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SpaceX Vehicles and Missions => SpaceX Falcon Missions Section => Topic started by: Chris Bergin on 12/06/2012 01:43 am

Title: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 12/06/2012 01:43 am
DISCUSSION thread for STP-2 mission.

NSF Threads for STP-2 : Discussion (https://forum.nasaspaceflight.com/index.php?topic=30544.0) / Updates (https://forum.nasaspaceflight.com/index.php?topic=48325.0) / ASDS (https://forum.nasaspaceflight.com/index.php?board=66.0) / Party (http://forum.nasaspaceflight.com/index.php?topic=42585.0)
NSF Articles for STP-2 :
https://www.nasaspaceflight.com/?s=STP-2 (https://www.nasaspaceflight.com/?s=STP-2)

Successful launch June 25, 2019 on Falcon Heavy from LC-39A at Cape Canaveral at 02:30 EDT (07:30 UTC).  Side boosters 1052.2 and 1053.2 successfully performed RTLS landings at LZ-1.  Center booster 1057.1 unsuccessfully attempted a downrange landing on the ASDS.  The fairing catcher ship Ms. Tree made its first successful catch of a fairing half.  The Air Force said the Integrated Payload Stack is 3700kg.

SpaceX mission page: https://www.spacex.com/stp-2 (https://www.spacex.com/stp-2)

https://www.youtube.com/watch?v=qLEuCn8RT14 (https://www.youtube.com/watch?v=qLEuCn8RT14)

Posts with payload lists: Post 1 (https://forum.nasaspaceflight.com/index.php?topic=30544.msg1795426#msg1795426).  Post 2 (https://forum.nasaspaceflight.com/index.php?topic=30544.msg1939713#msg1939713).  This is also the ELaNa XV CubeSat mission for NASA

Possible deployment locations:
   Oculus, cubesats : 300 x 860km at 28.5 deg?
   Prox-1, NPSat, OTB, GPIM, COSMIC-2 : 720 x 720km at 24 deg?
   DSX : 6000 x 12000km at 43 deg?
   "Propulsive passivation" : move second stage away from DSX, passivate and leave in MEO?

Other SpaceX resources on NASASpaceflight:
   SpaceX News Articles (Recent) (http://www.nasaspaceflight.com/tag/spacex/)  /   SpaceX News Articles from 2006 (Including numerous exclusive Elon interviews) (http://forum.nasaspaceflight.com/index.php?topic=21862.0)
   SpaceX Dragon Articles (http://www.nasaspaceflight.com/tag/dragon/)  /  SpaceX Missions Section (with Launch Manifest and info on past and future missions) (https://forum.nasaspaceflight.com/index.php?board=55.0)
   L2 SpaceX Section (https://forum.nasaspaceflight.com/index.php?board=60.0)




http://www.nasaspaceflight.com/2012/12/spacex-foot-eelv-door-double-launch-contract-win/ (http://www.nasaspaceflight.com/2012/12/spacex-foot-eelv-door-double-launch-contract-win/)

UGordan with the find on the description of STP-2 payload: https://www.fbo.gov/utils/view?id=36de6af7670d2636c8c195173dd500e1 (https://www.fbo.gov/utils/view?id=36de6af7670d2636c8c195173dd500e1)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: simonbp on 12/06/2012 02:05 am
Wow, this looks like a complicated mission. Two primary spacecraft inserted into different orbits (one LEO, one 12,000 km) and a ton of secondaries. Looks like every spare spacecraft the USAF could think of...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lee Jay on 12/06/2012 02:30 am
Interesting article.  Thanks!

"With these two missions supporting the EELV certification process for both the Falcon 9 and Falcon Heavy, SpaceX noted they will be able to prove the Falcon 9 and Falcon Heavy launch vehicles are designed for exceptional reliability, meeting the stringent US Air Force requirements for the Evolved Expendable Launch Vehicle (EELV) program."

Exceptional reliability?  To me, that would mean better than ULA, and that would require a very long string of successful missions, not just one successful demonstrator.  Is this just marketing/PR speak from SpaceX?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars_J on 12/06/2012 04:07 am
Of course it is marketing speak - until they can back it up.

But this will certainly be an interesting mission. It doesn't sound like a something pushing the lift capability to the limit, but they'll certainly give everything else a workout.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: spectre9 on 12/06/2012 04:14 am
Very cool!

Great article.

It's good to see support coming for Falcon Heavy.

Stacking all the payloads together is going to be the way to do it until somebody is willing to utilise the maximum payload to GTO. I think it's 12 tons? Not sure. Does anybody really know? With or without Merlin 1D and tank stretch  :P
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cleonard on 12/06/2012 04:19 am
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jason1701 on 12/06/2012 04:19 am
Very cool!

Great article.

It's good to see support coming for Falcon Heavy.

Stacking all the payloads together is going to be the way to do it until somebody is willing to utilise the maximum payload to GTO. I think it's 12 tons? Not sure. Does anybody really know? With or without Merlin 1D and tank stretch  :P

The quoted FH figures for the last few years have all been with 1D and stretch, but not always admitting that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 12/06/2012 04:35 am
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.

and from a pad whose construction has not been started.
I will trust Chris that this confirms that SpaceX will launch the FH from the East coast using LC-40. 
This will be interesting.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Ben the Space Brit on 12/06/2012 09:00 am
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?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: john smith 19 on 12/06/2012 09:28 am
But this will certainly be an interesting mission. It doesn't sound like a something pushing the lift capability to the limit, but they'll certainly give everything else a workout.

IIRC the "on ramp" for new launchers (reported on nasaspaceflight.com previously) has a scale of mission reliability. I suspect these payloads are not at top end so the customers can take the hit if it does not work out.

This is a huge opportunity to go head to head with ULA and start to build credibility and the all important "mission assurance" that these customers want.

I'm presuming this won't be the first F9H launch and even if it's in Q415 that's only (best case) 23 months away, which is not long for a 2nd launch of a new LV.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 12/06/2012 09:35 am
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.

and from a pad whose construction has not been started.
I will trust Chris that this confirms that SpaceX will launch the FH from the East coast using LC-40. 
This will be interesting.

Yep, the plan is to have a Falcon Heavy hanger and ramp, clocked 90 degrees (could be 180, but the Cape guys say 90) from the Falcon 9 Hanger and ramp. Other options include 39A - I just made Jim frown ;D -or a new pad.....if they don't need it, they don't need it.

Was pretty specific in the presser too: "The DSCOVR mission will be launched aboard a Falcon 9 and is currently slated for late 2014, while STP-2 will be launched aboard the Falcon Heavy and is targeted for mid-2015. Both are expected to launch from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida.".
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Galactic Penguin SST on 12/06/2012 09:39 am
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.

and from a pad whose construction has not been started.
I will trust Chris that this confirms that SpaceX will launch the FH from the East coast using LC-40. 
This will be interesting.

Yep, the plan is to have a Falcon Heavy hanger and ramp, clocked 90 degrees (could be 180, but the Cape guys say 90) from the Falcon 9 Hanger and ramp. Other options include 39A or a new pad.

Was pretty specific in the presser too: "The DSCOVR mission will be launched aboard a Falcon 9 and is currently slated for late 2014, while STP-2 will be launched aboard the Falcon Heavy and is targeted for mid-2015. Both are expected to launch from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida.".

But that sentence does not exclude the chances of building a new pad aside the current pad at SLC-40 (I've seen someone here call it "SLC-40B"), no?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Halidon on 12/06/2012 09:49 am
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 12/06/2012 09:51 am
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.

and from a pad whose construction has not been started.
I will trust Chris that this confirms that SpaceX will launch the FH from the East coast using LC-40. 
This will be interesting.

Yep, the plan is to have a Falcon Heavy hanger and ramp, clocked 90 degrees (could be 180, but the Cape guys say 90) from the Falcon 9 Hanger and ramp. Other options include 39A or a new pad.

Was pretty specific in the presser too: "The DSCOVR mission will be launched aboard a Falcon 9 and is currently slated for late 2014, while STP-2 will be launched aboard the Falcon Heavy and is targeted for mid-2015. Both are expected to launch from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida.".

But that sentence does not exclude the chances of building a new pad aside the current pad at SLC-40 (I've seen someone here call it "SLC-40B"), no?

Sure, but I know the "plan" is to launch both from the same spot. What they eventually decide is "TBA". Point is, "SLC-40".
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: woods170 on 12/06/2012 10:39 am
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.

and from a pad whose construction has not been started.
I will trust Chris that this confirms that SpaceX will launch the FH from the East coast using LC-40. 
This will be interesting.
Construction for the combined Falcon 9 / Falcon Heavy launchpad at Vandenburg has been on-going for some time now.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 12/06/2012 11:40 am
Wow, this looks like a complicated mission. Two primary spacecraft inserted into different orbits (one LEO, one 12,000 km) and a ton of secondaries. Looks like every spare spacecraft the USAF could think of...
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 24º. 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 45º. 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 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.

The Russian missions to GTO from their high latitude Proton launches are the only other ones I can think of with this many restarts, and they've had reliability problems over the years.   It's a lot of successive events, all of which must go right, and no alternatives....
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 12/06/2012 12:51 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: padrat on 12/06/2012 12:52 pm
It's a wonderful opportunity for Spacex, but they need to execute.  It might seem like it's a long way off in 2015, but it's really not that far off for a vehicle that has not flown yet.

and from a pad whose construction has not been started.
I will trust Chris that this confirms that SpaceX will launch the FH from the East coast using LC-40. 
This will be interesting.

Yep, the plan is to have a Falcon Heavy hanger and ramp, clocked 90 degrees (could be 180, but the Cape guys say 90) from the Falcon 9 Hanger and ramp. Other options include 39A - I just made Jim frown ;D -or a new pad.....if they don't need it, they don't need it.

Was pretty specific in the presser too: "The DSCOVR mission will be launched aboard a Falcon 9 and is currently slated for late 2014, while STP-2 will be launched aboard the Falcon Heavy and is targeted for mid-2015. Both are expected to launch from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida.".
All I'm saying is that I'm hearing decisions for the Heavy pad havent been finalized yet. 39A would be nice but so far it comes with a lot of red tape, which I'm sure Spacex would like to avoid....
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: kevin-rf on 12/06/2012 01:00 pm
Well, sounds like SpaceX will have it's hands full managing the boil off. Hats off if they pull off this Hat Trick.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: avollhar on 12/06/2012 01:04 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.


I am no orbital mechanics guy either, but had to do some math a few years ago. 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.

As others noted: a hell of a launch sequence..
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mlindner 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: baldusi 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Halidon 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Antares on 12/06/2012 07:51 pm
Sounds like a 3 burn mission to me.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FinalFrontier 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan 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).?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: oldAtlas_Eguy 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cleonard 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Ronsmytheiii on 12/07/2012 02:50 am
PDF on DSX

http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdf
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer 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!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Galactic Penguin SST on 12/07/2012 02:16 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: smoliarm 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?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: baldusi 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan 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
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: oldAtlas_Eguy 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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 12/10/2012 03:22 pm
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
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: baldusi on 12/10/2012 04:43 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
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 12/10/2012 04:53 pm
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Mader Levap on 12/10/2012 07:57 pm
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Antares on 12/11/2012 04:20 am
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: baldusi on 12/11/2012 05:59 pm
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?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MP99 on 12/13/2012 01:04 pm
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
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 12/14/2012 03:12 am

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 24º. 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 45º. 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 45º.  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?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 12/14/2012 12:25 pm
TEB for ignition and Helium for spin limit number of restarts
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: oldAtlas_Eguy on 12/14/2012 03:39 pm
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 12/14/2012 03:51 pm
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?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: oldAtlas_Eguy on 12/14/2012 04:44 pm
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
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 12/15/2012 01:17 pm
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...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 12/15/2012 01:49 pm
same chemical and supply
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: simonbp on 12/17/2012 02:33 pm
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...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: kevin-rf on 12/17/2012 03:07 pm
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 ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 12/17/2012 04:00 pm
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
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 12/17/2012 05:11 pm
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?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: oldAtlas_Eguy on 12/19/2012 04:43 pm
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 (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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Moe Grills on 03/28/2013 08:54 pm
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.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 03/28/2013 09:08 pm
Thread title fixed. Silly me! ;D
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: grythumn on 03/29/2013 02:00 am
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....?

Read the PDF in the first post; it has a lot of details.

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Moe Grills on 03/30/2013 08:06 pm
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....?

Read the PDF in the first post; it has a lot of details.

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

As you've confirmed, few details available.

But regarding the other matter; (I repeat this) It's most mysterious why Elon Musk hasn't decided to mount a fullsize/full-weight mockup of the Dragon (with basic radio transmitters) and send it on a free-return trajectory around the Moon using a test-launch Falcon Heavy. I assume he's planning two FH test flights at least; one of them STP-2.
Surely people from all over the world, and from this forum
would have flooded his email box with similar suggestions?
   The Falcon Heavy is more than capable of doing the job.

There are a lot of skeptics out there who believe that SpaceX is not up to the task of sending spacecraft and crew to the Moon. They are much more
skeptical about his Mars ambitions. One Falcon Heavy test-flight with an unmanned Dragon to the Moon would silence many critics. It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
  ;)   I think I stirred up an hornet's nest with that one.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lar on 03/30/2013 08:08 pm

There are a lot of skeptics out there who believe that SpaceX is not up to the task of sending spacecraft and crew to the Moon. They are much more
skeptical about his Mars ambitions. One Falcon Heavy test-flight with an unmanned Dragon to the Moon would silence many critics. It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
  ;)   I think I stirred up an hornet's nest with that one.

I'm not sure that Elon cares a lot what the skeptics think, unless they have launch contracts or some other decision making authority that impacts him. My view is that SpaceX have their roadmap mapped out a ways, subject to change, and don't think they have a lot to prove now, except to themselves about the things they want to refine.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 03/30/2013 08:12 pm
It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
  ;)   I think I stirred up an hornet's nest with that one.

You must be joking. What could be the reason to bump a military contract, which serves as a door-opener for the EELV-class business, for a publicity stunt?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars_J on 03/30/2013 08:32 pm
Yep, at this point they need more commercial and government payloads launched rather than stunts.

There's only going to be one FH demo where they have the leeway to test out as many features of the LV as possible - presumably they do not want to waste it on a risky BLEO Dragon stunt.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Moe Grills on 04/05/2013 10:09 pm
Yep, at this point they need more commercial and government payloads launched rather than stunts.

There's only going to be one FH demo where they have the leeway to test out as many features of the LV as possible - presumably they do not want to waste it on a risky BLEO Dragon stunt.

There's nothing wrong with your asssertion,....to a point.
Commercial launches will pad Elon's bank account. Nothing wrong with that.
But he knows, I know, you know that serious, commercial, human crew
missions to either the Moon or Mars will drain bank accounts of billions, not
pad them.
There's no doubt that Mr. Musk designed and is building Falcon Heavy
boosters for commercial purposes; but his greater agenda with the development of the FH is and was to send humans to the Moon and Mars;
a big financial drain.

OK! I'm starting to drift off topic. So to draw back, suffice to say that whether 2013, 0r 2015, the first Falcon test-flight is most unusual
in that it risks payloads built and paid for by others. Lack of insurance
must be an issue addressed here.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kabloona on 04/05/2013 10:20 pm

the first Falcon test-flight is most unusual
in that it risks payloads built and paid for by others. Lack of insurance
must be an issue addressed here.

It's not unusual at all. Launch vehicles don't insure payloads. If the payload wants insurance, they purchase it themselves.

US gov't payloads are self-insured, which means the gov't doesn't bother to purchase insurance. If the payloads are lost, the gov't can choose to build another one. Both primary payloads here fall in that category.

Pegasus and Taurus carried payloads "built and paid for by others" on their first flights. It's common for a first flight to carry an "expendable" payload for a discounted price. The payload gets a cheap ride in exchange for the risk they take by being first in line.

What *is* unusual is the complexity of the mission with 2 primaries and multiple secondary payloads.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: arachnitect on 04/06/2013 11:02 am

the first Falcon test-flight is most unusual
in that it risks payloads built and paid for by others. Lack of insurance
must be an issue addressed here.

It's not unusual at all. Launch vehicles don't insure payloads. If the payload wants insurance, they purchase it themselves.

US gov't payloads are self-insured, which means the gov't doesn't bother to purchase insurance. If the payloads are lost, the gov't can choose to build another one. Both primary payloads here fall in that category.

Pegasus and Taurus carried payloads "built and paid for by others" on their first flights. It's common for a first flight to carry an "expendable" payload for a discounted price. The payload gets a cheap ride in exchange for the risk they take by being first in line.

What *is* unusual is the complexity of the mission with 2 primaries and multiple secondary payloads.

STP-2 isn't the first Falcon Heavy.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClaytonBirchenough on 04/07/2013 01:50 am
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....?

Read the PDF in the first post; it has a lot of details.

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

As you've confirmed, few details available.

But regarding the other matter; (I repeat this) It's most mysterious why Elon Musk hasn't decided to mount a fullsize/full-weight mockup of the Dragon (with basic radio transmitters) and send it on a free-return trajectory around the Moon using a test-launch Falcon Heavy. I assume he's planning two FH test flights at least; one of them STP-2.
Surely people from all over the world, and from this forum
would have flooded his email box with similar suggestions?
   The Falcon Heavy is more than capable of doing the job.

There are a lot of skeptics out there who believe that SpaceX is not up to the task of sending spacecraft and crew to the Moon. They are much more
skeptical about his Mars ambitions. One Falcon Heavy test-flight with an unmanned Dragon to the Moon would silence many critics. It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
  ;)   I think I stirred up an hornet's nest with that one.

MANY Cubesats as a ballast? Seems like a cheap way to offer some quality space! ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 07/11/2013 04:37 pm
COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

One of the (up to) 6 auxiliary payloads is GPIM (http://space.skyrocket.de/doc_sdat/gpim.htm) (Green Propellant Infusion Mission).

The NASA video shows it as part of the STP-2 stack:

http://www.youtube.com/watch?v=0rKYHLAThYc&feature=player_embedded
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jason1701 on 07/12/2013 06:18 am
Great video, I think it's the first animation of the actual Falcon Heavy design.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: jongoff on 07/12/2013 09:14 pm
But regarding the other matter; (I repeat this) It's most mysterious why Elon Musk hasn't decided to mount a fullsize/full-weight mockup of the Dragon (with basic radio transmitters) and send it on a free-return trajectory around the Moon using a test-launch Falcon Heavy.

Simple. In spite of his sometimes bombastic manner, Elon's actually trying to not piss off those in Congress who already hate SpaceX anymore than he already has to. He's already fighting a huge battle with the Shelby's of the world to keep them from completely cutting Commercial Crew, and he doesn't need to provide them any more reason to hate and actively oppose SpaceX at the moment. This is also probably a big part of why SpaceX hasn't been supportive of Inspiration Mars, BTW. It's "bad enough" for SpaceX that us commercial people are constantly pointing out how Falcon Heavy might make SLS obsolete--the last thing he wants to do is to make it look like SpaceX is trying to make that argument too. You may not get this impression from following his Twitter feed, but Elon's actually quite capable of keeping his mouth shut and not intentionally antagonizing people in Congress who could screw his company (he's a better man than I in that regard).

Plus as others mentioned, flying paying payloads from customers that helps on-ramp them into the EELV program instead of a non-paying stunt is all the more reason not to do it.

~Jon
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: newpylong on 07/13/2013 11:28 pm
Considering the FH is estimated to be only good for 10 metric tons to TLI and the fully loaded Dragon is also 10 mt he might have a hard time doing that. They would look pretty bad sending the Dragon on a heliocentric or elliptical orbit because the US ran out of fuel before the full burn.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClaytonBirchenough on 07/13/2013 11:50 pm
Considering the FH is estimated to be only good for 10 metric tons to TLI and the fully loaded Dragon is also 10 mt he might have a hard time doing that. They would look pretty bad sending the Dragon on a heliocentric or elliptical orbit because the US ran out of fuel before the full burn.

Hmmm... I seem to remember the Falcon Heavy being able to throw more to TLI than 10 mt...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: jongoff on 07/14/2013 04:08 am
Considering the FH is estimated to be only good for 10 metric tons to TLI and the fully loaded Dragon is also 10 mt he might have a hard time doing that. They would look pretty bad sending the Dragon on a heliocentric or elliptical orbit because the US ran out of fuel before the full burn.

Hmmm... I seem to remember the Falcon Heavy being able to throw more to TLI than 10 mt...

I think it's a little more than 10mT to TLI, but it's much more amazing at getting big stuff to LEO than shoving big stuff up the hill beyond LEO. Someone pointed out recently that Atlas V Heavy, if it flew, would have a greater TLI payload than Falcon Heavy using the currently planned upper stage. I'm a huge SpaceX fan, but ULA's Centaur upper stage is still my favorite for BEO missions (though an ACES stage would obviously win if it ever flies).

~Jon
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: QuantumG on 07/14/2013 04:29 am
For either vehicle you get better performance using a third stage to do the TLI burn. Something like a Blok DM, which has a propellant mass fraction of 85% using LOX/RP-1, launched on a Falcon Heavy could throw 15 tons to TLI. Probably something like 20 tons using LOX/LH2.

Whether Dragon with some extra tankage, could throw itself to TLI, depends on what isp you think the Draco thruster has on-orbit, the mass of the Dragon, and a bunch of other stuff no-one knows.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: spectre9 on 07/14/2013 07:03 am
The Inspiration Mars paper gives a good wrap of the FH BEO capabilities.

IIRC they concluded 10mt to whatever C3 they calculated for their Mars flyby trajectory was a good guess.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClaytonBirchenough on 07/14/2013 12:51 pm
A while back on the Falcon Heavy Master Update thread someone poster:

Has SpaceX said (or has anyone surmised) what payload mass Falcon Heavy can push through TLI?

Wikipedia lists 16,000 kg through TLI, but as far as I can tell there is no basis for this figure.

16MT is what you get from mass fraction calculations using 53MT starting at LEO, a 350 ISP engine and adding the DV for TLI. Basicly thats the best. For a 450 ISP you get ~21MT TLI. Direct assent increase performance only slightly, enough to acomodate for whatever is being used as a TLI stage's dry weight.

Wikipedia did say 16,000 kg through TLI and it seems to be removed now.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rabidpanda on 07/14/2013 05:48 pm
In order to get 16MT you would need an additional stage.  What would Falcon Heavy's TLI performance be with just it's standard upper stage? 10MT doesn't seem like a bad guess.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClaytonBirchenough on 07/14/2013 06:26 pm
In order to get 16MT you would need an additional stage.  What would Falcon Heavy's TLI performance be with just it's standard upper stage? 10MT doesn't seem like a bad guess.

Mmmm... maybe I'm being too optimistic; I think Falcon Heavy can throw more than 10mt to TLI.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: smoliarm on 07/14/2013 06:51 pm
In order to get 16MT you would need an additional stage. 
...

IF we assume 53 t to LEO, then 16 t to TLI is a consistent proportional estimate (w/o any additional stage).

Actually, a while ago in Wiki there was full set of performance numbers for FH:
LEO -- 53 t
GEO -- 19 t
TLI -- 16 t
TMI -- 14 t
C3=0 -- 13 t
(as I recall it)
also, as I understand, TLI and TMI numbers were calculated by wiki contributors.

However, later SpaceX changed their estimate of GEO performance for FH to 13 t, leaving LEO unchanged.
Wiki changed numbers accordingly.
This set is kind of strange, the proportion GEO/LEO is too low, but we do not know their reasons.
And the rocket is not built yet, many things can change.

Ed Kyle's site gives performance for FH here
http://www.spacelaunchreport.com/falcon9v1-1.html
in the table "Vehicle Configurations"

-----------
Correction:
Should be GTO, not GEO.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClaytonBirchenough on 07/14/2013 07:22 pm
IF we assume 53 t to LEO, then 16 t to TLI is a consistent proportional estimate (w/o any additional stage).

Actually, a while ago in Wiki there was full set of performance numbers for FH:
LEO -- 53 t
GEO -- 19 t
TLI -- 16 t
TMI -- 14 t
C3=0 -- 13 t
(as I recall it)
also, as I understand, TLI and TMI numbers were calculated by wiki contributors.

However, later SpaceX changed their estimate of GEO performance for FH to 13 t, leaving LEO unchanged.
Wiki changed numbers accordingly.
This set is kind of strange, the proportion GEO/LEO is too low, but we do not know their reasons.
And the rocket is not built yet, many things can change.

Ed Kyle's site gives performance for FH here
http://www.spacelaunchreport.com/falcon9v1-1.html
in the table "Vehicle Configurations"


C3 = 0 is less than TMI of 14 t... am I missing something? ???
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: smoliarm on 07/14/2013 07:47 pm
...

C3 = 0 is less than TMI of 14 t... am I missing something? ???

Well, may be you are not, may be it is my recollection :)
Now you mentioned it, perhaps it was 12 t for TMI...
or 14 t for C3=0 ...
Sorry :)

I'm not an expert in orbital calculus, although I passed my exam with A, but it was 17 years ago, and I never used these formulas since.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rabidpanda on 07/14/2013 08:03 pm
However, later SpaceX changed their estimate of GEO performance for FH to 13 t, leaving LEO unchanged.
Wiki changed numbers accordingly.
This set is kind of strange, the proportion GEO/LEO is too low, but we do not know their reasons.
And the rocket is not built yet, many things can change.

The upper stage on Falcon Heavy is not really optimized for GEO or GTO performance.

According to SpaceX, FH can send 12mT to GTO.  The delta V for LEO to GTO is around 2.5 km/s.  Considering that TLI delta V is slightly more than that (Apollo was 3.05-3.25 km/s) 10mt to TLI seems realistic.

Of course you're right, this rocket doesn't even exist yet and a lot could change.  Honestly, if they just used a larger upper stage they would get much better BLEO performance.  But maybe that's not necessary for any of their future plans, 12mT is plenty for commercial GEO launches.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars_J on 07/14/2013 08:47 pm
However, later SpaceX changed their estimate of GEO performance for FH to 13 t, leaving LEO unchanged.
Wiki changed numbers accordingly.
This set is kind of strange, the proportion GEO/LEO is too low, but we do not know their reasons.
And the rocket is not built yet, many things can change.

The upper stage on Falcon Heavy is not really optimized for GEO or GTO performance.

According to SpaceX, FH can send 12mT to GTO.  The delta V for LEO to GTO is around 2.5 km/s.  Considering that TLI delta V is slightly more than that (Apollo was 3.05-3.25 km/s) 10mt to TLI seems realistic.

Of course you're right, this rocket doesn't even exist yet and a lot could change.  Honestly, if they just used a larger upper stage they would get much better BLEO performance.  But maybe that's not necessary for any of their future plans, 12mT is plenty for commercial GEO launches.

But the v1.1 and FH upper stage *IS* larger... It appears to be almost twice the tank volume of the v1.0 upper stage.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Excession on 07/14/2013 11:15 pm
They could just add another stage. A wide-body centaur placed ought to be able to put twenty or thirty tons into GTO when starting from LEO, and FH could definitely put it there...

But the v1.1 and FH upper stage *IS* larger... It appears to be almost twice the tank volume of the v1.0 upper stage.

They mean relative to the V1.1.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: SpacexULA on 07/15/2013 12:18 am
We have a Falcon Heavy speculation thread guys.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClaytonBirchenough on 07/15/2013 01:11 am
We have a Falcon Heavy speculation thread guys.

You're right. Sorry for contributing to OT conversation.

Here's an appropriate thread to discuss Falcon Heavy TLI payload:

http://forum.nasaspaceflight.com/index.php?topic=20615.0 (http://forum.nasaspaceflight.com/index.php?topic=20615.0)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 05/28/2014 09:19 am
Another payload on this mission is the SSTL built OTB satellite

https://directory.eoportal.org/web/eoportal/satellite-missions/d/dsac
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cartman on 05/28/2014 11:46 am
Quote
The DSAC mission will be a hosted payload onboard a Surrey Satellite Technology (SST-US) Orbital Test Bed (OTB) spacecraft, currently planned for launch into LEO (Low Earth Obit) in early 2016
looks like this has slipped to early 2016
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: wannamoonbase on 05/29/2014 02:18 pm
They could just add another stage. A wide-body centaur placed ought to be able to put twenty or thirty tons into GTO when starting from LEO, and FH could definitely put it there...

But the v1.1 and FH upper stage *IS* larger... It appears to be almost twice the tank volume of the v1.0 upper stage.

They mean relative to the V1.1.

Now that may allow the development of re-useability technology.   
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MTom on 05/29/2014 08:22 pm
Quote
The DSAC mission will be a hosted payload onboard a Surrey Satellite Technology (SST-US) Orbital Test Bed (OTB) spacecraft, currently planned for launch into LEO (Low Earth Obit) in early 2016
looks like this has slipped to early 2016

Not sure it has slipped:
SpaceX launch manifest speaking always about "Year indicates vehicle arrival at launch site."
Launch Early 2016 could easy mach with an arrival in 2015 (+ STP-2 US Air Force is the last but one in the manifes for 2015).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: AncientU on 06/05/2014 11:44 am
Quote
The DSAC mission will be a hosted payload onboard a Surrey Satellite Technology (SST-US) Orbital Test Bed (OTB) spacecraft, currently planned for launch into LEO (Low Earth Obit) in early 2016
looks like this has slipped to early 2016

Not sure it has slipped:
SpaceX launch manifest speaking always about "Year indicates vehicle arrival at launch site."
Launch Early 2016 could easy mach with an arrival in 2015 (+ STP-2 US Air Force is the last but one in the manifes for 2015).
First half of 2015 per Shotwell.  Also, tanks and engines currently being built at Hawthorne.
http://forum.nasaspaceflight.com/index.php?topic=34884.msg1209634#msg1209634
http://forum.nasaspaceflight.com/index.php?topic=34884.msg1209997#msg1209997
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MTom on 06/05/2014 09:12 pm
Quote
The DSAC mission will be a hosted payload onboard a Surrey Satellite Technology (SST-US) Orbital Test Bed (OTB) spacecraft, currently planned for launch into LEO (Low Earth Obit) in early 2016
looks like this has slipped to early 2016

Not sure it has slipped:
SpaceX launch manifest speaking always about "Year indicates vehicle arrival at launch site."
Launch Early 2016 could easy mach with an arrival in 2015 (+ STP-2 US Air Force is the last but one in the manifes for 2015).
First half of 2015 per Shotwell.  Also, tanks and engines currently being built at Hawthorne.
http://forum.nasaspaceflight.com/index.php?topic=34884.msg1209634#msg1209634
http://forum.nasaspaceflight.com/index.php?topic=34884.msg1209997#msg1209997

You mean the demo flight, it's ok.

The question was if STP-2 for US Air Force slipped also or it isn't.
Can be found any information about the original planned launch date?
"Early 2016" is the actual date.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: AncientU on 06/06/2014 10:46 am
Quote
The DSAC mission will be a hosted payload onboard a Surrey Satellite Technology (SST-US) Orbital Test Bed (OTB) spacecraft, currently planned for launch into LEO (Low Earth Obit) in early 2016
looks like this has slipped to early 2016

Not sure it has slipped:
SpaceX launch manifest speaking always about "Year indicates vehicle arrival at launch site."
Launch Early 2016 could easy mach with an arrival in 2015 (+ STP-2 US Air Force is the last but one in the manifes for 2015).
First half of 2015 per Shotwell.  Also, tanks and engines currently being built at Hawthorne.
http://forum.nasaspaceflight.com/index.php?topic=34884.msg1209634#msg1209634
http://forum.nasaspaceflight.com/index.php?topic=34884.msg1209997#msg1209997

You mean the demo flight, it's ok.

The question was if STP-2 for US Air Force slipped also or it isn't.
Can be found any information about the original planned launch date?
"Early 2016" is the actual date.
Sorry, missed that. You're correct.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: DaveJes1979 on 06/12/2014 10:39 pm
Does anyone actually believe that the demo flight is going to be out of KSC?  I know that is what they are currently saying, but it doesn't seem likely that that pad will be ready in time if they are sticking with a "first half of 2015" time frame.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: QuantumG on 06/12/2014 10:41 pm
Does anyone actually believe that the demo flight is going to be out of KSC?  I know that is what they are currently saying, but it doesn't seem likely that that pad will be ready in time if they are sticking with a "first half of 2015" time frame.

I don't think there's any point doing the demo until they have this while lawsuit business sorted out, anyway.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jcc on 06/13/2014 01:10 am
Does anyone actually believe that the demo flight is going to be out of KSC?  I know that is what they are currently saying, but it doesn't seem likely that that pad will be ready in time if they are sticking with a "first half of 2015" time frame.

I don't think there's any point doing the demo until they have this while lawsuit business sorted out, anyway.

I don't see why that would be the case. They need to demo FH if they want to attract customers for it.
I'm am curious about why they switched to KSC though, maybe they have a payload that needs to launch east.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: QuantumG on 06/13/2014 01:15 am
I don't see why that would be the case. They need to demo FH if they want to attract customers for it.

Unless there's been a drastic change, the only customer for this behemoth is the US air force.

The commsat folks would demand a lot more than just the one demonstration flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ChefPat on 06/13/2014 01:29 am
I don't see why that would be the case. They need to demo FH if they want to attract customers for it.

Unless there's been a drastic change, the only customer for this behemoth is the US air force.

The commsat folks would demand a lot more than just the one demonstration flight.

Bigelow.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: QuantumG on 06/13/2014 01:30 am
Bigelow.

Yeah, right.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: docmordrid on 06/13/2014 02:37 am
I don't see why that would be the case. They need to demo FH if they want to attract customers for it.

Unless there's been a drastic change, the only customer for this behemoth is the US air force.

The commsat folks would demand a lot more than just the one demonstration flight.

Bigelow, if the 5.2x19m fairing is any indication.  Seems perfect, if not purpose built, for BA-330.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Antares on 06/13/2014 02:54 am
There is a very good reason not to do demos out of the Cape, now that a Vandy launch site is available: the lack of beaches full of tourists and news crews, all filming the possible unscheduled fireworks display.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: docmordrid on 06/13/2014 03:02 am
Go check YouTube for videos of the CASSIOPE launch at Vandy.  There are plenty of places where a launch accident there could be seen & filmed by the public and news mongers
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: king1999 on 06/13/2014 03:05 am
There is a very good reason not to do demos out of the Cape, now that a Vandy launch site is available: the lack of beaches full of tourists and news crews, all filming the possible unscheduled fireworks display.
I think the last few words were what you wanted to say, but tried to dress it unsuccessfully. An old Russian engine is more likely to make it a July 4  for the US then 27 newly built and tested ones.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Antares on 06/13/2014 05:13 am
I think the last few words were what you wanted to say, but tried to dress it unsuccessfully. An old Russian engine is more likely to make it a July 4  for the US then 27 newly built and tested ones.

No, unlike what I'm typing right now, I said exactly what I wanted to say.  I will assume you're just new and don't realize that my moniker preceded the renamed launch vehicle by more than 4 years.

Pros know the relative reliability of the two launch systems, and pros in any business seek to minimize PR fall out.  SpaceX is in a high-stakes PR match with FAR 15 Old Space right now.  The Cape is much more accessible than Vandenberg.  Places to watch from are less important than opportunity to do so.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/13/2014 05:26 am
I'm am curious about why they switched to KSC though, maybe they have a payload that needs to launch east.

I'm guessing that KSC was chosen so that a used Dragon could be sent around the Moon on FH's first flight. I'm sure the connection to LC-39A having launched Apollo will not be lost on some.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jcc on 06/13/2014 10:57 am
I'm am curious about why they switched to KSC though, maybe they have a payload that needs to launch east.

I'm guessing that KSC was chosen so that a used Dragon could be sent around the Moon on FH's first flight. I'm sure the connection to LC-39A having launched Apollo will not be lost on some.

Nice thought, but they won't want to get NASA angry by upstaging Orion/SLS.
Speaking of NASA, they are a potential customer for interplanetary missions, including Mars.

First flight out of 39A is likely to have pad issues, maybe they want to shake those out on a demo flight rather than a CRS mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: woods170 on 06/13/2014 11:38 am
I'm am curious about why they switched to KSC though, maybe they have a payload that needs to launch east.

I'm guessing that KSC was chosen so that a used Dragon could be sent around the Moon on FH's first flight. I'm sure the connection to LC-39A having launched Apollo will not be lost on some.

Nice thought, but they won't want to get NASA angry by upstaging Orion/SLS.
Speaking of NASA, they are a potential customer for interplanetary missions, including Mars.
That would not actually upset NASA but mostly Congress critters.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 06/13/2014 11:40 am
I'm am curious about why they switched to KSC though, maybe they have a payload that needs to launch east.

I'm guessing that KSC was chosen so that a used Dragon could be sent around the Moon on FH's first flight. I'm sure the connection to LC-39A having launched Apollo will not be lost on some.

Np, they chose it for this payload, STP-2.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MTom on 06/13/2014 11:55 am
I'm am curious about why they switched to KSC though, maybe they have a payload that needs to launch east.

I'm guessing that KSC was chosen so that a used Dragon could be sent around the Moon on FH's first flight. I'm sure the connection to LC-39A having launched Apollo will not be lost on some.

Np, they chose it for this payload, STP-2.

Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 06/13/2014 01:20 pm

Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)

They will be one and the same
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Galactic Penguin SST on 06/13/2014 01:49 pm

Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)

They will be one and the same

Is there any written source that can confirm this? (although it is an obvious choice for the FH maiden flight)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MTom on 06/13/2014 07:21 pm

Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)

They will be one and the same

Is there any written source that can confirm this? (although it is an obvious choice for the FH maiden flight)

SpaceX launch manifest (still) says there will be two launches: FH demo flight and STP-2 for USAF.
Something changed?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Dudely on 06/13/2014 08:03 pm
I don't see why that would be the case. They need to demo FH if they want to attract customers for it.

Unless there's been a drastic change, the only customer for this behemoth is the US air force.

The commsat folks would demand a lot more than just the one demonstration flight.

Bigelow, if the 5.2x19m fairing is any indication.  Seems perfect, if not purpose built, for BA-330.

Yes, they have been building hardware to fly on FH specifically. They already have some completed and are waiting in storage to launch (remember FH has been delayed 2 years+).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: docmordrid on 06/13/2014 08:30 pm
Anyone know if Thin Red Line in Canada is still working with Bigelow?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: sublimemarsupial on 06/13/2014 08:32 pm

I don't see why that would be the case. They need to demo FH if they want to attract customers for it.

Unless there's been a drastic change, the only customer for this behemoth is the US air force.

The commsat folks would demand a lot more than just the one demonstration flight.

Bigelow, if the 5.2x19m fairing is any indication.  Seems perfect, if not purpose built, for BA-330.

Yes, they have been building hardware to fly on FH specifically. They already have some completed and are waiting in storage to launch (remember FH has been delayed 2 years+).

Do you have a source for that?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 06/13/2014 09:43 pm
Right then.

Let's all get on topic with THIS mission.

From this point onwards. Don't make me get out my big stick.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Llian Rhydderch on 06/13/2014 10:54 pm

Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)

They will be one and the same

Is there any written source that can confirm this? (although it is an obvious choice for the FH maiden flight)

So, do we have a source for the idea that the STP-2 payload will fly on the FH demo flight, the maiden flight of Falcon Heavy???

