Author Topic: SpaceX Falcon Heavy : STP-2 mission : LC-39A : mid 2018  (Read 142721 times)

Offline Chris Bergin

Posts after the above were not relevant to this pre-mission thread. Split and merged with a Falcon Heavy thread here:
http://forum.nasaspaceflight.com/index.php?topic=29214.msg989887#msg989887

Offline baldusi

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* v1.1 has not flown. From a propulsion standpoint it's sufficiently different than a v1.0 that it shouldn't be called a flown vehicle. Especially if you throw the 5 m fairing into the mix.

* FH premium is only lower if you assume the price advertised for "Greater than 6.4 ton to GTO", otherwise the listed "commercial" price is $83 M
v1.1 is quite similar to v1.0. The environment is sort of known. Even engine out has some history. In fact, next year should have at least two launches from two pads, may be even three launches, which would allow for a Category 2 certification.
FH might get to fly once before this mission, and probably from another pad. No vehicle has flown with three cores and more than one engine per core. They have no experience on the cross feed. They have very little history to extrapolate. They have very little insight on engine out for a booster case.
They will even need a new hangar, modify a pad and demonstrate a new process, since they can't just copy the VAFB hangar/pad combo.
And DSCOVR is a simple mission. Burn till close to escape and release. I think  will not even need a second US burn. And they have to integrate a single payload.
STP-2 on the other hand, will have to demonstrate at least four burns, integrate some ten to twelve payloads, do a circular orbit, change plane, get to a new elliptical orbit and dispose the US.
Just the analysis and integration work should be over 50M. May be SpaceX is selling at cost and they are actually charging 85M for the launch and 80M for the rest of the services.

Offline ugordan

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v1.1 is quite similar to v1.0. The environment is sort of known.

Never underestimate the headaches even "slight" changes can give you in this business. Sort of known doesn't quite cut it. Case in point: the mere choice of location of a vent on F9 has already bitten them in the rear twice, once causing a frozen roll nozzle and once damaging a niobium nozzle extension. The engines are arranged differently, different plumbing and thrust structure, probably different gimbals (single plane?), etc.

In fact, my uneducated opinion would be that it's a bigger jump from v1.0 to v1.1 than from v1.1 to a FH (without crossfeed, at least).

I will grant you that STP-2 is a much more challenging flight profile, obviously designed as a FH shakedown flight.

Offline Mader Levap

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v1.1 is quite similar to v1.0.
I think thrid mission of F1 wants to talk with you. Something about ablative vs regenerative cooling and thrust transients, I dunno.
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Offline Antares

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Presumably the USAF certification efforts will occur for the first launch.  The FH launch will only require certification of the differences.  So if things like avionics, engines, structures, sep mechanisms, power, etc. are the same between the two, they won't have to be re-rubber-stamped.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline baldusi

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v1.1 is quite similar to v1.0.
I think thrid mission of F1 wants to talk with you. Something about ablative vs regenerative cooling and thrust transients, I dunno.
How many separation events had they had before flt 3?

Offline MP99

Why are the prices so high?
-- Falcon 9: $M 97 / 54 = 1.8
-- Falcon H: $M 165 / 128 = 1.3

Or, maybe it's not a coincidence that the increment is similar for the two:-

-- Falcon 9: $M 97 - 54 = +$43m
-- Falcon H: $M 165 / 128 = +$37m

...especially when you also bear in mind Antares later post

Presumably the USAF certification efforts will occur for the first launch.  The FH launch will only require certification of the differences.  So if things like avionics, engines, structures, sep mechanisms, power, etc. are the same between the two, they won't have to be re-rubber-stamped.

cheers, Martin

Online Comga

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From the document:

Insertion Orbit #1

Deliver the IPS to a circular orbit with an orbital altitude of 720 km and an orbital inclination of 24. Deploy only the COSMIC-2 payload set, up to six APLs (TBR), and actuate up to eight P-PODs (TBR).

Insertion Orbit #2

Deliver the IPS (with remaining payloads) to the elliptical orbit with a perigee of 6,000 km, apogee of 12,000 km, and an orbital inclination of 45. Deploy the DSX payload followed by remaining APLs and actuate remaining P-PODs. After deployment of these payloads, the LV shall enter a coast phase of [3 hours threshold, 5 hours objective]. After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).

This looks like at least 5 burns of the second stage to me, over many hours.  #1, get into orbit with a 720 km apogee, 24 inclination.  #2, circularize at 720, release first payload.  #3, Next equator crossing, boost to a 6000 km perigee.  Coast until apogee, #4, boost to a 12000x6000 orbit and change plane to 45.  Wait the required 3 hours for the final stage restart (#5).

