Author Topic: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION  (Read 459770 times)

Online mlindner

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #20 on: 12/06/2012 02:22 pm »
I'm personally wondering about those cubesat P-PODs. My lab here has several nanosats in the pipeline that could be ready for launch in roughly that timeframe. Would be really cool to be on this launch. Only 1 of 3 planned is currently manifested.
« Last Edit: 12/06/2012 02:23 pm by mlindner »
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Offline baldusi

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #21 on: 12/06/2012 03:19 pm »
I'm personally wondering about those cubesat P-PODs. My lab here has several nanosats in the pipeline that could be ready for launch in roughly that timeframe. Would be really cool to be on this launch. Only 1 of 3 planned is currently manifested.
I always joked that you could launch 25k cubesats on a Falcon Heavy for 6000USD/cubesat. Jokes aside, I don't know what sort of cubesat could use a 24deg 720km circular orbit, or a 45deg x 12.000km x 6.000km. But if somebody can use it there's that 5.000kg of ballast to fill.
And it will test some very exiting ESPA technology.

Offline LouScheffer

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #22 on: 12/06/2012 05:57 pm »
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 45º.  Wait the required 3 hours for the final stage restart (#5).

I'm not an orbital mechanics guy, but you might get less delta-v by doing the last plane change at the 12,000 km apogee, rather than including it as part of burn #4.  That would be yet another burn, and a few more hours.


[...] Indeed, changing planes is most efficient with lowest orbital velocity: high apogee, low perigee.   Therefore my best guess is:

- Launch into 720x250km transfer orbit 24 deg inclination. The 4.5 deg difference to KSC latitude could be included already.
- Burn 1: 720x720km, 24 deg incl.
- Burn 2: 720x12000km, 24 deg incl.
- Burn 3: 720x12000km, plane change to 45 deg incl.
- Burn 4: 6000x12000km, 45 deg incl.
- Burn 5: as required by contract

I don't think there is a way around separating Burn 2/3. But 3/4 could be possibly joined as they both happen at apogee.
Burns 3/4 in your sequence would definitely be combined, thanks to the triangle inequality (The vector sum of two vectors is shorter than the sum of the lengths of the two vectors, unless they are colinear, which does not apply here.)  Whether the saving from the plane change with the lower perigee outweighs the orbital-raising benefit of doing each burn at the highest velocity is not obvious, at least to me.

I suspect the true solution is to do some of the plane change at each relevant firing. Due to the sin/cos relation, you can get a sideways delta-v of 10% of the maneuver total by giving up only 0.5% in the main direction.  So you'd pick up some of the plane change on the 750 circ->750x6000, some on the 750x6000->6000x12000, and the remainder (if any) at apogee.  I'm sure that someone at SpaceX has worked this out in detail already, to make sure they have enough delta-v.

Offline Halidon

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #23 on: 12/06/2012 06:18 pm »
At the time the type was officially announced, it was implied very strongly that DoD or USAF had urged SpaceX to proceed with Falcon Heavy more quickly than they had initially planned.  I wonder if STP-2 was the mission that they had in mind, even then?
I don't think this specific mission was on their minds, I think they pushed SpaceX to accelerate FH because F1v1 wasn't meeting their requirements in general. DoD's high valure payloads are big and may be getting bigger.

Huh?  Unwarranted speculation.  This is just a  mission made up to test the FH.  There is no pushing from the DOD either.  The onus is on Spacex to provide the vehicle, the DOD was not looking for another one.
You're misunderstanding me. I'm not saying SecDef called up Elon and said "build be a Heavy," I'm saying Falcon 9, at least V1, wasn't meeting requirements for the payloads DoD puts on EELVs.

DoD may not have been looking for another vehicle, but they are definitely looking to reduce costs. IF SpaceX can deliver lower costs with a reliable vehicle they'll get payloads.

Offline Antares

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #24 on: 12/06/2012 07:51 pm »
Sounds like a 3 burn mission to me.
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Offline FinalFrontier

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #25 on: 12/06/2012 07:57 pm »
Well between this, specualtion that FH might be the vehicle for GSC, ongoing CRS, ongoing CCDEV, and ongoing investigation into the engine one failure on the last flight, spacex sure has their hands full right now.

Really pulling for them to pull all this off.
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Online ugordan

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #26 on: 12/06/2012 07:57 pm »
Sounds like a 3 burn mission to me.

How do you get from 720x720 to 6000x12000 in one burn, because there is this final requirement for the insertion orbit #2 which accounts for an additional burn: After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).?

Offline Robotbeat

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #27 on: 12/06/2012 08:05 pm »
Sounds like a 3 burn mission to me.

How do you get from 720x720 to 6000x12000 in one burn, because there is this final requirement for the insertion orbit #2 which accounts for an additional burn: After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).?
Agreed, I immediately thought it sounded more like a 4-burn mission.
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Offline oldAtlas_Eguy

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #28 on: 12/06/2012 08:06 pm »
The launch of NET August 2015 is probably prior to the Intelsat launch making this one the test launch for the East coast of FH.