Jim claims it will be.

I realize that there are some insiders here, and that they may possibly have, and then choose to make public, such inside information.   But we are all better off if we know if a claim is from someone who is claiming inside knowledge, or if the information has been publically stated.

Let's make the implicit, explicit!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: QuantumG on 06/14/2014 12:51 am
Quote
1.3  MISSION OBJECTIVES
The goals of the SM-2.4 mission are to launch an Integrated Payload Stack (IPS) to the required
orbits and to provide an EELV New Entrant opportunity.


Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Llian Rhydderch on 06/14/2014 03:04 am
Quote
1.3  MISSION OBJECTIVES
The goals of the SM-2.4 mission are to launch an Integrated Payload Stack (IPS) to the required
orbits and to provide an EELV New Entrant opportunity.

Thanks QG. 

So I don't have the full context for the quote you provided..., but as I read it, it says nothing about the SM-2.4 mission (STP-2, I guess, based on the title of this thread) flying on the maiden flight of the Falcon Heavy.  In fact, that statement doesn't seem to indicate which ordinal FH flight STP-2 will fly on.

So I either Jim is not correct with his statement of "They will be one and the same" on a post following a substantive comment about "STP-2 and not FH demo flight" that immediately preceded his comment:


Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)

They will be one and the same

... or, if he didn't mean what that locution seemed to say, then I don't understand Jim's abbreviated prose.  In this case, Galactic Penquin, MTom and I all seemed to take it as FH flight 1 == STP-2 USG payload.

But actually, understanding Jim seems to be a problem many of us on these forums often seem to run into :o.   Communication is hard!   :D 
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: baldusi on 06/14/2014 11:50 am
He's the guy with most insight into this things. I would tend to think that he simply knows.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MTom on 06/14/2014 12:09 pm
Quote
1.3  MISSION OBJECTIVES
The goals of the SM-2.4 mission are to launch an Integrated Payload Stack (IPS) to the required
orbits and to provide an EELV New Entrant opportunity.

Thanks QG. 

So I don't have the full context for the quote you provided..., but as I read it, it says nothing about the SM-2.4 mission (STP-2, I guess, based on the title of this thread) flying on the maiden flight of the Falcon Heavy.  In fact, that statement doesn't seem to indicate which ordinal FH flight STP-2 will fly on.

So I either Jim is not correct with his statement of "They will be one and the same" on a post following a substantive comment about "STP-2 and not FH demo flight" that immediately preceded his comment:


Jim's post is a good point to come back on topic: STP-2 and not FH demo flight.   ;)

They will be one and the same

... or, if he didn't mean what that locution seemed to say, then I don't understand Jim's abbreviated prose.  In this case, Galactic Penquin, MTom and I all seemed to take it as FH flight 1 == STP-2 USG payload.

But actually, understanding Jim seems to be a problem many of us on these forums often seem to run into :o.   Communication is hard!   :D

Yes, that is also my question, because SpaceX launch manifest lists (still?) 2 FH flights.
(With the information mentioned before: STP-2 launch date is early 2016...)
http://forum.nasaspaceflight.com/index.php?topic=30544.msg1205265#msg1205265
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 06/14/2014 03:34 pm
The title needs to be updated to reflect the move of FH from SLC-40 to SLC-39A.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 06/14/2014 06:02 pm
Done.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MTom on 06/14/2014 09:25 pm
The title needs to be updated to reflect the move of FH from SLC-40 to SLC-39A.

... and the launch date could be also: Mid 2015 --> Early 2016

Edit/CR: updated from SLC-40 to SLC-39A in post title
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: docmordrid on 10/19/2014 07:29 am
Space News reports a slip into 2016

Link.... (http://www.spacenews.com/article/military-space/42221nasa-green-propellant-mission-to-host-three-pentagon-experiments)

Quote
SpaceX’s public manifest shows the STP-2 mission launching in 2015, but Ball [Aerospace] said it has pushed to 2016.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: tobi453 on 10/19/2014 08:02 am
So there will be a different payload on the FH maiden flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 10/19/2014 06:56 pm
Interessting document on the FORMOSAT-7/COSMIC-2 satellites with info on the payload stack
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: somepitch on 10/19/2014 07:12 pm
That's a remarkable failed attempt at spelling "courtesy" on that slide...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: arachnitect on 10/19/2014 07:14 pm
Interessting document on the FORMOSAT-7/COSMIC-2 satellites with info on the payload stack

I didn't recognize that at first.

I thought the previous design looked really cool. But I guess the new version (using ESPA rings) is probably a good choice.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 10/19/2014 07:16 pm
So there will be a different payload on the FH maiden flight.

Or (gasp!) FH will slip into 2016...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: veblen on 10/19/2014 07:43 pm
That's a remarkable failed attempt at spelling "courtesy" on that slide...

And it gets replicated. He probably relied on spell check. Typical result.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 10/19/2014 07:59 pm
That's a remarkable failed attempt at spelling "courtesy" on that slide...

And it gets replicated. He probably replied on spell check. Typical result.

Intentional irony?  ;D
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: veblen on 10/19/2014 08:28 pm
That's a remarkable failed attempt at spelling "courtesy" on that slide...

And it gets replicated. He probably replied on spell check. Typical result.

Intentional irony?  ;D

That sounds much better than brain fart;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Moe Grills on 10/19/2014 09:51 pm
The title needs to be updated to reflect the move of FH from SLC-40 to SLC-39A.

... and the launch date could be also: Mid 2015 --> Early 2016

Edit/CR: updated from SLC-40 to SLC-39A in post title
Could, maybe, likely, but still an opinion until the launch schedule firms up.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 10/22/2014 12:01 pm
From page 25 of that Formosat 7/Cosmic 2 presentation, launch is scheduled for May 2016.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 10/22/2014 02:19 pm
Reminder, this is not a party thread, so silly posts have and will be removed.

Sorry!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Karloss12 on 10/22/2014 10:19 pm
From page 25 of that Formosat 7/Cosmic 2 presentation, launch is scheduled for May 2016.

Sounds about right.  With the launch pad due for completion in mid 2015, FH Demo will be Q4 of 2015 leaving a few months to review flight data for STP-2.

I recon they will be fully recovering the side cores by then, even of the Demo flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: macpacheco on 01/27/2015 12:01 pm
I hope I can say this much. Interesting news on L2 about this.
Let's hope Chris doesn't slap me for saying this little.
 ;D
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Ben the Space Brit on 01/27/2015 12:07 pm
BTW, I have to say that it gives me a silly thrill to once again see in a launch discussion thread Launch Complex 39A. ;D
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mtakala24 on 01/27/2015 06:34 pm
https://www.youtube.com/watch?v=4Ca6x4QbpoM
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: llanitedave on 01/27/2015 07:27 pm
The TE seems to be sheathed with sheet metal in the video.  Is that new?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 01/27/2015 07:32 pm
Verry nice!
Of course everyone wants something different.  I would have liked to see the center core land on the barge "Instructions".  Butif we wait until we see what SpaceX will really do we won't need these spectatular annimations, so this is a wonderful preview. 

edit: The grid fins droop after touchdown like F9R-Dev1!  Fantastic detailing.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 01/27/2015 07:34 pm
The TE seems to be sheathed with sheet metal in the video.  Is that new?

New, or the modeling/animation crew avoiding modeling the TE accurately. ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Space OurSoul on 01/27/2015 08:19 pm
NERD CHILLS
Did y'all catch the braces retracting back into the center core after booster sep? (0:36s or so)

Edit: My bad. There's a stand-alone thread for the video:
http://forum.nasaspaceflight.com/index.php?topic=36660.0 (http://forum.nasaspaceflight.com/index.php?topic=36660.0)

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: guckyfan on 01/27/2015 09:11 pm
Is the Mid 2015 in the thread title new?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Ben the Space Brit on 01/27/2015 09:40 pm
Re.: The FH promo video: I wouldn't be surprised if, for the heaviest payloads, the central core landed on the barge in the mid-Atlantic somewhere.

Still, for average-sized payloads, the boosters and the main core should all make it back to KSC. Seeing them landing all in a neat row IRL will be quite the sight!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: deadman719 on 01/27/2015 09:45 pm
Re the FH video: Are there any concerns with sound waves bouncing off the fixed srevice structure, if it is enclosed and given its size, as the vehicle launches?  Would it be correct to assume enclosing it would be an attempt to lower maintenance costs by reducing the number of components exposed to the elements? 

Deadman
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Galactic Penguin SST on 01/28/2015 01:07 am
Is the Mid 2015 in the thread title new?

Nope, it's actually very old. I've changed the title to reflect what was reported one page back.  ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: guckyfan on 01/28/2015 05:12 am
Is the Mid 2015 in the thread title new?

Nope, it's actually very old. I've changed the title to reflect what was reported one page back.  ;)

Thanks. That is what I meant. It is new in the title, not that the data is new.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 01/28/2015 06:14 am
There seems to be a "bump" about 1/3 of the way up on the boosters. I wonder if this has anything to with the cross-feed mechanism.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 01/28/2015 07:18 am

There seems to be a "bump" about 1/3 of the way up on the boosters. I wonder if this has anything to with the cross-feed mechanism.

No, that exists on all F9s, although it is usually not very visible since it faces the erector at launch. (See image below) It is placed right around the common bulkhead, so it may be some kind of emergency tank vent.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rebel44 on 04/26/2015 08:08 am
How much delta v will this mission require?

thx
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 04/28/2015 05:06 am
Here's a JPL press release on the Deep Space Atomic Clock mission which is flying on STP-2. Only says it is flying in 2016 on Falcon Heavy.

http://www.jpl.nasa.gov/news/news.php?feature=4567
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 04/28/2015 06:06 am
Here's a JPL press release on the Deep Space Atomic Clock mission which is flying on STP-2. Only says it is flying in 2016 on Falcon Heavy.

http://www.jpl.nasa.gov/news/news.php?feature=4567

The Deep Space Atomic Clock is a hosted experiment on the OTB 1 satellite: http://space.skyrocket.de/doc_sdat/otb-1.htm
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jakusb on 03/09/2016 08:29 pm
According to Jeff Foust:
Gwynne Shotwell, SpaceX: expect first Falcon Heavy launch now late this year, three more to follow in subsequent 6 months. #satshow

Anybody care/dare to speculate on what this means?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat on 03/09/2016 08:46 pm
According to Jeff Foust:
Gwynne Shotwell, SpaceX: expect first Falcon Heavy launch now late this year, three more to follow in subsequent 6 months. #satshow

Anybody care/dare to speculate on what this means?
Sounds like they're realigning the projected Falcon Heavy launch date to realign with reality.

However, 3 more Falcon Heavies within 6 months from that shows a big ramp-up production. That's a total of 12 boosters, and 112 Merlin engines and 48 legs and 48 fins. But many are likely to RTLS at least the boosters, which they've already shown they can pull off...

...which implies to me at least SOME components could be reused.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/25/2016 03:59 am
Attached is an ELaNa presentation giving a launch date of 1 March 2017 (under review) for STP 2. This flight is carrying three cubesats on ELaNa XV; ARMADILLO, LEO and StangSat.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 12/07/2016 06:31 pm
Planetary Society: Ground finale? Deployment test moves LightSail 2 closer to handoff (http://www.planetary.org/blogs/jason-davis/2016/20161206-ls2-boom-only-ditl.html)
Quote
The Planetary Society's LightSail 2 spacecraft completed what may have been its final end-to-end systems test today here at Cal Poly San Luis Obispo...
LightSail 2 is nearly ready to be integrated with its P-POD, the spring-loaded box that will carry it to space. After integration takes place, the loaded P-POD will be shipped to the Air Force Research Laboratory in Albuquerque, New Mexico. Shipping may occur in January. At AFRL, LightSail's P-POD will be installed inside Prox-1, a Georgia Tech-built SmallSat that will hitch a ride to orbit aboard the second flight of SpaceX's new Falcon Heavy rocket.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 01/25/2017 09:35 pm
https://mobile.twitter.com/jeff_foust/status/824371954559836160 (https://mobile.twitter.com/jeff_foust/status/824371954559836160)
Quote
In talk on COSMIC-2, NOAA says Falcon Heavy demo launch scheduled for 2nd Q; STP-2 mission (with COSMIC-2) planned for Sept. 30. #AMS2017
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: butters on 03/09/2017 11:49 pm
Is this mission still okay following the last-minute issues with the 2017 authorization bill?

It seemed that the STP program was flagged as one of the concerns for the WH/DOJ?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: tater on 03/10/2017 01:31 am
https://mobile.twitter.com/jeff_foust/status/824371954559836160 (https://mobile.twitter.com/jeff_foust/status/824371954559836160)
Quote
In talk on COSMIC-2, NOAA says Falcon Heavy demo launch scheduled for 2nd Q; STP-2 mission (with COSMIC-2) planned for Sept. 30. #AMS2017

Where would they launch it when they have no pad ready for it?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim_LAX on 03/10/2017 04:11 pm
Quote from Shotwell at Satelite 2017 on March 8th:
Cape Canaveral’s Space Launch Complex-40 should be operational again this summer.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: woods170 on 03/10/2017 08:19 pm
Quote from Shotwell at Satelite 2017 on March 8th:
Cape Canaveral’s Space Launch Complex-40 should be operational again this summer.
August was publically mentioned by SpaceX. After that, SpaceX will need at least 60 days to modify the current LC-39A reaction frame to host the additional TSM's and holddown posts needed for FH. That period is also from public SpaceX statements.
So, assuming LC-40 is back in action this August, and assuming the 60-day modification period goes off without a hitch, it will be NET november 2017 for first FH launch attempt.
But that is assuming that the notorious SpaceX time dilation factor does not rear it's ugly head. If it does (like it almost always does) we could be looking at first FH launch attempt somewhere in Q1 of 2018.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: DOCinCT on 03/10/2017 09:14 pm
Quote from Shotwell at Satelite 2017 on March 8th:
Cape Canaveral’s Space Launch Complex-40 should be operational again this summer.
....After that, SpaceX will need at least 60 days to modify the current LC-39A reaction frame to host the additional TSM's and holddown posts needed for FH. That period is also from public SpaceX statements.
So, assuming LC-40 is back in action this August, and assuming the 60-day modification period goes off without a hitch, ....
Do you have some references for that statement?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: old_sellsword on 03/10/2017 09:20 pm
Quote from Shotwell at Satelite 2017 on March 8th:
Cape Canaveral’s Space Launch Complex-40 should be operational again this summer.
....After that, SpaceX will need at least 60 days to modify the current LC-39A reaction frame to host the additional TSM's and holddown posts needed for FH. That period is also from public SpaceX statements.
So, assuming LC-40 is back in action this August, and assuming the 60-day modification period goes off without a hitch, ....
Do you have some references for that statement?

https://www.nasaspaceflight.com/2017/03/spacex-falcon-9-echostar-23-slc-40-return/

Quote from: Chris Bergin
It was also noted that SpaceX is working a plan that involves returning operations to SLC-40 before then working on 39A to prepare it for the maiden launch of the Falcon Heavy rocket.

This work will take “at least 60 days” to complete, focusing on the 39A TEL table – which is currently specific to the single core Falcon 9 – and Tail Service Masts (TSM).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Pete on 03/11/2017 05:58 am
...So, assuming LC-40 is back in action this August, and assuming the 60-day modification period goes off without a hitch, it will be NET november 2018 for first FH launch attempt.
But that is assuming that the notorious SpaceX time dilation factor does not rear it's ugly head.
...
One would have to look hard to find a time dilation factor as bad as yours.
"this August" + 60 days == NET November 2018?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 03/11/2017 08:13 am
...So, assuming LC-40 is back in action this August, and assuming the 60-day modification period goes off without a hitch, it will be NET november 2018 for first FH launch attempt.
But that is assuming that the notorious SpaceX time dilation factor does not rear it's ugly head.
...
One would have to look hard to find a time dilation factor as bad as yours.
"this August" + 60 days == NET November 2018?

Well, he did get the year right at least...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: woods170 on 03/11/2017 02:50 pm
...So, assuming LC-40 is back in action this August, and assuming the 60-day modification period goes off without a hitch, it will be NET november 2018 for first FH launch attempt.
But that is assuming that the notorious SpaceX time dilation factor does not rear it's ugly head.
...
One would have to look hard to find a time dilation factor as bad as yours.
"this August" + 60 days == NET November 2018?
Good catch. Corrected in the original post. And thanks for pointing out.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: sdsds on 03/21/2017 07:44 pm
Although the launcher isn't explicitly mentioned, this article belongs here. (Yes?)

https://www.jpl.nasa.gov/news/news.php?feature=6784

Last month, the space agency's next-generation atomic clock was joined to the spacecraft that will take it into orbit in late 2017.

That instrument, the Deep Space Atomic Clock was developed by NASA's Jet Propulsion Laboratory in Pasadena, California. On Feb. 17, JPL engineers monitored integration of the clock on to the Surrey Orbital Test Bed spacecraft at Surrey Satellite Technology in Englewood, Colorado.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 05/25/2017 04:42 am
A recent presentation on the Cosmic-2 payload by Wei Xia-Serafino/NOAA.  PDF file is attached below.  There is an updated graphic of the STP-2 payload stack, and much information/pictures on Cosmic-2 of course.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Formica on 07/02/2017 02:41 am
What is the purpose of the 5 tonnes of ballast on this mission? Is it simply to ensure that FH is capable of meeting the EELV New Entrant specifications?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: woods170 on 07/02/2017 11:50 am
What is the purpose of the 5 tonnes of ballast on this mission? Is it simply to ensure that FH is capable of meeting the EELV New Entrant specifications?
No. The launcher is too powerfull for just the payload alone. It requires additional payload mass (provided by means of ballast) to prevent over-performance.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Pete on 07/02/2017 12:38 pm
About the date for this mission, it reminds me of a movie .

"Mission Impossible"?  no, that's not it
.
"Back to the Future"?  closer
.
"Days of our Lives"? almost
.
I have it.. Annie, singing "Tomorrow, Tomorrow, i love ya, your only a day away"


Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 07/21/2017 12:57 pm
Potentially great news. STP-2 is NET April 30th, 2018, according to the USAF.
http://www.planetary.org/blogs/jason-davis/2017/20170721-lightsail-2-updates-prox-1-launch-dates.html (http://www.planetary.org/blogs/jason-davis/2017/20170721-lightsail-2-updates-prox-1-launch-dates.html)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 08/07/2017 07:00 pm
That date appears again in this tweet from Jeff Foust showing a chart of educational nanosatellites missions.

https://mobile.twitter.com/jeff_foust/status/894608571186388992
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 08/07/2017 08:26 pm
I'm not going to believe any dates on this one yet, let's see how the first couple flights go.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 08/07/2017 08:32 pm
I'm not going to believe any dates on this one yet, let's see how the first couple flights go.

Isn't this the second FH flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: tvg98 on 08/07/2017 08:36 pm
I'm not going to believe any dates on this one yet, let's see how the first couple flights go.

Isn't this the second FH flight.

I thought Arabsat 6A was the second flight no?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 08/07/2017 08:40 pm
I'm not going to believe any dates on this one yet, let's see how the first couple flights go.

Isn't this the second FH flight.

Based on the link in my response above, the AF has reason to believe STP-2 could be the third FH launch. But it's understandably in flux and highly dependent upon the first launch. As gongora said, our best bet is to just wait for the first launch.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: titusou on 08/18/2017 04:36 pm
I'd talk with NSPO (Taiwan) team today. It's NET Apr,2018 right now.
Titus
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 08/18/2017 06:13 pm
I'd talk with NSPO (Taiwan) team today. It's NET Apr,2018 right now.
Titus

Thanks! Tentatively indicates that the inaugural launch is still relatively stable for now. Can't really read far into future schedules until FH's first success, but SpaceX is clearly relatively confident in the vehicle, at least internally.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kenp51d on 08/18/2017 07:13 pm
I'd talk with NSPO (Taiwan) team today. It's NET Apr,2018 right now.
Titus

Thanks! Tentatively indicates that the inaugural launch is still relatively stable for now. Can't really read far into future schedules until FH's first success, but SpaceX is clearly relatively confident in the vehicle, at least internally.
Mr. Musk puplicly lowered expectations, but I'd bet internally they are very confident of at least safely clearing the pad at minimum. So is NASA, they sure as heck are not willing to loose the pad for manned flights.
If they can make it past Max Q, and can throttle down for that, then my bet is successful booster sep, stage sep, and they then make orbit.
This is gonna be way cool!
Just unimagenabl to me they'd risk the pad.

Sent from my XT1565 using Tapatalk

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: AncientU on 08/18/2017 08:16 pm
They wouldn't be launching if they thought the chance of failure was high.
Think about it...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Space Ghost 1962 on 08/18/2017 08:37 pm
It's logistics/operations that one should fear before T0. So much has to go right before you make it to ignition. Could sit on the pad for a month. Complex beast, more like 5x the trouble for three boosters.

Next, it's the hold down time and validating vehicle before launch and after ignition. Static fire?

Then its that all the clamps go. Otherwise engine shutdown.

After off the pad, very likely to clear the tower, and find out how well the acoustics worked. Very loud as things don't scale linearly (overtones).

At some point leading up to MaxQ, the torques between the three boosters will attempt to tear apart the stack. But likely the oscillations will be damped and fall by flight software (to be later analyzed to improve vehicle performance). This starts where the most critical phase begins, ending with engine shutdown and side booster separation.

If they get through that, FH is a success as far as having a potential alternative to DIVH, which we haven't yet had ever. (Ironically, it increases DIVH's value because you have multiple alternatives so more payloads can be considered, although doubtful that has any meaning.)

Having three returning boosters land after that would be a showy tour de force.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 08/18/2017 09:23 pm
Ya'll realize this isn't the Demo Mission thread, right?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Space Ghost 1962 on 08/18/2017 09:51 pm
Applies to both. Actually, to the third flight as well, but lesser.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: IainMcClatchie on 08/20/2017 09:49 pm
....After off the pad, very likely to clear the tower, and find out how well the acoustics worked. Very loud as things don't scale linearly (overtones).

Can you elaborate how overtones don't scale linearly?  That is, how three cores would produce more than three times as much accoustic pressure in some direction.

My best guess is that you might get a bit of a phased array effect normal to the axis of attachment.

I'm also expecting something interesting to happen to the core plume as all three get underexpanded in the upper atmosphere.  A single core plume gets to expand in two dimensions.  A center core of three really only  expands along one dimension.  My guess is they'll get more of the plume crawling it's way up the sides of the rocket.  Combined with a longer burn time from running throttled down part of the way, and that center core is going to see a significantly toastier ride on the way up.  But maybe that's dominated by re-entry and landing.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: tyrred on 08/21/2017 05:03 am
It would be interesting if the combined exhaust plumes have the appearance of the three-engine landing burns, three hydras expanding perpendicular to the core arrangement. Great big eye of Sauron?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Mike_1179 on 08/21/2017 02:48 pm
It would be interesting if the combined exhaust plumes have the appearance of the three-engine landing burns, three hydras expanding perpendicular to the core arrangement. Great big eye of Sauron?


Would have to fire up the CFD to do more than arm-waving, but remember that the 3-engine re-entry burn is done when the stage is traveling supersonic and engine first, so you get some pretty interesting shockwaves and boundary conditions. A stage accelerating up with three cores burning would look, well, different.

There's no shockwaves forcing the exhaust and firey bits into a small cone shape when the stage is going up. Instead the exhaust expands outward radially like you see from the 9 engines of a F9 as it gets closer to MECO. However, the boosters are gone well before the stage gets up as high as the F9 MECO, so we won't see the super-wide plumes we're used to seeing from all three boosters firing simultaneously. Might just be a more orange and more sooty version of a Delta IV Heavy.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jim on 08/21/2017 03:04 pm
It would be interesting if the combined exhaust plumes have the appearance of the three-engine landing burns, three hydras expanding perpendicular to the core arrangement. Great big eye of Sauron?


It shouldn't be much different than the two RD-180 nozzles.  Just a large scale..
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 08/22/2017 09:17 am
My best guess is that you might get a bit of a phased array effect normal to the axis of attachment.

That would be very likely for the shock wave interaction between the plumes. However, acoustic phased array effects are strongest when each source is outputting the same waveform, like in a PA system. In the case of rocket engines, the flow is turbulent, so although the spectrum is reasonably consistent over time, the waveforms are independent. The rms response can be obtained by combining those waveforms, but the result, especially at higher frequencies, can be quite chaotic, leading to effects like the crackling sound we hear from Falcon 9 and others.

It would be interesting if the combined exhaust plumes have the appearance of the three-engine landing burns, three hydras expanding perpendicular to the core arrangement. Great big eye of Sauron?
... Instead the exhaust expands outward radially like you see from the 9 engines of a F9 as it gets closer to MECO. However, the boosters are gone well before the stage gets up as high as the F9 MECO, so we won't see the super-wide plumes we're used to seeing from all three boosters firing simultaneously ...

Although the FH boosters will stage earlier, due to FH's phenomenal T/W, they will do so at a similar altitude and higher velocity than the F9 core. Forgive the crude rendering, but the plume could be quite spectacular.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 09/15/2017 09:14 am
Quote
Peter B. de Selding‏ @pbdes 35s seconds ago

Taiwan NSPO: Six US/Taiwan Formosat-7/COSMIC-2 sats to launch Q2 2018 on @SpaceX Falcon Heavy; will be 1st launch after Nov FH demo flight.

https://twitter.com/pbdes/status/908619097189027840

If I'm reading the above correctly, that puts 2nd FH flight in Q2 2018 so STP-2 presumably pushes back?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Galactic Penguin SST on 09/15/2017 09:28 am
Quote
Peter B. de Selding‏ @pbdes 35s seconds ago

Taiwan NSPO: Six US/Taiwan Formosat-7/COSMIC-2 sats to launch Q2 2018 on @SpaceX Falcon Heavy; will be 1st launch after Nov FH demo flight.

https://twitter.com/pbdes/status/908619097189027840

If I'm reading the above correctly, that puts 2nd FH flight in Q2 2018 so STP-2 presumably pushes back?

They are actually one of the main payloads on the STP-2 flight.  ;)

That means the Arabsat flight once reported to be 2nd in queue must have slipped behind.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 10/30/2017 09:16 pm
This report on Formosat 5 has at the end I believe a paragraph on Formosat 7, flying along with STP-2.

https://www.inside.com.tw/2017/10/30/formosat-5-cmos-modify

The Bing translation is

"On the other hand, a few days ago, because the United States funds can not be put in place, the Space Center canceled the second group of seventh, the launch plan, and Zhang Liaowan insists on the current status of the progress of the seven. Chen Liangki responded that the current satellite of the first group of Fowei seventh had been placed in the plant and was expected to be launched on schedule next 5 June."

If my understanding is correct, this means the launch has been delayed to 5 June 2018.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 10/31/2017 01:22 am
The Bing translation doesn't seem to be correct.  In the manifest thread this was posted earlier:

NSPO still hopes to launch Formosat-7 sats in May/June, 2018
https://www.inside.com.tw/2017/10/30/formosat-5-cmos-modify

The May/June timeframe is also mentioned in this English language article:
[Focus Taiwan] FormoSat-7 satellite group to be launched in mid-2018 (http://focustaiwan.tw/news/ast/201710300017.aspx)
Quote
A constellation of six satellites under the FormoSat-7/COSMIC-2 project, a U.S.-Taiwan collaboration, will be launched in May or June next year, Taiwan's Science and Technology Minister Chen Liang-gee (陳良基) said Monday.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 11/21/2017 04:59 pm
From Gwynne's recent interview (http://spacenews.com/spacex-aims-to-follow-a-banner-year-with-an-even-faster-2018-launch-cadence/):
Quote
“We should ship the first Block 5 this year,” she said. “We are going to spend some time in Texas testing it, [then] it should fly in late Q1.”
[...]
Shotwell said the Block 5 Falcon 9 should be able to refly “10 or more times” with limited refurbishment. The Falcon Heavy will also use Block 5 cores, she said, with the exception of the first mission.

Having to wait for F9 block 5 might push back some estimates of FH's second flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 11/21/2017 05:45 pm
From Gwynne's recent interview (http://spacenews.com/spacex-aims-to-follow-a-banner-year-with-an-even-faster-2018-launch-cadence/):
Quote
“We should ship the first Block 5 this year,” she said. “We are going to spend some time in Texas testing it, [then] it should fly in late Q1.”
[...]
Shotwell said the Block 5 Falcon 9 should be able to refly “10 or more times” with limited refurbishment. The Falcon Heavy will also use Block 5 cores, she said, with the exception of the first mission.

Having to wait for F9 block 5 might push back some estimates of FH's second flight.

She didn't say that FH would only use block 5 cores. Perhaps its using Block 5 center boosters and flight-proven side boosters. russianhalo said that the side boosters were already being manufactured early this year.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mgeagon on 11/22/2017 06:27 am
I think the term "core" in this context means the center booster. I agree that until customers start using high-energy returned boosters in a single stick launch, Falcon Heavy might be the only avenue to reuse some of the flight proven block 3s and 4s. It seems economically unlikely that all three boosters in the Demo 2 mission will be block 5s.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Formica on 12/08/2017 05:58 pm
Spaceflight Now has updated their launch schedule, putting STP-2 NET June 2018.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jakusb on 01/01/2018 06:05 pm
Spaceflight Now has updated their launch schedule, putting STP-2 NET June 2018.
Isn’t the most likely reason the much later launch of FH-Demo? 6 months to:
- review all launch data
- review all FH Demo hardware (safely landed in one piece)
- adjust design where needed
- build brand new improved block 5 center core
- build OR convert 2 side cores

All given a successful flight of FH Demo...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: IanThePineapple on 01/01/2018 06:11 pm
Spaceflight Now has updated their launch schedule, putting STP-2 NET June 2018.
Isn’t the most likely reason the much later launch of FH-Demo? 6 months to:
- review all launch data
- review all FH Demo hardware (safely landed in one piece)
- adjust design where needed
- build brand new improved block 5 center core
- build OR convert 2 side cores

All given a successful flight of FH Demo...

I'm wondering whether they'll reuse the center core and perhaps the two side cores.

If not I'd guess they'd convert two B4 cores for boosters, and 1 B5 for center. Just a guess.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 01/01/2018 06:19 pm
The vehicle for this flight should be all new Block 5 cores.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: IanThePineapple on 01/01/2018 06:44 pm
The vehicle for this flight should be all new Block 5 cores.

Ah, nice!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 02/14/2018 06:46 pm
We have a date! NET April 30, with two month window stretching to June.


STP-2 is scheduled for a window from April until June and Arabsat is confirmed to be second launching Falcon Heavy, according to NASA's budget released today (Page 537).

As I think I've mentioned before, I've got tickets to this launch courtesy of the Lightsail Kickstarter years and years ago, so I've started clearing my schedule!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 02/14/2018 06:54 pm
We have a date! NET April 30, with two month window stretching to June.


STP-2 is scheduled for a window from April until June and Arabsat is confirmed to be second launching Falcon Heavy, according to NASA's budget released today (Page 537).

As I think I've mentioned before, I've got tickets to this launch courtesy of the Lightsail Kickstarter years and years ago, so I've started clearing my schedule!

Well, that was the schedule when FH Demo was going to fly in December...  If this is still the third FH then unlikely it flies in that window.  If it swaps places with Arabsat 6A then it would still be possible (but probably not April, I'm guessing F9 Block 5 doesn't even debut until mid-April.)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: pb2000 on 02/14/2018 07:42 pm
Well, that was the schedule when FH Demo was going to fly in December...  If this is still the third FH then unlikely it flies in that window.  If it swaps places with Arabsat 6A then it would still be possible (but probably not April, I'm guessing F9 Block 5 doesn't even debut until mid-April.)
Does the STP-2 contract stipulate new cores? If not, it might be possible to launch 6A and assuming full recovery be ready to launch again in ~6 weeks, if Elon's gas and go model pans out.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 02/14/2018 08:48 pm
Well, that was the schedule when FH Demo was going to fly in December...  If this is still the third FH then unlikely it flies in that window.  If it swaps places with Arabsat 6A then it would still be possible (but probably not April, I'm guessing F9 Block 5 doesn't even debut until mid-April.)
Does the STP-2 contract stipulate new cores? If not, it might be possible to launch 6A and assuming full recovery be ready to launch again in ~6 weeks, if Elon's gas and go model pans out.

The contract we've seen is almost 6 years old and has been amended multiple times since then.  We really don't know for sure what's in it now.  I would assume new cores.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 02/14/2018 08:55 pm
We have a date! NET April 30, with two month window stretching to June.


STP-2 is scheduled for a window from April until June and Arabsat is confirmed to be second launching Falcon Heavy, according to NASA's budget released today (Page 537).

As I think I've mentioned before, I've got tickets to this launch courtesy of the Lightsail Kickstarter years and years ago, so I've started clearing my schedule!

Well, that was the schedule when FH Demo was going to fly in December...  If this is still the third FH then unlikely it flies in that window.  If it swaps places with Arabsat 6A then it would still be possible (but probably not April, I'm guessing F9 Block 5 doesn't even debut until mid-April.)

Elon indicated that the single stick block 5 debut flight would be in a couple of months.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 02/14/2018 09:21 pm
Well, that was the schedule when FH Demo was going to fly in December...  If this is still the third FH then unlikely it flies in that window.  If it swaps places with Arabsat 6A then it would still be possible (but probably not April, I'm guessing F9 Block 5 doesn't even debut until mid-April.)

Elon indicated that the single stick block 5 debut flight would be in a couple of months.

In this context, I think STP-2's launch date is going to be highly contingent on the launch of Arabsat 6A, which will in essence be the debut of an entirely new iteration of Falcon Heavy derived from Block 5. If SpaceX is also required to build an entirely new Block 5 Falcon Heavy for STP-2 on top of the new vehicle for Koreasat, late 2018 may be a more realistic launch window.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 02/14/2018 11:01 pm
[Bloomberg] SpaceX's Falcon Heavy Mission for Air Force Targets June Launch (https://www.bloomberg.com/news/articles/2018-02-14/spacex-s-falcon-heavy-mission-for-air-force-targets-june-launch)
Quote
The U.S. Air Force is targeting that month for its Space Test Program 2 mission, or STP-2, a spokeswoman for the Space and Missile Systems Center said in an email.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cebri on 02/15/2018 08:12 am
Really considering flying from Europe to watch this.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: macpacheco on 02/15/2018 01:20 pm
Given that FH side cores are interchangeable with F9 cores, FH launch contracts that stipulate new cores will be handled building the 3 new cores, launching the set, then giving the side boosters interstages and launching them as F9 cores.
And if Arabsat accepts reused cores, it could launch with two previously flown F9 cores as side boosters.
It seems SpaceX will end up with 3 or 4 FH center cores, enough to launch to a long while.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jakusb on 02/22/2018 02:38 am
With ArabSat-6A delayed to end-of-2018, will STP-2 be the 2nd FH and still aiming june 2018?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 02/22/2018 06:33 am
With ArabSat-6A delayed to end-of-2018, will STP-2 be the 2nd FH and still aiming june 2018?
Where is this information on ArabSat 6A coming from? I can't find it here on NSF.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Paul_G on 02/22/2018 06:48 am
With ArabSat-6A delayed to end-of-2018, will STP-2 be the 2nd FH and still aiming june 2018?
Where is this information on ArabSat 6A coming from? I can't find it here on NSF.

I saw this mentioned on Twitter. A search for Arsbsat 6a returned this article which says testing un

http://satelliteprome.com/news/lockheed-martin-completes-assembly-on-arabsat-6a/

Quote
During the trip from Denver to Sunnyvale, Arabsat-6A was housed in a “mobile cleanroom,” which keeps the satellite secure and in pristine condition, free of virtually any specks of dust and contaminants that could damage its precision electronics.

In California, the satellite will undergo multiple tests to ensure it is fit for flight. The satellite will be blasted with sound, exposed to extreme heat and cold, and subjected to a total vacuum to simulate what it will endure during its launch and operations in space. The testing will be completed and the satellite ready for delivery to the launch site by the end of the year.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: soltasto on 03/03/2018 01:03 am
NET June 13

http://planetary.org/blogs/jason-davis/2018/20180302-lightsail-2-launch-update.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Demidrol on 03/03/2018 08:09 am
There were some mentions about an ISAT demonstrator as part of the STP-2 mission. But now I can't find any information about it. So are they still going to launch the ISAT on FH?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 03/03/2018 09:51 am
There were some mentions about an ISAT demonstrator as part of the STP-2 mission. But now I can't find any information about it. So are they still going to launch the ISAT on FH?

AFAIK, ISAT is pretty dead since many years (i think, i need to update my website on ISAT).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 03/03/2018 09:43 pm
I started trying to cross-reference the payloads mentioned in the recent Spaceflight Now article with Gunter's site, need to look at this more later.

[Spaceflight Now] Rideshare mission for U.S. military confirmed as second Falcon Heavy launch (https://spaceflightnow.com/2018/03/01/rideshare-mission-for-u-s-military-confirmed-as-second-falcon-heavy-launch/)
Quote
Known as the Space Test Program-2, or STP-2, mission, the Falcon Heavy launch will launch with 25 spacecraft inside its nose cone, according to a spokesperson from the U.S. Air Force’s Space and Missile Systems Center.
...
Most of the STP-2 payloads will go into circular low-altitude orbits around 447 miles (720 kilometers) above Earth, inclined 24 degrees to the equator. Then the Falcon Heavy will boost the DSX satellite into an unusual elliptical orbit ranging in altitude between 3,728 miles (6,000 kilometers) and 7,456 miles (12,000 kilometers), with a ground track shifting between 43 degrees north and south of the equator.

6x COSMIC-2/Formosat 7
DSX (http://space.skyrocket.de/doc_sdat/dsx.htm) (600kg)
NASA GPIM (http://space.skyrocket.de/doc_sdat/gpim.htm)
Orbital Test Bed (http://space.skyrocket.de/doc_sdat/otb-1.htm) (includes atomic clock)
Prox 1 (http://space.skyrocket.de/doc_sdat/prox-1.htm) + Lightsail 2 (http://space.skyrocket.de/doc_sdat/lightsail-1.htm)
USAF Academy FalconSat 7 (http://space.skyrocket.de/doc_sdat/falconsat-7.htm) (3U CubeSat)
Naval Postgraduate School NPSat 1 (http://space.skyrocket.de/doc_sdat/npsat1.htm) (86kg)
Naval Research Laboratory TEPCE 1,2 (http://space.skyrocket.de/doc_sdat/tepce.htm) (2x1.5U Cubesat)
UT Austin ARMADILLO (http://space.skyrocket.de/doc_sdat/armadillo.htm) (3U CubeSat)
Michigan Tech Oculus-ASR (http://space.skyrocket.de/doc_sdat/oculus-asr.htm) (70kg)
Cal Poly / Merritt Island High School LEO/CP 9 (http://space.skyrocket.de/doc_sdat/cp-9.htm) (2U CubeSat) and StangSat (http://space.skyrocket.de/doc_sdat/stangsat.htm) (1U CubeSat)
----
US Naval Academy BRICSat 2 (http://space.skyrocket.de/doc_sdat/bricsat-2.htm) (1.5U CubeSat)
US Naval Academy PSat 2 (http://aprs.org/psat2.html) (1.5U CubeSat, Gunter's site (http://space.skyrocket.de/doc_sdat/psat-2.htm))
TBEx (http://space.skyrocket.de/doc_sdat/tbex.htm) (2x 3U CubeSats)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OnWithTheShow on 03/04/2018 04:54 am
A Celestis space burial mission will also fly on this mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 03/04/2018 05:03 am
A Celestis space burial mission will also fly on this mission.

