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#80
by
baldusi
on 12 May, 2016 15:57
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Doesn't SpaceX have to complete modifications to the TEL and launchpad infrastructure at Vandenberg to support Falcon 9 v1.2 anyhow?
I agree SpaceX has to modify the SLC-4E facilities. But if it holds back the launch from VDB they really have planned badly. The last launch from SLC-4E was F9-21 with Jason-3 17 January 2016. They already have had four months to do the modifications. And they already build infrastructure there before the Jason3 launch. I don't expect it to be a problem.
The range system maintenance on the other hand, could hold the launches from Vandenberg.
In fact, they tested and validated the subcooling process in VAFB. They should be more than ready. And it will be devoted to the Iridium contract, too. So they better keep up because this is their biggest commercial contract.
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#81
by
kevin-rf
on 12 May, 2016 16:26
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In fact, they tested and validated the subcooling process in VAFB. They should be more than ready. And it will be devoted to the Iridium contract, too. So they better keep up because this is their biggest commercial contract.
I realize that sub cooled propellants was tested at VAFB because it was available, but to they need it for Iridium? I thought Iridium and Formosat-5 was well within the Falcon 9's capabilities.
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#82
by
John Alan
on 12 May, 2016 16:47
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In fact, they tested and validated the subcooling process in VAFB. They should be more than ready. And it will be devoted to the Iridium contract, too. So they better keep up because this is their biggest commercial contract.
I realize that sub cooled propellants was tested at VAFB because it was available, but to they need it for Iridium? I thought Iridium and Formosat-5 was well within the Falcon 9's capabilities.
There is some opinion (like myself) that Subcooled prop is required for running Merlin D at the planned higher thrust uprates...
In particular the chilled RP-1 helps with chamber wall cooling...
No source to back this... take it for what you think it's worth...
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#83
by
Robotbeat
on 12 May, 2016 16:53
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In fact, they tested and validated the subcooling process in VAFB. They should be more than ready. And it will be devoted to the Iridium contract, too. So they better keep up because this is their biggest commercial contract.
I realize that sub cooled propellants was tested at VAFB because it was available, but to they need it for Iridium? I thought Iridium and Formosat-5 was well within the Falcon 9's capabilities.
There is some opinion (like myself) that Subcooled prop is required for running Merlin D at the planned higher thrust uprates...
In particular the chilled RP-1 helps with chamber wall cooling...
No source to back this... take it for what you think it's worth...
Huh? There's definitely source for this (SpaceX has said the propellant density increase allows higher thrust). Also, basic physics:
Higher propellant density means that the same turbopump can pump more mass of propellant to the same pressure for a given energy.
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#84
by
tleski
on 12 May, 2016 17:20
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As far as I understand, and it was discussed extensively before, the current version of Falcon 9 requires subcooled propellants. So, there is no option of loading the warmer LOX on launches requiring lower performance. BTW, the performance is needed to bring the first stage back in most cases.
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#85
by
deruch
on 12 May, 2016 20:05
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Falcon 9 has had the location of the common bulkhead between RP-1/LOX moved to adjust for changing propellant loads achievable with densification. Switching back to non-densified propellants would require bespoke production of stages, something that runs counter to their philosophy. Also, the lengthened upper stage and consequently higher GLOW was partially predicated on running at higher thrust. So, would they have to go back to the shorter U/S? Go back to the shorter MVac nozzle? And, in addition to changing the actual hardware build, they'd have to go back to previous iteration of ground operations during launch. Basically, it'd be a revert to the old F9v1.1. Better to just make all launches the same (i.e. using densified prop.) whether the mission needs the performance upgrades or not.
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#86
by
the_other_Doug
on 12 May, 2016 21:18
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In other words, there is no F9 v1.1 (or even v1.2/FT), there is just the current iteration of the F9. It uses sub-cooled propellants. There is no version now available of an F9 that doesn't use sub-cooled propellants. This is simply a feature of the F9 from here on out. It is not something you can choose to do or not, it's how the launcher now works. No decisions to be made on a flight-by-flight basis in re sub-cooling the propellants; it will always happen.
I get the feeling that SpaceX is finally pretty happy with the performance characteristics of the F9, that the F9 is finally mature to the point where further iterations will only encompass minor improvements. It rather follows that this is what they were waiting for before they went ahead and put together the Falcon Heavy. It wouldn't have made sense to do so before the F9 itself was matured up to the point where further improvements would be minor.