Offline cleonard

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #29 on: 12/06/2012 08:17 pm »
Sounds like a 3 burn mission to me.

Launch into  720x720km, 24 deg incl.
Restart 1: Increase altitude to 720x12000km, 24 deg incl.
Restart 2: Increase altitude to 6000x12000 and plane change to 45 deg
Restart 3: as required by contract

How do you get from 720x720 to 6000x12000 in one burn, because there is this final requirement for the insertion orbit #2 which accounts for an additional burn: After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).?
Agreed, I immediately thought it sounded more like a 4-burn mission.

Offline Ronsmytheiii

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Offline LouScheffer

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #31 on: 12/07/2012 11:19 am »
PDF on DSX

http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdf

From this document:

DSX is slated to fly in a 6,000 km x 12,000 km elliptical orbit at 120 degrees retrograde.

Lucky they relaxed this requirement.  That would be the mother of all plane changes!

Offline Galactic Penguin SST

PDF on DSX

http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdf

From this document:

DSX is slated to fly in a 6,000 km x 12,000 km elliptical orbit at 120 degrees retrograde.

Lucky they relaxed this requirement.  That would be the mother of all plane changes!

The original plan, IIRC, was to fly it along with the next DMSP mission to a polar orbit on an Atlas V (401!) with a lot of excess capability. A plane change from 98 to 120 degrees with such a payload at apogee isn't that difficult.
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Offline Orbiter

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #33 on: 12/07/2012 02:24 pm »
PDF on DSX

http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdf

From this document:

DSX is slated to fly in a 6,000 km x 12,000 km elliptical orbit at 120 degrees retrograde.

Lucky they relaxed this requirement.  That would be the mother of all plane changes!

The original plan, IIRC, was to fly it along with the next DMSP mission to a polar orbit on an Atlas V (401!) with a lot of excess capability. A plane change from 98 to 120 degrees with such a payload at apogee isn't that difficult.

It is if you're trying to get to a retrograde (ie. east to west) orbit instead of the normal prograde orbit from KSC! :) Unless I read what you guys are talking about wrong.
« Last Edit: 12/07/2012 02:27 pm by Orbiter »
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Offline LouScheffer

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #34 on: 12/07/2012 02:46 pm »
PDF on DSX

http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdf

From this document:

DSX is slated to fly in a 6,000 km x 12,000 km elliptical orbit at 120 degrees retrograde.

Lucky they relaxed this requirement.  That would be the mother of all plane changes!

The original plan, IIRC, was to fly it along with the next DMSP mission to a polar orbit on an Atlas V (401!) with a lot of excess capability. A plane change from 98 to 120 degrees with such a payload at apogee isn't that difficult.
Agreed, for a dedicated mission it's not hard.  But now it's a dual mission, and the satellite dropped off just before wants a 24 degree prograde orbit.

Offline smoliarm

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #35 on: 12/09/2012 12:45 pm »
NBS reports more details on contracts:

The U.S. Air Force will pay $97 million for a Falcon 9 rocket to launch in 2014 the Deep Space Climate Observatory, a solar telescope that will be operated by NASA. It will also pay $165 million for a Falcon Heavy rocket for the military's Space Test Program-2 satellite, which is expected to fly in 2015.

http://www.msnbc.msn.com/id/50094995/ns/technology_and_science-space/#.UMSQT3dacgp

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

Is it because these missions are much more complex than typical satellite launch?
Or, do they request some additional services?

Offline Jim

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #36 on: 12/09/2012 01:12 pm »
NBS reports more details on contracts:

The U.S. Air Force will pay $97 million for a Falcon 9 rocket to launch in 2014 the Deep Space Climate Observatory, a solar telescope that will be operated by NASA. It will also pay $165 million for a Falcon Heavy rocket for the military's Space Test Program-2 satellite, which is expected to fly in 2015.

http://www.msnbc.msn.com/id/50094995/ns/technology_and_science-space/#.UMSQT3dacgp

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

Is it because these missions are much more complex than typical satellite launch?
Or, do they request some additional services?

Gov't launches are always more expensive.  They ask for more data  and services since they are self insured.

This has been stated many times on this forum, the govt does not get the website price.
« Last Edit: 12/09/2012 01:12 pm by Jim »

Offline baldusi

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #37 on: 12/09/2012 02:30 pm »
I'm wondering why the "premium" is higher for the Falcon 9, a flown vehicle with probably more flight history, than the Falcon Heavy, which will need not only more analysis, but also has a way more complicated integration work.

Online ugordan

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #38 on: 12/09/2012 02:38 pm »
* 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

Offline oldAtlas_Eguy

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Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
« Reply #39 on: 12/09/2012 06:46 pm »
The whole intent of STP-2 is to demonstrate the full capability of the booster. So it would be a cross feed FH at a commercial price of $125M.

Notice that the add on services seem to be a fixed amount regardless of booster at about $40M.

BTW even this service done by ULA seems to be $40M. So it is a well defined manpower intensive service (lots of paperwork) that dosen't vary by booster or provider.

Tags: Falcon Heavy SpaceX 
 

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