Do the you know the mission or name for this Celestis payload?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 03/04/2018 08:54 am
A Celestis space burial mission will also fly on this mission.

Do the you know the mission or name for this Celestis payload?

It is called "Heritage Flight". The Celestis capsule is integrated into the OTB satellite.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Nehkara on 03/09/2018 08:28 pm
Is there any confirmation that SpaceX has been cleared by the Air Force to use flight-proven side boosters on this mission?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 03/09/2018 08:41 pm
Is there any confirmation that SpaceX has been cleared by the Air Force to use flight-proven side boosters on this mission?
It is previously stated that the next launch which is now this flight will use all block-5 cores which in earlier announcement were to be all new. I have not come across anything different information wise.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ChrisGebhardt on 03/09/2018 10:15 pm
Is there any confirmation that SpaceX has been cleared by the Air Force to use flight-proven side boosters on this mission?
It is previously stated that the next launch which is now this flight will use all block-5 cores which in earlier announcement were to be all new. I have not come across anything different information wise.

I know the center core will be a new Block 5 as it has to be custom-built for FH.  Where's the link to the announcement that both side cores (regular F9 Block 5s with nose cones instead of interstages) are going to be new Block 5s for this mission?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kansan52 on 03/09/2018 10:34 pm
CG, going from other posts that reported after the first mixmaster FH launch, all FH would be constructed using Block 5.

But nothing has stated the side F9s would be new. I inferred there would not be any flight proven Block 5 available for the next FH. Just to little time.

Still, the SX tempo could mean flight proven Block 5s could be available.

Fun to watch!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 03/10/2018 09:30 am
Is there any confirmation that SpaceX has been cleared by the Air Force to use flight-proven side boosters on this mission?
It is previously stated that the next launch which is now this flight will use all block-5 cores which in earlier announcement were to be all new. I have not come across anything different information wise.

I know the center core will be a new Block 5 as it has to be custom-built for FH.  Where's the link to the announcement that both side cores (regular F9 Block 5s with nose cones instead of interstages) are going to be new Block 5s for this mission?

I believe Elon also stated it a couple of times in interviews around the demo flight of the FH.

Here’s one example.

https://techcrunch.com/2018/02/09/spacex-aims-to-make-history-3-more-times-in-2018/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ChrisGebhardt on 03/10/2018 09:35 am
CG, going from other posts that reported after the first mixmaster FH launch, all FH would be constructed using Block 5.

But nothing has stated the side F9s would be new. I inferred there would not be any flight proven Block 5 available for the next FH. Just to little time.

Still, the SX tempo could mean flight proven Block 5s could be available.

Fun to watch!

Gotcha.  Could be wrong, but I would imagine that the first Block 5 would be available.  If it flies around 5 April as intended, that would that would be 2.5 month before the FH-2 flight.  If they're serious about rapid reuse, that core should be available.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 03/10/2018 02:08 pm
CG, going from other posts that reported after the first mixmaster FH launch, all FH would be constructed using Block 5.

But nothing has stated the side F9s would be new. I inferred there would not be any flight proven Block 5 available for the next FH. Just to little time.

Still, the SX tempo could mean flight proven Block 5s could be available.

Fun to watch!

Gotcha.  Could be wrong, but I would imagine that the first Block 5 would be available.  If it flies around 5 April as intended, that would that would be 2.5 month before the FH-2 flight.  If they're serious about rapid reuse, that core should be available.

It really comes down to what the customer wants them to demonstrate.  It's an Air Force launch, and I doubt they put in any language allowing reused boosters when they signed the contract 5 years ago.  Maybe the Air Force would be willing to try it on a test launch like this but that would have to be negotiated.  SpaceX can't just stick a used booster on a flight unless the contract allows it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: jpo234 on 03/10/2018 03:15 pm
SpaceX can't just stick a used booster on a flight unless the contract allows it.

Is it enough if the contract doesn't forbid it?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Nomadd on 03/10/2018 04:15 pm
SpaceX can't just stick a used booster on a flight unless the contract allows it.

Is it enough if the contract doesn't forbid it?
"That which is not expressly forbidden is allowed?" or "That which is not expressly allowed is forbidden?"
 The basic SX contract could be written for used with the option to request new or the other way around.
 I would imagine the former.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Michael Baylor on 03/10/2018 06:31 pm
To settle the above discussion, all cores on this FH mission will be Block V.

Ok, my bad. This doesn't settle the above discussion, but here's the most detailed response that Elon has given up regarding the side cores.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 03/10/2018 08:41 pm
To settle the above discussion, all cores on this FH mission will be Block V.

We've known that for months, it doesn't settle anything.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Michael Baylor on 03/10/2018 10:41 pm
To settle the above discussion, all cores on this FH mission will be Block V.

We've known that for months, it doesn't settle anything.
Yeah, my bad. I missed the part about this being specific to new Block V side cores.

Nothing has been settled.  :(
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Mader Levap on 03/12/2018 02:01 pm
SpaceX can't just stick a used booster on a flight unless the contract allows it.

Is it enough if the contract doesn't forbid it?
It would not be enough, but I am very sure they all have in contracts something about reuse (even if it amounts to "[BLEEEP] NO"). It is not like SpaceX's reuse ambitions were secret.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Nehkara on 03/12/2018 02:05 pm
SpaceX can't just stick a used booster on a flight unless the contract allows it.

Is it enough if the contract doesn't forbid it?
It would not be enough, but I am very sure they all have in contracts something about reuse (even if it amounts to "[BLEEEP] NO"). It is not like SpaceX's reuse ambitions were secret.

STP-2 was awarded in 2012.  It's possible there is nothing in the contract about re-use.

http://www.spacex.com/press/2012/12/19/spacex-awarded-two-eelv-class-missions-united-states-air-force
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 03/12/2018 02:15 pm
SpaceX can't just stick a used booster on a flight unless the contract allows it.

Is it enough if the contract doesn't forbid it?
It would not be enough, but I am very sure they all have in contracts something about reuse (even if it amounts to "[BLEEEP] NO"). It is not like SpaceX's reuse ambitions were secret.

STP-2 was awarded in 2012.  It's possible there is nothing in the contract about re-use.

http://www.spacex.com/press/2012/12/19/spacex-awarded-two-eelv-class-missions-united-states-air-force

The USAF has a whole boatload of qualification requirements that assume a new booster. As I understand it, those would be very difficult to meet with a used booster because the process is not designed to qualify a used booster.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 03/21/2018 05:34 pm
The date on STP-2 was updated from NET June to NET June 13th in the general launch log thread last week. Is that a reasonably solid date?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 03/21/2018 05:41 pm
The date on STP-2 was updated from NET June to NET June 13th in the general launch log thread last week. Is that a reasonably solid date?
It still says its a NET but it is more of a promising date than just NET June. Keep in mind that for a while now in the USA launch schedule the launch date is NET 13 June 2018 to NLT 13 August 2018.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 03/21/2018 06:15 pm
The date on STP-2 was updated from NET June to NET June 13th in the general launch log thread last week. Is that a reasonably solid date?

The 13th is probably a solid NET date but I wouldn't consider it a solid launch date yet.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/13/2018 10:48 pm
You never know what you'll find when you get bored and poke around the FCC database...

ELS File Number 0235-EX-PL-2016
Quote
TBEx will be inserted into the nominal STP-2 CubeSat orbit with apogee at 860 km, perigee
at 300 km, and an inclination of 28.4.

This was from a 2017 document, which is five years newer than the publicly released mission requirements document you can find at the top of the thread.

edit: attach document with cubesat mission details
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/14/2018 12:46 am
Here is the ODAR for the three ELaNa XV CubeSats.  It gives the orbit as 300x860 at 28.5 degrees.  It also shows the June 13 target date was already set as of Dec. 12, 2017 (a couple months before the FH Demo launch).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/14/2018 05:40 pm
The Planetary Society hasn't changed their ODAR for Lightsail-2, it still shows deployment at 720km circular, 24 degrees.
FCC application still pending, FCC ELS File Number 0338-EX-ST-2018
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: tleski on 04/16/2018 12:57 am
On the Space Show dated April 10th, Casey Dreier (Planetary Society) mentioned that the Lightsail-2 launch slipped from June to September. It would mean STP-2 slipped. Do we have any information confirming this from other sources? He seems to be pretty well informed.

Link to the interview (the Lightsail-2 is discussed ~33minutes into the show):
http://thespaceshow.com/show/10-apr-2018/broadcast-3098-casey-dreier
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/16/2018 01:06 am
It would not be surprising at all if it slips a few months.  There wasn't really any chance of June happening.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cebri on 04/20/2018 10:18 am
Kind of a bummer, i'll probably be in the States in June and i was hoping to see it go. Not really that suprised tho.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/24/2018 09:34 pm
General Atomics Completes Ready-For-Launch Testing of Orbital Test Bed Satellite (http://www.ga.com/general-atomics-completes-ready-for-launch-testing-of-orbital-test-bed-satellite)
Quote
SAN DIEGO, CA, 23 APRIL 2018 - General Atomics Electromagnetic Systems (GA-EMS) announced today that it has completed full system and “ready for launch” pre-flight testing of its Orbital Test Bed (OTB) satellite. OTB will launch as part of the U.S. Air Force’s Space Technology Program (STP-2) flight on the SpaceX Falcon Heavy rocket. The OTB hosts multiple payloads on a single platform for on-orbit technology demonstration. Among the hosted payloads on OTB is NASA’s Space Technology Mission Directorate’s Deep Space Atomic Clock, designed and built at NASA’s Jet Propulsion Laboratory, which supports deep space navigation and exploration.

“The completion of system testing marks a significant milestone, allowing us to effectively “button up” the OTB satellite in anticipation of delivery to Cape Canaveral for launch into space,” stated Scott Forney, president of GA-EMS. “We believe OTB is a new paradigm in hosted payload satellite design and is paving the way to make space more affordable and accessible to customers looking to demonstrate and validate their technologies on-orbit.”

GA-EMS’ low-Earth orbit OTB is a versatile, modular platform designed for the simultaneous launch of multiple demonstration payloads. Hosting multiple payloads on a single satellite eliminates the need for customers to bear the costly burden of a dedicated platform and launch.

“As the small satellite industry grows, the OTB hosted payload platform can increase the number of flight opportunities, reduce the cost to access space, and provide a more adaptable approach to managing the integration, launch, and on-orbit operations to support commercial, civil, educational, and military payloads,” added Nick Bucci, vice president of Missile Defense and Space at GA-EMS. “From the perspective of both the payload customer and host provider, this new approach offers significant advantages and benefits over classic space industry practices to help rapidly space-qualify new equipment.”

GA-EMS continues to expand its portfolio of small satellites and mission-support capabilities, providing ground-to-on-orbit solutions that offer a high degree of modularity and payload flexibility to suit a variety of mission and customer requirements.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Eagandale4114 on 05/09/2018 10:32 pm
Now NET October 2018 according to Bloomberg  (https://www.bloomberg.com/news/articles/2018-05-09/spacex-s-second-falcon-heavy-rocket-spectacle-slips-to-october)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 05/11/2018 05:38 pm
NET Oct. 30

http://www.planetary.org/blogs/jason-davis/2018/20180511-lightsail2-launch-slip.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 06/08/2018 01:44 am
A system engineer working a payload on STP-2 told me that SpaceX has told the team with  that the launch is now targeted for November 19. 
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/08/2018 01:58 am
It will be interesting to see where DM-1 ends up in relation to this flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: deruch on 06/08/2018 07:43 pm
It will be interesting to see where DM-1 ends up in relation to this flight.

I wouldn't be surprised if current delays in preparation of LC-39 for DM-1 are causing the slippage of STP-2 since both need that pad.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 06/10/2018 02:56 am
What is the purpose of the 5 tonnes of ballast on this mission? Is it simply to ensure that FH is capable of meeting the EELV New Entrant specifications?
No. The launcher is too powerfull for just the payload alone. It requires additional payload mass (provided by means of ballast) to prevent over-performance.

Perhaps this is an ignorant question, but why is this mission still manifested on a Falcon Heavy? I'm trying to figure out the rationale, especially given the unbelievably severe delays STP-2 has been beset with as a result of LV choice. Sunk cost fallacy?

It's just hard for me to see any actual value in adding a huge amount of ballast to "stress" test a LV that has already been successfully demonstrated with an interplanetary launch.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/10/2018 02:59 am
What is the purpose of the 5 tonnes of ballast on this mission? Is it simply to ensure that FH is capable of meeting the EELV New Entrant specifications?
No. The launcher is too powerfull for just the payload alone. It requires additional payload mass (provided by means of ballast) to prevent over-performance.

Perhaps this is an ignorant question, but why is this mission still manifested on a Falcon Heavy? I'm trying to figure out the rationale, especially given the unbelievably severe delays STP-2 has been beset with as a result of LV choice. Sunk cost fallacy?

It's just hard for me to see any actual value in adding a huge amount of ballast to "stress" test a LV that has already been successfully demonstrated with an interplanetary launch.

The STP contracts are an onramp to DoD certification for new vehicles.  It's a test flight.  The payload isn't all that relevant.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 07/13/2018 06:15 pm
I wonder what the requirements for this actually are now.  I don't see why it would ever go to 720km-circular unless a government secondary payload needs that orbit.  The initial permit request for Prox-1 back in 2016 was denied by the FCC because that orbit was so high.  Most of the smaller payloads are now showing a 300x860 at 28.5 degrees orbit, and Formosat-7's operational (not necessarily deployment) orbit is only 550-km at 24 degrees.

This article mentions the launch being pushed toward the end of the year (which we already knew), and has a couple other tidbits about the Formosat-7 sats.
http://www.taipeitimes.com/News/taiwan/archives/2018/07/14/2003696663
Quote
In April and May, the US sent experts to replace some of Formosat-7’s components after the NSPO detected signal interference among its scientific payloads, he said, adding the satellite cluster is now ready for launch.
...
The second set’s seventh satellite, which was made by Taiwan, would still be launched, and the NSPO would seek other rocket suppliers to help with the plan, he said.

It would budget NT$540 million (US$17.67 million) for the seventh satellite’s separate launch, which is scheduled for 2020, Yu added.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 08/02/2018 06:38 pm
https://blogs.nasa.gov/commercialcrew/2018/08/02/nasas-commercial-crew-program-target-test-flight-dates-3/

Targeted Test Flight Dates:
Boeing Orbital Flight Test (uncrewed): late 2018 / early 2019
Boeing Crew Flight Test (crewed): mid-2019
SpaceX Demo-1 (uncrewed): November 2018
SpaceX Demo-2 (crewed): April 2019

DM-1 now has a November target, not sure if that will have any effect on the STP-2 schedule.  I guess it may be another couple months before it's clear whether either or both of them will actually make November  :)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: John Alan on 08/02/2018 11:34 pm
Do we have any idea how long SpaceX will need to switch 39A back and forth between F9 and FH as it currently stands?...  ???

DM-1 in early Nov and STP-2 in late Nov seems a possibility...  :-\
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: IanThePineapple on 08/02/2018 11:37 pm
Do we have any idea how long SpaceX will need to switch 39A back and forth between F9 and FH as it currently stands?...  ???

DM-1 in early Nov and STP-2 in late Nov seems a possibility...  :-\

I believe I read it took 2 days to convert 39A from FH to F9 capability after the demo flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mazen hesham on 08/06/2018 01:12 am
the launch schedule thread says this launch is now early December, what's the source for that ?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 08/06/2018 03:45 am
the launch schedule thread says this launch is now early December, what's the source for that ?

To what “launch schedule thread” are you referring?
The public SpaceX Manifest Thread still says 2018-11.
Although my suspicion is that a slip to December is probable...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Galactic Penguin SST on 08/06/2018 04:46 am
the launch schedule thread says this launch is now early December, what's the source for that ?

To what “launch schedule thread” are you referring?
The public SpaceX Manifest Thread still says 2018-11.
Although my suspicion is that a slip to December is probable...

It's this one: https://forum.nasaspaceflight.com/index.php?topic=8184.1840 (https://forum.nasaspaceflight.com/index.php?topic=8184.1840)
This is probably a misread of the "FPIP chart" made by smoliarm as that wasn't meant to be accurate.

Updated FPIP:

(https://forum.nasaspaceflight.com/assets/43418.0/1502410.jpg)
https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=43418.0;attach=1502409;sess=17024
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 08/06/2018 05:49 am
the launch schedule thread says this launch is now early December, what's the source for that ?

To what “launch schedule thread” are you referring?
The public SpaceX Manifest Thread still says 2018-11.
Although my suspicion is that a slip to December is probable...

It's this one: https://forum.nasaspaceflight.com/index.php?topic=8184.1840 (https://forum.nasaspaceflight.com/index.php?topic=8184.1840)
This is probably a misread of the "FPIP chart" made by smoliarm as that wasn't meant to be accurate.

Updated FPIP:

(https://forum.nasaspaceflight.com/assets/43418.0/1502410.jpg)
https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=43418.0;attach=1502409;sess=17024 (https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=43418.0;attach=1502409;sess=17024)

Ah
We are, as they say, “in violent agreement”.
With SpaceX DM-1 said to have to wait until November, it is a reasonable assumption that STP-2 will slip into December.
But that’s all it is, a reasonable assumption. 
Let’s hope for an announcement soon.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: SimonFD on 08/06/2018 07:50 am
Given DM- is big held up by other schedules, couldn't STP-2 move to the left and go first?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 08/06/2018 03:49 pm
Given DM- is big held up by other schedules, couldn't STP-2 move to the left and go first?

Because I imagine the former is a higher priority for Space X than the latter.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 08/06/2018 04:14 pm
Given DM- is big held up by other schedules, couldn't STP-2 move to the left and go first?

If STP-2 was able to move left then it probably wouldn't have moved right in the first place.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: rosbif73 on 08/07/2018 10:52 am
Given DM- is big held up by other schedules, couldn't STP-2 move to the left and go first?

If STP-2 was able to move left then it probably wouldn't have moved right in the first place.

Depends whether we're talking absolute left and right (i.e. calendar dates) or just relative left and right (i.e. order of missions). STP-2 probably can't move very far to the left in absolute terms, but it could conceivably stay at the same NET date whilst the DM slips rightwards past it due to ISS scheduling constraints.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 08/07/2018 03:18 pm
http://focustaiwan.tw/news/asoc/201808030023.aspx
Quote
Taipei, Aug. 3 (CNA) The FormoSat-7 satellite group, a U.S.-Taiwan collaboration that could be launched by the end of this year, will greatly improve the world's typhoon prediction capabilities, the deputy head of the Central Weather Bureau said Friday.
http://www.taipeitimes.com/News/front/archives/2018/08/04/2003697944
Quote
While Lai said that Formosat-7 would be delivered to the US at the end of next month, agency officials appeared more reserved about its launch schedule, which has been postponed several times.
The satellite cluster will most likely be launched next year, Lin said, adding that the actual date has yet to be determined.
As Formosat-7’s launch is managed by the US Air Force and US company SpaceX, the NSPO can only wait for notification two months prior to launch, he said.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 08/08/2018 09:35 pm
Quote
Jason Davis • August 8, 2018
LightSail 2 updates: Launch date slips, environmental test complete, new video released

The Planetary Society's LightSail 2 spacecraft has proved it can withstand the rigors of launch aboard SpaceX's Falcon Heavy, the powerhouse rocket that will carry it into orbit. But that ride to space won't happen until at least November 30, as SpaceX works through a list of other payloads in line to fly first.

http://www.planetary.org/blogs/jason-davis/lightsail-2-launch-nov30.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mazen hesham on 09/05/2018 03:20 pm
STP-2 NET March 2019 per Teslarati.
Quote
Currently NET March 2019 as well, SpaceX’s third dedicated USAF launch – STP-2 on Falcon Heavy – is being set up primarily to help the USAF certify SpaceX’s newest heavy-lift rocket for national security launches.
https://www.teslarati.com/spacex-second-usaf-mission-december-gps-satellite-launch-target/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Michael Baylor on 09/05/2018 03:43 pm
STP-2 NET March 2019 per Teslarati.
Quote
Currently NET March 2019 as well, SpaceX’s third dedicated USAF launch – STP-2 on Falcon Heavy – is being set up primarily to help the USAF certify SpaceX’s newest heavy-lift rocket for national security launches.
https://www.teslarati.com/spacex-second-usaf-mission-december-gps-satellite-launch-target/
Pretty sure that was sourced based on this forum post. I could be wrong though.
A question mark is not needed
STP-2 is NET March 2019
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 10/30/2018 05:14 am
STP-2 NET March 2019 per Teslarati.
Quote
Currently NET March 2019 as well, SpaceX’s third dedicated USAF launch – STP-2 on Falcon Heavy – is being set up primarily to help the USAF certify SpaceX’s newest heavy-lift rocket for national security launches.
https://www.teslarati.com/spacex-second-usaf-mission-december-gps-satellite-launch-target/
Pretty sure that was sourced based on this forum post. I could be wrong though.
A question mark is not needed
STP-2 is NET March 2019

Sorry, just saw this. Comga's comment cued me to ask a friend and they corroborated with "Q1/Q2". No reason to question Comga's NET, as such.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 12/20/2018 02:32 am
This is surprising.  STP-2 is not an EELV launch so I guess it's a good time for USAF to give it a try.

NASA looking to launch delayed space science missions in early 2019 (https://spacenews.com/nasa-looking-to-launch-delayed-space-science-missions-in-early-2019/)
Quote
Fox said the mission [STP-2] will launch on the second of two back-to-back launches of SpaceX’s Falcon Heavy rocket, after the launch of the Arabsat-6A spacecraft. “It will launch after the successful launch of Arabsat, which is currently manifested for March,” she said.

The two launches, she said, will use the same set of first stage booster cores. “They will recover and reuse the boosters,” she said, with the second launch taking place about a month after the first.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kenp51d on 12/20/2018 03:27 am
Does this mean just the two side cores, or maybe also the center core?
The way it reads to me seems a bit ambiguous. And maybe it's just me.

Ken
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lar on 12/20/2018 04:31 am
Does this mean just the two side cores, or maybe also the center core?
The way it reads to me seems a bit ambiguous. And maybe it's just me.

Ken
It seemed ambiguous to me as well. If they had said "side and center cores" it might have been clearer. Maybe they are still not sure they can stick the center core landing and have a second center core in production just in case? This wording gives them wiggle room.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 12/20/2018 04:35 am
I really have no idea what this mission looks like now as far as the orbits it will go through.  Originally it was 720km x 720km x 24deg for the first deployment and then went to 6000 x 12000 x 45deg for the second deployment.  Cosmic-2 sats were then supposed to use their own propulsion to lower their orbits to 520 x 520 x 24deg.

At some point a 300 x 860 x 28.5 orbit seems to have been added so that some of the secondary payloads without propulsion would deorbit in a reasonable amount of time.  Cosmic-2 also doesn't necessarily need to be at 24deg, they could probably use 28.5deg

In their FCC permit filing (0338-EX-ST-2018), LightSail team said they didn't want to go below 720km because drag would overcome the solar pressure on the sail.  A failure to deploy the sail would result in it taking about 90 years to deorbit from that altitude.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kenp51d on 12/21/2018 04:54 am
Does this mean just the two side cores, or maybe also the center core?
The way it reads to me seems a bit ambiguous. And maybe it's just me.

Ken
It seemed ambiguous to me as well. If they had said "side and center cores" it might have been clearer. Maybe they are still not sure they can stick the center core landing and have a second center core in production just in case? This wording gives them wiggle room.

I think I stumble over the answer by accident.  Side boosters and center cores will be recovered (at least that the intent) of Arabsat 6A, then refurbish the in 60 days and fly SAF’s Space Test Program 2 (STP-2) with them.
https://www.teslarati.com/ (https://www.teslarati.com/)
Original post is from SpaceNews.
At least that is what the article says but not confirmed by Spacex

Ken
edited to add the last sentence disclaimer
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 01/10/2019 09:51 am
Taiwan saying Q2 for this launch with Formosat satellites to be transported soon (February) to US:

Quote
Taiwanese satellites soon to head for launch from Florida
Formosat-7 satellites will enter space atop SpaceX’s Falcon Heavy rockets
By Asia Times staff January 7, 2019 6:46 PM (UTC+8)

Taiwanese authorities say the island’s new Formosat satellites will soon be transported to the US by China Airlines, the island’s flag carrier. This could happen after the Lunar New Year break in February, with the satellites then being launched into service aboard SpaceX’s Falcon Heavy rocket from Kennedy Space Center in Florida in the second quarter of 2019.

http://www.atimes.com/article/taiwanese-satellites-soon-to-head-for-launch-from-florida/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 01/30/2019 12:27 pm
New FCC filing for the Lightsail 2 satellite (0055-EX-ST-2019):
Quote
This STA will be used to provide the communication for a short-term small satellite project. The launch date slipped significantly requiring a new or extended STA. New launch date is NET 30 APRIL 2019
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 01/30/2019 05:02 pm
New FCC filing for the Lightsail 2 satellite (0055-EX-ST-2019):
Quote
This STA will be used to provide the communication for a short-term small satellite project. The launch date slipped significantly requiring a new or extended STA. New launch date is NET 30 APRIL 2019

54 days after the Arabsat NET? That sounds more like the time needed to turn around the boosters.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 01/30/2019 05:05 pm
We don't have real dates for either of these FH missions.  Comga suggested a week ago on the manifest thread that this mission would be heading for May, and that looks likely.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 01/30/2019 05:08 pm
Slips are more likely than not. Either way, I'd expect at least about 2 months between the two for booster turnaround.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 01/30/2019 06:23 pm
New FCC filing for the Lightsail 2 satellite (0055-EX-ST-2019):
Quote
This STA will be used to provide the communication for a short-term small satellite project. The launch date slipped significantly requiring a new or extended STA. New launch date is NET 30 APRIL 2019

For what length of time is this valid?
We have confidence that it's not launching BEFORE May. 
The question is how long after the start, or even the end, of May.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 01/30/2019 07:08 pm
New FCC filing for the Lightsail 2 satellite (0055-EX-ST-2019):
Quote
This STA will be used to provide the communication for a short-term small satellite project. The launch date slipped significantly requiring a new or extended STA. New launch date is NET 30 APRIL 2019

For what length of time is this valid?
We have confidence that it's not launching BEFORE May. 
The question is how long after the start, or even the end, of May.

The initial STA is usually 6 months (and that's what this application has).  If it doesn't launch by then they'll just file another one.  You can also extend them after launch.  Aerospace Corp has been extending the experimental license for a cubesat launched in 2012 that is still active.

edit:  ARMADILLO's grant is Sep. 2018 to Sep. 2019, TBEx grant is Mar. 2018 to Nov. 2019.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 02/14/2019 12:14 am
Taiwan's Minister of Science and Technology apparently said this on February 12th.
http://www.taipeitimes.com/News/taiwan/archives/2019/02/14/2003709706

Quote
Asked about the launch date of Formosat-7, Lin said that as Taiwan is partnering with the US for the launch, it would need to wait for the US to notify them.

Formosat-7’s six satellites are on standby at the NSPO, and can be packaged and delivered to the US as soon as it receives notice from the US, he said.

The ministry plans to launch Formosat-7 this year.

Also worth noting that there's now a strong chance that STP-2 will run into range issues similar to Flight 1, mainly ULA's request that SpaceX avoid risky Falcon Heavy ops to mitigate potential damage to Atlas V and SBIRS-4 at LC-41. Boeing's Starliner Demo-1 is currently NET late April, Falcon Heavy Flight 3 is probably NET a similar time frame barring some sort of rapid reuse miracle after Flight 2.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 02/14/2019 12:37 am
Starliner Demo-1 is expected for first half of May: https://ria.ru/20190131/1550174772.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 02/14/2019 12:56 am
Starliner Demo-1 is expected for first half of May: https://ria.ru/20190131/1550174772.html

Thanks for reminding me. Still safe to assume that Boeing/ULA will be starting launch preparations well in advance, and the fact that Formosat-7 isn't even in the US yet is probably a good sign that STP-2 is NET the absolute end of April, if not May or later. Atlas V and Starliner are probably going to be integrated for weeks before they launch, so it could be a bit of an awkward scheduling situation depending on how the range perceives the risk profile of Falcon Heavy's second flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: virnin on 02/15/2019 01:58 am
Starliner is not a DoD or Government launch.  I don't believe commercial launches can ask for the same risk avoidance as NROL.  Especially between launch sites operated by different government entities.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 02/15/2019 02:57 am
Starliner is not a DoD or Government launch.  I don't believe commercial launches can ask for the same risk avoidance as NROL.  Especially between launch sites operated by different government entities.

Demo-1 is explicitly a government launch and is permitted and certified by NASA with NASA funds. The destruction or damage of Demo-1's Starliner and Atlas V could be perceived as a direct threat to NASA's ability to provide the US assured access to the International Space Station and prevent major cost overruns, issues that are both steeped heavily in US politics, agency image, and simple pragmatism.

If the USAF saw SBIRS-4 (a ~$1.7B satellite) as valuable enough to disrupt nearby launch ops, I have no doubt that NASA/ULA/Boeing could easily make the same case for a similar range exception.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: woods170 on 02/15/2019 06:27 am
Starliner is not a DoD or Government launch.  I don't believe commercial launches can ask for the same risk avoidance as NROL.  Especially between launch sites operated by different government entities.

Demo-1 is explicitly a government launch and is permitted and certified by NASA with NASA funds. The destruction or damage of Demo-1's Starliner and Atlas V could be perceived as a direct threat to NASA's ability to provide the US assured access to the International Space Station and prevent major cost overruns, issues that are both steeped heavily in US politics, agency image, and simple pragmatism.

If the USAF saw SBIRS-4 (a ~$1.7B satellite) as valuable enough to disrupt nearby launch ops, I have no doubt that NASA/ULA/Boeing could easily make the same case for a similar range exception.

Starliner's Demo-1 is actually called OFT (Orbital Flight Test).

Crew Dragon Demo-1 is actually called DM-1 (Demonstration Mission 1).

I suggest you all refer to those test mission by their proper name. Demo-1, technically speaking, applies to neither mission. The fact that the term "Demo-1" incorrectly exists is courtesy of NASA, who managed to get DM-1 wrong, most recently in one of it's blog posts: https://blogs.nasa.gov/commercialcrew/2019/02/06/ (https://blogs.nasa.gov/commercialcrew/2019/02/06/)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: yg1968 on 02/15/2019 11:57 am
DM is an abbreviation. Demo is short for Demonstration. Neither are official names. The official name is Demonstration Mission 1.  Demo-1 is fine as a shortcut (for SpaceX's uncrewed test flight).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 02/15/2019 01:47 pm
This is the STP-2 thread.  Extended discussions of Commercial Crew Program mission names should move elsewhere.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vaporcobra on 02/20/2019 10:38 pm
Quote
Minister of Science and Technology Chen Liang-gee (陳良基) said Formosat-7 is to be launched using SpaceX’s Falcon Heavy rocket. Relevant bodies will be notified 60 days prior to the launch date once it is confirmed.
https://www.taiwannews.com.tw/en/news/3640857

Reading between the lines, a typical bureaucratic qualification like "notified no fewer than 60 days before launch" would put STP-2 NET late April.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 02/25/2019 01:45 pm
Launch is now NET June

https://twitter.com/jeff_foust/status/1100042388104466432
Quote
Fox also says the Space Environment Testbed payload, part of the Air Force STP-2 mission, is now scheduled for launch no earlier than June. It will be the second of two Falcon Heavy launches planned for this spring using the same set of boosters.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Norm38 on 03/08/2019 02:07 am
This article explains why the center core is new. Risk reduction.
https://www.nasaspaceflight.com/2019/03/falcon-heavy-starlink-headline-spacexs-manifest/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZChris13 on 03/09/2019 12:29 pm
A sensible choice, SpaceX haven't had a chance to inspect a Heavy center core post-flight yet. At least, not one that hasn't hit the water at terminal velocity.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 03/26/2019 02:49 pm
Nicky Fox, head of NASA’s heliophysics division, to National Academy of Sciences committee:

https://twitter.com/stephenclark1/status/1110557020862775301

Quote
Fox says launch of NASA’s SET-1 payload, one of many payloads on the Air Force’s STP-2 launch on Falcon Heavy, is still tracking toward a launch readiness date of no earlier than June. That follows the Falcon Heavy/Arabsat 6A launch in early April.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 03/27/2019 07:10 pm
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=91026

The ASDS and boat locations are right offshore from LZ-1, so this will be a near 3x RTLS. I wonder how visible the center core landing will be at that distance, about 37 km from the Jetty Park Pier.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ChrisGebhardt on 03/27/2019 07:34 pm
https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=91026

The ASDS and boat locations are right offshore from LZ-1, so this will be a near 3x RTLS. I wonder how visible the center core landing will be at that distance, about 37 km from the Jetty Park Pier.

37 km = 23 miles.  I think viewing at that distance might be highly dependent on time of day of the launch.  Do we the the distance off shore for the Vandy RTLS that landed on the barge late last year?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Jdeshetler on 03/27/2019 07:50 pm
Do we the the distance off shore for the Vandy RTLS that landed on the barge late last year?

the distance between SLC-4E and the drone ship location is 47.55 kilometers

https://forum.nasaspaceflight.com/index.php?topic=38551.msg1882770#msg1882770
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 03/27/2019 11:05 pm
The only way you'll be able to see the landing on the ASDS is if you're on top of the VAB or on top of the Exploration Tower in Port Canaveral. The entry and landing burns should all be visible from the normal viewing locations though.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 03/28/2019 03:14 pm
At 27 km around a nominally 6378 km radius Earth visiblity will be down to 57 meters above the ocean
If one is on a dock with eyes 3 meters above the waterline, the horizon is 6 km away.
That’s 21 km from the ASDS.
Visibility at 21 km is down to 34 meters.
My guess is that the top of the first stage sitting on the ASDS is ~53 meters above the waterline.
So the top third, 17 meters or so, should be visible from a dock on the shore like Jetty Park.
YMMV

Of course, this is the one I get the official invitation to watch, but without VIP viewing from the OBSS observation deck (I’ve been there!) there won’t be a clear view to the ocean.

edit for Orbiter:  From the roof of the VAB one could see the SpaceX logo on the ASDS.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: rpapo on 03/28/2019 09:10 pm
From the roof of the VAB one could see the SpaceX logo on the ASDS.
Unless you have eyes like a hawk, you'll need binoculars to do that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 03/28/2019 09:50 pm
From the roof of the VAB one could see the SpaceX logo on the ASDS.
Unless you have eyes like a hawk, you'll need binoculars to do that.
How very literal of you. 😊
It’s not assured that one could a actually resolve the logo through that much atmosphere, even with binoculars, but you would be well above the plane of the ASDS deck.
But the main point remains: from the coast, like the Jetty Park pier, one should be able to see all three boosters all the way down.
Do we have an estimate of the time lag between side and center booster landings?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/03/2019 07:00 pm
Not news, but confirms they did a contract mod for the reused boosters.

From written testimony of Lieutenant General David D. Thompson, USAF at recent Senate hearing:
https://www.armed-services.senate.gov/hearings/19-03-27-military-space-operations-policy-and-programs

Quote
In an effort to lean forward on reusing hardware for launch, SMC and SpaceX
completed a contract modification allowing the reuse of the Falcon Heavy side core boosters for
the Air Force’s Space Test Program-2 mission. This first mission with a re-used booster further
demonstrates our commitment to balance risk with increased responsiveness and flexibility.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: rcoppola on 04/03/2019 07:39 pm
This continues an excellent trend and I'm super enthused how supportive the AF is being. Certifying these boosters should directly help in having a certification plan in place for pre-flown Falcon 9s to be offered in future contracts.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/13/2019 08:01 pm
https://technews.tw/2019/04/08/formosat-7-apr-15th-to-usa/
Quote
The Formosa Satellites will be transported from the National Space Center to the Huayuan Company next to Taoyuan Airport on the 14th and will be shipped to the United States on the 15th. Previously released by the Space Center must be shipped to the United States 69 days prior to launch, and the estimated launch date may fall in late June.

(h/t to u/hebeguess on reddit for posting this info)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Olaf on 04/15/2019 11:50 am
https://twitter.com/taoyuanairport/status/1117675866606063616
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 04/15/2019 02:50 pm
https://technews.tw/2019/04/08/formosat-7-apr-15th-to-usa/
Quote
The Formosa Satellites will be transported from the National Space Center to the Huayuan Company next to Taoyuan Airport on the 14th and will be shipped to the United States on the 15th. Previously released by the Space Center must be shipped to the United States 69 days prior to launch, and the estimated launch date may fall in late June.

(h/t to u/hebeguess on reddit for posting this info)

I'm curious if there is a timeline here were they would push STP-2 til after DM-2. I think it's about a week for FH<->F9 pad changeover, and from what I've read, it sounds like with a FH in the hanger, they can't really stack a second vehicle.

I would assume the DM-2 is a higher priority all around, so I just ponder how far right the STP-2 payload can move before the ordering is swapped.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/15/2019 02:55 pm
It's extremely unlikely STP-2 could slip enough for DM-2 to be a concern.  The In-Flight Abort Test is what will be closer to STP-2, and I still don't really see a problem.  Those are the only two flights from 39A in the next few months.  DM-2 is still listed as NET July but I think most of us expect it to launch a bit later than that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/15/2019 03:54 pm
http://www.taipeitimes.com/News/front/archives/2019/04/15/2003713416
http://focustaiwan.tw/news/ast/201904150012.aspx
https://www.taiwannews.com.tw/en/news/3680497

Taiwanese news reports mention June 22 for launch date, I'd treat that as a NET for now.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 04/15/2019 04:04 pm
Taiwanese news reports mention June 22 for launch date, I'd treat that as a NET for now.
Sounds like it's currently slated for around the same time and from the same pad as the inflight abort (late June (http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html)). I would think SpaceX would like to get STP-2 out of the way before IFA so that it doesn't have to keep reconfiguring the TE back and forth, but that assumes pretty quick refurbishment process for the Arabsat side boosters. Will be interesting to see how it shakes out.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 04/15/2019 04:07 pm
Taiwanese news reports mention June 22 for launch date, I'd treat that as a NET for now.
Sounds like it's currently slated for around the same time and from the same pad as the inflight abort (late June (http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html)). I would think SpaceX would like to get STP-2 out of the way before IFA so that it doesn't have to keep reconfiguring the TE back and forth, but that assumes pretty quick refurbishment process for the Arabsat side boosters. Will be interesting to see how it shakes out.