I get the feeling that SpaceX's insistence that, from here on out, the base stage is simply the F9 and there shall be no version differentiators, means they feel the current design, as implemented, is the mature vehicle. Good to see, actually -- it makes you feel comfortable that we now know what the performance envelope will be for the F9 and FH, going forward.
IMHO, anyway...
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#87
by
a_langwich
on 12 May, 2016 21:29
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I get the feeling that SpaceX's insistence that, from here on out, the base stage is simply the F9 and there shall be no version differentiators, means they feel the current design, as implemented, is the mature vehicle. Good to see, actually -- it makes you feel comfortable that we now know what the performance envelope will be for the F9 and FH, going forward.
IMHO, anyway...
From here on out, referring to that future time when they have implemented the 10% thrust increase Musk mentioned?
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#88
by
AncientU
on 13 May, 2016 00:38
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I get the feeling that SpaceX's insistence that, from here on out, the base stage is simply the F9 and there shall be no version differentiators, means they feel the current design, as implemented, is the mature vehicle. Good to see, actually -- it makes you feel comfortable that we now know what the performance envelope will be for the F9 and FH, going forward.
IMHO, anyway...
From here on out, referring to that future time when they have implemented the 10% thrust increase Musk mentioned?
While they may eek out incremental improvements (e.g., thrust, operations software), I believe the frozen part of the design is the interface with ground systems. They have a unique challenge -- reusing a portion of the launch vehicles on a set of pads which will be used for new vehicles, too.
They have to stop changing interfacing configuration or they'll never get reuse going. An example is the perfectly fine 3-engine booster that they were going to use for follow-on testing for grasshopper... never needed because the launch-while-you-test regime (or is it the test-while-you-launch regime?) solved the problem before SA was ready. That booster probably will never be used because it no longer interfaces with the GSE.
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#89
by
Galactic Penguin SST
on 13 May, 2016 02:36
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In other news I have recently checked Taiwan's NSPO website - I didn't see any news about Formosat-5 since November last year so I presume that the satellite has not been shipped out yet.
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#90
by
mtakala24
on 13 May, 2016 09:03
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#91
by
jhan6301
on 13 May, 2016 11:55
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In other news I have recently checked Taiwan's NSPO website - I didn't see any news about Formosat-5 since November last year so I presume that the satellite has not been shipped out yet.
In according to the Minister of Science and Technology of Taiwan, the satellite will be shipped to the States on May 17th.
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#92
by
mtakala24
on 15 May, 2016 20:21
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In numerous news articles (in Finnish) about Aalto-1's payload integration activities this week, there is talk about launch in July. One of them even mentions the range closure.
Don't know if the sources have current accurate information, though...
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#93
by
linxiaoyi
on 16 May, 2016 11:03
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In other news I have recently checked Taiwan's NSPO website - I didn't see any news about Formosat-5 since November last year so I presume that the satellite has not been shipped out yet.
In according to the Minister of Science and Technology of Taiwan, the satellite will be shipped to the States on May 17th.
Look likes a July launch is assured!
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#94
by
oldAtlas_Eguy
on 16 May, 2016 16:57
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If F9 actual does sport a GPS autonomous FTS like as mentioned a year ago that SpaceX was planning to introduce on F9 this year, then even though many of the tracking assets at VAFB are down the AF has stated that with a GPS autonomous FTS they could still launch.
So does the F9 really have a certified GPS AFTS?
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#95
by
ugordan
on 16 May, 2016 16:58
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So does the F9 really have a certified GPS AFTS?
Not yet.
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#96
by
baldusi
on 16 May, 2016 21:26
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AFAIK, they tried but haven't been able to flight certify it.
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#97
by
CameronD
on 16 May, 2016 23:23
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AFAIK, they tried but haven't been able to flight certify it.
Because it keeps blowing up?!?
(Sorry.. bad joke!)
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#98
by
kevin-rf
on 17 May, 2016 01:37
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AFAIK, they tried but haven't been able to flight certify it.
Because it keeps blowing up?!?
(Sorry.. bad joke!)
I would go with, because it hadn't blown up... A loose HE bottle does not count.
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#99
by
linxiaoyi
on 25 May, 2016 04:18
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According to this news, SpaceX had told NSPO this mission must be delayed, due to range closure. And we know Formosat-5 was undergone a successful test in Taiwan on May 20.
Now I reckon Formosat-5 will be launched NET August, Iridium NEXT will be FIRST possibly.
http://www.chinatimes.com/realtimenews/20160523005380-260410