That is an answer to an open question: How many restarts a Merlin-1D-Vac can perform.  Five seems to be a pretty big number. 
Are they limited by the number of onboard "start cartridges" or can they be repeated as long as there are supplies like pressurization and power and fuel?
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Jim

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TEB for ignition and Helium for spin limit number of restarts

Offline oldAtlas_Eguy

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If I remember correctly the M1C (not the MVAC) was mentioned having 10 TEB's to support multiple rapid countdown reset starts. The M1D would probably have the same, which would mean the M1DVAC would have the same capability of the M1D causing the limiting factor primarily being the spin-up. A larger or second Helium tank could allow for more starts. Remember that during thrust the prop tank pressure must be maintained for structural strength.

Offline ugordan

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If I remember correctly the M1C (not the MVAC) was mentioned having 10 TEB's to support multiple rapid countdown reset starts.

I thought that was implied for ground storage at the pad, not onboard TEA/TEB?

Offline oldAtlas_Eguy

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If I remember correctly the M1C (not the MVAC) was mentioned having 10 TEB's to support multiple rapid countdown reset starts.

I thought that was implied for ground storage at the pad, not onboard TEA/TEB?

If someone who knows which thread the discussion of TEB count on the M1C was on then the actual source (if any) for the reference can be determined and maybe part of the answer for just how many restarts a M1DVAC can do will be answered. Adding extra Helium tanks is not difficult. Redesing the engine is.

edit fix grammer
« Last Edit: 12/14/2012 04:45 PM by oldAtlas_Eguy »

Offline LouScheffer

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If I remember correctly the M1C (not the MVAC) was mentioned having 10 TEB's to support multiple rapid countdown reset starts.

I thought that was implied for ground storage at the pad, not onboard TEA/TEB?

If someone who knows which thread the discussion of TEB count on the M1C was on then the actual source (if any) for the reference can be determined and maybe part of the answer for just how many restarts a M1DVAC can do will be answered. Adding extra Helium tanks is not difficult. Redesing the engine is.

edit fix grammer
Presumably the engine needs to re-ignite the gas generator as well.  How is this done?  If pyro, it would need as many sets as the main ignitors...

Offline Jim

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same chemical and supply

Offline simonbp

That is an answer to an open question: How many restarts a Merlin-1D-Vac can perform.  Five seems to be a pretty big number.

How many can Centaur or DCSS do? I'd be willing to bet it's the same as MVAC...

Offline kevin-rf

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How many can Centaur or DCSS do? I'd be willing to bet it's the same as MVAC...
Doesn't the RL-10 use LH boil off to spin up the turbine, and a spark plug as an igniter, so the answer would be as many as it has fuel and battery for ;)
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Offline Jim

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How many can Centaur or DCSS do? I'd be willing to bet it's the same as MVAC...
Doesn't the RL-10 use LH boil off to spin up the turbine, and a spark plug as an igniter, so the answer would be as many as it has fuel and battery for ;)

and Helium for tank pressurization

Online Comga

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TEB for ignition and Helium for spin limit number of restarts

Is the TEB stored in bulk or in discrete format, like "cartridges"?
Is it a significant issue to have sufficient TEB for many restarts?
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline oldAtlas_Eguy

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The FY2013 National Defense Authorization Act (NDAA), H.R. 4310 seems to contain funding for STP so this flight is being funded (maybe).

http://www.spacepolicyonline.com/news/house-and-senate-agree-on-fy2013-defense-authorization-bill-update-2

With a real reason for existing, funding for STP looks to be continued in FY2013 and later appropriations.

Offline Moe Grills

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OK! A revival of this topic.
I'm trying to sort out the facts, few as they are.
The STP-2 mission, hopefully in 2015, will involve a Falcon Heavy attempting to launch a....?
(please fill in the blank).
I've checked wikipedia, spacex.com, etc., and there is supposedly
an earlier test flight at Vandenberg this year.

   I'm interested in the Falcon Heavy test-flight payloads.
Boilerplate (mockup) payloads? That's how they used to do it for
new untried launchers.

  Or maybe Elon Musk is waiting on Facebook for one of you
to suggest to him a payload to mount on a Falcon Heavy test-flight.  ;D

Rats!  :'(  I've put off registering for an account on Facebook for too long.
It's not easy trying to send Elon Musk an email with suggestions
or questions without Facebook; maybe one of you, like me have tried.

Anyways! I'm puzzled why Elon Musk hasn't planned to mount a mockup,
fullsized unmanned Dragon on the first or second Falcon Heavy and send it
on a free-return trajectory around the Moon.
What other commercial firm has ever sent any payload to the Moon at its
own expense? Did you say, Hughes Aerospace? Yes, they were the only ones so far to do it.
« Last Edit: 03/28/2013 08:56 PM by Moe Grills »

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