I believe it's more likely IFA is in July now.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 04/15/2019 05:14 pm
Air Force says NET 19 June for STP-2.

https://twitter.com/AF_SMC/status/1117836328182267907

Quote from: AF SMC
The returned side cores from the Arabsat 6A mission will require analysis to determine reusability. Pending the condition of the side cores, the target launch date is NET Jun 19.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/15/2019 05:26 pm
I'm inclined to believe the Taiwanese date would be more current.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/15/2019 09:00 pm
https://twitter.com/StephenClark1/status/1117891234343702530
Quote
2 months out, so take this with a grain of salt. I’ve asked for clarification on the launch date from the Air Force, but from many years working with SMC, the phrasing of this tweet suggests to me STP-2’s launch is no earlier than June 2019. They typically put day before month.

I've had another person suggest the same thing to me.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 04/15/2019 09:55 pm
https://twitter.com/ChrisG_NSF/status/1117893681439051776

Quote from: Chris G
And I’ve been informed that the Air Force’s tweet is unintentionally misleading. It’s not “June 19” as stated, it’s “June 2019.” Latest NET actually comes from Formosat and is NET 22 June 2019. Still. Just about two months away! #FalconHeavy #SpaceX #STP2

To be precise: That 22 June date may be Taiwan time, therefore the launch date is NET 21 June UTC.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 04/15/2019 10:21 pm
Based on the Arabsat FH center core being lost (toppled over in rough seas), I'm guessing the decision makers for this mission feel pretty good that they insisted on a new-build FH center core.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 04/15/2019 10:56 pm
Based on the Arabsat FH center core being lost (toppled over in rough seas), I'm guessing the decision makers for this mission feel pretty good that they insisted on a new-build FH center core.

Source for "the decision makers insisted", which implies that someone at SpaceX did not want to build a new center core?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 04/15/2019 11:04 pm
Based on the Arabsat FH center core being lost (toppled over in rough seas), I'm guessing the decision makers for this mission feel pretty good that they insisted on a new-build FH center core.

Source for "the decision makers insisted", which implies that someone at SpaceX did not want to build a new center core?

What I mean is the prime customer - USAF. I can't seem to find the source for it at the moment, I could be mistaken. I will edit the post if I find it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: crandles57 on 04/15/2019 11:36 pm
Perhaps
https://www.nasaspaceflight.com/2019/03/falcon-heavy-starlink-headline-spacexs-manifest/

Quote
However, it is important to note that despite reports that all three cores from Arabsat 6A would be reused for STP-2, NASASpaceflight.com understands that the mission will in fact use a brand new center core.
...
STP-2 will then feature the second flights of B1052 and B1053 along with B1057 – a brand new center core.

The existence of a second center core makes sense, as B1055’s landing during Arabsat 6A will likely be one of SpaceX’s most challenging to date. Due to Falcon Heavy’s flight profile, the booster will reach a higher than usual velocity. Consequently, the booster will make a hot reentry and land on OCISLY nearly 1,000 kilometers downrange – making it by far the farthest recovery attempt in SpaceX’s history.

Therefore, by having a second center core for STP-2, SpaceX will eliminate the risk of a significant delay if B1055 were to be lost or require substantial refurbishment.

That isn't clear whether it was SpaceX's decision or the customer, USAF.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 04/16/2019 07:20 pm
SpaceX has put an exclusive page on their website just for this mission with descriptions of the payloads and a launch animation

www.spacex.com/stp-2

https://www.youtube.com/watch?v=FWymne93DFY
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/16/2019 08:11 pm
The video shows the deployments being:

Oculus, cubesats : 300 x 860km at 28.5 deg?

Prox-1, NPSat, OTB, GPIM, COSMIC-2 : 720 x 720km at 24 deg?

DSX : 6000 x 12000km at 43 deg?

"Propulsive passivation" I guess means they'll move it away from DSX, passivate and leave in MEO.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 04/17/2019 09:58 pm
https://twitter.com/SurreySat/status/1118500672360648704 (https://twitter.com/SurreySat/status/1118500672360648704)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 04/19/2019 11:19 am
SpaceX has put an exclusive page on their website just for this mission with descriptions of the payloads and a launch animation

www.spacex.com/stp-2

https://www.youtube.com/watch?v=FWymne93DFY

Looks like they changed the link:

https://youtu.be/qLEuCn8RT14
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 04/19/2019 04:54 pm
Questions on the video:
It ends with a "three hour coast" followed by a "propulsive passivation".
Do we know why they plan to coast that long before passivation?
They were careful to show the passivation emitting cold gas, not igniting and heating up the engine bell.
Do we know why this is labeled "propulsive"?
Can blowing down the cold propellants change the orbit appreciably?
(I ask if we know why because guessing is OK, but sourced knowledge is what I'm after.)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/19/2019 05:49 pm
They specifically say 4 upper stage engine burns, and the original contract (which has been modified many times since it was signed) called for a relight after the coast.  Can they do all of the satellite deployments with the first 3 burns?  This was probably intended to be the first long coast demo flight, but with the STP-2 delays they've already done it a few times on other flights.  More practice doesn't hurt.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 04/19/2019 06:46 pm
They specifically say 4 upper stage engine burns, and the original contract (which has been modified many times since it was signed) called for a relight after the coast.  Can they do all of the satellite deployments with the first 3 burns?  This was probably intended to be the first long coast demo flight, but with the STP-2 delays they've already done it a few times on other flights.  More practice doesn't hurt.
But they clearly show the passivation as not igniting the engine.
It looks very intentional, as they have the stage lighting three times earlier in the video.
They could have glossed over the orbital insertion.
Do we know if its a continuous burn to the initial 300 x 860 km orbit, or if they do a coast and burn?
Scattered around we do have enough data to calculate how long a burn it would take to drop the perigee of the 6,000 by 12,000 km final orbit to ~200 km, for quick decay, but it shouldn't be much.  There must be a good reason for not doing that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 04/19/2019 09:07 pm
They specifically say 4 upper stage engine burns, and the original contract (which has been modified many times since it was signed) called for a relight after the coast.  Can they do all of the satellite deployments with the first 3 burns?  This was probably intended to be the first long coast demo flight, but with the STP-2 delays they've already done it a few times on other flights.  More practice doesn't hurt.
But they clearly show the passivation as not igniting the engine.
It looks very intentional, as they have the stage lighting three times earlier in the video.
They could have glossed over the orbital insertion.

Don't treat the video as gospel. There very little to go on there, and what is there is not detailed enough.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: aviators99 on 04/20/2019 03:28 pm
One of the Facebook groups has an "event time" of 2300.  Is this the current plan?  With all of the deployments, I imagine the window is very, very small, right?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ChrisGebhardt on 04/20/2019 03:47 pm
One of the Facebook groups has an "event time" of 2300.  Is this the current plan?  With all of the deployments, I imagine the window is very, very small, right?

No daily launch windows have been announced, nor are any pending approval right now on the Eastern Range for STP-2.

Random Facebook event aside, basic rule here on NSF is that as soon as a date and time are known, we let folks know because of the immense interest and planning that people need to do to attend the launches.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 04/20/2019 03:48 pm
If it is the SpaceX facebook group, all the times there are just placeholders because Facebook requires some time for an event to be posted on the group, the launch time is currently not publicly known
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: GWR64 on 04/20/2019 05:28 pm
How comes the upper stage with the last burn from the LEO to the MEO? COSMIC-2 -> DSX  ???
Something is wrong in the animation.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 04/24/2019 01:52 pm
Satellite data; some FCC filings missing
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: soltasto on 04/24/2019 02:05 pm
Satellite data; some FCC filings missing

GPIM is from NASA so they shouldn't need any FCC permit.

The Formosat 7 satellites are from NSPO but it also is a collaboration with NOAA so maybe the NOAA side will sort it out by themselves.

I'm not quite sure about the BRICSat 2 and the PSat 2 cubesats as they should be operated by the US Naval Academy Satellite Lab that has strong ties with the government, but I have no idea about their licensing.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: GWR64 on 04/24/2019 08:42 pm
Satellite data; some FCC filings missing

Thanks,
I still think, from 720 km cirkular to 6000 x 12000 km with the last ignition,
it does not work. Something does not fit with the animation.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/24/2019 09:00 pm
Satellite data; some FCC filings missing

Thanks,
I still think, from 720 km cirkular to 6000 x 12000 km with the last ignition,
it does not work. Something does not fit with the animation.

They say they're doing four burns of the second stage.  It's not clear now if they still have to relight the engine after coast, or if that would be counted as one of the four burns.  They may be able to use two burns to reach one of the deployment orbits.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: soltasto on 04/24/2019 10:05 pm
It can be like this:

First burn (Insertion Burn): 300kmx860kmx28.5°
First payload deploy.
Second Burn -> fire the engine at the descending node while climbing to 720 km altitude, also make a slight inclination change there (not fully prograde, but also a bit radial in and normal): 720kmx720kmx24°
Second payload deploy
Now, two options:
Option 1 (More efficient, requires more time)
Third burn -> Make a burn at the Ascending node, rise the apogee to 12000km: 720kmx12000kmx24°
Fourth burn -> Make a burn at the Descending node (Also the Apogee), rise the Perigee and change the inclination (not fully prograde, also a bit anti-normal): 6000kmx12000kmx43°
DSX deploy

Option 2 (Less efficient, requires less time)
Third burn -> Make a burn at the Ascending node, rise the apogee to 6000km: 720kmx6000kmx24°
Fourth burn -> Make a burn at the Descending node (Also the Apogee), rise the Apogee and change the inclination (not fully prograde, also a bit anti-normal): 6000kmx12000kmx43°
DSX deploy
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 04/24/2019 10:28 pm
According to SpaceX website, total mission duration will be ~ 6 hours, and there will be a ~ 3 hours coast before passivation. This means that DSX will be deployed ~ 3 hours after liftoff. Would this help to select one of the two options?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: soltasto on 04/25/2019 10:01 am
Yes, we can get an approximation by getting the usual time between liftoff and SES-2 for a normal GTO mission, then adding the semi periods of the various intermediate orbits by using the obital period forumla: T/2 = pi*sqrt((a^3)/(G*M)) with a being the Semi major axis of the orbit. I would need a piece of paper to do that but I am only from mobile now so I will do it tonight if no one else does it before then!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: soltasto on 04/25/2019 04:59 pm
Alright did some math:

Liftoff to SES-2 (300km x 860km x 28.5°): 27.5 min (at least, Arabsat-6 time)
SECO-2 to SES-3 (720km x 720km x 24°): 49.5 min
Option 1:
SECO-3 to SES-4 (720km x 12000km x 24°): 119.1 min
SECO-4 to passivation (6000km x 12000km x 43°): 180 min
Mission time to DSX deploy: 196.1 min = 3.27 hours (at least)
Total mission time: 376.1 min = 6.27 hours (at least)

Option 2:
SECO-3 to SES-4 (720km x 6000km x 24°) 79.6 min
SECO-4 to passivation (6000km x 12000km x 43°) 180 min
Mission time to DSX deploy: 156.6 min = 2.61 hours (at least)
Total mission time: 336.6 min = 5.61 hours (at least)

So I would bet on the second one, assuming the FH has enough performance to do it, but would think it has.
But there isn't much difference since we only know approx times.

Adjusting the Liftoff to SES-2 time (pi/1.6 rad revolution and 300km x 860km orbit) gives me 30 min travel time instead, so almost no difference.

We either have to wait for more accurate timings or some hints from someone who knows.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 04/27/2019 06:01 am
https://twitter.com/spacex/status/1121974223566561281

Quote
Falcon Heavy center core booster completed a static fire test at our rocket development facility in McGregor, Texas ahead of its next mission → spacex.com/stp-2
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 04/29/2019 01:16 am
The DSX satellite looks pretty light.  The paper Design and Systems Engineering of AFRL’s Demonstration and Science Experiments (https://pdfs.semanticscholar.org/dc5e/7ba559de673aa7c9c798eb369534a25a252f.pdf) says it masses less than 600 kg.  This should give FH plenty of performance.  Arabsat went into a transfer orbit that required LEO+2960 m/s.  Reducing the mass from 6465 to 600 kg provides a lot more performance.  With the usual assumptions (107t fuel, 5.5 empty mass + residuals, ISP=348), about 2125 m/s more, so a total of LEO+5085 m/s available.  This should be enough to put the satellites in final orbit, and then actively dispose of the stage. So I wonder why they are not doing that?  Maybe they don't want to put the droneship out so far and stress the second stage.  Maybe the second stage cannot light 5 times?

The below calculations use the law of cosines: if you have one vector of length a m/s, and you want a vector of length b m/s at an angle of theta away, you need dv = sqrt(a^2+b^2-2*a*b*cos(theta))

So they start with a 28.5o LEO, and release the first satellites.  Then they need about 600 m/s to do a 4.5o plane change to 720x720x24o, and release the second set.

Next, assume they go to a 720x6000x24o, coast to the top, then boost to a 6000x12000x43o.  This is not the most efficient (better to do the plane change at 12000 km, and also better to do some of the plane change with each burn) but it's a worst case.  Also it's the shortest time to final satellite release, which may be preferable for reliability.

720x720 -> 720x6000, both 24o, takes 956 m/s.  (7497.5 m/s in LEO, need 8453.5 m/s)
720x6000x24o -> 6000x12000x43o takes 2264 m/s.  Going 4845.3 at top of transfer orbit, need 6205.6 at bottom of final orbit, plane change of 19o.

Now they drop of DSX in its orbit.  So far they have used 600 + 956 + 2264 = 3820 m/s after LEO.

Now (in theory) they should still have plenty of delta-V left to dispose of the stage.  At the top of a 6000x12000 orbit, speed is 4179 m/s.   To reduce this to a 0 x 12000 orbit, need to reduce the speed to 3343 m/s, or remove 836 m/s.  They should easily have this left over.

NOTE added later:  This neglects that first (orbital) burn and plane change are done with more mass, and the mass of the dispenser.   So the margin might not be there...

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/29/2019 01:26 am
The original requirements had them carrying a significant amount of ballast throughout the mission.  We really don't know the amount of ballast they may or may not be carrying now.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 04/29/2019 01:26 am
There is supposed to be 5 tons of ballast.

Quote
The LSC shall plan and execute a mission that includes the insertion orbits detailed below. The LSC shall also demonstrate a minimum of three upper stage burns and carry 5,000 kg (TBR) of LSC-provided ballast for the entire mission.

Source (https://www.fbo.gov/utils/view?id=36de6af7670d2636c8c195173dd500e1) (PDF)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/29/2019 01:42 am
There is supposed to be 5 tons of ballast.

Quote
The LSC shall plan and execute a mission that includes the insertion orbits detailed below. The LSC shall also demonstrate a minimum of three upper stage burns and carry 5,000 kg (TBR) of LSC-provided ballast for the entire mission.

Source (https://www.fbo.gov/utils/view?id=36de6af7670d2636c8c195173dd500e1) (PDF)

You might want to take note of the "TBR" there, and also there have been many changes to the requirements over the last 7 years (one of the deployment orbits is not in that requirements document).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 04/29/2019 01:32 pm
This means that the total payload mass at launch will be 7.2 tons.

Makes sense to land the center core really close to the shore (~40 kilometers downrange) since not that much performance is needed besides the four Stage 2 burns.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 04/29/2019 02:33 pm
This means that the total payload mass at launch will be 7.2 tons.

Makes sense to land the center core really close to the shore (~30 kilometers downrange) since not that much performance is needed besides the three Stage 2 burns.

There are four Stage 2 burns.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 04/29/2019 02:59 pm
Yet another possible reason for doing passivation to a graveyard orbit rather than an explicit de-orbit - maybe they need to qualify this procedure since this will be needed for direct-to-GEO missions, where there is not enough performance for an explicit de-orbit,
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Karloss12 on 04/29/2019 09:03 pm
The structural strength and natural frequency checks of the FH is hardly being tested.
I would have thought they would have gone from 6 tonnes for the previous launch to something like 12 tonnes for this launch.
And work the way up to maximum weight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OccasionalTraveller on 04/30/2019 11:31 am
The structural strength and natural frequency checks of the FH is hardly being tested.
I would have thought they would have gone from 6 tonnes for the previous launch to something like 12 tonnes for this launch.
And work the way up to maximum weight.

You can only launch the payloads that customers book launches for. Well, without adding mass simulators, but that is a waste of resources with obvious space debris/re-entry problems. SpaceX are running a business, not playing Top Trumps: they don't launch unless someone is paying. (The FH Demo excepted, where they couldn't find anyone willing to take the risk of losing their payload.)

SpaceX clearly feel that their computer models and structural tests adequately characterise the launcher's performance, they don't need to actually demonstrate the maximum capability. Not least, they don't actually have any missions on the manifest that need the full advertised capability: everything booked so far is GTO or GEO with mass probably well under 10 tonnes.

There's a good chance that the theoretical LEO capability is never actually demonstrated, that it is only ever used for higher-energy missions.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rondaz on 05/03/2019 03:49 am
SpaceX’s third Falcon Heavy launch on track as custom booster aces static fire..

By Eric Ralph Posted on May 2, 2019

https://www.teslarati.com/spacex-falcon-heavy-static-fire-third-launch/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 05/07/2019 05:41 am
Quote
Here's a surprise to brighten your day: a new #NASASocial! 🚀
 
We're opening our doors in June for you to see @SpaceX's Falcon Heavy rocket launch from @NASAKennedy in Florida. Apply to go behind the scenes, meet experts from @AFspace & much more: go.nasa.gov/2Y9ceJ8

https://twitter.com/nasasocial/status/1125476186363133952

https://www.nasa.gov/social/spacex-falcon-heavy-launch
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 05/09/2019 04:01 pm
https://twitter.com/exploreplanets/status/1126516420106276865

Quote
LightSail 2 is officially on the road to launch! Our citizen-funded solar sailing CubeSat has successfully shipped to the Air Force Research Laboratory: http://planetary.org/blogs/jason-davis/lightsail-2-integrated-prox-1.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 05/09/2019 04:04 pm

Quote
LightSail 2 is officially on the road to launch! Our citizen-funded solar sailing CubeSat has successfully shipped to the Air Force Research Laboratory: http://planetary.org/blogs/jason-davis/lightsail-2-integrated-prox-1.html

It amazes me that payloads are making their way to integration so close to launch. I get that is a benefit standardized sat interfaces, but still...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 05/10/2019 10:17 pm
But this is very much likely to move to the right as per natural and expectations, so remember what NET means when booking flights!

https://twitter.com/NASASpaceflight/status/1126966130780909568
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OnWithTheShow on 05/11/2019 10:47 pm
Air Force has officially announced June 22nd as the launch date.

http://spaceref.com/news/viewpr.html?pid=54055
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 05/12/2019 12:19 am
Air Force has officially announced June 22nd as the launch date.

http://spaceref.com/news/viewpr.html?pid=54055

And that date might be confirmed following the upcoming static fire.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: dkopacz on 05/12/2019 09:03 pm
When might more details come out as far as launch window. Thinking about traveling for this launch.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Targeteer on 05/16/2019 02:10 am
May 15, 2019
MEDIA ADVISORY M19-037

Media Invited to SpaceX Falcon Heavy Launch of Four NASA Missions

Media accreditation is open for SpaceX’s third Falcon Heavy launch, targeted for Saturday, June 22, from NASA’s Kennedy Space Center in Florida. Four unique NASA technology missions that will help improve future spacecraft design and performance are among the two dozen spacecraft aboard the U.S. Air Force Space Test Program-2 (STP-2) mission.

Members of the media who are foreign nationals and interested in covering the launch must fill out this SpaceX media accreditation form and provide a photocopy of their passport and valid visa to [email protected] by no later than 5 p.m. EDT on Tuesday, May 21. Members of the media who are U.S. citizens or permanent residents and interested in covering the launch must fill out this media accreditation form by no later than 5 p.m. EDT on Thursday, June 13.

The NASA technologies aboard this mission – including a small spacecraft, pair of CubeSats, payload and testbed of instruments – will help better equip and support the agency’s future exploration plans, including returning astronauts to the Moon in five years.

The Green Propellant Infusion Mission (GPIM) is NASA's first attempt to use a new non-toxic fuel and propulsion system in space. The technology replaces conventional chemical propulsion systems and offers simplified prelaunch processing, increased payload mass, enhanced spacecraft maneuverability, and longer mission durations. A successful demonstration of this capability on a Ball Aerospace spacecraft will benefit future missions by providing safer propellant options for spaceflight.

The Enhanced Tandem Beacon Experiment (E-TBEx) explores “bubbles” in the electrically-charged layers of Earth's upper atmosphere, which can disrupt key communications and GPS signals that we rely on down on the ground. Such bubbles currently appear and evolve unpredictably, making them difficult to characterize from the ground. Increasing our understanding of them will help us prevent the disruption of the many radio signals that pass through Earth's upper atmosphere. The two NASA CubeSats on this mission will work in concert with the six satellites of NOAA's COSMIC-2 mission. Varying orbital positions among the eight spacecraft will give scientists chances to study these bubbles from multiple angles at once. 

A new kind of atomic clock aims to let spacecraft conduct precise navigation on their own, instead of waiting for trajectory information from Earth. This versatile technology also has science and exploration applications. The Deep Space Atomic Clock can be used to study planetary gravity fields and atmospheres, or could even enable a GPS-like capability on the surface of the Moon. The technology demonstration mission, developed by NASA’s Jet Propulsion Laboratory in Pasadena, California, is the primary payload on General Atomics’ Orbital Test Bed spacecraft.

Space Environment Testbeds (SET) works in the harsh radiation of near-Earth space to gather data on the very nature of space itself, which is constantly shaped by the Sun. Energetic particles can spark sudden computer problems or memory damage in spacecraft, and degrade hardware over time. Hosted on the Air Force Research Lab’s Demonstration and Science Experiments spacecraft and equipped with a space weather monitor and three circuit board experiments, SET will study this space radiation and how it affects instruments. This information can be used to improve spacecraft design, engineering, and operations in order to protect spacecraft and the work they do from harmful radiation.

STP-2 is managed by the U.S. Air Force Space and Missile Systems Center. The Department of Defense mission will demonstrate the capabilities of the Falcon Heavy rocket while delivering satellites to multiple orbits around Earth over the course of about six hours.

To learn more about the STP-2 mission, visit:

https://www.spacex.com/stp-2

To stay updated about the NASA technology aboard this launch, visit:

www.nasa.gov/spacex
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Norm38 on 05/16/2019 02:29 pm
I'm excited for the green propellant mission.  Hopefully they get the performance they hope for.  Seeing the mess caused by the Dragon 2 mishap, getting rid of hydrazine is the way to go.
https://en.wikipedia.org/wiki/Green_Propellant_Infusion_Mission
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 05/24/2019 05:11 pm
Ben Cooper reports that this launch would be around midnigt on 22/23 June.

http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 05/29/2019 05:27 pm
Posted on the launch viewing thread:
I've got tickets to see the Falcon Heavy STP-2 launch from kickstarter (years and years ago now!) -- anyone else interested in meeting up, discussing hotel options, etc?
I suppose if there's enough interest we could set up a dedicated thread...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 05/30/2019 02:22 am
https://twitter.com/AF_SMC/status/1133886398556016640 (https://twitter.com/AF_SMC/status/1133886398556016640)

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 05/30/2019 07:35 am
Ben Cooper reports that this launch would be around midnigt on 22/23 June.

http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html

11:30 pm Eastern on June 22 - same source

(03:30 UTC on June 23)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Olaf on 05/30/2019 09:49 am
https://twitter.com/AF_SMC/status/1133889180554031104
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 05/30/2019 03:00 pm
11:30 pm Eastern on June 22 - same source

(03:30 UTC on June 23)

Just to add a +1 to this, I got the same date/time from a different, official, source a few days ago.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: StuffOfInterest on 05/31/2019 03:30 pm
How loud are the returning booster sonic booms in comparison to a close by thunder clap?  I would imagine that the people living near by won't appreciate an 11:40 PM set of booms.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: DaveS on 05/31/2019 03:34 pm
How loud are the returning booster sonic booms in comparison to a close by thunder clap?  I would imagine that the people living near by won't appreciate an 11:40 PM set of booms.
They lived with the shuttle's iconic twin sonic booms occurring.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: StuffOfInterest on 05/31/2019 04:33 pm
How loud are the returning booster sonic booms in comparison to a close by thunder clap?  I would imagine that the people living near by won't appreciate an 11:40 PM set of booms.
They lived with the shuttle's iconic twin sonic booms occurring.
True, but night landings were pretty rare and it has been far too many years since the Cape was graced with that distinctive sound.  I was just trying to get some context of how loud it is.  Wake up with your heart pounding vs. roll over and not even notice it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 06/01/2019 02:25 am
How loud are the returning booster sonic booms in comparison to a close by thunder clap?  I would imagine that the people living near by won't appreciate an 11:40 PM set of booms.
They lived with the shuttle's iconic twin sonic booms occurring.
True, but night landings were pretty rare and it has been far too many years since the Cape was graced with that distinctive sound.  I was just trying to get some context of how loud it is.  Wake up with your heart pounding vs. roll over and not even notice it.
I experienced the sonic boom of the CRS-10 booster from about 9 miles distance.
It was significant and impressive, but not astounding.
People 20 miles away in their homes won't be alarmed.
Long ago someone posted on NSF maps of the sound level contours from returning Falcon first stages. 
They were limited to the immediate area of the Cape.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/02/2019 08:52 am
https://twitter.com/exploreplanets/status/1134138853755801600 (https://twitter.com/exploreplanets/status/1134138853755801600)

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/02/2019 02:41 pm
The Lightsail Kickstarter updates are still hedging on the June 22 date:
https://www.kickstarter.com/projects/theplanetarysociety/lightsail-a-revolutionary-solar-sailing-spacecraft/posts/2523089

"I know how frustrating this is not to have more specific information. We are doing everything we can to lock down details, but we can't act until we get those details from the STP-2 mission managers and the good people at KSC VC. What we can do is commit to sharing with you everything that we can."

Any idea what's keeping KSC from making the June 22 date official?  Any chance it's still going to slip?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/02/2019 04:27 pm
Any chance it's still going to slip?

How long have you been following rocket launches now?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/02/2019 04:32 pm
Any chance it's still going to slip?

How long have you been following rocket launches now?

Ha!

The be fair, this launch seems to have a bit more wishy-washy-ness surrounding it than usual.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat on 06/02/2019 06:50 pm
Not gonna lie, watching the video preview of this launch makes me nervous. This is a super complex mission. I hope they take their time to get things right.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/03/2019 12:00 am
The one issue that had caught my attention is the LZ-1 site remediation progress prior to launch for the booster landings. The latest news that I have read is from this article'''

SpaceX cleaning up Cape Canaveral landing zone after Crew Dragon explosion
https://www.floridatoday.com/story/tech/science/space/2019/05/24/spacex-cleaning-up-cape-canaveral-landing-zone-after-crew-dragon-explosion/1227473001/ (https://www.floridatoday.com/story/tech/science/space/2019/05/24/spacex-cleaning-up-cape-canaveral-landing-zone-after-crew-dragon-explosion/1227473001/)

a few snips of the article...

"SpaceX teams continue cleanup efforts at the Cape Canaveral site where a Crew Dragon spacecraft exploded during testing in April, according to an update from the Florida Department of Environmental Protection."

"Over the last two weeks SpaceX has been completing the initial steps of cleanup, including clearing debris from the site," the department told FLORIDA TODAY via email on Wednesday. "Their next step is to begin soil sampling, which will be taking place throughout the month of June."

snip

"If all goes according to plan, the company will launch a Falcon Heavy rocket from Kennedy Space Center no earlier than June 22 with a series of Air Force and NASA payloads. The sites at Landing Zone 1 will be necessary if the company aims to recover two of its side boosters."

------

I hope this goes well. We also have a  NASA "social" in progress which should be real exciting for the participants.

Just a bit curious about this quote though as I may have misinterpreted the meaning...

Any chance it's still going to slip?

How long have you been following rocket launches now?

Ha!

The be fair, this launch seems to have a bit more wishy-washy-ness surrounding it than usual.

SpaceX and DOD appear to be following along with this being the 3rd launch of FH, as agreed upon, and progress is being made. I am therefore not sure where to place the ""wishy-washy-ness". Data from the first two FH missions required a review and the DOD is allowing "previously enjoyed" boosters for this mission. I may have missed something  entirely though.

Mission statement...

USAF Space & Missile Systems Center announces June 22 launch date for joint DOD/NASA/NOAA mission on SpaceX Falcon Heavy

http://spaceref.com/news/viewpr.html?pid=54055 (http://spaceref.com/news/viewpr.html?pid=54055)

a few snips...

"The upcoming Department of Defense’s Space Test Program-2 (STP-2) mission, carrying 24 payloads aboard a SpaceX Falcon Heavy launch vehicle, is scheduled to liftoff from the historic Launch Complex 39A at NASA’s Kennedy Space Center on June 22, 2019."

snip

"STP-2 will mark the first-ever DOD launch using a SpaceX Falcon Heavy launch vehicle, as well as the first-ever DOD mission with re-used rocket flight hardware. SpaceX plans to reuse the two Falcon Heavy side boosters recently flown on the successful Arabsat-6A mission.  It is among the most challenging launches in SpaceX history, with four separate upper-stage engine burns, three separate deployment orbits, and a final propulsive passivation maneuver during a total mission duration of over six hours."

snip

"The STP-2 mission will also provide the U.S. Air Force with insight into the SpaceX booster recovery and refurbishment process, enabling future National Security Space Launch missions on SpaceX launch vehicles using previously flown boosters."

-------------------

This will be a difficult mission but it appears SpaceX have demonstrated most of the procedures in prior launches and are as well equipped as any provider when it comes to spacecraft manoeuvring. There are always risks but I feel that they have a handle on this. This may shift to the right but it will be close enough to be reasonable, I would think.

Just my 2 cents...please correct if i have made an error or two...Thanx.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 06/03/2019 09:38 am
https://twitter.com/AF_SMC/status/1133886398556016640 (https://twitter.com/AF_SMC/status/1133886398556016640)
http://spaceref.com/news/viewpr.html?pid=54055 (http://spaceref.com/news/viewpr.html?pid=54055)

a few snips...

"The upcoming Department of Defense’s Space Test Program-2 (STP-2) mission, carrying 24 payloads aboard a SpaceX Falcon Heavy launch vehicle, is scheduled to liftoff from the historic Launch Complex 39A at NASA’s Kennedy Space Center on June 22, 2019."

Whoops - we have a new payload #24 here. The count on https://www.spacex.com/stp-2 also has been updated from 23 to 24. What could this be?

20 payloads listed on SpaceX site: DSX, Cosmic-2 (x 6), GPIM, Oculus, OTB, NPSAT, Prox-1, E-TBEx (x 2), LEO, Stangsat, PSAT, TEPCE (x 2), Lightsail-B

3 payloads expected to launch with STP-2: Armadillo, Bricsat-2, Falconsat-7

1 unknown
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Zed_Noir on 06/03/2019 12:31 pm
....
http://spaceref.com/news/viewpr.html?pid=54055 (http://spaceref.com/news/viewpr.html?pid=54055)

a few snips...

"The upcoming Department of Defense’s Space Test Program-2 (STP-2) mission, carrying 24 payloads aboard a SpaceX Falcon Heavy launch vehicle, is scheduled to liftoff from the historic Launch Complex 39A at NASA’s Kennedy Space Center on June 22, 2019."

Whoops - we have a new payload #24 here. The count on https://www.spacex.com/stp-2 also has been updated from 23 to 24. What could this be?

20 payloads listed on SpaceX site: DSX, Cosmic-2 (x 6), GPIM, Oculus, OTB, NPSAT, Prox-1, E-TBEx (x 2), LEO, Stangsat, PSAT, TEPCE (x 2), Lightsail-B

3 payloads expected to launch with STP-2: Armadillo, Bricsat-2, Falconsat-7

1 unknown

My WAG  :)
1 unknown = 1 Starlink ver 0.9 comsat drop off after the first SECO.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OnWithTheShow on 06/03/2019 01:05 pm
There is the Celestis space burial payload but I think that is manifested as part of the OTB sat.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 06/03/2019 03:17 pm
Ben Cooper reports that this launch would be around midnigt on 22/23 June.

http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html

11:30 pm Eastern on June 22 - same source

(03:30 UTC on June 23)

NASA confirms time Ben Cooper reported, so first night time FH launch:

https://twitter.com/jeff_foust/status/1135564925546508291

Quote
The upcoming STP-2 Falcon Heavy launch will be the first night launch of that rocket; a NASA media advisory lists the scheduled liftoff time as 11:30 pm EDT June 22.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 06/03/2019 03:52 pm
Quote
June 3, 2019
MEDIA ADVISORY M19-048
Media Briefing Highlights NASA Tech on Next SpaceX Falcon Heavy Launch

NASA is sending four technology missions that will help improve future spacecraft design and performance into space on the next SpaceX Falcon Heavy rocket launch. Experts will discuss these technologies, and how they complement NASA’s Moon to Mars exploration plans, during a media teleconference Monday, June 10 at 1 p.m. EDT.

Audio of the teleconference will be streamed live online at:

https://www.nasa.gov/live

Participants in the briefing will be:

    Jim Reuter, acting associate administrator of NASA’s Space Technology Mission Directorate, will discuss how technology drives exploration to the Moon and beyond.
    Todd Ely, principal investigator for the Deep Space Atomic Clock at NASA’s Jet Propulsion Laboratory, will discuss how to advance exploration in deep space with a miniaturized, ultra-precise, mercury-ion atomic clock that is orders of magnitude more stable than today’s best navigation clocks.
    Don Cornwell, director of the Advanced Communications and Navigation Division of NASA’s Space Communications and Navigation program, will discuss how a more stable, space-based atomic clock could benefit future missions to the Moon and Mars.
    Christopher McLean, principal investigator for NASA’s Green Propellant Infusion Mission (GPIM) at Ball Aerospace, will discuss the demonstration of a green alternative to conventional chemical propulsion systems for next-generation launch vehicles and spacecraft.
    Joe Cassady, executive director for space at Aerojet Rocketdyne, will discuss the five thrusters and propulsion system aboard GPIM.
    Nicola Fox, director of the Heliophysics Division of NASA’s Science Mission Directorate, will discuss Space Environment Testbeds and the importance of protecting satellites from space radiation.
    Richard Doe, payload program manager for the Enhanced Tandem Beacon Experiment at SRI International, will discuss how a pair of NASA CubeSats will work with six satellites of the National Oceanographic and Atmospheric Administration’s (NOAA’s) COSMIC-2 mission to study disruptions of signals that pass through Earth’s upper atmosphere.

To participate in the teleconference, media must contact Clare Skelly at 202-358-4273 or [email protected] by 10 a.m. June 10. Media questions may be submitted on Twitter during the teleconference using the hashtag #askNASA.

NASA’s four missions will share a ride on the Falcon Heavy with about 20 satellites from government and research institutions that make up the Department of Defense’s Space Test Program-2 (STP-2) mission. SpaceX and the U.S. Air Force Space and Missile Systems Center, which manages STP-2, are targeting 11:30 p.m. Saturday, June 22, for launch from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

Charged with returning astronauts to the Moon within five years, NASA’s Artemis lunar exploration plans are based on a two-phase approach: the first is focused on speed – landing astronauts on the Moon by 2024 – while the second will establish a sustained human presence on and around the Moon by 2028. We will use what we learn on the Moon to prepare to send astronauts to Mars. The technology missions on this launch will advance a variety of future exploration missions.

For more information about NASA’s Moon to Mars exploration plans, visit:

https://www.nasa.gov/moontomars

For more information about the NASA technologies aboard this launch, visit:

https://www.nasa.gov/spacex

-end-

https://www.nasa.gov/press-release/media-briefing-highlights-nasa-tech-on-next-spacex-falcon-heavy-launch/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/03/2019 08:45 pm
The one issue that had caught my attention is the LZ-1 site remediation progress prior to launch for the booster landings. The latest news that I have read is from this article'''

If they are just onto soil remediation, that usually involves digging up soil, sending it to a special landfill or processor, and replacing it with clean soil - although I don't know any specifics of what they are doing.

I would expect that they can resume some/most pad operations if that is where they are. Soil remediation is more about returning the site to its baseline state rather than an imminent risk to personal or the environment, and I would think they would just schedule around operations. Just don't eat the dirt.


Just a bit curious about this quote though as I may have misinterpreted the meaning...

Ha!

The be fair, this launch seems to have a bit more wishy-washy-ness surrounding it than usual.

Sorry, that was a poor statement/wording. It feels like there has been more than the usual amount of unofficial uncertainty around this launch date, and pretty slow to make a launch window public officially. That very well just may be me, since I am paying more attention to this launch than usual.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/05/2019 12:50 am
https://twitter.com/AF_SMC/status/1136065718250643456
Quote
SpaceX's Falcon Heavy center core, powering SMC's STP-2 mission, arrived near Launch Complex-39A in Florida over the weekend! This hardware will return to SpaceX's Autonomous Spaceport Drone Ship, "Of Course I Still Love You" in the Atlantic. Visit: http://www.spacex.com/stp-2
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/05/2019 03:56 pm
GPIM has a passenger:
0470-EX-CN-2019

Quote
Iridium Satellite LLC (“Iridium”) is a limited liability company with
headquarters in McLean, VA. Iridium seeks experimental authority to add the Air
Force Institute of Technology’s (“AFIT”) Space Object Self-Tracker (“SOS”) CubeSat as a
point of communication, since Iridium’s Part 25 space station license does not cover
space-to-space communications.

A single Iridium modem model 9602 will be installed on the AFIT SOS, which is
scheduled to launch as a payload on NASA’s Green Propellant Infusion Mission
(“GPIM”) satellite on June 22, 2019. AFIT seeks to develop an identification and
precision tracking capability for future space situational awareness architectures and a
method for accurately estimating orbits using GPS and Low Earth Orbit satellites.

Iridium requests an experimental license for 18 months, from July 22, 2019, to
January 22, 2021. This time period reflects the 12-month scheduled duration of the
mission plus six months to account for any possible launch or other technical delays
common to spacecraft missions.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 06/06/2019 07:39 am
Press release about the DSAC payload.

Five Things to Know about NASA's Deep Space Atomic Clock (https://www.jpl.nasa.gov/news/news.php?feature=7415)

NASA is sending a new technology to space on June 22 that will change the way we navigate our spacecraft - even how we send astronauts to Mars and beyond. Built by NASA's Jet Propulsion Laboratory in Pasadena, California, the Deep Space Atomic Clock is a technology demonstration that will help spacecraft navigate autonomously through deep space. No larger than a toaster oven, the instrument will be tested in Earth orbit for one year, with the goal of being ready for future missions to other worlds.

Here are five key facts to know about NASA's Deep Space Atomic Clock:

It works a lot like GPS

The Deep Space Atomic Clock is a sibling of the atomic clocks you interact with every day on your smart phone. Atomic clocks aboard satellites enable your phone's GPS application to get you from point A to point B by calculating where you are on Earth, based on the time it takes the signal to travel from the satellite to your phone.

But spacecraft don't have GPS to help them find their way in deep space; instead, navigation teams rely on atomic clocks on Earth to determine location data. The farther we travel from Earth, the longer this communication takes. The Deep Space Atomic Clock is the first atomic clock designed to fly onboard a spacecraft that goes beyond Earth's orbit, dramatically improving the process.

It will help our spacecraft navigate autonomously

Today, we navigate in deep space by using giant antennas on Earth to send signals to spacecraft, which then send those signals back to Earth. Atomic clocks on Earth measure the time it takes a signal to make this two-way journey. Only then can human navigators on Earth use large antennas to tell the spacecraft where it is and where to go.

