a FH with crossfeed. By putting crossfeed in the critical path for FH testing, they're potentially delaying operational capability for the FH if anything goes wrong with crossfeed, at no incremental market gain.

So the contrary view is that they'd be better off introducing FH without crossfeed to gain market share as rapidly as possible, then introduce crossfeed later as an upgrade when there could be a market for it.
JRF

Offline Namechange User

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 7301
  • Liked: 0
  • Likes Given: 0
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #33 on: 06/21/2011 12:12 am »
The flip side of that is that even without crossfeed, FH has enough capacity to carry all existing payloads at a price no existing launcher can match. There are no payloads, existing or planned, that are too heavy for a FH without crossfeed that could be lifted by a FH with crossfeed. By putting crossfeed in the critical path for FH testing, they're potentially delaying operational capability for the FH if anything goes wrong with crossfeed, at no incremental market gain.

So the contrary view is that they'd be better off introducing FH without crossfeed to gain market share as rapidly as possible, then introduce crossfeed later as an upgrade when there could be a market for it.

Concur.  In addition a lot of the development testing for the crossfeed application can likely be done not in flight, incrementally, leading up to a full-up flight. 
Enjoying viewing the forum a little better now by filtering certain users.

Offline Dave G

  • Senior Member
  • *****
  • Posts: 2275
  • Liked: 1065
  • Likes Given: 1232
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #34 on: 06/21/2011 01:47 am »
... even without crossfeed, FH has enough capacity to carry all existing payloads at a price no existing launcher can match.

We don't know what discussions SpaceX has had with potential customers.  There may be payloads planned for the near future that require crossfeed. 

We do know that most FH customers are interested in GTO, not LEO (from the FH press conference). 

We also know that some SpaceX customers have expressed interest in putting up multiple GTO satelites on a single FH launch (from the Space Show interview with Gwynne).

Offline beancounter

  • Full Member
  • ****
  • Posts: 1252
  • Perth, Western Australia
  • Liked: 106
  • Likes Given: 167
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #35 on: 06/21/2011 02:05 am »
Will they be able to manifest 3 - 5 flights per year as promised? 

"Our rough ball-park estimate is something on the order of 20 launches a year, of which roughly half are Falcon Heavy and roughly half are Falcon 9, and of those roughly 60%-70% going out of Cape Canaveral."

Comments above starting around 15:40.





Well this may be all well and good however their current manifest doesn't show anywhere near this number.  2013 pushes up to 7 flights with 9 for 2014.  This excludes FH other than the test flight which is scheduled for 2012 anyway although I believe this to be highly unlikely when you apply the SpaceX time dilation factor.

I was also getting well and truly confused by all the various combinations of extended tanks, Merlin 1d, and so on.  The speculation's exhausting.  I think we really just need another launch so that we've got some facts to discuss as opposed to guesses. :)
Beancounter from DownUnder

Offline Blackjax

  • Full Member
  • ***
  • Posts: 353
  • Liked: 26
  • Likes Given: 33
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #36 on: 06/21/2011 04:05 am »
Well this may be all well and good however their current manifest doesn't show anywhere near this number.  2013 pushes up to 7 flights with 9 for 2014. 

I suspect that they have a queue of more conservative companies that want to see more flight history, particularly once SpaceX has switched to mass production, and more routine operations before signing on the dotted line. 

Offline hop

  • Senior Member
  • *****
  • Posts: 3352
  • Liked: 484
  • Likes Given: 842
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #37 on: 06/21/2011 04:08 am »
We don't know what discussions SpaceX has had with potential customers.  There may be payloads planned for the near future that require crossfeed. 
Doubtful. Almost anything that big will take a long time to develop and cost a lot of money. If there are customers who want that kind of payload, it's extremely unlikely they will commit significant money until there is high confidence in F9-H ability to meet the claimed numbers. That suggests that serious engineering on this kind of payload would not have started yet, and any flight would be years away.

Multiple heavy comsats could work, but there's little motivation for that. Launching them singly on a regular F9-H would still be cheaper the current market rate, and launch costs isn't really a driver for those payloads even now.
« Last Edit: 06/21/2011 04:08 am by hop »

Offline beancounter

  • Full Member
  • ****
  • Posts: 1252
  • Perth, Western Australia
  • Liked: 106
  • Likes Given: 167
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #38 on: 06/21/2011 06:17 am »
We don't know what discussions SpaceX has had with potential customers.  There may be payloads planned for the near future that require crossfeed. 
Doubtful. Almost anything that big will take a long time to develop and cost a lot of money. If there are customers who want that kind of payload, it's extremely unlikely they will commit significant money until there is high confidence in F9-H ability to meet the claimed numbers. That suggests that serious engineering on this kind of payload would not have started yet, and any flight would be years away.

Multiple heavy comsats could work, but there's little motivation for that. Launching them singly on a regular F9-H would still be cheaper the current market rate, and launch costs isn't really a driver for those payloads even now.

Elon did say he's got potential customers for the FH flights two to four that they're talking with.  Can't for the life of me think who they might be unless it's Bigelow and/or NASA.  He also mentioned, I think, 4 FH flights per year to make it worthwhile.  That's a big bet unless he knows something no-one else does or else they're not talking.   
Beancounter from DownUnder

Offline hop

  • Senior Member
  • *****
  • Posts: 3352
  • Liked: 484
  • Likes Given: 842
Re: SpaceX: General Falcon and Dragon discussion (Thread 4)
« Reply #39 on: 06/21/2011 07:29 am »
He also mentioned, I think, 4 FH flights per year to make it worthwhile.  That's a big bet unless he knows something no-one else does or else they're not talking.   
If SpaceX flies a decent number of regular F9 flights, I don't see them having trouble picking up some of the existing large ( > 5 ton) GEO payloads that are too big for single stick F9. Those customers also have the option of switching to another LV if things don't work out with SpaceX, so the risk of signing up early is less.

But as Jorge pointed out, SpaceX can serve that market even without crossfeed, raising the question of how quickly they will pursue it.

I was specifically responding to DaveGs suggestion that payloads too large for existing LVs (e.g. requiring the full capability of the crossfeed FH) might be waiting in the wings. That is unlikely IMO. People might be thinking about that kind of payload, but I doubt they are building them yet.

Another possible wrinkle in this is stage re-use: The crossfeed FH is grossly over-sized for existing payloads, but that would give you a lot of mass for recovery hardware.

Tags: