Author Topic: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement  (Read 264033 times)

Offline WulfTheSaxon

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #720 on: 05/01/2011 06:45 PM »
@Comga (2011-04-30, 23:08:11)

Better pic.

Offline simonbp

WRT SMD payloads on either F9 or FH, the lead-time for any of them is so long (>6 years) that both should have been certified by SOMD well before launch.

The availability of FH for science payloads is especially important, as there are no other vehicles with comparable performance. Thus, mission proposals can't play the dance they are now, where they really want F9 (on grounds of cost), but have to list (and design to) Atlas and/or Delta as a backup.

Offline JNobles

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #722 on: 05/02/2011 12:50 AM »
Please excuse me if this is a stupid question.  The FH is going to need three times the LOX, right?  So is SpaceX going to have to buy two more of those big tanks?

And what about the extra kerosene?  Do they just order three times as many truck loads and keep the tankers there until final fueling is accomplished?
-- Why do I support Commercial Space?  I want the most Rogers for my Buck.  Period. --

Offline Jim

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #723 on: 05/02/2011 12:53 AM »
Please excuse me if this is a stupid question.  The FH is going to need three times the LOX, right?  So is SpaceX going to have to buy two more of those big tanks?

And what about the extra kerosene?  Do they just order three times as many truck loads and keep the tankers there until final fueling is accomplished?

VAFB doesnt have any tanks now, so they can be properly sized when constructed.

As for CCAFS, there might not be an issue, since they reused existing tanks for other programs.  They weren't sized specifically for F9
« Last Edit: 05/02/2011 12:55 AM by Jim »

Offline Cherokee43v6

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #724 on: 05/02/2011 05:59 PM »
Please excuse me if this is a stupid question.  The FH is going to need three times the LOX, right?  So is SpaceX going to have to buy two more of those big tanks?

And what about the extra kerosene?  Do they just order three times as many truck loads and keep the tankers there until final fueling is accomplished?

VAFB doesnt have any tanks now, so they can be properly sized when constructed.

As for CCAFS, there might not be an issue, since they reused existing tanks for other programs.  They weren't sized specifically for F9

I would also say that after their fiasco with running short on LOX during one of the early Falcon1 attempts that they have most likely taken significant margin into account in their planning relating to multiple launch attempts.
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Offline ugordan

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #725 on: 05/02/2011 06:04 PM »
The LOX sphere they have at CCAFS right now holds 125,000 gallons. Block 1 F9 first stage holds about 39,000 gallons LOX so I would say any Falcon Heavy would definitely need the storage capacity beefed up. Probably the same for the RP-1 farm.

Offline renclod

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #726 on: 05/02/2011 08:05 PM »
...  One pair in the center rocket would keep the fuel and oxidizer from flowing from the center tank to the engines until staging. 
... This would seem to require space, part of the increase in length of the rocket. 

If they just cross-connect the tanks, and continuously pressurize the booster tanks with a somewhat larger pressure than the core tanks,
then
the core tanks could stay full even as the core engines are being fed from them.

« Last Edit: 05/02/2011 08:10 PM by renclod »

Online Comga

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #727 on: 05/02/2011 10:37 PM »
...  One pair in the center rocket would keep the fuel and oxidizer from flowing from the center tank to the engines until staging. 
... This would seem to require space, part of the increase in length of the rocket. 

If they just cross-connect the tanks, and continuously pressurize the booster tanks with a somewhat larger pressure than the core tanks,
then the core tanks could stay full even as the core engines are being fed from them.

But they would still need eight valves:  Left and Right sides, Core and Booster, LOX and RP1.   If they weren't inside the tanks, immersed in the LOX or RP1, they might cause the boosters to stand off a bit from the core.  Perhaps they could put this plumbing in the existing volume near the current lines between the tanks and the engines.  I don't know anywhere near enough about rocket structures or valves to judge if any of these would be a problem or not.

Edit:  They could pressurize the core tanks minimally until just before staging and do what you said without raising the pressure of the boosters.
« Last Edit: 05/02/2011 10:39 PM by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline edkyle99

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #728 on: 05/05/2011 02:19 PM »
I've been wondering about Merlin 1D.  By my figuring, the engine, in addition to its 140 Klbf liftoff thrust, likely provides record-breaking specific impulse for a kerosene/LOX gas generator engine.  This might be due to much-improved turbopump efficiency, or to higher chamber pressure, or maybe to something else. 

I recently read an account that described testing involving Rocketdyne's Experimental X-1 engine (precursor to the H-1 engine) during the late 1950s.  Engineers reportedly tried something funky with this engine that sounded like a tap-off cycle to power the turbo-pump.  No gas generator, in other words, which automatically increases ISP.  The engine worked, but Rocketdyne dropped the idea due to challenges with thrust control.  The company tried many other such ideas over the years - goofy ideas that worked, or nearly worked, but were shelved.

It left me wondering what options are out there that might appear on Merlin 1D. 

 - Ed Kyle
« Last Edit: 05/05/2011 02:20 PM by edkyle99 »

Offline ugordan

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Re: LIVE: SpaceX: Falcon Heavy Thread - April 5 announcement
« Reply #729 on: 05/05/2011 02:24 PM »
I've been wondering about Merlin 1D.  By my figuring, the engine, in addition to its 140 Klbf liftoff thrust, likely provides record-breaking specific impulse for a kerosene/LOX gas generator engine.

I don't know. Musk said the Merlin 1D has a significant thrust upgrade and "some performance improvement". Doesn't sound radically better than what your typical GG engine would be.

Then again, their Merlin 2 specs on paper are significantly better, but it is a much bigger engine to start with...

Tags: SpaceX