If we want humans to explore the solar system, we need a better, faster way for the astronauts aboard a spacecraft to know where they are, ideally without needing to send signals back to Earth. A Deep Space Atomic Clock on a spacecraft would allow it to receive a signal from Earth and determine its location immediately using an onboard navigation system.

It loses only 1 second in 9 million years

Any atomic clock has to be incredibly precise to be used for this kind of navigation: A clock that is off by even a single second could mean the difference between landing on Mars and missing it by miles. In ground tests, the Deep Space Atomic Clock proved to be up to 50 times more stable than the atomic clocks on GPS satellites. If the mission can prove this stability in space, it will be one of the most precise clocks in the universe.

It keeps accurate time using mercury ions

Your wristwatch and atomic clocks keep time in similar ways: by measuring the vibrations of a quartz crystal. An electrical pulse is sent through the quartz so that it vibrates steadily. This continuous vibration acts like the pendulum of a grandfather clock, ticking off how much time has passed. But a wristwatch can easily drift off track by seconds to minutes over a given period.

An atomic clock uses atoms to help maintain high precision in its measurements of the quartz vibrations. The length of a second is measured by the frequency of light released by specific atoms, which is same throughout the universe. But atoms in current clocks can be sensitive to external magnetic fields and temperature changes. The Deep Space Atomic Clock uses mercury ions - fewer than the amount typically found in two cans of tuna fish - that are contained in electromagnetic traps. Using an internal device to control the ions makes them less vulnerable to external forces.

It will launch on a SpaceX Falcon Heavy rocket

The Deep Space Atomic Clock will fly on the Orbital Test Bed satellite, which launches on the SpaceX Falcon Heavy rocket with around two dozen other satellites from government, military and research institutions. The launch is targeted for June 22, 2019, at 8:30 p.m. PDT (11:30 p.m. EDT) from NASA's Kennedy Space Center in Florida and will be live-streamed here:

https://www.nasa.gov/live

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/07/2019 04:49 pm
https://twitter.com/StephenClark1/status/1137038154899349504
Quote
USAF Lt. Col. Ryan Rose: Currently looking at no earlier than June 24 for Falcon Heavy launch with the STP-2 rideshare mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 06/07/2019 05:47 pm
https://twitter.com/emrekelly/status/1137042334401671168

Quote
Same launch time: 2330 ET / 0330 UTC +1.

Edit to add: more time needed for payload integration

https://twitter.com/ken_kremer/status/1137054280387612673

Quote
The @usairforce just confirmed 2 day launch delay for @SpaceX #FalconHeavy to NET Jun 24 from Jun 22 for #STP2 mission.  More time needed to integrate the 24 satellites.Window still opens 1130 PM for 1st night launch of 3core FH. All 3 boosters to be recovered including 2 by land
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Zed_Noir on 06/07/2019 07:35 pm
Shouldn't the launch be on June 25th in UTC time if the launch time is 23h30 ET (11:30 PM) on June 24th?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/10/2019 01:01 pm
reminder...

https://twitter.com/NASA_Technology/status/1138056032838651904 (https://twitter.com/NASA_Technology/status/1138056032838651904)

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rondaz on 06/10/2019 04:12 pm
SpaceX and DoD Targeting June 24 for Falcon Heavy Launch

Sarah Loff Posted on June 10, 2019

SpaceX and the Department of Defense are targeting no earlier than Monday, June 24 at 11:30 p.m. EDT to launch the U.S. Air Force Space and Missile Systems Center’s Space Test Program-2 (STP-2) mission. A Falcon Heavy rocket will lift off from Launch Complex 39A at NASA’s Kennedy Space Center in Florida with about two dozen satellites aboard, including four NASA missions. The NASA technology demonstrations and science missions will help improve future spacecraft design and performance.

Learn more about the exciting NASA space tech launching on the Falcon Heavy later this month:

Deep Space Atomic Clock – a navigation payload hosted on General Atomics Orbital Test Bed satellite

Green Propellant Infusion Mission – a small satellite that will demonstrate a non-toxic fuel and propulsion system

Space Environment Testbeds – instruments hosted on the Air Force Research Lab’s Demonstration and Science

Experiments spacecraftto study how to protect satellites in space

Enhanced Tandem Beacon Experiment – twin CubeSats to study disruptions of signals that pass-through Earth’s upper atmosphere

https://blogs.nasa.gov/spacex/2019/06/10/spacex-and-dod-targeting-june-24-for-falcon-heavy-launch/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Chris Bergin on 06/10/2019 09:46 pm
FEATURE ARTICLE: NASA highlights payloads on next Falcon Heavy; LZ-1 cleared for normal operations -

https://www.nasaspaceflight.com/2019/06/nasa-payloads-next-falcon-heavy-lz-1/

By Chris Gebhardt

https://twitter.com/NASASpaceflight/status/1138196953412583424
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ChrisC on 06/11/2019 12:12 pm
We know that the launch window opens at 11:30pm local time, but do we know how long that window is?  5 minutes? 2 hours? 4 hours?  I suspect "hours" but am wondering if we know for sure yet.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 06/11/2019 12:14 pm
We know that the launch window opens at 11:30pm local time, but do we know how long that window is?  5 minutes? 2 hours? 4 hours?  I suspect "hours" but am wondering if we know for sure yet.
4 hours
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: yoram on 06/11/2019 10:28 pm
Looking over the list of payloads, none sounds very heavy. A lot of them are cubesats. Is there some payload that is much heavier than the others? How much of the capacity of the FH is actually used?

Maybe that was already discussed, don't have time to dig through the whole thread.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/11/2019 10:34 pm
Looking over the list of payloads, none sounds very heavy. A lot of them are cubesats. Is there some payload that is much heavier than the others? How much of the capacity of the FH is actually used?

Maybe that was already discussed, don't have time to dig through the whole thread.

Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 06/11/2019 11:22 pm
Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.
Originally, the plan was to also include 5 tons of ballast, but I'm guessing that changed, considering the center core is able to RTLS on this launch.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/12/2019 12:45 am
Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.
Originally, the plan was to also include 5 tons of ballast, but I'm guessing that changed, considering the center core is able to RTLS on this launch.

That guess of 7 tons would include the ballast.  We don't actually know what the payload mass is.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: smoliarm on 06/12/2019 01:14 pm
Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.
Originally, the plan was to also include 5 tons of ballast, but I'm guessing that changed, considering the center core is able to RTLS on this launch.

That guess of 7 tons would include the ballast.  We don't actually know what the payload mass is.

Well, we do know - approximately, see attachment.
What we don't know - if the ballast is there  ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 06/12/2019 10:08 pm
Total payload mass is a bit over 7 tons. They’re doing this as an Air Force test flight and this is an opportunity to show how a Falcon 9 second stage can maneuver to four orbits in one mission.
Originally, the plan was to also include 5 tons of ballast, but I'm guessing that changed, considering the center core is able to RTLS on this launch.

That guess of 7 tons would include the ballast.  We don't actually know what the payload mass is.

Well, we do know - approximately, see attachment.
What we don't know - if the ballast is there  ;)
Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: PM3 on 06/12/2019 10:38 pm
Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 06/13/2019 05:50 am
Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.
Then why does USAF and the permit state it as a CubeSat unless GPIM also has an SOS payload or there is an error in the permit text.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gamesyns on 06/13/2019 05:50 pm
Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/13/2019 06:07 pm
Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.
Then why does USAF and the permit state it as a CubeSat unless GPIM also has an SOS payload or there is an error in the permit text.

I saw another permit the other day from Globalstar for communications with the Ubiquitilink "cubesat" on the next Cygnus mission, pretty sure that's just equipment mounted to the outside of the Cygnus.  ¯\_(ツ)_/¯
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: watermod on 06/13/2019 06:57 pm
As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: pb2000 on 06/13/2019 07:24 pm
As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?
One does not simply bolt a mothballed spacecraft to the top of a rocket (unless it contains the one ring and is a sub-orbital express to mount doom).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 06/13/2019 07:52 pm
As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?

There aren't many 5-tonne military spacecraft that unexpectedly find themselves without budget for a ride to space. Building a spacecraft that size is expensive.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/13/2019 08:34 pm
Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

It's weird they move the fairing with the payload to the HIF before the static fire, that's usually done after the static fire. I guess it's to save some time. If they have the payloads ready then no need to wait.

Edit: Wait, wait. That fairing... it has no logo, it is also not the half with the US flag.
O . o
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat on 06/14/2019 03:02 am
Missing GPIM's AFIT-SOS rideshare CubeSat from USAF on spreadsheet (see several posts back).

That is included in the 180 kg GPIM payload mass.

https://space.skyrocket.de/doc_sdat/gpim.htm
http://www.coloradospacenews.com/ball-aerospace-green-propellant-infusion-mission-to-host-three-dod-space-experiments/

I don't think it is a real cubesat, but it rather will be firmly integrated with GPIM.

https://scholar.afit.edu/cgi/viewcontent.cgi?article=1429&context=etd

Image of SOS from the above document is appended.
Then why does USAF and the permit state it as a CubeSat unless GPIM also has an SOS payload or there is an error in the permit text.

I saw another permit the other day from Globalstar for communications with the Ubiquitilink "cubesat" on the next Cygnus mission, pretty sure that's just equipment mounted to the outside of the Cygnus.  ¯\_(ツ)_/¯
According to Spaceflightnow, yeah. https://spaceflightnow.com/2019/02/08/cygnus-ng10-departure/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: jjyach on 06/14/2019 04:03 pm
Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

It's weird they move the fairing with the payload to the HIF before the static fire, that's usually done after the static fire. I guess it's to save some time. If they have the payloads ready then no need to wait.

Edit: Wait, wait. That fairing... it has no logo, it is also not the half with the US flag.
O . o

Has encapsulation even happened yet? The fairing has to be empty and they are getting ready to roll out to the encapsulation site using the payload transporter.  Current time before launch fits that scenario and they won't want the payload around until around SF.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: yoram on 06/14/2019 04:31 pm
As a taxpayer I have a simple question to ask...
Instead of ballast doesn't the Air Force have some sat that lost a ride in some budget battle and they just could lob into space because "Why Not?" ?

There aren't many 5-tonne military spacecraft that unexpectedly find themselves without budget for a ride to space. Building a spacecraft that size is expensive.

If the second stage tank has enough capacity they could also in theory carried more fuel, don't deorbit it, and use it as in orbit fuel tank for some future mission (similar to ULA distributed launch). Of course that would have needed significant technology development for storage and docking. But since the mission was delayed by ~5 years maybe there would have been enough time to do so.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/14/2019 05:28 pm
KSC just put launch viewing tickets on sale. That seems to indicate a level of confidence in the current launch date.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/14/2019 06:09 pm
Here is a photo of STP-2 in the HIF from this Monday.

https://www.flickr.com/photos/181996126@N04/48053492057/in/album-72157709059314903/

Looks like the Fairing just arrived earlier in the day.

It's weird they move the fairing with the payload to the HIF before the static fire, that's usually done after the static fire. I guess it's to save some time. If they have the payloads ready then no need to wait.

Edit: Wait, wait. That fairing... it has no logo, it is also not the half with the US flag.
O . o

Has encapsulation even happened yet? The fairing has to be empty and they are getting ready to roll out to the encapsulation site using the payload transporter.  Current time before launch fits that scenario and they won't want the payload around until around SF.

That's what I was wondering. A fairing with nothing painted on it on the HIF this early before the launch... I can only think they may be doing fairing re-rad tests but I certainly don't know if they are done in the HIF or elsewhere at the Cape. They must have a reason why that fairing is inside there.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Mandella on 06/14/2019 07:49 pm
KSC just put launch viewing tickets on sale. That seems to indicate a level of confidence in the current launch date.

Not much confidence. The tickets are good for whenever the launch happens -- unless of course there is a scrub the day of, in which case there are no refunds.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/14/2019 09:39 pm
KSC just put launch viewing tickets on sale. That seems to indicate a level of confidence in the current launch date.

Not much confidence. The tickets are good for whenever the launch happens -- unless of course there is a scrub the day of, in which case there are no refunds.
Yes, but historically KSC doesn't put them on sale until the date is nailed down.  Scrubs happen, of course, as do unexpected delays.  But we're getting closer to launch and this is just one more small sign things are still on the expected schedule.  Don't make too much of it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rondaz on 06/15/2019 01:04 pm
A NASA Atomic Clock on SpaceX's Next Falcon Heavy Will Pioneer Mars Travel Tech..

By Meghan Bartels 17 hours ago 6/14/2019

https://www.space.com/nasa-deep-space-atomic-clock-on-falcon-heavy-stp-2.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 06/18/2019 06:26 am
 NASA Prepares to Launch Twin Satellites to Study Signal Disruption From Space (https://www.nasa.gov/feature/goddard/2019/nasa-prepares-to-launch-twin-satellites-to-study-signal-disruption-from-space)

NASA's twin E-TBEx CubeSats — short for Enhanced Tandem Beacon Experiment — are scheduled to launch in June 2019 aboard the Department of Defense's Space Test Program-2 launch. The launch includes a total of 24 satellites from government and research institutions. They will launch aboard a SpaceX Falcon Heavy from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

The E-TBEx CubeSats focus on how radio signals that pass through Earth's upper atmosphere can be distorted by structured bubbles in this region, called the ionosphere. Especially problematic over the equator, these distortions can interfere with military and airline communications as well as GPS signals. The more we can learn about how these bubbles evolve, the more we can mitigate those problems — but right now, scientists can't predict when these bubbles will form or how they'll change over time.

"These bubbles are difficult to study from the ground," said Rick Doe, payload program manager for the E-TBEx mission at SRI International in Menlo Park, California. "If you see the bubbles start to form, they then move. We're studying the evolution of these features before they begin to distort the radio waves going through the ionosphere to better understand the underlying physics."

The ionosphere is the part of Earth's upper atmosphere where particles are ionized — meaning they're separated out into a sea of positive and negative particles, called plasma. The plasma of the ionosphere is mixed in with neutral gases, like the air we breathe, so Earth's upper atmosphere — and the bubbles that form there — respond to a complicated mix of factors.

Because its particles have electric charge, the plasma in this region responds to electric and magnetic fields. This makes the ionosphere responsive to space weather: conditions in space, including changing electric and magnetic fields, often influenced by the Sun's activity. Scientists also think that pressure waves launched by large storm systems can propagate up into the upper atmosphere, creating winds that shape how the bubbles move and change. This means the ionosphere — and the bubbles — are shaped by terrestrial weather and space weather alike.

The E-TBEx CubeSats send radio beacon signals at three frequencies — close to those used by communications and GPS satellites — to receiving stations on the ground, at which point scientists can detect minute changes in the signals' phase or amplitude. Those disruptions can then be mapped back to the region of the ionosphere through which they passed, giving scientists information about just how these bubbles form and evolve.

"All signals are created at the same time — with the same phase — so you can tell how they get distorted in passing through the bubbles," said Doe. "Then, by looking at the distortions, you can back out information about the amount of roughness and the density in the bubbles."

The data produced by the twin CubeSats is complemented by similar beacons onboard NOAA's six COSMIC-2 satellites. Like the E-TBEx CubeSats, the COSMIC-2 beacons send signals at three frequencies — slightly different than those used by E-TBEx — to receiving stations on the ground. The combination of measurements from all eight satellites will give scientists chances to study some of these bubbles from multiple angles at the same time.

E-TBEx's beacon was built by a team at SRI International, which also designed and fabricated the beacons on COMSIC-2. The E-TBEx CubeSats were developed with Michigan Exploration Lab at the University of Michigan in Ann Arbor. The design, fabrication, integration and testing was carried out mostly by teams of undergraduate and graduate students.

"Building and testing E-TBEx was pretty complex because of the number of deployable parts," said James Cutler, an aerospace engineering professor at University of Michigan who led the student teams that worked on E-TBEx. "The payload is essentially a flying radio station, so we have five antennas to deploy — four with two segments each — and, also, four solar panels."

What scientists learn from E-TBEx could help develop strategies to avoid signal distortion — for instance, allowing airlines to choose a frequency less susceptible to disruption, or letting the military delay a key operation until a potentially disruptive ionospheric bubble has passed.

STP-2 is managed by the U.S. Air Force Space and Missile Systems Center. The Department of Defense mission will demonstrate the capabilities of the Falcon Heavy rocket while delivering satellites to multiple orbits around Earth over the course of about six hours. These satellites include three additional NASA projects to improve future spacecraft design and performance.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/18/2019 03:34 pm
https://twitter.com/StephenClark1/status/1140996040876863488
Quote
SpaceX’s drone ship is heading for a landing zone hundreds of miles off the Florida coast, multiple sources say. No center core landing close to shore, as suggested in an FCC filing earlier this year.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: intelati on 06/18/2019 04:06 pm
Quote
SpaceX’s drone ship is heading for a landing zone hundreds of miles off the Florida coast, multiple sources say. No center core landing close to shore, as suggested in an FCC filing earlier this year.

Try 2.0 Now with improved Roomba!

Edit: remove Twitter embed
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/18/2019 06:44 pm
Why are they taking the drone ship 1,000 km out to sea again? Let me know if any of the following factors are true or false.

They want to try to do the hottest reentry for the center core again and grab the engine base properly.

They want to give more performance for the upper stage to use for the four burns needed to complete the mission. Therefore, they will not position the drone ship 39 km downrange.

They want to do it just because.


Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 06/18/2019 07:11 pm
Maybe they decided to add more ballast to show off the payload capability (or test something)?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Norm38 on 06/18/2019 08:19 pm
I would guess upper stage performance.  They can use fuel as ballast.  And they can demonstrate extra performance with a longer disposal burn if they don't end up needing the fuel for the mission.
I don't know why they'd put extra performance anywhere except in orbit where it belongs.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/18/2019 09:44 pm
Updated FCC filing for STP-2 recovery: 1112-EX-ST-2019 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=93066&RequestTimeout=1000)

North  27  56  52   West  68  0  55   Autonomous Drone Ship

For those of you that might want to know the distance, that's 1234km from LC-39A (kinda funny the distance is 1234). That'll break the previous record of furthest landing of a Falcon booster by at least 300km.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/18/2019 10:07 pm
https://twitter.com/AF_SMC/status/1141099481628364808
Quote
The 3700 kg Integrated Payload Stack (IPS) for #STP2 has been completed! Have a look before it blasts off on the first #DoD Falcon Heavy launch! #SMC #SpaceStartsHere

So would the Integrated Payload Stack be the full mass?  It sounds like it should be.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Elthiryel on 06/18/2019 10:14 pm
If that's right, it means no ballast and around 800-900 kg for adapters/dispensers according to mass data provided by Gunter's Space Page.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/18/2019 10:17 pm
It looks like they ditched one of the ESPA rings and mounted a couple of the COSMIC-2 sats to DSX?  (Either that or the perspective is just confusing me.)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/18/2019 10:17 pm
Is the FCC license for the original drone ship position still available to download? I don’t see the coordinates in Raul’s SpaceX Map, and I was wanting to input those coordinates in my Google Earth files.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/18/2019 10:19 pm
Is the FCC license for the original drone ship position still available to download? I don’t see the coordinates in Raul’s SpaceX Map, and I was wanting to input those coordinates in my Google Earth files.

The original was 0546-EX-ST-2019 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=91026&RequestTimeout=1000)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/18/2019 10:26 pm
Is the FCC license for the original drone ship position still available to download? I don’t see the coordinates in Raul’s SpaceX Map, and I was wanting to input those coordinates in my Google Earth files.

The original was 0546-EX-ST-2019 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=91026&RequestTimeout=1000)

Thanks for that, but before Raul deleted his marker of where the drone ship was gonna be, I saw different coordinates than the ones on the FCC.

Basically, I just calculated the distance from SLC-40 to the coordinates on the FCC, and it was 35 kilometers downrange. For Raul’s coordinates, I remember doing the distance calculation, which was 40 kilometers downrange. Where do those other coordinates come from?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/18/2019 10:58 pm
Is the FCC license for the original drone ship position still available to download? I don’t see the coordinates in Raul’s SpaceX Map, and I was wanting to input those coordinates in my Google Earth files.

The original was 0546-EX-ST-2019 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=91026&RequestTimeout=1000)

Thanks for that, but before Raul deleted his marker of where the drone ship was gonna be, I saw different coordinates than the ones on the FCC.

Basically, I just calculated the distance from SLC-40 to the coordinates on the FCC, and it was 35 kilometers downrange. For Raul’s coordinates, I remember doing the distance calculation, which was 40 kilometers downrange. Where do those other coordinates come from?

Remember the mission is launching from LC-39A not SLC-40, that 5km difference may be due to that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: jimothytones on 06/18/2019 11:10 pm
Any weather folks know anything about that cyclone to the north of the LZ?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kabloona on 06/18/2019 11:18 pm
Any weather folks know anything about that cyclone to the north of the LZ?

Apparently no concern through next week.

https://www.accuweather.com/en/hurricane/atlantic

The windy.com model shows the circulation being pushed east gradually, with essentially no pressure drop in the eye, which is forecast to remain over 30 in Hg, and winds around 10 kts in the landing zone in early/midweek, so it looks quite good actually.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/19/2019 12:22 am
Is the FCC license for the original drone ship position still available to download? I don’t see the coordinates in Raul’s SpaceX Map, and I was wanting to input those coordinates in my Google Earth files.

The original was 0546-EX-ST-2019 (https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=91026&RequestTimeout=1000)

Thanks for that, but before Raul deleted his marker of where the drone ship was gonna be, I saw different coordinates than the ones on the FCC.

Basically, I just calculated the distance from SLC-40 to the coordinates on the FCC, and it was 35 kilometers downrange. For Raul’s coordinates, I remember doing the distance calculation, which was 40 kilometers downrange. Where do those other coordinates come from?

Remember the mission is launching from LC-39A not SLC-40, that 5km difference may be due to that.

Sorry. Wasn't thinking about the actual launch pad.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 06/19/2019 12:58 am
Any weather folks know anything about that cyclone to the north of the LZ?

Not sure what that's about, there's no active tropical storms in the area. That might just be a leftover from TS Andrea a few weeks ago.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/19/2019 02:03 am
https://twitter.com/StephenClark1/status/1141145678627971074
Quote
USAF official confirms no ballast, approximate total value of the mission (including spacecraft and launch services) roughly $750 million.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 06/19/2019 05:29 am
It looks like they ditched one of the ESPA rings and mounted a couple of the COSMIC-2 sats to DSX?  (Either that or the perspective is just confusing me.)

I don't think so. I guess, the perspective from below gives this illusion. The ESPA, which is integral part of the DSX satellite is too small to accommodate the COSMIC-2 satellites.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/19/2019 11:05 am
https://twitter.com/spaceflightnow/status/1141286545334382592

Is there a fairing attached here? And maybe this will sound stupid, but could it be a "dummy" fairing, with nothing in it? Remember the other day we saw a fairing without markings on it in the HIF?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FutureSpaceTourist on 06/19/2019 11:43 am
Eric Ralph discusses various possible reasons for centre core recovery being so far downrange:

Quote
A SpaceX surprise: Falcon Heavy booster landing to smash distance record
By Eric Ralph
Posted on June 19, 2019

In an unexpected last-second change, SpaceX has moved Falcon Heavy Flight 3’s center core landing on drone ship Of Course I Still Love You (OCISLY) from 40 km to more than 1240 km (770 mi) off the coast of Florida.

https://www.teslarati.com/spacex-surprise-falcon-heavy-booster-landing-distance-record/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: su27k on 06/19/2019 12:00 pm
https://twitter.com/spaceflightnow/status/1141286545334382592

Is there a fairing attached here? And maybe this will sound stupid, but could it be a "dummy" fairing, with nothing in it? Remember the other day we saw a fairing without markings on it in the HIF?

That would be my guess, one of the benefits of having some used fairing lying around.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/19/2019 12:04 pm
Yes, I think there's no payload inside and  it's just a dummy fairing. It might be a pair of flight-proven fairing halves and they put them on it to test the loads during integration, erection on the pad and the static fire and things like that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ketivab on 06/19/2019 12:12 pm
Yes, I think there's no payload inside and  it's just a dummy fairing. It might be a pair of flight-proven fairing halves and they put them on it to test the loads during integration, erection on the pad and the static fire and things like that.

Is there a fairing attached here? And maybe this will sound stupid, but could it be a "dummy" fairing, with nothing in it? Remember the other day we saw a fairing without markings on it in the HIF?

This photo from Julia would favor the "dummy fairing" speculation. No mission patch visible on the fairing.

https://twitter.com/julia_bergeron/status/1141310662750146561
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/19/2019 02:13 pm
Eric Ralph discusses various possible reasons for centre core recovery being so far downrange:

Quote
A SpaceX surprise: Falcon Heavy booster landing to smash distance record
By Eric Ralph
Posted on June 19, 2019

In an unexpected last-second change, SpaceX has moved Falcon Heavy Flight 3’s center core landing on drone ship Of Course I Still Love You (OCISLY) from 40 km to more than 1240 km (770 mi) off the coast of Florida.

https://www.teslarati.com/spacex-surprise-falcon-heavy-booster-landing-distance-record/

Let's hope that third time's a charm for the center core. Technically, the Arabsat 6A center core DID stick the landing, but it's kind of controversial when it comes to both landing and towing back to port.

So, I'd constitute the Arabsat 6A center core landing as a 50:50 success/failure.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: RocketLover0119 on 06/19/2019 08:47 pm
Fairing is indeed a dummy fairing:

https://spaceflightnow.com/2019/06/18/falcon-heavy-stp-2-launch-preps/

(Scroll down to live updates)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 06/19/2019 08:49 pm
Rough weather going over LC-39A now.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/19/2019 08:59 pm
Rough weather going over LC-39A now.

Is rough weather a possible factor of delaying any static fire? Not just this one.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 06/19/2019 09:15 pm
Rough weather going over LC-39A now.

Is rough weather a possible factor of delaying any static fire? Not just this one.

Yes, absolutely. Can't have a lightning warning in effect to fuel the rocket. In Florida, you get those quite often in June (basically every day).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: kdhilliard on 06/19/2019 09:26 pm
Fairing is indeed a dummy fairing:
https://spaceflightnow.com/2019/06/18/falcon-heavy-stp-2-launch-preps/
(Scroll down to live updates)
Thanks!  And the reason for the fairing is given in that article:
Quote
The fairing is a "non-flight" component, and was added for the static fire at the request of the Air Force to collect acoustic data.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/20/2019 12:03 am
https://twitter.com/exploreplanets/status/1141493728495845376

Here's Our First Look at LightSail 2 Installed on SpaceX's Falcon Heavy Rocket (http://planetary.org/blogs/jason-davis/lightsail-2-on-falcon-heavy.html)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Elthiryel on 06/20/2019 11:13 am
Do we know what are the three different deployment orbits planned for this mission?

Yes, we do.

300 km x 860 km x 28.5 deg
720 km x 720 km x 24 deg
6000 km x 12000 km x 43 deg

https://forum.nasaspaceflight.com/index.php?topic=30544.msg1939713#msg1939713
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: billh on 06/20/2019 01:46 pm
Do we know what are the three different deployment orbits planned for this mission?

Yes, we do.

300 km x 860 km x 28.5 deg
720 km x 720 km x 24 deg
6000 km x 12000 km x 43 deg

https://forum.nasaspaceflight.com/index.php?topic=30544.msg1939713#msg1939713
Wow! They really are putting S2 through its paces!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/20/2019 01:50 pm
Do we know what are the three different deployment orbits planned for this mission?

Yes, we do.

300 km x 860 km x 28.5 deg
720 km x 720 km x 24 deg
6000 km x 12000 km x 43 deg

https://forum.nasaspaceflight.com/index.php?topic=30544.msg1939713#msg1939713
Wow! They really are putting S2 through its paces!

Don't forget the passivation burn that inserts Stage 2 into a disposal orbit. That's another part of "being put through its paces".

Quick question for F9 experts: how many times can MVac be reignited on a typical mission with different orbits? Not including STP-2.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: wannamoonbase on 06/20/2019 02:57 pm
Do we know what are the three different deployment orbits planned for this mission?

Yes, we do.

300 km x 860 km x 28.5 deg
720 km x 720 km x 24 deg
6000 km x 12000 km x 43 deg

https://forum.nasaspaceflight.com/index.php?topic=30544.msg1939713#msg1939713
Wow! They really are putting S2 through its paces!

Don't forget the passivation burn that inserts Stage 2 into a disposal orbit. That's another part of "being put through its paces".

Quick question for F9 experts: how many times can MVac be reignited on a typical mission with different orbits? Not including STP-2.

The Merlin 1D's used for RTLS go through 4 burns in a flight.  They don't seem to mind starting them. 

For S2, it likely comes down to how long the stage is viable once on orbit and how much TEA/TEB they have on board. 

So far we know about 6 hours and 4 burns, 3 changes in orbital plane is pretty cool, looking forward to seeing this one fly.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/21/2019 01:47 am
It would appear that core stage will have a much higher apogee on STP-2 than on Arabsat.

From the Arabsat webcast, the core staged at 100 km altitude, coasted for about 220 seconds (3:35 to 7:15),  then started the entry burn.  The entry burn starts at about 60 km altitude, so we can find the vertical speed a separation that results in these numbers (h  = 100,000 + v*t - 1/2*g*t^2 = 60,000, where t = 220 seconds).  It's about 900 m/s vertical.  The cutoff speed was 10730 km/hr = 2981 m/s.  So the horizontal speed is sqrt(2981^2-900^2) = 2841 m/s horizontal.   During the 220 second coast, the stage will travel 220*2841 meters = 625 km downrange, the bulk of the travel.  The rest is the distance from takeoff to cutoff (a few hundred km) and the distance after the entry burn, which can't be much since the glide angle will not be great.  So all is consistent.

For STP-2 to get 300 km further downrange in the same amount of time is not possible.  To get 300 km further in 220 seconds would require more than 1,000 m/s additional x velocity.  The FH test saved 30 seconds of fuel for after booster separation and got something like 2650 m/s.  Arabsat 6 burned for 64 seconds after booster sep and got 2980 m/s, or an incremental 330 m/s.  This is pretty close the limit - if the center core went full thrust for 30 seconds (to minimize gravity losses), then throttled down to 40% (the lowest we've heard of) for the next 120 seconds, then it would have 72 seconds of fuel left.  That's only 8 seconds more than Arabsat, so it's already pretty close to maxed out.   Maybe they can squeeze 100 m/s more at staging, but that's about it, absent wild strategies like shutting core engines down during the side booster burn, which I doubt they are ready to try yet.

So how do you get 300 km further downrange, if you can't increase the horizontal velocity?  The only way is to increase the apogee, so your coast is longer.  To go 300 km more, at a slightly smaller 2800 m/s, you need to coast for 107 more seconds.  To do this, you need to increase the vertical velocity by 107*g/2,  or about 535 ms.  Your new vertical speed is 900+535 or 1435 m/s.  This gives a horizontal speed of roughly sqrt(3000^2-1435^2) = 2635 m/s.   You could iterate to improve this consistency but given how rough these figures are I doubt it's worth it (except to SpaceX).

With this extra vertical speed, the stage will coast higher.  Starting from the 100 km staging, 143.5 seconds later it will peak out at 203 km, as opposed to the (calculated) 141 km of Arabsat.

So overall, I'm guessing:
  - The cutoff speed will be similar, at most a little better (<100 m/s better)
  - The coast will be much longer (about 107 seconds longer).  So landing at 11:47 or so.
  - The apogee of the core will be much higher (200 km-ish, rather than the 140 km-ish of Arabsat)

EDIT:wording
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/21/2019 02:47 am
It would appear that core stage will have a much higher apogee on STP-2 than on Arabsat.

From the Arabsat webcast, the core staged at 100 km altitude, coasted for about 220 seconds (3:35 to 7:15),  then started the entry burn.  The entry burn starts at about 60 km, so we can find the vertical speed a separation that results in these numbers (h  = 100,000 + v*t - 1/2*g*t^2 = 60,000, where t = 220 seconds).  It's about 900 m/s vertical.  The cutoff speed was 10730 km/hr = 2981 m/s.  So the horizontal speed is sqrt(2981^2-900^2) = 2841 m/s horizontal.   During the 220 second coast, the stage will travel 220*2841 = 625 km downrange, the bulk of the travel.  The rest is the distance from takeoff to cutoff (a few hundred km) and the distance after the entry burn, which can't be much since the glide angle will not be great.  So all is consistent.

For STP-2 to get 300 km downrange in the same amount of time is not possible.  To get 300 km further in 220 seconds would require more than 1,000 m/s additional x velocity.  The FH test saved 30 seconds of fuel for after booster separation and got something like 2650 m/s.  Arabsat 6 burned for 64 seconds after booster sep and got 2980 m/s, or an incremental 330 m/s.  This is pretty close the limit - if the center core went full thrust for 30 seconds (to minimize gravity losses), then throttled down to 40% (the lowest we've heard of) for the next 120 seconds, then it would have 72 seconds of fuel left.  That's only 8 seconds more than Arabsat, so it's already pretty close to maxed out.   Maybe they can squeeze 100 m/s more at staging, but that's about it absent wild strategies like shutting core engines down during the side booster burn, which I doubt they are ready to try yet.

So how do you get 300 km further downrange, if you can't increase the horizontal velocity?  The only way is to increase the apogee, so you coast longer.  To go 300 km more, at a slightly smaller 2800 m/s, you need to coast for 107 more seconds.  To do this, you need to increase the vertical velocity by 107*g/2,  or about 535 ms.  Your new vertical speed is 900+535 or 1435 m/s.  This gives a horizontal speed of roughly sqrt(3000^2-1435^2) = 2635 m/s.   You could iterate to improve this consistency but given how rough these figures are I doubt it's worth it (except to SpaceX).

With this extra vertical speed, the stage will coast higher.  Starting from the 100 km staging, 143.5 seconds later it will peak out at 203 km, as opposed to the (calculated) 141 km of Arabsat.

So overall, I'm guessing:
  - The cutoff speed will be similar, at most a little better (<100 m/s better)
  - The coast will be much longer (about 107 seconds longer).  So landing at 11:47 or so.
  - The apogee of the core will be much higher (200 km-ish, rather than the 140 km-ish of Arabsat)

A higher apogee makes also sense if you look at the orbits the payloads are going to go. The insertion orbit will probably be the initial 300x860km at 28.5°. This would mean the second stage will have to be around 300km in altitude at MECO with the apogee at the other side of the Earth at 860km in altitude. So instead of a lower altitude at SECO like on Arabsat 6A, this time the second stage will have to go higher to 300km so it makes sense the center core will also go higher up to push the second stage higher too.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: intelati on 06/21/2019 02:08 pm
My modest contribution from Playalinda beach yesterday around 4 pm.
Not the best quality compare to the traditional profi reporters here, but its my first personal "close" encounter with FH so I'm pretty excited.  :D

Loving the contrast between the used boosters and the clean core.  ;D
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/22/2019 05:57 am
Do we know what are the three different deployment orbits planned for this mission?

Yes, we do.

300 km x 860 km x 28.5 deg
720 km x 720 km x 24 deg
6000 km x 12000 km x 43 deg

https://forum.nasaspaceflight.com/index.php?topic=30544.msg1939713#msg1939713

I calculate 597.8 m/s from the first to second orbit and 2829.9 m/s from the second to third orbit. Total delta-V is 3427.7 m/s.

http://www.sworld.com.au/steven/space/orbit.zip

Delta-V calculator by Steven S. Pietrobon. 22 Jun 2019.
Enter negative perigee height to exit program.
Enter negative height for geosynchronous altitude.

Enter initial perigee height (km): 300
Enter initial apogee height (km): 860
Enter required inclination change (deg): 4.5
Enter required perigee height (km): 720
Enter required apogee height (km): 720

Burn at   860.0 km: theta1 =  4.50 deg, dv1 =  586.6 m/s
Burn at   720.0 km: theta2 =  0.00 deg, dv2 =   36.5 m/s
dv =  623.1 m/s

Burn at   860.0 km: theta1 =  3.68 deg, dv1 =  484.3 m/s
Burn at   720.0 km: theta2 =  0.82 deg, dv2 =  113.5 m/s
dv =  597.8 m/s

Enter initial perigee height (km): 720
Enter initial apogee height (km): 720
Enter required inclination change (deg): 19
Enter required perigee height (km): 6000
Enter required apogee height (km): 12000

Burn at   720.0 km: theta1 =  0.00 deg, dv1 = 1507.4 m/s
Burn at 12000.0 km: theta2 = 19.00 deg, dv2 = 1440.6 m/s
dv = 2947.9 m/s

Burn at   720.0 km: theta1 =  4.25 deg, dv1 = 1625.8 m/s
Burn at 12000.0 km: theta2 = 14.75 deg, dv2 = 1204.1 m/s
dv = 2829.9 m/s
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/22/2019 03:27 pm

[First orbit]         300 km x 860 km x 28.5 deg
[second orbit]     720 km x 720 km x 24 deg

I calculate 597.8 m/s from the first to second orbit [...]

http://www.sworld.com.au/steven/space/orbit.zip

Delta-V calculator by Steven S. Pietrobon. 22 Jun 2019.
Enter negative perigee height to exit program.
Enter negative height for geosynchronous altitude.

Enter initial perigee height (km): 300
Enter initial apogee height (km): 860
Enter required inclination change (deg): 4.5
Enter required perigee height (km): 720
Enter required apogee height (km): 720

[...]

Burn at   860.0 km: theta1 =  3.68 deg, dv1 =  484.3 m/s
Burn at   720.0 km: theta2 =  0.82 deg, dv2 =  113.5 m/s
dv =  597.8 m/s
Seems correct, but this is not the way SpaceX will do this, I think, since number of burns is a tighter limit than delta-V.   This can be done with one burn - as the 300 x 800 orbit crosses 720km, a single burn can re-direct into a 720x720 at any inclination.   The magnitude of this burn will require full 3D trig to figure out, though.  I suspect it's comparable.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: TorenAltair on 06/22/2019 03:38 pm
I wonder if the flight profile represents the way that the DoD conducts or wants to conduct its launches: launch in one direction, then after first stage separation change orbit/inclination multiple times and drop the sat(s) some time before the end of the whole second stage mission to make things harder for an observer.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/22/2019 04:52 pm
I have a question about the length of the webcast.

Obviously, they’ll show the early ascent culminating with SECO-1 and the center core touchdown, but what I’m wondering is if they’ll show the second and third burns before ending the webcast at the start of the 3-hour coast.

Is that a possible theory?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 06/22/2019 06:22 pm
I wonder if the flight profile represents the way that the DoD conducts or wants to conduct its launches: launch in one direction, then after first stage separation change orbit/inclination multiple times and drop the sat(s) some time before the end of the whole second stage mission to make things harder for an observer.

I suspect what Space X are after is showing they can launch payloads like the KH-11 &amp; Advanced Orion which probably represent big bucks.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/22/2019 06:59 pm
I wonder if the flight profile represents the way that the DoD conducts or wants to conduct its launches: launch in one direction, then after first stage separation change orbit/inclination multiple times and drop the sat(s) some time before the end of the whole second stage mission to make things harder for an observer.

I don't think inclination changes like this will be a normal thing for DoD missions.  They had several payloads that needed rides, and they had a launch vehicle to test that supposedly was going to have a lot of performance, so they came up with this mission to see what it could do.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Mandella on 06/22/2019 07:26 pm
I have a question about the length of the webcast.

Obviously, they’ll show the early ascent culminating with SECO-1 and the center core touchdown, but what I’m wondering is if they’ll show the second and third burns before ending the webcast at the start of the 3-hour coast.

Is that a possible theory?

I'm guessing they will do like they usually do and just pause and resume their live coverage as they have anything interesting to show.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/22/2019 07:37 pm
I have a question about the length of the webcast.

Obviously, they’ll show the early ascent culminating with SECO-1 and the center core touchdown, but what I’m wondering is if they’ll show the second and third burns before ending the webcast at the start of the 3-hour coast.

Is that a possible theory?

I'm guessing they will do like they usually do and just pause and resume their live coverage as they have anything interesting to show.

Yeah, I don't think any part of this mission is classified, so I would think we will get the normal webcast.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/22/2019 08:13 pm

[First orbit]         300 km x 860 km x 28.5 deg
[second orbit]     720 km x 720 km x 24 deg

I calculate 597.8 m/s from the first to second orbit [...]

http://www.sworld.com.au/steven/space/orbit.zip

Delta-V calculator by Steven S. Pietrobon. 22 Jun 2019.
Enter negative perigee height to exit program.
Enter negative height for geosynchronous altitude.

Enter initial perigee height (km): 300
Enter initial apogee height (km): 860
Enter required inclination change (deg): 4.5
Enter required perigee height (km): 720
Enter required apogee height (km): 720

[...]

Burn at   860.0 km: theta1 =  3.68 deg, dv1 =  484.3 m/s
Burn at   720.0 km: theta2 =  0.82 deg, dv2 =  113.5 m/s
dv =  597.8 m/s
Seems correct, but this is not the way SpaceX will do this, I think, since number of burns is a tighter limit than delta-V.   This can be done with one burn - as the 300 x 800 orbit crosses 720km, a single burn can re-direct into a 720x720 at any inclination.   The magnitude of this burn will require full 3D trig to figure out, though.  I suspect it's comparable.
Thinking about this further, it can be reduced to two 2D problems.  Use the reference frame tangent to a 720 km sphere where the original orbit crosses it, with the X axis aligned with the original orbit plane.  The two orbits cross at the origin in this frame.  Using the formula v=sqrt(gm * (2/r - 1/sma)), we find that

old_v = 7421.59  m/s (original orbit)
new_v= 7497.48 (new orbit)

Now the flight path angle, which is the angle of the rising orbit, can be found as cos-1(sam/(r*v)), where sam = Specific Angular Momentum, a conserved quantity (equal to r*v at apogee or perigee) . In this case it is 0.0348994 radians, or  1.99959 degrees.  Now we have two 2-D problems in the tangent space:

x0 = old_v*cos(fpa);
y0 = 0;                  # because we picked the X axis to align with this frame.
z0 = old_v*sin(fpa);

With PC being the angle of the plane change,
x1 = new_v*cos(pc);
y1 = new_v*sin(pc);
z1 = 0;                  # because the new orbit, being circular, is tangent to the plane.

Now we take the difference between the two vectors to get
delta-V= 645.27 m/s

So a single burn can do the trick, but it's slightly less efficient than the two-burn solution calculated above.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/22/2019 11:37 pm
I have a question about the length of the webcast.

Obviously, they’ll show the early ascent culminating with SECO-1 and the center core touchdown, but what I’m wondering is if they’ll show the second and third burns before ending the webcast at the start of the 3-hour coast.

Is that a possible theory?

I'm guessing they will do like they usually do and just pause and resume their live coverage as they have anything interesting to show.

Yeah, I don't think any part of this mission is classified, so I would think we will get the normal webcast.

So basically, they'll take a three-hour break before coming back with the end of mission?

I didn't mean by the webcast ending because of classification. I was judging it based off of how long the viewers would want to sit and watch.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: lonestriker on 06/23/2019 12:22 am
I have a question about the length of the webcast.

Obviously, they’ll show the early ascent culminating with SECO-1 and the center core touchdown, but what I’m wondering is if they’ll show the second and third burns before ending the webcast at the start of the 3-hour coast.

Is that a possible theory?

I'm guessing they will do like they usually do and just pause and resume their live coverage as they have anything interesting to show.

Yeah, I don't think any part of this mission is classified, so I would think we will get the normal webcast.

So basically, they'll take a three-hour break before coming back with the end of mission?

I didn't mean by the webcast ending because of classification. I was judging it based off of how long the viewers would want to sit and watch.

IIRC when SpaceX has had a very long delay, they've just closed the webcast and told people to follow them on social media for deployment and updates.  I doubt they'll play hold music for 3 hours and wait, especially given the launch is 30 minutes before midnight Eastern Daylight Time.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rondaz on 06/23/2019 12:43 am
Falcon Heavy L-2 Weather Forecast: 70% Chance Favorable

Sarah Loff Posted on June 22, 2019

Meteorologists with the U.S. Air Force 45th Space Wing predict a 70% chance of favorable weather for liftoff of a SpaceX Falcon Heavy rocket Monday, June 24, from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. The launch window opens at 11:30 p.m. EDT.

The Falcon Heavy will launch two dozen satellites to space for the U.S. Department of Defense Space Test Program-2 mission.

Aboard are two NASA technology demonstrations to improve how spacecraft propel and navigate, as well as two NASA science missions to help us better understand the nature of space and how it impacts technology on spacecraft and the ground.

Forecast Details
An upper-level ridge remains over the Southeast U.S., reducing the coverage of the shower and thunderstorm activity over Central Florida. The surface ridge axis will remain south of the Space Coast however, keeping the east coast sea breeze pinned close to shore with only isolated afternoon showers. This southwesterly flow will also bring high temperatures in the 90s over the Spaceport. This pattern will begin to change Sunday into Monday, as a storm system digs into the Gulf Coast States, destabilizing the atmosphere and increasing shower and thunderstorm activity across Central Florida. The primary weather concerns for a launch attempt overnight Monday into early Tuesday morning are lingering anvil and thick layer clouds from afternoon convection.

On Tuesday, the upper-level ridge will continue moving east, allowing the storm system to drop into Northern Florida. Consequently, the coverage and intensity of showers and storms are expected to increase.

Prelaunch Technology Show: June 23
A prelaunch NASA technology show is scheduled for Sunday, June 23 at noon from Kennedy. NASA will stream the briefing live at https://www.nasa.gov/live.

Launch Coverage: June 24
Live NASA Television coverage of the Falcon Heavy launch will begin 30 minutes before liftoff.

While each has a unique set of objectives, the NASA missions on this launch have a common goal: improve future spacecraft design and performance, no matter the destination. For additional information about the NASA technologies aboard the launch, visit: www.nasa.gov/spacex

https://blogs.nasa.gov/spacex/2019/06/22/falcon-heavy-l-2-weather-forecast-70-chance-favorable/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/23/2019 03:27 am
I have a question about the length of the webcast.

Obviously, they’ll show the early ascent culminating with SECO-1 and the center core touchdown, but what I’m wondering is if they’ll show the second and third burns before ending the webcast at the start of the 3-hour coast.

Is that a possible theory?

I'm guessing they will do like they usually do and just pause and resume their live coverage as they have anything interesting to show.

Yeah, I don't think any part of this mission is classified, so I would think we will get the normal webcast.

So basically, they'll take a three-hour break before coming back with the end of mission?

I didn't mean by the webcast ending because of classification. I was judging it based off of how long the viewers would want to sit and watch.

IIRC when SpaceX has had a very long delay, they've just closed the webcast and told people to follow them on social media for deployment and updates.  I doubt they'll play hold music for 3 hours and wait, especially given the launch is 30 minutes before midnight Eastern Daylight Time.

Exactly. That was my point from the beginning. They did that during the early commercial missions for the v1.1 version. Examples include SES-8 and Thaicom 6.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/23/2019 07:57 pm
Note that at a briefing I just came from, the STP-2 mission manager said the second stage will just be disposed of in the DSX orbit.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/23/2019 09:04 pm
Note that at a briefing I just came from, the STP-2 mission manager said the second stage will just be disposed of in the DSX orbit.

No surprise on that, tbh. Considering they dropped the deorbit burn and now it's just passivation of the second stage.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/23/2019 09:12 pm
Note that at a briefing I just came from, the STP-2 mission manager said the second stage will just be disposed of in the DSX orbit.

No surprise on that, tbh. Considering they dropped the deorbit burn and now it's just passivation of the second stage.

Yeah, I just wanted to state it, basically from the horses mouth, since there has recently been talk in this thread about it, if they would be doing a burn or not, etc.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/24/2019 03:09 am
How many hours in advance will the press kit be released tomorrow?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Scylla on 06/24/2019 03:26 am
How many hours in advance will the press kit be released tomorrow?
Just posted it to the update thread.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Skyrocket on 06/24/2019 06:07 am
https://twitter.com/exploreplanets/status/1141493728495845376

Here's Our First Look at LightSail 2 Installed on SpaceX's Falcon Heavy Rocket (http://planetary.org/blogs/jason-davis/lightsail-2-on-falcon-heavy.html)

Is this really the Prox1 satellite, where Lightsat is hitching it's ride? It looks more like a dummy (e.g. no solar cells, no camera or sensor apertures) holding the PPod. This is, what Prox1 was supposed to look like (https://prox-1.gatech.edu/):
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 06/24/2019 10:58 am
How many hours in advance will the press kit be released tomorrow?
Just posted it to the update thread.

STP-2 Max-Q is at T+00:42, a full 27 seconds earlier than for Arabsat-6A at T+01:09. This is going to be interesting.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/24/2019 11:32 am
https://twitter.com/exploreplanets/status/1141493728495845376

Here's Our First Look at LightSail 2 Installed on SpaceX's Falcon Heavy Rocket (http://planetary.org/blogs/jason-davis/lightsail-2-on-falcon-heavy.html)

Is this really the Prox1 satellite, where Lightsat is hitching it's ride? It looks more like a dummy (e.g. no solar cells, no camera or sensor apertures) holding the PPod. This is, what Prox1 was supposed to look like (https://prox-1.gatech.edu/):

I don't know, but I will say Oculus is missing all its solar cells in the integrated stack photo as well...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/24/2019 01:48 pm
At the Lightsail mission briefing, Dave Spencer mentioned that Prox-2 had to be radically "descoped" to make its mission deadline after a last minute change to the hardware.  This entailed stripping out the cameras and many other components so that it was basically just a container for Lightsail 2.  It is still Georgia Tech's first satellite and will provide educational experience, just won't be able to do the full station-keeping mission originally envisioned.

(Apparently the original computer had trouble booting properly in a space environment during testing, and they had to switch to a different SBC with (I think) a different architecture, and that required extensive software changes at a time when the author of their original software had graduated/moved on; they couldn't spin up new software with all the original functionality in time to make the integration deadlines.)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Rondaz on 06/24/2019 03:40 pm
Launch Day Arrives for Space Test Program-2 Mission

Danielle Sempsrott Posted on June 24, 2019

A SpaceX Falcon Heavy rocket stands at Kennedy Space Center’s Launch Complex 39A in Florida for tonight’s launch of the Department of Defense’s (DoD) Space Test Program-2 (STP-2) mission. Lift off is scheduled for 11:30 p.m. EDT, with a four-hour launch window. The mission, managed by the U.S. Air Force Space and Missile Systems Center, will deliver 24 satellites to space, including four NASA payloads.

Meteorologists with the U.S. Air Force 45th Space Wing predict an 80% chance of favorable weather for liftoff. Primary weather concerns are anvil cloud rule and thick cloud layer rule.

Tonight’s launch will be among one of the most challenging in SpaceX’s history with four separate upper-stage engine burns, three separate deployment orbits and a propulsive passivation maneuver, where the engine continues to run until it empties out the second stage of fuel. SpaceX also plans to recover the rocket’s three boosters after launch by landing the two side boosters at the Cape Canaveral landing site and the center core downrange on the drone ship “Of Course I Still Love You.”

https://blogs.nasa.gov/spacex/2019/06/24/launch-day-arrives-for-space-test-program-2-mission/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: duh on 06/24/2019 08:15 pm
Somehow I messed up the following in trying to quote from an earlier post. Sorry
===================================================
STP-2 Max-Q is at T+00:42, a full 27 seconds earlier than for Arabsat-6A at T+01:09. This is going to be interesting.
[/quote]
====================================================

My comment(s):

Am I missing something on the other side of T-0 or have the times changed for the fuel and oxidizer loading????

SpaceX Launch Director verifies go for propellant load
 It is llsted as -53 minutes. My memory tells me it used to be 38 minutes.


1st stage RP-1 (rocket grade kerosene) loading begins
 This also, according to my memory and calculation, suggests this is also move forward by 15 minutes

1st stage LOX (liquid oxygen) loading begins
  Another 15 minute change

Also the final  satellite deployment is at:
   03:34:09

Prior indications were that this is a 6 hour mission. Is some interesting stuff being left out of the press kit
or is my imagination  running wild or ???????
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/24/2019 08:22 pm
Somehow I messed up the following in trying to quote from an earlier post. Sorry
===================================================
STP-2 Max-Q is at T+00:42, a full 27 seconds earlier than for Arabsat-6A at T+01:09. This is going to be interesting.
====================================================

My comment(s):

Am I missing something on the other side of T-0 or have the times changed for the fuel and oxidizer loading????

SpaceX Launch Director verifies go for propellant load
 It is llsted as -53 minutes. My memory tells me it used to be 38 minutes.


1st stage RP-1 (rocket grade kerosene) loading begins
 This also, according to my memory and calculation, suggests this is also move forward by 15 minutes

1st stage LOX (liquid oxygen) loading begins
  Another 15 minute change

Also the final  satellite deployment is at:
   03:34:09

Prior indications were that this is a 6 hour mission. Is some interesting stuff being left out of the press kit
or is my imagination  running wild or ???????

FH seems to have longer load times than F9 (they have to pump a lot more propellant into the rocket).  These are the same timings given for the Arabsat launch.

Everything I saw before today said around a 6 hour mission, maybe that was wrong.  All of the engine burns are listed in the press kit.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/24/2019 08:25 pm
Everything I saw before today said around a 6 hour mission, maybe that was wrong.  All of the engine burns are listed in the press kit.

Maybe there is still a coast phase between releasing the last payload and passivating the second stage?  That would explain the difference in times.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: TrueBlueWitt on 06/24/2019 08:28 pm
Somehow I messed up the following in trying to quote from an earlier post. Sorry
===================================================
STP-2 Max-Q is at T+00:42, a full 27 seconds earlier than for Arabsat-6A at T+01:09. This is going to be interesting.
====================================================

My comment(s):

Am I missing something on the other side of T-0 or have the times changed for the fuel and oxidizer loading? ???

SpaceX Launch Director verifies go for propellant load
 It is llsted as -53 minutes. My memory tells me it used to be 38 minutes.


1st stage RP-1 (rocket grade kerosene) loading begins
 This also, according to my memory and calculation, suggests this is also move forward by 15 minutes

1st stage LOX (liquid oxygen) loading begins
  Another 15 minute change

Also the final  satellite deployment is at:
   03:34:09

Prior indications were that this is a 6 hour mission. Is some interesting stuff being left out of the press kit
or is my imagination  running wild or ??? ??? ?

Have to wonder if there was some added parameter to the mission.. Air Force wants to demonstrate mission requirements met while having flexibility for a 15 minute launch window(after fueling commences)?

Being forced to launch with less dense LOX and RP1 than normal would explain the ASDS move far downrange.. Correct?

Feels like the Air Force is making SpaceX demonstrate they're still capable even with both hands tied behind their backs..

The 6 hours goes out to the final burn to lower orbit and deplete all propellants if I remember correctly?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: llanitedave on 06/24/2019 08:45 pm
Somehow I messed up the following in trying to quote from an earlier post. Sorry
===================================================
STP-2 Max-Q is at T+00:42, a full 27 seconds earlier than for Arabsat-6A at T+01:09. This is going to be interesting.
====================================================

My comment(s):

Am I missing something on the other side of T-0 or have the times changed for the fuel and oxidizer loading? ???

SpaceX Launch Director verifies go for propellant load
 It is llsted as -53 minutes. My memory tells me it used to be 38 minutes.


1st stage RP-1 (rocket grade kerosene) loading begins
 This also, according to my memory and calculation, suggests this is also move forward by 15 minutes

1st stage LOX (liquid oxygen) loading begins
  Another 15 minute change

Also the final  satellite deployment is at:
   03:34:09

Prior indications were that this is a 6 hour mission. Is some interesting stuff being left out of the press kit
or is my imagination  running wild or ??? ??? ?

Have to wonder if there was some added parameter to the mission.. Air Force wants to demonstrate mission requirements met while having flexibility for a 15 minute launch window(after fueling commences)?

Being forced to launch with less dense LOX and RP1 than normal would explain the ASDS move far downrange.. Correct?

Feels like the Air Force is making SpaceX demonstrate they're still capable even with both hands tied behind their backs..

The 6 hours goes out to the final burn to lower orbit and deplete all propellants if I remember correctly?


Lower orbit, or higher orbit?  Seems like it would take a lot of fuel to lower from a 6000 km x 12000 km orbit to a point where it would decay in a reasonable amount of time.  I'd think a higher orbit than that, in an area little used by satellites, would keep it out of the way.


Just guessing here, though.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/24/2019 08:56 pm
Have to wonder if there was some added parameter to the mission.. Air Force wants to demonstrate mission requirements met while having flexibility for a 15 minute launch window(after fueling commences)?

Being forced to launch with less dense LOX and RP1 than normal would explain the ASDS move far downrange.. Correct?

Feels like the Air Force is making SpaceX demonstrate they're still capable even with both hands tied behind their backs.. ?

This is the same timing as the previous FH flight.  It doesn't using the F9 timings.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/24/2019 09:10 pm
For a quick comparison...

https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf (https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf)

https://www.spacex.com/sites/spacex/files/arabsat-6a_press_kit.pdf (https://www.spacex.com/sites/spacex/files/arabsat-6a_press_kit.pdf)

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: TrueBlueWitt on 06/24/2019 09:28 pm
Have to wonder if there was some added parameter to the mission.. Air Force wants to demonstrate mission requirements met while having flexibility for a 15 minute launch window(after fueling commences)?

Being forced to launch with less dense LOX and RP1 than normal would explain the ASDS move far downrange.. Correct?

Feels like the Air Force is making SpaceX demonstrate they're still capable even with both hands tied behind their backs.. ?

This is the same timing as the previous FH flight.  It doesn't using the F9 timings.

Extrapolating from Faulty data.. Mea Culpa
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/24/2019 10:30 pm
Will they use the F9 prop loading procedure for Falcon Heavy in the near future?

My reasoning is so that it can get more performance when launching heavier payloads or when going to extreme orbits (geostationary, hyperbolic, or several orbits like in STP-2).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/24/2019 10:34 pm
Will they use the F9 prop loading procedure for Falcon Heavy in the near future?

My reasoning is so that it can get more performance when launching heavier payloads or when going to extreme orbits (geostationary, hyperbolic, or several orbits like in STP-2).

F9 and FH use slightly different amounts of propellants.  Is the infrastructure even capable of filling those two vehicles in the same amount of time?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: whitelancer64 on 06/24/2019 10:39 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/24/2019 10:58 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?

They're little numbers below the grid fins.  I haven't seen a picture from today that is clear enough to read them.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ulm_atms on 06/24/2019 11:37 pm
https://twitter.com/elonmusk/status/1143287719075950593

Quote
Odds of center core surviving are about 50% imo, as it’s coming in about 4 times faster than a rifle bullet

OK, since this mission has been on the books for quite a while even before B3 and B4 if I remember right....they had to be planning a multi-droneship capture at that time.  Since they only have one drone ship currently, the boosters have to RTLS and they figured why not try to catch the center core.  This one does seem to be on the edge of "survivable"

So questions:

How many times has this mission changed over the years?  When it was announced...and if it had the same mission as now....I don't see how it could not be 100% expendable.  Could the 2nd stage even do it at that point in time?

Other question....Has there ever been a mission with this many orbital requirements/changes and a disposal burn?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/24/2019 11:59 pm
OK, since this mission has been on the books for quite a while even before B3 and B4 if I remember right....they had to be planning a multi-droneship capture at that time.  Since they only have one drone ship currently, the boosters have to RTLS and they figured why not try to catch the center core.  This one does seem to be on the edge of "survivable"

So questions:

How many times has this mission changed over the years?  When it was announced...and if it had the same mission as now....I don't see how it could not be 100% expendable.  Could the 2nd stage even do it at that point in time?

Other question....Has there ever been a mission with this many orbital requirements/changes and a disposal burn?

This contract was signed when SpaceX was flying F9 v1.0.  The original plan must have been expendable.  They added the first orbit where most of the cubesats are getting released (720-circular was a bit high to be dumping a bunch of cubesats that may not have propulsion.  Prox-1/Lightsail is only being released at 720 because they can't use the sail at lower altitudes).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/25/2019 12:06 am
[...]
From: 720 km x 720 km x 24 deg
To:     6000 km x 12000 km x 43 deg

I calculate [...] 2829.9 m/s from the second to third orbit.

Enter initial perigee height (km): 720
Enter initial apogee height (km): 720
Enter required inclination change (deg): 19
Enter required perigee height (km): 6000
Enter required apogee height (km): 12000

Burn at   720.0 km: theta1 =  0.00 deg, dv1 = 1507.4 m/s
Burn at 12000.0 km: theta2 = 19.00 deg, dv2 = 1440.6 m/s
dv = 2947.9 m/s

Burn at   720.0 km: theta1 =  4.25 deg, dv1 = 1625.8 m/s
Burn at 12000.0 km: theta2 = 14.75 deg, dv2 = 1204.1 m/s
dv = 2829.9 m/s
This is good burn sequence for minimum delta-V, but it's not the way SpaceX seems to be doing it.  As specified above, there would be a coast of 1/2 of a 720 x 12000 km orbit.  That's 1.98 hours, or about 118 minutes.

Instead, SpaceX appears to be going to a 720 x 6000 orbit, then firing at apogee to create the 6000 x 12000 orbit.  The coast in this case should be 1.33 hours, or 80 minutes, almost exactly what is specified in the press kit (2:08:04 to 3:27:29).  It's going to be slightly less efficient, since the plane change is done at a lower altitude, but I guess SpaceX prefers the shorter coast to the smaller delta-V.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/25/2019 12:35 am
Any chance the 2am delay isn't official yet because they are discussing a scrub instead?  I've got to decide whether to get on the bus at KSC...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: RocketLover0119 on 06/25/2019 12:49 am
Any chance the 2am delay isn't official yet because they are discussing a scrub instead?  I've got to decide whether to get on the bus at KSC...

Could be wrong, but honestly if it was an official delay/scrub spacex would have tweeted by now, and that’s not the case, wondering if someone on clock team goofed?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/25/2019 12:53 am
Any chance the 2am delay isn't official yet because they are discussing a scrub instead?  I've got to decide whether to get on the bus at KSC...

Could be wrong, but honestly if it was an official delay/scrub spacex would have tweeted by now, and that’s not the case, wondering if someone on clock team goofed?
I like how you think. Fingers crossed...

Edit: delay not scrub. That's still okay... (My kids are just going to be very sleepy, and my 8am flight home is going to be... fun.)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Yellowstone10 on 06/25/2019 12:55 am
New T-0 of 2:30 am EDT / local.

https://twitter.com/SpaceX/status/1143321392785477633
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OxCartMark on 06/25/2019 01:19 am
From Gizmodo - https://gizmodo.com/all-the-cool-things-going-to-space-tonight-aboard-a-spa-1835816425 (https://gizmodo.com/all-the-cool-things-going-to-space-tonight-aboard-a-spa-1835816425)

"The Falcon Heavy will also release a dozen Oculus-ASR nanosatellites, each weighing 154 pounds (70 kg). Built by a student group from Michigan Technological University, these satellites will be used as targets for calibrating ground-based telescopes tasked with monitoring spacecraft in orbit."

I don't know where the classification breaks are (or if there are any official break points) but 154 pounds seems to me to be more than "nano".  What I do know for sure though is that those folks up at Michigan Technological University are super awesome   8)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/25/2019 01:24 am
From Gizmodo - https://gizmodo.com/all-the-cool-things-going-to-space-tonight-aboard-a-spa-1835816425 (https://gizmodo.com/all-the-cool-things-going-to-space-tonight-aboard-a-spa-1835816425)

"The Falcon Heavy will also release a dozen Oculus-ASR nanosatellites, each weighing 154 pounds (70 kg). Built by a student group from Michigan Technological University, these satellites will be used as targets for calibrating ground-based telescopes tasked with monitoring spacecraft in orbit."

I don't know where the classification breaks are (or if there are any official break points) but 154 pounds seems to me to be more than "nano".  What I do know for sure though is that those folks up at Michigan Technological University are super awesome   8)

That has to be a typo.  It should be 1 Oculus-ASR sat.

edit:  It seems they had an editing error where they smushed together a sentence about a dozen nanosats and one about Oculus-ASR (which is a microsatellite).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/25/2019 03:21 am
Hmm, less than 10 minutes and no music yet? Does that mean scrub?

Edit: now at T-4 min and still no music :-(

Edit: T-2:00 and still nothing. This can't be good.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: techdude06 on 06/25/2019 03:27 am
Delayed till 2:30 edt

Sent from my SM-N960U using Tapatalk

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/25/2019 03:31 am
Delayed till 2:30 edt

Sent from my SM-N960U using Tapatalk

Ah, I didn't realise that was a 2 hours shift. I'll watch it from work then.
They could have updated that countdown clock a bit sooner . grrrr.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lar on 06/25/2019 03:40 am
Delayed till 2:30 edt

Sent from my SM-N960U using Tapatalk

Ah, I didn't realise that was a 2 hours shift. I'll watch it from work then.
They could have updated that countdown clock a bit sooner . grrrr.
It's actually a 3 hour shift
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: catdlr on 06/25/2019 03:48 am
Delayed till 2:30 edt

Sent from my SM-N960U using Tapatalk

Ah, I didn't realise that was a 2 hours shift. I'll watch it from work then.
They could have updated that countdown clock a bit sooner . grrrr.
It's actually a 3 hour shift
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/25/2019 05:42 am
Here is the Oculus-ASR patch. Wasn't includes in the updates thread.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Joseph Peterson on 06/25/2019 06:00 am
Rocket getting frosty, from the NSF webcast

What's the link for this? I can't find it on Youtube.

https://www.twitch.tv/dasvaldez

Yet another reason NSF is awesome.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: yokem55 on 06/25/2019 06:40 am
Almost had a heart attack seeing the infra-red startup of the booster. For a second it looked like the stage had exploded.... Phew..
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Halidon on 06/25/2019 06:43 am
Hair-raising near-miss by the center core.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: drzerg on 06/25/2019 06:43 am
looks like it almost do divert maneuver at the end of first core landing to safe droneship
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: catdlr on 06/25/2019 06:44 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 06/25/2019 06:48 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.

Doubtful, IMO. If your theory was correct, then it would never have made it as close to landing as it did.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: kessdawg on 06/25/2019 06:50 am
Center core thrust started to impinge on the dinner ship, then it started to move off course.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Pete on 06/25/2019 06:50 am
looks like it almost do divert maneuver at the end of first core landing to safe droneship

Sure looks like it.
The initial rocket blast was pretty much dead center, so the *aim* was good.
Possibly the booster detected that it would stop short, and lacking a hover ability its only option then is to abort away from the droneship.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: drzerg on 06/25/2019 06:53 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.

Doubtful, IMO. If your theory was correct, then it would never have made it as close to landing as it did.
agree. you could even see exhaust plume on the center of droneship at some moment. something goes wrong at very last moment. may be gimbaling. terminal velocity was clearly slow
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: catdlr on 06/25/2019 06:53 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.

Doubtful, IMO. If your theory was correct, then it would never have made it as close to landing as it did.
  Understand.  Just a guess based on the video I posted (now deleted).

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/25/2019 06:53 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.

I don't know which screen you mean, but just before impact, landing legs were deployed and there was no spin.


You can see the core come dead center from above the droneship (see exhaust impinge on deck) (attachement)

then the core suddenly drifts of, gives full power and flies away at extreme angle of attack, almost as if aborting the landing to save the droneship. it then hits the water way behind the dronship flying away from it.

you can see the deployed landing legs looking from behind into the engines. there was no spin




Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: catdlr on 06/25/2019 06:55 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.

I don't know which screen you mean, but just before impact, landing legs were deployed and there was no spin.


You can see the core come dead center from above the droneship (see exhaust impinge on deck) (attachement)

then the core suddenly drifts of, gives full power and flies away at extreme angle of attack, almost as if aborting the landing to save the droneship. it then hits the water way behind the dronship flying away from it.

you can see the deployed landing legs looking from behind into the engines. there was no spin






I totally agree with you. But I have seen in a prior landing that the engine firing could cancel out the spin.  I'm not saying the spin caused the aborted landing.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Damon Hill on 06/25/2019 06:56 am
Payloads are successfully deploying and the boosters are safely recovered, so it's still a very successful mission.  Maybe a few good data points on core functionality after an extreme reentry.  We'll have to wait for the evaluation and details.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: georgegassaway on 06/25/2019 06:59 am
Theory: Core reached zero velocity above deck, going back upwards (can't throttle low enough). Software realizing a hopeless situation and ditched the core away from the ASDS.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MATTBLAK on 06/25/2019 06:59 am
In the Web cast coverage we seem to seeing a lot of 'debris' wobbling around the forward view from the upper stage - oxygen ice?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: 1 on 06/25/2019 06:59 am
I'm not saying the spin caused the aborted landing.

I don't think the center core is spinning at all. IMO. The large surrounding exhaust plume is from the central core, which doesn't shut off its engines that early. The spinning object looks to have been liberated from one of the side boosters; possibly one of the nose cones.

I think the center core just came in a bit hotter than they knew how to control; simple as that.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Asteroza on 06/25/2019 07:03 am
Hard to tell, but did all 4 legs deploy properly? I could see it aborting if a leg didn't come down and lock.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: catdlr on 06/25/2019 07:09 am
I'm not saying the spin caused the aborted landing.

I don't think the center core is spinning at all. IMO. The large surrounding exhaust plume is from the central core, which doesn't shut off its engines that early. The spinning object looks to have been liberated from one of the side boosters; possibly one of the nose cones.

I think the center core just came in a bit hotter than they knew how to control; simple as that.

Yes, I'm now in full agreement (noSpin).  and I agree with the above post.

https://forum.nasaspaceflight.com/index.php?topic=30544.msg1959911#msg1959911
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/25/2019 07:12 am
Hard to tell, but did all 4 legs deploy properly? I could see it aborting if a leg didn't come down and lock.

We're going to have to see. Could be a throttle issue, could be legs, could be a sensor issue. Most likely cause is the hot entry, but I don't think we are going to hear anything more until Elon tweets :)

Important thing is that the mission's succeeds, although the SpaceX FH center-core-bad-luck-streak is starting to get a wee bit annoying.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: MATTBLAK on 06/25/2019 07:20 am
I'm loving the Earth views from the upper stage! The high-Def views of Madagascar and the clouds above the Indian Ocean as I'm writing this are really cool.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: flyright on 06/25/2019 07:26 am
Almost had a heart attack seeing the infra-red startup of the booster. For a second it looked like the stage had exploded.... Phew..

Glad I wasn't the only one that thought it had exploded. It took a while to calm down and realize all was cool with both side boosters!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Grandpa to Two on 06/25/2019 07:29 am
PPOD 8 has deployed LEO and StangSat (top of view).
This was the first time I heard the air supply launching this satellite. Very nice.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: 1 on 06/25/2019 07:42 am
Watching the replay, I love how gleeful SpaceX HQ sounded after the center core splashed. Initial disappointment, then immediate cheers and applause.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/25/2019 07:44 am
Yayyyyyy  Go Miss Treeee :-)     Kite got caught :-)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/25/2019 07:48 am
https://twitter.com/SpaceXFleet/status/1143424741514125312 (https://twitter.com/SpaceXFleet/status/1143424741514125312)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: eeergo on 06/25/2019 07:55 am
[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: HeartofGold2030 on 06/25/2019 08:00 am
[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: kevinof on 06/25/2019 08:01 am
Huh? What you smoking? What about re-using on OTHER flights? This is what SpaceX does month after month.

[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/25/2019 08:08 am
Huh? What you smoking? What about re-using on OTHER flights? This is what SpaceX does month after month.

[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.

FH side boosters are almost identical to Falcon9 single sticks and can be converted by swapping the nosecone for an interstage. Those sideboosters each have 2 FH flights on their belt, which are effectively low energy return to launchsite trajectories, making them prime candidates for reuse.

If the next FH flight is so long away, I think reuse as single sticks is more likely than keeping them in storage for that long.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 06/25/2019 08:13 am
[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.

Is that an NRO mission?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: HeartofGold2030 on 06/25/2019 08:16 am
[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.

Is that an NRO mission?

AFSC-152 for the Airforce Space Command, it’s a direct to GEO mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: HeartofGold2030 on 06/25/2019 08:19 am
Huh? What you smoking? What about re-using on OTHER flights? This is what SpaceX does month after month.

[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.

FH side boosters are almost identical to Falcon9 single sticks and can be converted by swapping the nosecone for an interstage. Those sideboosters each have 2 FH flights on their belt, which are effectively low energy return to launchsite trajectories, making them prime candidates for reuse.

If the next FH flight is so long away, I think reuse as single sticks is more likely than keeping them in storage for that long.

I believe the Airforce would want to preserve the first reused hardware ever flown on a DoD mission instead of reusing it; therefore, it’s more likely imo that the side boosters are put on display at the Cape than reused for a future mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: WannaWalnetto on 06/25/2019 08:20 am
Thought I just heard them call out on the webcast that the Texas site is now tracking the second stage.  Guess that means Boca Chica?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/25/2019 08:48 am
https://twitter.com/SpaceX/status/1143439449230938112 (https://twitter.com/SpaceX/status/1143439449230938112)

It has been great to have this webcast up the full time so far.

2nd stage hanging in there...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: eeergo on 06/25/2019 08:58 am
I believe the Airforce would want to preserve the first reused hardware ever flown on a DoD mission instead of reusing it; therefore, it’s more likely imo that the side boosters are put on display at the Cape than reused for a future mission.

I disagree, although it is certainly more probable the side boosters will see further missions as single first stages for F9's. However, it does not change the fact that the F9/FH system is now mostly reusable (bar 2nd stage, a pity IMO) or, in the case of FH, has demonstrated it can be made up of mostly reused elements, even if they're not necessarily coming from a previous FH flight.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 06/25/2019 09:10 am
[They caught the fairing!]

Had they succeeded in avoiding that last-second issue with the center core, this launch would have meant the world's most powerful rocket in service to be recovered for reuse! Extraordinary every time I stop to reflect about it.

None of this rocket is getting reused, the next launch is a classified mission for the airforce in over a years time and will require a clean sheet booster.

Is that an NRO mission?

AFSC-152 for the Airforce Space Command, it’s a direct to GEO mission.

Thank you. Beyond the first three launches I hadn’t seen anything much about further FH launches.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/25/2019 09:13 am
Look to me that the first stage started to spin wildly on the leftmost monitor.  Guessing one of the Grid fines did not deploy and went wild.

Doubtful, IMO. If your theory was correct, then it would never have made it as close to landing as it did.
  Understand.  Just a guess based on this video.

https://www.youtube.com/watch?v=Dzrx569K_8g

That would be the ground IR camera view that was tracking the returning boosters, not onboard core stage video.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/25/2019 10:01 am
Some weird lighting effect!

Thrusters firing to settle propellant.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/25/2019 10:10 am
https://twitter.com/AdamGlambert304/status/1143460605963231232 (https://twitter.com/AdamGlambert304/status/1143460605963231232)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: alang on 06/25/2019 10:45 am
Some weird lighting effect!

Thrusters firing to settle propellant.

https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=48325.0;attach=1566541;image

Are you certain it's just ullage?
I understand that there is an MVac chill down prior to first ignition. Does that chill down happen prior to later ignition s as well? If so then what happens to the propellant used for cooling?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/25/2019 10:55 am
Some weird lighting effect!

Thrusters firing to settle propellant.

https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=48325.0;attach=1566541;image

Are you certain it's just ullage?

Yes, it was 4 separate pulses of GN2

I understand that there is an MVac chill down prior to first ignition. Does that chill down happen prior to later ignition s as well? If so then what happens to the propellant used for cooling?

Yes, prior to any ignition. That GOX/LOX is dumped overboard during chilldown but it looks visually different than this and it's continuous venting for a while.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/25/2019 11:21 am
AFSC-152 for the Airforce Space Command, it’s a direct to GEO mission.

Its AFSPC 52 in September 2020.

https://forum.nasaspaceflight.com/index.php?topic=45886.0
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/25/2019 11:22 am
Hard to tell, but did all 4 legs deploy properly? I could see it aborting if a leg didn't come down and lock.

We're going to have to see. Could be a throttle issue, could be legs, could be a sensor issue. Most likely cause is the hot entry, but I don't think we are going to hear anything more until Elon tweets :)

If it wasn't a deliberate evasive burn due to too much vertical velocity (it didn't really look to me that it was going to lawn-dart OCISLY, though), I'm wondering if it was a center engine gimbal failure.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/25/2019 11:27 am
Congratulations to SpaceX and USAF for the successful launch!

Some screen grabs I missed. I couldn't get any more grabs from earlier in the flight because the YouTube link now starts at T+1:36:52.

Fairing separation.

Nice infrared view of booster just before the landing burn.

Another shot of the booster landings.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/25/2019 12:11 pm
Looking at the drone ship camera showing the center core, it looks like while it was divebombing towards the water, the oxidizer cut out right before impact.

If it's not the oxidizer, then the fuel must have run out at that time.

Compare that to the Eutelsat/ABS F2 landing failure.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 06/25/2019 12:30 pm
Hard to tell, but did all 4 legs deploy properly? I could see it aborting if a leg didn't come down and lock.

We're going to have to see. Could be a throttle issue, could be legs, could be a sensor issue. Most likely cause is the hot entry, but I don't think we are going to hear anything more until Elon tweets :)

If it wasn't a deliberate evasive burn due to too much vertical velocity (it didn't really look to me that it was going to lawn-dart OCISLY, though), I'm wondering if it was a center engine gimbal failure.

Agreed. Looks to me like a TVC issue resulting in the tip-over. Since it was lined up correctly in the first place, maybe it throttled up on purpose to get away from OCISLY.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/25/2019 12:36 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?

They're little numbers below the grid fins.  I haven't seen a picture from today that is clear enough to read them.

The answer to this is on L2

Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: codav on 06/25/2019 01:41 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?

They're little numbers below the grid fins.  I haven't seen a picture from today that is clear enough to read them.

The answer to this is on L2

Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.

I'm not sure if the booster numbers really are L2-only content, even if the many beautiful high-res photos there certainly are. The side booster positions were assigned identical to the Arabsat-6A mission, with B1052 on the west side on the pad (facing the FSS) and B0153 on the east.

Regarding AFSPC-52, the target transfer orbit (185x35188km with a 27° inclination) is nearly the same as Arabsat-6A and the satellite even weighs a bit less, so I'd expect a very similar flight profile.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Prettz on 06/25/2019 01:59 pm
Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.
Had this been discussed publicly before? I might have just forgotten seeing it, but I didn't remember this mission being planned to expend the center. (Obviously, this is not a very searchable question)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: meekGee on 06/25/2019 02:45 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?

They're little numbers below the grid fins.  I haven't seen a picture from today that is clear enough to read them.

The answer to this is on L2

Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.

I'm not sure if the booster numbers really are L2-only content, even if the many beautiful high-res photos there certainly are. The side booster positions were assigned identical to the Arabsat-6A mission, with B1052 on the west side on the pad (facing the FSS) and B0153 on the east.

Regarding AFSPC-52, the target transfer orbit (185x35188km with a 27° inclination) is nearly the same as Arabsat-6A and the satellite even weighs a bit less, so I'd expect a very similar flight profile.
Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.
Had this been discussed publicly before? I might have just forgotten seeing it, but I didn't remember this mission being planned to expend the center. (Obviously, this is not a very searchable question)
And double droneship landing?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Draggendrop on 06/25/2019 03:46 pm
https://twitter.com/NOAASatellites/status/1143520496660746240 (https://twitter.com/NOAASatellites/status/1143520496660746240)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/25/2019 04:39 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?

They're little numbers below the grid fins.  I haven't seen a picture from today that is clear enough to read them.

The answer to this is on L2

Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.

I'm not sure if the booster numbers really are L2-only content, even if the many beautiful high-res photos there certainly are. The side booster positions were assigned identical to the Arabsat-6A mission, with B1052 on the west side on the pad (facing the FSS) and B0153 on the east.

Regarding AFSPC-52, the target transfer orbit (185x35188km with a 27° inclination) is nearly the same as Arabsat-6A and the satellite even weighs a bit less, so I'd expect a very similar flight profile.
Also, for the next FH mission (the AFSPC 52) I would expect double side booster drone ship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.
Had this been discussed publicly before? I might have just forgotten seeing it, but I didn't remember this mission being planned to expend the center. (Obviously, this is not a very searchable question)
And double drone ship landing?

That's if they get "A Shortfall Of Gravitas" ready for that mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: meekGee on 06/25/2019 04:49 pm
Is SpaceX still putting tail numbers on each booster? Is soot obscuring them or am I looking in the wrong place?

They're little numbers below the grid fins.  I haven't seen a picture from today that is clear enough to read them.

The answer to this is on L2

Also, for the next FH mission (the AFSPC 52) I would expect double side booster droneship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.

I'm not sure if the booster numbers really are L2-only content, even if the many beautiful high-res photos there certainly are. The side booster positions were assigned identical to the Arabsat-6A mission, with B1052 on the west side on the pad (facing the FSS) and B0153 on the east.

Regarding AFSPC-52, the target transfer orbit (185x35188km with a 27° inclination) is nearly the same as Arabsat-6A and the satellite even weighs a bit less, so I'd expect a very similar flight profile.
Also, for the next FH mission (the AFSPC 52) I would expect double side booster drone ship landing and center core expended, pretty much what they initially planned for this mission before dropping the second stage deorbit burn.
Had this been discussed publicly before? I might have just forgotten seeing it, but I didn't remember this mission being planned to expend the center. (Obviously, this is not a very searchable question)
And double drone ship landing?

That's if they get "A Shortfall Of Gravitas" ready for that mission.
Yeah, but it could not have been planned for this mission
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: JimO on 06/25/2019 04:59 pm
Yes, prior to any ignition. That GOX/LOX is dumped overboard during chilldown but it looks visually different than this and it's continuous venting for a while.

Were we seeing the GOX/LOX dumps for the trans-Mars burn observed from SW US?

FH [falcon heavy] escape burn to Mars Feb 06, 2018 observed from SW USA 
http://satobs.org/seesat_ref/misc/180206_fh_s2_burn3_d2.pdf
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kabloona on 06/25/2019 05:02 pm

That's if they get "A Shortfall Of Gravitas" ready for that mission.

"A Shortfall Of Gravitas" seems to be like Schrodinger's cat, existing in some people's minds while not existing in other's. Shortly after Elon announced that ASoG was in the works, a reliable source involved in SpaceX marine operations talked to some of the SpaceX recovery guys, and they swore there was no other ASDS in the works, and they didn't know why Elon was saying publicly that there was.

Some of us on the ASDS thread also did our own sleuthing trying to locate any other shipyards that might be working on an ASoG, since the source said McDonough Marine, owner of the Marmacs, had no knowledge of an ASoG project either, and we came up completely empty. Nobody knew anything about it.

One possibility is that shortly after Elon announced ASoG, SpaceX changed plans and decided not to proceed. JRtI is seriously under-utilized at VAFB, and perhaps they decided to consider moving JRtI back to the Cape. Or they just decided that one ASDS per coast was enough. There's also the Super Heavy/Starship factor, and SpaceX may have decided they want to transition away from Falcon Heavy as soon as possible, meaning no more need for dual-ASDS missions to catch the FH side boosters.

The other possiblity is that ASoG construction has been proceeding somewhere extremely well hidden during the 16 months since Elon announced it, with no photos, no leaks, no tweets, no nothing.

My money is on option #1, that plans for ASoG were quietly dropped.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/25/2019 05:09 pm
If Vandenberg is going to be shut down in favor of using the excess performance available w/ FH to run dogleg routes to polar orbits from the Cape, then it certainly would make sense to relocate JRtI.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 06/25/2019 05:24 pm
A few shots from my end.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: edkyle99 on 06/25/2019 07:22 pm
Four starts over a 3.5 hour mission for a LOX/kerosene engine.  A long record of successful performance leading up to this flight, including several long-coast to restart tests.  Rugged, simple engine cycle yet still throttleable and efficient. 

Is Merlin 1D Vacuum the best rocket engine yet flown?  It must be compared with the likes of RL10, AJ10, Bell 8096, J-2, the LM engines, etc.

 - Ed Kyle
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 06/25/2019 07:34 pm

One possibility is that shortly after Elon announced ASoG, SpaceX changed plans and decided not to proceed. JRtI is seriously under-utilized at VAFB, and perhaps they decided to consider moving JRtI back to the Cape. Or they just decided that one ASDS per coast was enough.
Elon mentioned ASOG twice. First time it was during the FH Demo press conference in February 2018 and then again on Twitter 6 months later where he even said ASOG would be ready in summer 2019. It could have been cancelled since then, of course, but it doesn't seem to me like it was a spur of the moment kind of thing.

https://twitter.com/elonmusk/status/1023073822080098304

As for SpaceX moving JRTI to Florida, I had the same idea recently and posted my thoughts on Reddit (https://www.reddit.com/r/SpaceXLounge/comments/c2jwyk/will_spacex_move_jrti_to_florida/). But it's hard argue one way or the other because it depends a lot on ASOG being available (if and when).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kabloona on 06/25/2019 08:04 pm

One possibility is that shortly after Elon announced ASoG, SpaceX changed plans and decided not to proceed. JRtI is seriously under-utilized at VAFB, and perhaps they decided to consider moving JRtI back to the Cape. Or they just decided that one ASDS per coast was enough.
Elon mentioned ASOG twice. First time it was during the FH Demo press conference in February 2018 and then again on Twitter 6 months later where he even said ASOG would be ready in summer 2019. It could have been cancelled since then, of course, but it doesn't seem to me like it was a spur of the moment kind of thing.

https://twitter.com/elonmusk/status/1023073822080098304

As for SpaceX moving JRTI to Florida, I had the same idea recently and posted my thoughts on Reddit (https://www.reddit.com/r/SpaceXLounge/comments/c2jwyk/will_spacex_move_jrti_to_florida/). But it's hard argue one way or the other because it depends a lot on ASOG being available (if and when).

Re Elon's later tweet in July 2018, I forgot to mention that, several months after this *second* public mention of ASoG, his own director of recovery ops said he didn't know anything about a third ASDS. He may have been obfuscating, but why bother? It would be easier, and maybe less embarrassing to say, oh yeah, we're building a third one just like Elon said. Instead, he claimed total ignorance.

Weird tea leaves.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/25/2019 08:55 pm
Ok so to clarify. The original FCC position was just an error, that was not the initially planned landing point, in fact it was quite surprising considering the many burns the second stage needed. The very original plan, obviously, was to expend everything because it was all v1.0. When landings started to be a thing the plan changed to sides ASDS and center core expended. Back then the mission included a 5th burn to deorbit the stage but SpaceX clearly wanted to spare the center core (now they might regret that hehe). The Block 5 performance is huge so they could do boosters RTLS and they asked USAF to drop that last burn to recover the center core. This is info that not only I have heard before but also quite a few others have told me similar things. Maybe it's not 100% the total picture of how things have gone but it's what I understand to a high degree of confidence. The plan of double droneship landing was still on until late last year, now think about why Elon said ASoG would be ready by this year's summer  ;)

Re:AFSPC-52 orbit. As far as I know the target orbit is GEO, not GTO. 6 tons to GEO means expendable center core. They might be able to RTLS the boosters but considering the second stage then has to be thrown to a graveyard orbit and perform another burn and being the DoD... I'm skeptical. As I always say: let's see and enjoy  :D
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: codav on 06/25/2019 09:10 pm

Re:AFSPC-52 orbit. As far as I know the target orbit is GEO, not GTO. 6 tons to GEO means expendable center core.

The only public information I could find everywhere about the target insertion orbit - which SpaceX might choose to supersede - is that GTO. It was specified in the Instructions to Offerors (https://www.fbo.gov/utils/view?id=48225d4ede311af575565e97893be3f3) (page 18 section 10.1.1.1) published by the USAF. If there is any updated/contrary information available, I'm quite interested in it. L2 link via PM if it's been mentioned there ;)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/25/2019 09:28 pm

Re:AFSPC-52 orbit. As far as I know the target orbit is GEO, not GTO. 6 tons to GEO means expendable center core.

The only public information I could find everywhere about the target insertion orbit - which SpaceX might choose to supersede - is that GTO. It was specified in the Instructions to Offerors (https://www.fbo.gov/utils/view?id=48225d4ede311af575565e97893be3f3) (page 18 section 10.1.1.1) published by the USAF. If there is any updated/contrary information available, I'm quite interested in it. L2 link via PM if it's been mentioned there ;)

I think I know from where my error came. I read the wrong document back then and now I'm realizing it is not even for the same mission. I'm stupid  ::)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: WannaWalnetto on 06/25/2019 10:55 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Orbiter on 06/25/2019 11:07 pm

Re:AFSPC-52 orbit. As far as I know the target orbit is GEO, not GTO. 6 tons to GEO means expendable center core. They might be able to RTLS the boosters but considering the second stage then has to be thrown to a graveyard orbit and perform another burn and being the DoD... I'm skeptical. As I always say: let's see and enjoy  :D

They can do 6k to GEO and RTLS the side boosters based on the performance calculations I've seen. 8k and beyond is when RTLS becomes impossible.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kabloona on 06/25/2019 11:09 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf

Per the SpaceX mission animation, the stage did a "propulsive passivation," presumably  to move away from the DSX orbit, leaving it in MEO (?)

https://forum.nasaspaceflight.com/index.php?topic=48325.msg1955315#msg1955315
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/25/2019 11:10 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf

Propulsive depassivation and it has been left out in a graveyard orbit.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 06/26/2019 01:52 am
Hard to tell, but did all 4 legs deploy properly? I could see it aborting if a leg didn't come down and lock.

We're going to have to see. Could be a throttle issue, could be legs, could be a sensor issue. Most likely cause is the hot entry, but I don't think we are going to hear anything more until Elon tweets :)

If it wasn't a deliberate evasive burn due to too much vertical velocity (it didn't really look to me that it was going to lawn-dart OCISLY, though), I'm wondering if it was a center engine gimbal failure.

Agreed. Looks to me like a TVC issue resulting in the tip-over. Since it was lined up correctly in the first place, maybe it throttled up on purpose to get away from OCISLY.

And Elon confirmed it was a TVC failure.

https://twitter.com/elonmusk/status/1143690145255841797
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mn on 06/26/2019 02:28 am
Hard to tell, but did all 4 legs deploy properly? I could see it aborting if a leg didn't come down and lock.

We're going to have to see. Could be a throttle issue, could be legs, could be a sensor issue. Most likely cause is the hot entry, but I don't think we are going to hear anything more until Elon tweets :)

If it wasn't a deliberate evasive burn due to too much vertical velocity (it didn't really look to me that it was going to lawn-dart OCISLY, though), I'm wondering if it was a center engine gimbal failure.

Agreed. Looks to me like a TVC issue resulting in the tip-over. Since it was lined up correctly in the first place, maybe it throttled up on purpose to get away from OCISLY.

And Elon confirmed it was a TVC failure.

https://twitter.com/elonmusk/status/1143690145255841797

If the TVC failed, how did the computer intentionally divert?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClayJar on 06/26/2019 02:32 am
If the TVC failed, how did the computer intentionally divert?

The center engine TVC failed, but it was not a single-engine landing.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: VDD1991 on 06/26/2019 02:51 am
Finally, SpaceX is picking up the pace with scheduled Falcon Heavy launches, considering that the STP-2 launch was originally scheduled for October 2016. With the last scheduled launch of single-stick Delta IV coming next month, who knows when the next Falcon Heavy launch will be, given that Delta IV Heavy will share the American heavy-lift spotlight with Falcon Heavy.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mn on 06/26/2019 02:51 am
If the TVC failed, how did the computer intentionally divert?

The center engine TVC failed, but it was not a single-engine landing.

I'll rephrase my question: if you are lined up with the asds why divert? Just continue regulating thrust. If not lined up then you can't call that intentionally diverted.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Norm38 on 06/26/2019 03:28 am
I would love to see a dramatic style CGI video of the center core divert burn. It got flat horizontal. Must have looked damn cool from certain angles.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Asteroza on 06/26/2019 04:09 am
I guess a 2 out of 3 engine landing wasn't in the cards then. Not enough time left to do a longer burn after an emergency center engine shutdown, but with two engines they had enough thrust to abort, so logically landing was possible? I guess that means they might have been able to land with two, but crippled TVC is too scary to try, thus the abort...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lars-J on 06/26/2019 04:42 am
If the TVC failed, how did the computer intentionally divert?

How do you know it diverted? The TVC failed just before landing (since it got so close), and it seems to have done a hard turn. It just may just have looked like an intentional diversion. With TVC out, there is no control. And the other engines cannot pick up the slack.

EDIT: update after Musks tweet where he assumes it diverted.

But with no TVC control, this may have been an intentional/controlled divert just as much as you can divert a car where the steering wheel locks up. Not much control left. :) (The center engine has much more gimbal range than the two others)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat on 06/26/2019 04:45 am
If the TVC failed, how did the computer intentionally divert?

How do you know it diverted? The TVC failed just before landing (since it got so close), and it seems to have done a hard turn. It just looked like an intentional diversion.
Musk seems to think it probably did.

https://twitter.com/elonmusk/status/1143690145255841797?s=21
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: XenIneX on 06/26/2019 04:57 am
I'll rephrase my question: if you are lined up with the asds why divert? Just continue regulating thrust. If not lined up then you can't call that intentionally diverted.
Landing is an inherently unstable process, which requires active, precision maneuvering.  Successfully doing after an engine has spontaneously decided to start flapping in the breeze is exceedingly unlikely.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CJ on 06/26/2019 05:21 am
Do we know exactly what kind of a 3-engine landing burn the center core was attempting?

The reason I ask is we've seen (first FH side core landings) a 1-3-1 burn for landing. *If* that is the "3 engine landing" the center core was attempting, and the center core TVC was out, the core could not land suvivably. Either it diverted, or, shut down the two outer engines, leaving an off-center center engine running, an unintentional divert.   
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ThatOldJanxSpirit on 06/26/2019 06:26 am
Do we know exactly what kind of a 3-engine landing burn the center core was attempting?

The reason I ask is we've seen (first FH side core landings) a 1-3-1 burn for landing. *If* that is the "3 engine landing" the center core was attempting, and the center core TVC was out, the core could not land suvivably. Either it diverted, or, shut down the two outer engines, leaving an off-center center engine running, an unintentional divert.   

It still has throttle authority, so even with no effective directional control it could still have attempted some kind of abort.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: lrk on 06/26/2019 07:03 am
I guess a 2 out of 3 engine landing wasn't in the cards then. Not enough time left to do a longer burn after an emergency center engine shutdown, but with two engines they had enough thrust to abort, so logically landing was possible? I guess that means they might have been able to land with two, but crippled TVC is too scary to try, thus the abort...

Two engines was probably too much thrust to land, as the rocket usually cuts to 1 engine just before landing and even then the TWR is much greater than 1.  Not to mention an engine-out capability for landing is not a trivial thing to add to the control logic, even if theoretically doable. 
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/26/2019 09:45 am

twitter.com/elonmusk/status/1143686587877691392

Quote
Yes, but we couldn’t take a chance on 2nd stage failing it’s 4th maneuver. This mission was more complex than anything I’m aware of in history of rockets. RIP center core, you did your duty well.

I believe Proton-M/Briz-M missions are more complicated. The Briz-M does five burns plus a tank separation (parking orbit insertion, intermediate orbit insertion, transfer orbit insertion 1, tank separation, transfer orbit insertion 2 and geosynchronous transfer orbit insertion). Mission duration is 11 hours. In comparison, the FH second stage only did four burns and had a mission duration of 3.5 hours.

http://www.russianspaceweb.com/mexsat1.html
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Semmel on 06/26/2019 11:14 am

twitter.com/elonmusk/status/1143686587877691392

Quote
Yes, but we couldn’t take a chance on 2nd stage failing it’s 4th maneuver. This mission was more complex than anything I’m aware of in history of rockets. RIP center core, you did your duty well.

I believe Proton-M/Briz-M missions are more complicated. The Briz-M does five burns plus a tank separation (parking orbit insertion, intermediate orbit insertion, transfer orbit insertion 1, tank separation, transfer orbit insertion 2 and geosynchronous transfer orbit insertion). Mission duration is 11 hours. In comparison, the FH second stage only did four burns and had a mission duration of 3.5 hours.

http://www.russianspaceweb.com/mexsat1.html

Yeah, he overtrumped that statement quite a bit. This was a complex mission, and maybe SpaceXes most complex mission. But there are plenty more complex missions. Even if you restrict it to launch vehicles only.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: HeartofGold2030 on 06/26/2019 11:39 am

twitter.com/elonmusk/status/1143686587877691392

Quote
Yes, but we couldn’t take a chance on 2nd stage failing it’s 4th maneuver. This mission was more complex than anything I’m aware of in history of rockets. RIP center core, you did your duty well.

I believe Proton-M/Briz-M missions are more complicated. The Briz-M does five burns plus a tank separation (parking orbit insertion, intermediate orbit insertion, transfer orbit insertion 1, tank separation, transfer orbit insertion 2 and geosynchronous transfer orbit insertion). Mission duration is 11 hours. In comparison, the FH second stage only did four burns and had a mission duration of 3.5 hours.

http://www.russianspaceweb.com/mexsat1.html

So the most complex mission done with cryogenic propellants then? Briz-M is a hypergolic tug, so multiple relights with coasts in between isn’t really that impressive because hypergols don’t suffer from the same problems cryos do when stored on orbit for lengthy periods e.g. boil off. These aforementioned problems are what makes STP-2 such a complex mission.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: rsdavis9 on 06/26/2019 11:41 am

twitter.com/elonmusk/status/1143686587877691392

Quote
Yes, but we couldn’t take a chance on 2nd stage failing it’s 4th maneuver. This mission was more complex than anything I’m aware of in history of rockets. RIP center core, you did your duty well.

I believe Proton-M/Briz-M missions are more complicated. The Briz-M does five burns plus a tank separation (parking orbit insertion, intermediate orbit insertion, transfer orbit insertion 1, tank separation, transfer orbit insertion 2 and geosynchronous transfer orbit insertion). Mission duration is 11 hours. In comparison, the FH second stage only did four burns and had a mission duration of 3.5 hours.

http://www.russianspaceweb.com/mexsat1.html

So the most complex mission done with cryogenic propellants then? Briz-M is a hypergolic tug, so multiple relights with coasts in between isn’t really that impressive because hypergols don’t suffer from the same problems cryos do when stored on orbit for lengthy periods e.g. boil off. These aforementioned problems are what makes STP-2 such a complex mission.

And don't most(all?) hypergols have bladders?
So no fuel settling.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: kdhilliard on 06/26/2019 11:58 am
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf
Propulsive depassivation and it has been left out in a graveyard orbit.
Does that imply a fifth engine start, with burn to depletion?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/26/2019 11:59 am
Anyone know what the inclination of the DSX payload was supposed to be in the end? Preflight orbit target showed it to be 43 deg, whereas it actually ended up in a 42.2 deg inclination.

Since both the apogee and perigee are right on target in the TLEs (within expected accuracy), the inclination discrepancy of 0.8 deg seems to be too significant, unless that was the plan all along.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/26/2019 12:00 pm
Would it have been possible for the center core to be expended while the side boosters still returned to LZ-1 and LZ-2?

My logic is so that we wouldn’t have to worry about a potential landing going awry. But then again, maybe SpaceX wanted to recover the center core to reuse it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/26/2019 12:03 pm
Would it have been possible for the center core to be expended while the side boosters still returned to LZ-1 and LZ-2?

Why wouldn't it be possible? What the center core does after BECO is of no consequence to booster RTLS, at that point it would behave just like an expendable F9 launch and just provide more margin to the 2nd stage.

My logic is so that we wouldn’t have to worry about a potential landing going awry. But then again, maybe SpaceX wanted to recover the center core to reuse it.

Of course they wanted to recover it. If not to reuse it, at least to inspect for potential weak points during high energy returns.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ClayJar on 06/26/2019 12:15 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf
Propulsive depassivation and it has been left out in a graveyard orbit.
Does that imply a fifth engine start, with burn to depletion?

Judging by the term and what it looked like in CGI in the pre-mission video, it looked more like venting through the engine (i.e. out the nozzle).  I wouldn't suggest we always use the videos as canonical references, of course, but in this case it looks like the propulsive passivation is basically venting the tanks using the Merlin as a cold gas thruster with a really large nozzle.

I don't know what the Isp is for an MVac as a cold gas thruster with propellant consisting of helium pressurant and what LOX may boil, but I suppose it's something.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ThatOldJanxSpirit on 06/26/2019 12:22 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf
Propulsive depassivation and it has been left out in a graveyard orbit.
Does that imply a fifth engine start, with burn to depletion?

Judging by the term and what it looked like in CGI in the pre-mission video, it looked more like venting through the engine (i.e. out the nozzle).  I wouldn't suggest we always use the videos as canonical references, of course, but in this case it looks like the propulsive passivation is basically venting the tanks using the Merlin as a cold gas thruster with a really large nozzle.

I don't know what the Isp is for an MVac as a cold gas thruster with propellant consisting of helium pressurant and what LOX may boil, but I suppose it's something.

Last parameters update I saw had the rocket body and DSX payload in orbits with just a few km difference in apogee and perigee, so no indication of a fifth burn yet.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/26/2019 12:29 pm
Do we know exactly what kind of a 3-engine landing burn the center core was attempting?

The reason I ask is we've seen (first FH side core landings) a 1-3-1 burn for landing. *If* that is the "3 engine landing" the center core was attempting, and the center core TVC was out, the core could not land suvivably. Either it diverted, or, shut down the two outer engines, leaving an off-center center engine running, an unintentional divert.   

I think it was a 1-3-1 landing burn, primarily based on the symmetry of the plume on the video as the stage pitched away.  As far as it being an intentional maneuver, I don't think Musk *knows*, I think he believes it *could* have.  A landing stage is really unstable, to the point you need two active control systems (RCS and engine gimbal) to keep things under control.  So if the TVS failed for whatever reason (my personal is that hydraulic system was breached and depleted right before touchdown), it's going to pitch over really dramatically, and really quickly.

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/26/2019 02:18 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf
Propulsive depassivation and it has been left out in a graveyard orbit.
Does that imply a fifth engine start, with burn to depletion?

It's what NASA defines it to be a propulsive depassivation but I don't certainly know if they ended up doing it. If you look at the difference between the FH S2 orbit and the DSX orbit, there is not much difference so either they determined it was not safe to run the engine again or the tanks literally had no more fuel to make the engine run and just vented off gasses, the ACS gas and all of that and drained the batteries (which is a standard passivation maneuver).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: eeergo on 06/26/2019 03:04 pm

twitter.com/elonmusk/status/1143686587877691392

Quote
Yes, but we couldn’t take a chance on 2nd stage failing it’s 4th maneuver. This mission was more complex than anything I’m aware of in history of rockets. RIP center core, you did your duty well.

I believe Proton-M/Briz-M missions are more complicated. The Briz-M does five burns plus a tank separation (parking orbit insertion, intermediate orbit insertion, transfer orbit insertion 1, tank separation, transfer orbit insertion 2 and geosynchronous transfer orbit insertion). Mission duration is 11 hours. In comparison, the FH second stage only did four burns and had a mission duration of 3.5 hours.

http://www.russianspaceweb.com/mexsat1.html

So the most complex mission done with cryogenic propellants then? Briz-M is a hypergolic tug, so multiple relights with coasts in between isn’t really that impressive because hypergols don’t suffer from the same problems cryos do when stored on orbit for lengthy periods e.g. boil off. These aforementioned problems are what makes STP-2 such a complex mission.

And don't most(all?) hypergols have bladders?
So no fuel settling.


Briz-M uses ullage thrusters, and has the toroidal APT crossfed to the central stage which has to be jettisoned.

Concerning the cryo storage, Centaur has achieved many 3h+ missions with a fully (not semi-) cryogenic stage. It's true that, as far as I'm aware, the stage has only demonstrated 3-burn missions, but cryo loiter times have been much longer, up to 5h. Delta IV's also fully-cryo DCSS has multi-start capability for <7h missions.

Maybe it can be argued STP-2's upper stage made the most challenging multi-burn profile of a semicryo upper stage ever, and indeed landing attempts has been the most complex behavior of lower stages to date for a while now, not just on this mission - but that's kind of different than "most complex mission in the history of rockets".
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: JamesH65 on 06/26/2019 03:15 pm
One could argue that the added complexity of landing three stages pushes it past some arbitrary level. The complexity of the entire mission should probably include those features.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: intelati on 06/26/2019 03:21 pm
One could argue that the added complexity of landing three stages pushes it past some arbitrary level. The complexity of the entire mission should probably include those features.

Even subtracting the first stage considerations, it's a complex mission on its own. That's my view of the launch anyways.

Add in the booster seperations and landingS...!!!
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: abaddon on 06/26/2019 03:23 pm
One could argue that the added complexity of landing three stages pushes it past some arbitrary level. The complexity of the entire mission should probably include those features.
...catching one of the fairing halves, recovering the other one, drone ship, landing pads...

Yeah.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lar on 06/26/2019 03:26 pm
What happened to the spent second stage?  There is no mention of it’s final disposition in the press kit:  https://www.spacex.com/sites/spacex/files/stp-2_press_kit.pdf
Propulsive depassivation and it has been left out in a graveyard orbit.

What is propulsive DEpassivation? Is that like activation?

It still has throttle authority, so even with no effective directional control it could still have attempted some kind of abort.
If you have thrust off center and you want to control which direction you skitter off in (to abort more safely, say, deliberately avoiding travel in the direction of support vessels for example) rather than a random direction, doing a roll with the nitrogen thrusters might be a way to choose your direction. Roll till the off center thrust is diverting you in the direction you want to go, then stop rolling.

Actually landing by using fancy rolls to make your off center thrust cancel out over time seems a stretch but not completely impossible. The booster would appear to be gyrating wildly.

In both cases you'd have to have programmed that failure mode in though I think.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kansan52 on 06/26/2019 03:42 pm
My understanding of "propulsive DEpassivation" is placing the stage in the chosen orbit and venting fuel and oxidizer to reduce the chance of explosion and debris cloud later.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Prettz on 06/26/2019 03:54 pm

twitter.com/elonmusk/status/1143686587877691392

Quote
Yes, but we couldn’t take a chance on 2nd stage failing it’s 4th maneuver. This mission was more complex than anything I’m aware of in history of rockets. RIP center core, you did your duty well.

I believe Proton-M/Briz-M missions are more complicated. The Briz-M does five burns plus a tank separation (parking orbit insertion, intermediate orbit insertion, transfer orbit insertion 1, tank separation, transfer orbit insertion 2 and geosynchronous transfer orbit insertion). Mission duration is 11 hours. In comparison, the FH second stage only did four burns and had a mission duration of 3.5 hours.

http://www.russianspaceweb.com/mexsat1.html

So the most complex mission done with cryogenic propellants then? Briz-M is a hypergolic tug, so multiple relights with coasts in between isn’t really that impressive because hypergols don’t suffer from the same problems cryos do when stored on orbit for lengthy periods e.g. boil off. These aforementioned problems are what makes STP-2 such a complex mission.

And don't most(all?) hypergols have bladders?
So no fuel settling.
Isn't it that only spacecraft use bladders for hypergolic tanks? I can't think of any hypergolic rocket stages that use that. You've got Delta K, Ariane 5 EPS, the Agena family, Transtage, etc. Unless Russian tug stages do use it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kabloona on 06/26/2019 03:55 pm
My understanding of "propulsive DEpassivation" is placing the stage in the chosen orbit and venting fuel and oxidizer to reduce the chance of explosion and debris cloud later.

Lar was asking a rhetorical question about "DEpassivation," which is the grammatical equivalent of "irregardless."

What Alexphysics meant to say is "propulsive passivation."

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Kansan52 on 06/26/2019 04:03 pm
Ahhh.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Lar on 06/26/2019 04:54 pm
My understanding of "propulsive DEpassivation" is placing the stage in the chosen orbit and venting fuel and oxidizer to reduce the chance of explosion and debris cloud later.
Lar was asking a rhetorical question about "DEpassivation," which is the grammatical equivalent of "irregardless."

What Alexphysics meant to say is "propulsive passivation."
Exactly. I know what passivation is. Make the stage passive!

I'm not clear on how to DEpassivate something after you passivated it (unless you have on orbit refueling and battery recharging to undo the passivation you did by venting and discharging... that day is coming but not here yet) Hence my question to Alexphysics
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/26/2019 04:57 pm
Would it have been possible for the center core to be expended while the side boosters still returned to LZ-1 and LZ-2?

Why wouldn't it be possible? What the center core does after BECO is of no consequence to booster RTLS, at that point it would behave just like an expendable F9 launch and just provide more margin to the 2nd stage.

My logic is so that we wouldn’t have to worry about a potential landing going awry. But then again, maybe SpaceX wanted to recover the center core to reuse it.

Of course they wanted to recover it. If not to reuse it, at least to inspect for potential weak points during high energy returns.

What I meant by "is it possible" is because of your answer: providing more margin for the upper stage to complete the mission without running out of delta-v.

However, another factor to that question is what if the side boosters did not have enough delta-v to return to the Cape since there is not a second drone ship for one of the side boosters. Even though expending the center core provides more margin, they would still want to recover the side boosters using the right amount of delta-v.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: whitelancer64 on 06/26/2019 05:03 pm
My understanding of "propulsive DEpassivation" is placing the stage in the chosen orbit and venting fuel and oxidizer to reduce the chance of explosion and debris cloud later.
Lar was asking a rhetorical question about "DEpassivation," which is the grammatical equivalent of "irregardless."

What Alexphysics meant to say is "propulsive passivation."
Exactly. I know what passivation is. Make the stage passive!

I'm not clear on how to DEpassivate something after you passivated it (unless you have on orbit refueling and battery recharging to undo the passivation you did by venting and discharging... that day is coming but not here yet) Hence my question to Alexphysics

It's obviously a typo. Don't be a jerk about it.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/26/2019 05:21 pm
Would it have been possible for the center core to be expended while the side boosters still returned to LZ-1 and LZ-2?

Why wouldn't it be possible? What the center core does after BECO is of no consequence to booster RTLS, at that point it would behave just like an expendable F9 launch and just provide more margin to the 2nd stage.

What I meant by "is it possible" is because of your answer: providing more margin for the upper stage to complete the mission without running out of delta-v.

However, another factor to that question is what if the side boosters did not have enough delta-v to return to the Cape since there is not a second drone ship for one of the side boosters. Even though expending the center core provides more margin, they would still want to recover the side boosters using the right amount of delta-v.

I'm not sure what you're getting at here. Why would the fate of the center core have any direct say in what happens to the boosters?

The center core pretty much runs at lowest throttle the whole time shortly after clearing the pad until BECO and so whether or not the center core is expended afterwards, it does not change the staging point of the boosters (neglecting the modest mass of recovery hardware on the center core) if they were to RTLS. The subsequent burn time of the center core does not play into that trade.

There is nothing practical that prevents a combination of 1) booster RTLS and 2) center core expenditure.

Now, whether or not SpaceX would ever choose to fly such a profile or if it makes sense for one reason or another is a different question.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ZachS09 on 06/26/2019 05:31 pm
Would it have been possible for the center core to be expended while the side boosters still returned to LZ-1 and LZ-2?

Why wouldn't it be possible? What the center core does after BECO is of no consequence to booster RTLS, at that point it would behave just like an expendable F9 launch and just provide more margin to the 2nd stage.

What I meant by "is it possible" is because of your answer: providing more margin for the upper stage to complete the mission without running out of delta-v.

However, another factor to that question is what if the side boosters did not have enough delta-v to return to the Cape since there is not a second drone ship for one of the side boosters. Even though expending the center core provides more margin, they would still want to recover the side boosters using the right amount of delta-v.

I'm not sure what you're getting at here. Why would the fate of the center core have any direct say in what happens to the boosters?

The center core pretty much runs at lowest throttle the whole time shortly after clearing the pad until BECO and so whether or not the center core is expended afterwards, it does not change the staging point of the boosters (neglecting the modest mass of recovery hardware on the center core) if they were to RTLS. The subsequent burn time of the center core does not play into that trade.

There is nothing practical that prevents a combination of 1) booster RTLS and 2) center core expenditure.

Now, whether or not SpaceX would ever choose to fly such a profile or if it makes sense for one reason or another is a different question.

You're right. I guess my theory didn't make sense in the first place.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Star One on 06/26/2019 05:57 pm
How many more flights does FH have to do to be certified to carry the various classes of NASA science payloads?

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180007026.pdf
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vanoord on 06/26/2019 05:59 pm
Would it have been possible for the center core to be expended while the side boosters still returned to LZ-1 and LZ-2?

My logic is so that we wouldn’t have to worry about a potential landing going awry. But then again, maybe SpaceX wanted to recover the center core to reuse it.

The justification to expend the centre core for this mission would (presumably) have been to enable the second stage to retain enough fuel for a de-orbit burn.

However, the opportunity existed to bring a centre core home for the first time; and to subject a core to the most extreme heating one has yet endured and see what happened.

This time, the core didn't survive. Next time it might - and the lessons learned, even from a core that might not fly again, may be invaluable.

*If* SpaceX had got this core back and it turned out it had only just made it back but was in very bad shape, that might have increased the odds of the next Falcon Heavy with this sort of flight profile flying in expendable mode to negate the risk of losing the grid fins and legs etc. - but we won't know until they have got one back after this sort of punishment.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/26/2019 06:29 pm
My understanding of "propulsive DEpassivation" is placing the stage in the chosen orbit and venting fuel and oxidizer to reduce the chance of explosion and debris cloud later.
Lar was asking a rhetorical question about "DEpassivation," which is the grammatical equivalent of "irregardless."

What Alexphysics meant to say is "propulsive passivation."
Exactly. I know what passivation is. Make the stage passive!

I'm not clear on how to DEpassivate something after you passivated it (unless you have on orbit refueling and battery recharging to undo the passivation you did by venting and discharging... that day is coming but not here yet) Hence my question to Alexphysics

It's obviously a typo. Don't be a jerk about it.

Yep, a typo, don't know what I was thinking about. Sorry for the confusion :(
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: punder on 06/26/2019 06:45 pm
How many more flights does FH have to do to be certified to carry the various classes of NASA science payloads?

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180007026.pdf

Sometimes I wonder if NASA even knows the FH exists.

And yes, that's unhelpful cynical fanboi sarcasm. What I really meant to say was, Congrats SpaceX! What a spectacular mission. And bonus, a solar sail. Sure hope it works.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: XenIneX on 06/26/2019 07:00 pm
If you have thrust off center and you want to control which direction you skitter off in (to abort more safely, say, deliberately avoiding travel in the direction of support vessels for example) rather than a random direction, doing a roll with the nitrogen thrusters might be a way to choose your direction. Roll till the off center thrust is diverting you in the direction you want to go, then stop rolling.

Actually landing by using fancy rolls to make your off center thrust cancel out over time seems a stretch but not completely impossible. The booster would appear to be gyrating wildly.

In both cases you'd have to have programmed that failure mode in though I think.
Too complicated.  Just push TVC and RCS over to one side and throttle up.  Between them, they should overpower the malfunctioning engine -- and the rocket would be unstable anyway.  The rocket will tumble, arcing several hundred feet away from the ASDS, and since the support ships are miles away, they're perfectly safe.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/26/2019 07:00 pm
Don't forget that even though the center core missed the drone ship, SpaceX got full telemetry from it: the drone ship acquires signal from the booster, and I believe several of the GO sisters can as well. It's recorded, not real time, so SpaceX likely won't have the full data for a week or so yet until the fleet returns (it took six days for OCISLY to get on station).  But there's a lot of data coming back from this attempt.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Okie_Steve on 06/26/2019 08:49 pm
Given how close it got to the "X" on deck before aborting I have to wonder when the TVC failed and how. It would not surprise me if boostback and entry have the engines at dead center and the landing burn starts that way. So, was the TVC fried earlier and not noticed or was it damaged earlier and gave up the ghost at the very end? It looked like it might have made it to somewhere on the deck it it had not aborted. I wonder what the lawn dart damage cost last time vs getting the stage back intact. Interesting trade off.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/26/2019 09:02 pm
Some computed values for the STP-2 launch:

Center core cutoff at 11083 km/hr ( = 3079 m/s) at altitude of 123 km and time 3:34. Staging speed is therefore 99 m/s more then Arabsat 6, which was 2980 m/s.   Re-entry burn starts at 9:43, so coast was 6:10 or 370 seconds.

Assuming re-entry burn at 60 km, we can solve for vertical component of velocity by solving 123,000 + v*t - 9.8/2*t^2 = 60,000, where t = 370 seconds.  We find a vertical velocity at cutoff of 1643 m/s.  Given the overall speed of 3079 m/s, horizontal speed is 2604 m/s.  Coasting at this speed, in 370 seconds the stage covers 963 km, so all is consistent.  (The rest is launch to sep, and entry to landing).

Peak altitude is 261 km at 167.5 seconds after staging.  The energy per kg that must be lost by the stage in landing is g*h + 1/2*v^2, and is 5,946,000 joules/kg.   For comparison, Arabsat (103 km, 2970 m/s) was 5,449,000 joules/kg.  So this landing was 9% more energetic.  More significant, most likely, are (a) less fuel left for slowing down, as more was used for boost, and (b) a steeper angle of re-entry from the much more lofted trajectory.

From webcast telemetry I got a vertical velocity at MECO of about 1km/s which corresponds to a tangent velocity of about 2.9km/s and for those values, at the altitude it was at MECO (123km) our friend Newton says the apogee would have been 180km (almost 181km if you round up the number) and not 261km :/
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 06/26/2019 11:28 pm
Some computed values for the STP-2 launch:

Center core cutoff at 11083 km/hr ( = 3079 m/s) at altitude of 123 km and time 3:34. Staging speed is therefore 99 m/s more then Arabsat 6, which was 2980 m/s.   Re-entry burn starts at 9:43, so coast was 6:10 or 370 seconds.

Assuming re-entry burn at 60 km, we can solve for vertical component of velocity by solving 123,000 + v*t - 9.8/2*t^2 = 60,000, where t = 370 seconds.  We find a vertical velocity at cutoff of 1643 m/s.  Given the overall speed of 3079 m/s, horizontal speed is 2604 m/s.  Coasting at this speed, in 370 seconds the stage covers 963 km, so all is consistent.  (The rest is launch to sep, and entry to landing).

Peak altitude is 261 km at 167.5 seconds after staging.  The energy per kg that must be lost by the stage in landing is g*h + 1/2*v^2, and is 5,946,000 joules/kg.   For comparison, Arabsat (103 km, 2970 m/s) was 5,449,000 joules/kg.  So this landing was 9% more energetic.  More significant, most likely, are (a) less fuel left for slowing down, as more was used for boost, and (b) a steeper angle of re-entry from the much more lofted trajectory.

From webcast telemetry I got a vertical velocity at MECO of about 1km/s which corresponds to a tangent velocity of about 2.9km/s and for those values, at the altitude it was at MECO (123km) our friend Newton says the apogee would have been 180km (almost 181km if you round up the number) and not 261km :/

Are you including the sub-orbital nature of the trajectory? Altitude = v²/2g only applies in the idealized case where horizontal velocity is an inconsequential fraction of orbital velocity.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: edkyle99 on 06/26/2019 11:36 pm
Given how close it got to the "X" on deck before aborting I have to wonder when the TVC failed and how.
I keep reading statements like this - that the stage "aborted" at the last second.  Is there a basis for such assertions? 
Wouldn't the stage behave in similar fashion if TVC failed in the final moments (which is the failure mode described by Elon)?

 - Ed Kyle
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Coastal Ron on 06/26/2019 11:57 pm
Given how close it got to the "X" on deck before aborting I have to wonder when the TVC failed and how.
I keep reading statements like this - that the stage "aborted" at the last second.  Is there a basis for such assertions?

Yes, Elon Musk on Twitter:

Quote
Everyday Astronaut: And did the computer know that and know to divert?!?!

Elon Musk: Most likely. It is programmed to do so.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/27/2019 12:25 am
Well, IMO, "most likely" doesn't translate into "that's what it did."  It *might* have, but think about it: how can you tell from an external video source if the pitch over was a commanded response or just a result of the failure itself?

If S1 *did* abort, then I'd re-examine the criteria for an abort.  It appeared that the vertical velocity was right on target for an attempted landing, so if it did fail on landing the damage to ASDS would be no worse than any other failed landing attempt.

HUGE GUESSING ALERT:  I'm not saying this is what happened, it's just my guess.  And I'd say I've got a really small chance of getting this right:

I'm guessing that the damage to the TVC was in the actuator hydraulic.  If there was a leak on the return line of the hydraulics loop, the supply could have been depleted over time, finally running out right at the end. 

I don't know how much authority the RCS has during the terminal phase compared to TVC, but if it's large then that shoots a pretty big hole in my theory.

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ulm_atms on 06/27/2019 12:27 am
Doesn't the TVC use RP-1 for the hydraulic fluid?  I wonder if the hydraulic pump pulled air and stalled the TVC...or reentry fried a feed line to the pump for the air pull to happen.  They were already so close on fuel to begin with for this.  Maybe Elon will give more info in the future.  :)

I do see them drawing a 1000km line however between reusable/expendable for ASDS landings.  Since heat breached the engine bay (from Elon), they would have to redesign some of the protection down there...with all their money into Starship...I don't see it being a high priority at this point.  What was the longest successful ASDS?  I think this was the first ASDS over 1000km  ???
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ulm_atms on 06/27/2019 12:32 am
I don't know how much authority the RCS has during the terminal phase compared to TVC, but if it's large then that shoots a pretty big hole in my theory.

The TVC is like 98% of the control authority in the last few seconds.  Air speed is too slow for the fins to do too much and the GN2 can't do much at ground level.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/27/2019 12:35 am
I think they use normal hydraulic fluid to drive the actuators.  But they're driven by turbo-pumps, so if the fuel system burped then it could affect the system.  BUT, I think we would have seen some significant engine instability at the same time, which I didn't see until the stage was almost horizontal.

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Herb Schaltegger on 06/27/2019 01:09 am
Just to toss out support for Elon's tweet (like that should even be necessary but here we are) ...

Hydraulic TVC systems can have multiple failure modes. Elon's initial tweet indicating that the system failed does not specify which of the numerous failure mode or modes actually occurred, nor does his tweet say the system was completely non-functional. It is quite possible that the system failed in one axis, or that hydraulic pressure was falling and thus unlikely to be able to control safely to landing, thus leading the guidance software to command a divert maneuver.

In short, we ought to respect his comment and realize we don't know nearly as much about the detailed hardware designs or the control software as he does.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/27/2019 01:25 am
I have no issue with what Elon said in his tweet:  "Most likely."  He didn't say "yes it did", he said that was a likely scenario. 
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Okie_Steve on 06/27/2019 02:28 am
The early Merlins did use RP-1 for gimbal as I recall, but no longer.

I should have said "divert" instead of "abort" in my original post. As I understand it, much like RTL landings aim off shore until fairly close and the retargets to the LZ so the debris path in case of failure,  ASDS landings aim for a near miss to avoid lawn darts on failure and retarget to the "X"  when fairly close. Since we could see exhaust painting said "X"  from less than one Falcon length* up I think that qualifies as close. Only then did it divert. While it is hard to measure nearly empty tanks they clearly thought there was enough propellant to go for the landing. And given the length of the divert burn I think they were correct in that thought.

Elon said the root cause was reenty heat damage, but when did the TVC actually pack it in? Did it fail during the landing burn or was it only discovered during the landing burn? Or, possibly, was it known ahead of time and they tried to compensate as long as possible anyway but ultimately had to punt and thus diverted. Which now that I think about it might be good practice toward landing on Mars where divert is not an option, along the lines of "Any landing you can walk away from ..."

Any one have a good estimate how close to the deck the feet got before the divert?

I am still curious about the relative expense of ASDS lawn dart repairs vs the value of a recovered booster in (apparently) borderline situations like this.

*New unit of measure
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/27/2019 02:49 am
Elon said the root cause was reenty heat damage, but when did the TVC actually pack it in? Did it fail during the landing burn or was it only discovered during the landing burn? Or, possibly, was it known ahead of time and they tried to compensate as long as possible anyway but ultimately had to punt and thus diverted.

Well, the landings are totally autonomous, so the booster would have to determine when to divert (maybe that's what you meant).  ASSUMING my theory of hydraulic fluid depletion is correct (btw, this is just a fun conversation until we learn more), then they probably saw the fluid level dropping on telemetry, but obviously couldn't do anything about it.

<engage Daffy Duck voice> "of coase, I cud be wong."

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: rubicondsrv on 06/27/2019 02:57 am

I am still curious about the relative expense of ASDS lawn dart repairs vs the value of a recovered booster in (apparently) borderline situations like this.

*New unit of measure

Steel is cheap even when tens of tons are being replaced.  the propulsion system is more costly than steel plate, but likely still fairly inexpensive. IMO the biggest concern would be schedule impacts due to repairs.   
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/27/2019 03:13 am
Some computed values for the STP-2 launch:

Center core cutoff at 11083 km/hr ( = 3079 m/s) at altitude of 123 km and time 3:34. Staging speed is therefore 99 m/s more then Arabsat 6, which was 2980 m/s.   Re-entry burn starts at 9:43, so coast was 6:10 or 370 seconds.

Assuming re-entry burn at 60 km, we can solve for vertical component of velocity by solving 123,000 + v*t - 9.8/2*t^2 = 60,000, where t = 370 seconds.  We find a vertical velocity at cutoff of 1643 m/s.  Given the overall speed of 3079 m/s, horizontal speed is 2604 m/s.  Coasting at this speed, in 370 seconds the stage covers 963 km, so all is consistent.  (The rest is launch to sep, and entry to landing).

Peak altitude is 261 km at 167.5 seconds after staging.  The energy per kg that must be lost by the stage in landing is g*h + 1/2*v^2, and is 5,946,000 joules/kg.   For comparison, Arabsat (103 km, 2970 m/s) was 5,449,000 joules/kg.  So this landing was 9% more energetic.  More significant, most likely, are (a) less fuel left for slowing down, as more was used for boost, and (b) a steeper angle of re-entry from the much more lofted trajectory.

From webcast telemetry I got a vertical velocity at MECO of about 1km/s which corresponds to a tangent velocity of about 2.9km/s and for those values, at the altitude it was at MECO (123km) our friend Newton says the apogee would have been 180km (almost 181km if you round up the number) and not 261km :/
I agree that the altitude number was changing more slowly than expected, but computing velocity by differentiating a delayed, filtered, and quantized number is susceptible to lots of potential errors.

If the altitude at cutoff was 123 km, and the vertical velocity 1000 m/s, then we can calculate the altitude 370 seconds later at entry burn.  It is h0 +v*t - 1/2*g*t^2, or 123000 + 1000*370 - 9.8/2*370^2 = -177.8 km.   It's pretty clear that the entry burn was in the atmosphere, not the earth's mantle, so the vertical velocity must be quite a bit higher.   Since we know for sure the entry burn was above sea level, we know vertical velocity must be at least (-123000 + 0.5*9.8*370^2)/370 = 1480 m/s.  (But see the sub-orbital correction below.)  A more realistic assumption of a 60 km entry burn gives the numbers above.

Are you including the sub-orbital nature of the trajectory? Altitude = v²/2g only applies in the idealized case where horizontal velocity is an inconsequential fraction of orbital velocity.
This is a reasonable correction.   Since horizontal v is about 2600 m/s, and the Earth's radius about 6356 km, then the acceleration induced is v^2/r =2600^2/6456000 = 1.05 m/s^2.  So instead of 9.8 m/s^2, we should use 8.75 m/s^2.   We then solve for the vertical v where 123000+v*370 - 1/2*a*370^2 = 60000, and get a corrected vertical velocity of 1448 m/s.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 06/27/2019 03:43 am
Since horizontal v is about 2600 m/s, and the Earth's radius about 6356 km, then the acceleration induced is v^2/r =2600^2/6456000 = 1.05 m/s^2.  So instead of 9.8 m/s^2, we should use 8.75 m/s^2.   We then solve for the vertical v where 123000+v*370 - 1/2*a*370^2 = 60000, and get a corrected vertical velocity of 1448 m/s.

So, updating:
Flight path angle sin-1(1448/3079) = 28°
Horizontal component = cos(28°) x 3079 = 2,717m/s
Downrange distance covered = 370s x 2,717m/s = 1,005kms

Plus a bit more due to the increased induced acceleration.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Okie_Steve on 06/27/2019 04:43 am

I am still curious about the relative expense of ASDS lawn dart repairs vs the value of a recovered booster in (apparently) borderline situations like this.

*New unit of measure

Steel is cheap even when tens of tons are being replaced.  the propulsion system is more costly than steel plate, but likely still fairly inexpensive. IMO the biggest concern would be schedule impacts due to repairs.   

Very good point, I had not thought about that
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: CorvusCorax on 06/27/2019 05:25 am
When would the stage abort a landing and how would it know when to do so?

I don't know how SpaceX implements it, but if I were to design it, instead if trying to cope with many different possible damage models and their expected symptoms, I'd go by a simple criteria similar to the autonomous LAS:

Constantly check whether the vehicles position, velocity and attitude is within a safe corridor to make a safe landing. Try the best to stay within this corridor with whatever actuators are available.

The stage would have done exactly that, and while still going fast enough for grid fins having sufficient control authority over a malfunctionibg TVC, it was seemingly spot on, definitely within the corridor.

The corridor can be calculated dynamically. It would simply be the space from which in an intact, functioning stage has sufficient control authority to make a succesful landing. If you ever go outside of that, you know you can't possibly make it anymore.

The corridor becomes narrower and narrower towards touchdown. At the same time any issue with TVC would become worse due to decreasing grid fin authority.

We did not see the stage in that phase, but my guess is the attitude rate and/or horizontal speed became too high, it left the corridor, knew it wouldnt make it and throttled up for the emergency fallback (safe ocisly)

That would look pretty much the same regardless of the exact type of failure or its cause.

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/27/2019 06:02 am
Some computed values for the STP-2 launch:

Center core cutoff at 11083 km/hr ( = 3079 m/s) at altitude of 123 km and time 3:34. Staging speed is therefore 99 m/s more then Arabsat 6, which was 2980 m/s.   Re-entry burn starts at 9:43, so coast was 6:10 or 370 seconds.

Assuming re-entry burn at 60 km, we can solve for vertical component of velocity by solving 123,000 + v*t - 9.8/2*t^2 = 60,000, where t = 370 seconds.  We find a vertical velocity at cutoff of 1643 m/s.  Given the overall speed of 3079 m/s, horizontal speed is 2604 m/s.  Coasting at this speed, in 370 seconds the stage covers 963 km, so all is consistent.  (The rest is launch to sep, and entry to landing).

Peak altitude is 261 km at 167.5 seconds after staging.  The energy per kg that must be lost by the stage in landing is g*h + 1/2*v^2, and is 5,946,000 joules/kg.   For comparison, Arabsat (103 km, 2970 m/s) was 5,449,000 joules/kg.  So this landing was 9% more energetic.  More significant, most likely, are (a) less fuel left for slowing down, as more was used for boost, and (b) a steeper angle of re-entry from the much more lofted trajectory.

From webcast telemetry I got a vertical velocity at MECO of about 1km/s which corresponds to a tangent velocity of about 2.9km/s and for those values, at the altitude it was at MECO (123km) our friend Newton says the apogee would have been 180km (almost 181km if you round up the number) and not 261km :/
I agree that the altitude number was changing more slowly than expected, but computing velocity by differentiating a delayed, filtered, and quantized number is susceptible to lots of potential errors.

If the altitude at cutoff was 123 km, and the vertical velocity 1000 m/s, then we can calculate the altitude 370 seconds later at entry burn.  It is h0 +v*t - 1/2*g*t^2, or 123000 + 1000*370 - 9.8/2*370^2 = -177.8 km.   It's pretty clear that the entry burn was in the atmosphere, not the earth's mantle, so the vertical velocity must be quite a bit higher.   Since we know for sure the entry burn was above sea level, we know vertical velocity must be at least (-123000 + 0.5*9.8*370^2)/370 = 1480 m/s.  (But see the sub-orbital correction below.)  A more realistic assumption of a 60 km entry burn gives the numbers above.

Are you including the sub-orbital nature of the trajectory? Altitude = v²/2g only applies in the idealized case where horizontal velocity is an inconsequential fraction of orbital velocity.
This is a reasonable correction.   Since horizontal v is about 2600 m/s, and the Earth's radius about 6356 km, then the acceleration induced is v^2/r =2600^2/6456000 = 1.05 m/s^2.  So instead of 9.8 m/s^2, we should use 8.75 m/s^2.   We then solve for the vertical v where 123000+v*370 - 1/2*a*370^2 = 60000, and get a corrected vertical velocity of 1448 m/s.

I didn't use a parabolic equation for that mainly because the Earth is not flat at 1200km of distance. If you use the conservation of energy equation you just need the radial component of the velocity at MECO and the altitude to get the apogee altitude. It might be off by maybe 10 or even 20km mainly because I used the mean earth radius because I don't know the actual radius of the earth at those positions but one can do an estimate with the maximum radius of the earth and one at the minimum radius and do an average of that. And for one speed: I just did a quick interpolation frame by frame of the altitude. I just took 2 seconds of data which is short enough to consider vertical speed to still be sort of constant (I know, not entirely constant, but in such short amount of time one could even improve that and take an average value but within such a short amount of time the average would end up being very close to the actual value you get the other way).
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 06/27/2019 07:12 am
I just did a quick interpolation frame by frame of the altitude. I just took 2 seconds of data which is short enough to consider vertical speed to still be sort of constant (I know, not entirely constant, but in such short amount of time one could even improve that and take an average value but within such a short amount of time the average would end up being very close to the actual value you get the other way).

Assuming 2,717m/s is the horizontal component at 123kms, the induced acceleration is v²/r = 2717²/6456000 = 1.14m/s upwards. So, the total acceleration is 9.8 - 1.14 = 8.66m/s. The vertical velocity is 1,448m/s, so from apogee = v²/2g, the core stage apogee would be at 123,000 + 1,448²/(2*8.66) = 244,057m or 244kms.

I will try to complete a simulation of STP-2 by the weekend, it might be interesting to compare results then.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/27/2019 09:03 am
I just did a quick interpolation frame by frame of the altitude. I just took 2 seconds of data which is short enough to consider vertical speed to still be sort of constant (I know, not entirely constant, but in such short amount of time one could even improve that and take an average value but within such a short amount of time the average would end up being very close to the actual value you get the other way).

Assuming 2,717m/s is the horizontal component at 123kms, the induced acceleration is v²/r = 2717²/6456000 = 1.14m/s upwards. So, the total acceleration is 9.8 - 1.14 = 8.66m/s. The vertical velocity is 1,448m/s, so from apogee = v²/2g, the core stage apogee would be at 123,000 + 1,448²/(2*8.66) = 244,057m or 244kms.

I will try to complete a simulation of STP-2 by the weekend, it might be interesting to compare results then.

Yeah that's the problem. I got about 1.04km/s of vertical speed and about 2.89km/s of horizontal speed at MECO and not those other numbers. At apogee the velocity is just the tangent component of the velocity which is constant over the flight at 2.89km/s. Using that as the final velocity you can figure out that the apogee can be calculated as:

rf = (1/ri - (vi^2-vf^2)/2GM)^-1

And then you substract the radius of the earth from rf and you get the apogee altitude.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Pete on 06/27/2019 09:26 am
Guys, you cannot just plug in earth-surface kinematic equations and expect accuracy.
For one example, the value of "g" at 250km is a good 7% less than at the surface.

Rather than try to compensate for each of the oddities, just approach the problem using *orbital* equations?
It should be quite easy to determine the exact shape of an orbit, given known velocity , direction and altitude at a point on this orbit. Just calculate the Apogee of that orbit to know how high the stage will be at max.

The fact that a very big part of the orbit will lie below the surface of the earth is not relevant, as long as the body in question does not actually interact with that surface. i.e. valid until it hits atmosphere.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/27/2019 11:43 am
Guys, you cannot just plug in earth-surface kinematic equations and expect accuracy.
For one example, the value of "g" at 250km is a good 7% less than at the surface.

Rather than try to compensate for each of the oddities, just approach the problem using *orbital* equations?
It should be quite easy to determine the exact shape of an orbit, given known velocity , direction and altitude at a point on this orbit. Just calculate the Apogee of that orbit to know how high the stage will be at max.

The fact that a very big part of the orbit will lie below the surface of the earth is not relevant, as long as the body in question does not actually interact with that surface. i.e. valid until it hits atmosphere.

And that's why I used the energy conservation equation. The term vi^2 - vf^2 gives just the radial velocity squared so it doesn't matter if the speed on the webcast is relative to the surface because it cancels on the formula. You only need to estimate the vertical speed and know the distance to the center of Earth at MECO and you get rf which would be the apogee of the orbit relative to the center of the earth.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mn on 06/27/2019 02:45 pm
When would the stage abort a landing and how would it know when to do so?

I don't know how SpaceX implements it, but if I were to design it, instead if trying to cope with many different possible damage models and their expected symptoms, I'd go by a simple criteria similar to the autonomous LAS:

Constantly check whether the vehicles position, velocity and attitude is within a safe corridor to make a safe landing. Try the best to stay within this corridor with whatever actuators are available.

The stage would have done exactly that, and while still going fast enough for grid fins having sufficient control authority over a malfunctionibg TVC, it was seemingly spot on, definitely within the corridor.

The corridor can be calculated dynamically. It would simply be the space from which in an intact, functioning stage has sufficient control authority to make a succesful landing. If you ever go outside of that, you know you can't possibly make it anymore.

The corridor becomes narrower and narrower towards touchdown. At the same time any issue with TVC would become worse due to decreasing grid fin authority.

We did not see the stage in that phase, but my guess is the attitude rate and/or horizontal speed became too high, it left the corridor, knew it wouldnt make it and throttled up for the emergency fallback (safe ocisly)

That would look pretty much the same regardless of the exact type of failure or its cause.

Here is what I don't understand and why I question the intentional divert.

What exactly do you mean by 'knew it wouldn't make it'.

I see two possibilities.

1. If your calculations show that you will hit the target, continue adjusting thrust and hope you hit the target very softly.

2. If your calculations show that you will miss the target, there is no need to divert, you already missed.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/27/2019 02:49 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mn on 06/27/2019 02:52 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: emerrill on 06/27/2019 02:58 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.

True. Although the barge is worth more than the sticker price. If you take it out of commission, you affect your ability to recover boosters from future missions. At least til they get a second one operational.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: intelati on 06/27/2019 03:00 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.

True. Although the barge is worth more than the sticker price. If you take it out of commission, you affect your ability to recover boosters from future missions. At least til they get a second one operational.

Opportunity cost. In this case, I think a 50% chance of a successful landing is more than enough chance of failure to divert and save the barge. (Thus allowing you to catch other boosters in a timely manner)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 06/27/2019 03:03 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.

Without center engine TVC, the probability of landing successfully is likely near zero. Especially if the engine is stuck hard over like the grid fins were on B1050.

At that point, the choice is pretty much either hit and damage the barge and lose the core anyway, or throw away the core and hope it misses the barge.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mn on 06/27/2019 03:08 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.

Without center engine TVC, the probability of landing successfully is likely near zero. Especially if the engine is stuck hard over like the grid fins were on B1050.

At that point, the choice is pretty much either hit and damage the barge and lose the core anyway, or throw away the core and hope it misses the barge.

If the chances of landing are near zero it means you didn't need to divert, you were already in the water (mathematically).

I'm not suggesting that you can land with a failed TVC, I am only questioning that this was an 'intentional' divert.

Edit to add: Why would you 'hit and damage the barge'? TVC effects your ability to hit a particular target, not how hard you will hit it, You either land softly or hit the ocean. I'm looking for a scenario where a failed TVC will cause you to hit the barge but hard rather than soft. (Oh I'm sure we can contrive a scenario, definitely possible, but I think too farfetched to believe this was by design)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 06/27/2019 03:18 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.

Without center engine TVC, the probability of landing successfully is likely near zero. Especially if the engine is stuck hard over like the grid fins were on B1050.

At that point, the choice is pretty much either hit and damage the barge and lose the core anyway, or throw away the core and hope it misses the barge.

If the chances of landing are near zero it means you didn't need to divert, you were already in the water (mathematically).

I'm not suggesting that you can land with a failed TVC, I am only questioning that this was an 'intentional' divert.

Edit to add: Why would you 'hit and damage the barge'? TVC effects your ability to hit a particular target, not how hard you will hit it, You either land softly or hit the ocean. I'm looking for a scenario where a failed TVC will cause you to hit the barge but hard rather than soft. (Oh I'm sure we can contrive a scenario, definitely possible, but I think too farfetched to believe this was by design)

Review the CRS-6 landing attempt. A small stiction delay in the thrust vector system controls caused the booster to land with excess horizontal velocity and tip over hard on the barge.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mn on 06/27/2019 03:25 pm
It may calculate a probability of success or soemthing similar. Not everything is black and white.

It also could have determined it wouldn't have the fuel to complete the soft touchdown.

Yes I understand that it could have this and it could have that.

I wouldn't decide to throw 50mil overboard because it might not land safely.

Without center engine TVC, the probability of landing successfully is likely near zero. Especially if the engine is stuck hard over like the grid fins were on B1050.

At that point, the choice is pretty much either hit and damage the barge and lose the core anyway, or throw away the core and hope it misses the barge.

If the chances of landing are near zero it means you didn't need to divert, you were already in the water (mathematically).

I'm not suggesting that you can land with a failed TVC, I am only questioning that this was an 'intentional' divert.

Edit to add: Why would you 'hit and damage the barge'? TVC effects your ability to hit a particular target, not how hard you will hit it, You either land softly or hit the ocean. I'm looking for a scenario where a failed TVC will cause you to hit the barge but hard rather than soft. (Oh I'm sure we can contrive a scenario, definitely possible, but I think too farfetched to believe this was by design)

Review the CRS-6 landing attempt. A small stiction delay in the thrust vector system controls caused the booster to land with excess horizontal velocity and tip over hard on the barge.

Yes I've seen all the tip over videos, the barge didn't seem to care.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Coastal Ron on 06/27/2019 03:44 pm
Well, IMO, "most likely" doesn't translate into "that's what it did."  It *might* have, but think about it: how can you tell from an external video source if the pitch over was a commanded response or just a result of the failure itself?

Echoing what Herb Schaltegger said, you are arguing that Elon Musk knows less about what happened than you do. And while I'm sure Elon Musk is working with imperfect information, he does have the advantage in knowing what the failure modes are for the Falcon 9 1st stage.

Quote
If S1 *did* abort, then I'd re-examine the criteria for an abort.  It appeared that the vertical velocity was right on target for an attempted landing, so if it did fail on landing the damage to ASDS would be no worse than any other failed landing attempt.

I disagree. I think their decision tree is very specific, and if they detect that part of their critical systems are not working properly then they trigger an abort. Why? Because out of all of the potential scenarios that could happen when critical systems fail during decent, very few would result in the recovery of a usable 1st stage.

And remember decisions have to be made on a split second basis, because the stage is coming in literally "Hot and Heavy".

The only reason to proceed with a landing attempt is if there is a high degree of potential success, because the vast amount of other scenarios result in financial penalties - costs to repair the ASDS, or possibility to have to replace the ASDS entirely. And other than stripping parts off of damaged stage, a damaged stage is no longer an asset, it is a liability.

My $0.02
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: RonM on 06/27/2019 04:18 pm
When would the stage abort a landing and how would it know when to do so?

I don't know how SpaceX implements it, but if I were to design it, instead if trying to cope with many different possible damage models and their expected symptoms, I'd go by a simple criteria similar to the autonomous LAS:

Constantly check whether the vehicles position, velocity and attitude is within a safe corridor to make a safe landing. Try the best to stay within this corridor with whatever actuators are available.

The stage would have done exactly that, and while still going fast enough for grid fins having sufficient control authority over a malfunctionibg TVC, it was seemingly spot on, definitely within the corridor.

The corridor can be calculated dynamically. It would simply be the space from which in an intact, functioning stage has sufficient control authority to make a succesful landing. If you ever go outside of that, you know you can't possibly make it anymore.

The corridor becomes narrower and narrower towards touchdown. At the same time any issue with TVC would become worse due to decreasing grid fin authority.

We did not see the stage in that phase, but my guess is the attitude rate and/or horizontal speed became too high, it left the corridor, knew it wouldnt make it and throttled up for the emergency fallback (safe ocisly)

That would look pretty much the same regardless of the exact type of failure or its cause.

Here is what I don't understand and why I question the intentional divert.

What exactly do you mean by 'knew it wouldn't make it'.

I see two possibilities.

1. If your calculations show that you will hit the target, continue adjusting thrust and hope you hit the target very softly.

2. If your calculations show that you will miss the target, there is no need to divert, you already missed.

3. If your calculations show that you will hit the target, but outside the parameters for a safe landing, divert.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/27/2019 05:00 pm
Well, IMO, "most likely" doesn't translate into "that's what it did."  It *might* have, but think about it: how can you tell from an external video source if the pitch over was a commanded response or just a result of the failure itself?

Echoing what Herb Schaltegger said, you are arguing that Elon Musk knows less about what happened than you do.

Huh??  Of *course* Elon has more knowledge than I do.  It's absurd to think otherwise.  I was quoting Elon, who said it was "most likely" that the stage aborted the landing.  "Most likely" does not translate well into the English language as "Yes".  It's a statement of probability, not a certainty.  I expect that SpaceX now knows exactly what the stage did, but as best I know nothing beyond Elon's original tweet has been published.

Quote

I disagree. I think their decision tree is very specific, and if they detect that part of their critical systems are not working properly then they trigger an abort. Why? Because out of all of the potential scenarios that could happen when critical systems fail during decent, very few would result in the recovery of a usable 1st stage.

That's a good point.

Quote
And remember decisions have to be made on a split second basis, because the stage is coming in literally "Hot and Heavy".

The control system is running at its normal rate throughout the landing sequence (at least we never changed our execution frame rate during operations).

Quote
The only reason to proceed with a landing attempt is if there is a high degree of potential success, because the vast amount of other scenarios result in financial penalties - costs to repair the ASDS, or possibility to have to replace the ASDS entirely. And other than stripping parts off of damaged stage, a damaged stage is no longer an asset, it is a liability.

My $0.02

That's another good point.  My main reason was to try to save the data recorder and any other evidence for the investigation.  However, their telemetry may have enough bandwidth that they don't use data recorders.

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Barley on 06/27/2019 05:02 pm

Here is what I don't understand and why I question the intentional divert.

What exactly do you mean by 'knew it wouldn't make it'.

I see two possibilities.

1. If your calculations show that you will hit the target, continue adjusting thrust and hope you hit the target very softly.

2. If your calculations show that you will miss the target, there is no need to divert, you already missed.
The "target" is not just a position.  It's a position, and a velocity, and an orientation and an angular velocity.  There are a lot of cases where you can be sure that it will both hit the barge and disassemble.  In those cases it would make sense to divert.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Barley on 06/27/2019 05:11 pm
And other than stripping parts off of damaged stage, a damaged stage is no longer an asset, it is a liability.
A (moderately) damaged stage could be quite valuable to the engineering team doing failure analysis, far beyond the value of strippable parts.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/27/2019 05:11 pm
Elon/SpaceX might be just getting the telemetry recordings now, with the arrival of Ms. Tree in port.  That assumes Ms. Tree captured non-fairing telemetry or rendezvoused with another Go sister before sprinting back to port.  They may be waiting for the rest of the fleet to reach port to deliver the recorded telemetry from the center core.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: vanoord on 06/27/2019 05:49 pm
I see two possibilities.

1. If your calculations show that you will hit the target, continue adjusting thrust and hope you hit the target very softly.

2. If your calculations show that you will miss the target, there is no need to divert, you already missed.

As I understand it, when an aeroplane is on a landing approach it has to come in between two lines, one high and one low. If it goes outside those, the landing has to be aborted.

The original suggestion that the core comes down into what's effectively a cone would be a valid way to programme the stage to abort - if it goes outside pre-determined parameters, it throttles up and ends up somewhere other than the drone ship.

The more simple answer is that a TVC failure caused the stage to veer off-target and what we saw was a doomed attempt to correct it.


Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/27/2019 07:19 pm
Guys, you cannot just plug in earth-surface kinematic equations and expect accuracy.
For one example, the value of "g" at 250km is a good 7% less than at the surface.

Rather than try to compensate for each of the oddities, just approach the problem using *orbital* equations?
It should be quite easy to determine the exact shape of an orbit, given known velocity , direction and altitude at a point on this orbit. Just calculate the Apogee of that orbit to know how high the stage will be at max.
The reason you might want to compensate for each of the oddities is that then you can do the computation in one line on a calculator.  The pure physics solution you suggest is called Lambert's problem and has no closed form solution.  All known solutions require iterations and mathematicians have been arguing about the best way to solve it (https://www.esa.int/gsp/ACT/doc/MAD/pub/ACT-RPR-MAD-2014-RevisitingLambertProblem.pdf) for centuries.

Furthermore, the three main tweaks get very close to the right answer.  They are:
  (a) Gravity is weaker higher up, by about 0.5 m/s at 150 km
  (b) The forward velocity generates an additional acceleration of v^2/r in the Earth frame.  For this you need the inertial velocity, not the rotating frame velocity shown in the SpaceX webcast (I made this mistake above).  This means the horizontal velocity is about 400 m/s faster than the SpaceX numbers.  Plugging in 3200 m/s horizontal and Earth's radius gives 1.58 m/s^2.
  (c) The Earth is not flat.  This effect is small (the landing location is about 2 km below a plane defined by the start of coast location).  Since we are guessing the 60 km altitude for start of entry burn anyway, this can be ignored.

So with these tweaks, we should use an effective g of 9.8 - 0.5 - 1.58 = 7.72 m/s.  Knowing the 370 second coast, the 123 km start altitude, and the 60 km end altitude, then we solve for 123000 + v*t - 1/2*g*t = 60000, to get vertical v = 1257 m/s.  This is within 1% of the correct value of 1265 m/s, as determined by the physics based computation below (in Python).  The estimated peak altitude is 226.6 km as opposed to the correct 225.6 km.  So the few tweaks get a result that is likely more accurate than the input data we are using.

import math
Re = 6356000            # Radius of Earth in meters
mu = 3.985744e14        # Gravitational constant of Earth
Erot = 40000000/86400.0*math.cos(28.5/180.0*math.pi)  # Rotation speed of earth at 28.5 degrees north
x = 0;
y = Re+123000           # Initial altitude is 123 km
vy = 1265.0             # Initial vertical velocity (tweak this to get right result)
vx = math.sqrt(3079**2 - vy**2)  # Initial velocity in Earth-rotating frame is 3079 m/s, find X component
vx += Erot                       # Add Earth's rotation to convert to velocity in inertial frame
print("vx = ", vx, "Earth rotation added", Erot, "m/s")
r = math.sqrt(x**2+y**2)
t = 0
dt = 0.1
while t < 370-dt/2:
  a = mu/r**2           # Find the acceleration magnitude
  ax = a * (x/r)        # Find x and y components
  ay = a * (y/r)
  vx = vx - ax*dt       # Update velocity = integral of acceleration
  vy = vy - ay*dt
  x = x + vx*dt         # Update position, integral of velocity (in inertial space)
  y = y + vy*dt
  t += dt
  r = math.sqrt(x**2+y**2)
  theta = math.pi/2 - math.atan(y/x)  # angle from vertical
  dr = Re*theta - Erot*t              # distance downrange, compensation for Earth rotation
  print("t={0:5.1f} g={1:6.4f} m/s^2  dr={2:8.3f} km  y={3:8.3f} alt={4:8.3f}".format(t,a, dr/1000.0, y/1000.0, (r - Re)/1000.0))

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: jpo234 on 06/27/2019 09:25 pm
https://twitter.com/nasawatch/status/1144332878026641408

Quote
In this #satellite image from June 26th, you can see Falcon Heavy's two side boosters at @SpaceX's Landing Zones 1 & 2 at Cape Canaveral from the June 25th STP-2 mission. spacex.com/webcast

OK, I know I need glasses, but where are the boosters?

Here, I think.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Marine_Mustang on 06/27/2019 09:37 pm
Here, I think.

Looks like they removed the legs from the booster still near the upper pad and laid them down on the pad.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: scr00chy on 06/28/2019 12:03 am
How the heck did they move the LZ-2 booster all the way there? With a mobile crane?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 06/28/2019 12:58 am
How the heck did they move the LZ-2 booster all the way there? With a mobile crane?
Wonder if they have Land Roomba's.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: russianhalo117 on 06/28/2019 12:59 am
Here, I think.

Looks like they removed the legs from the booster still near the upper pad and laid them down on the pad.
NOTE: the legs looks white on the booster hugging side so they are probably from FH-01.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: wannamoonbase on 06/28/2019 05:31 am
How the heck did they move the LZ-2 booster all the way there? With a mobile crane?
Wonder if they have Land Roomba's.

A crane moving with a load under hook is not unusual.   They just need to make sure the crawling surface is suitable as a crane pad.

I worked on a slurry wall construction project with rebar cages that were longer, wider and heavier than an F9 core.  It’s not a problem.

Why they needed to ,over it is a more interesting question. 
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: EspenU on 06/28/2019 06:48 am
During the booster boostback burn there was something "flying around" with a gaseous "tail" in the plume interactions. It can be seen in the IR view from T+02:45 to 02:50 (from 27:43 in the Youtube video). Does anyone know what it was?
I'm not suggesting that anything went wrong, I'm just curious.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Steven Pietrobon on 06/28/2019 08:25 am
So with these tweaks, we should use an effective g of 9.8 - 0.5 - 1.58 = 7.72 m/s.  Knowing the 370 second coast, the 123 km start altitude, and the 60 km end altitude, then we solve for 123000 + v*t - 1/2*g*t = 60000, to get vertical v = 1257 m/s.  This is within 1% of the correct value of 1265 m/s, as determined by the physics based computation below (in Python).  The estimated peak altitude is 226.6 km as opposed to the correct 225.6 km.  So the few tweaks get a result that is likely more accurate than the input data we are using.

Python makes my head spin! I redid the code in Pascal. Here's my output, which finds the maximum altitude. If I were to do the code though, I would use fourth-order Runga-Kutta to solve the differential equations, plus add in the drag from the thin upper atmosphere. :-)

vx = 3214 m/s. Earth rotation added 407 m/s.
t=  0.0 s, g=9.4950 m/s^2, dr=   0.000 km, y=6479.000 km, alt= 123.000 km
t=163.1 s, g=9.2011 m/s^2, dr= 437.223 km, y=6560.991 km, alt= 225.638 km
t=370.0 s, g=9.6823 m/s^2, dr= 996.027 km, y=6311.894 km, alt=  60.003 km
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/28/2019 08:43 am
During the booster boostback burn there was something "flying around" with a gaseous "tail" in the plume interactions. It can be seen in the IR view from T+02:45 to 02:50 (from 27:43 in the Youtube video). Does anyone know what it was?
I'm not suggesting that anything went wrong, I'm just curious.

It's basically the high altitude version of a Mach diamond. It's normal and can be seen with many kerolox rockets, here's an example on a Saturn V (https://www.esa.int/spaceinimages/Images/2009/06/Apollo_11_Saturn_V_in_flight)

Recent F9 launch seen pretty much from sideways, starting at around 30 seconds in: https://www.youtube.com/watch?v=GDinkcft23Y
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/28/2019 10:52 am
During the booster boostback burn there was something "flying around" with a gaseous "tail" in the plume interactions. It can be seen in the IR view from T+02:45 to 02:50 (from 27:43 in the Youtube video). Does anyone know what it was?
I'm not suggesting that anything went wrong, I'm just curious.

I was curious about that as well.  My first guess was that it's the cross-brace that ties the 3 boosters together right above the grid fins, but then I remembered that retracts forward against the booster body.

It sure doesn't look like any kind of plume interaction.  So I guess I have no idea what it is.

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/28/2019 01:07 pm

Why they needed to ,over it is a more interesting question.

I believe that's where the fixed stand is that they attach the booster to in order to fold/remove the legs.

I think both boosters are currently on their fixed stands, having been brought from their landing spots (grey smudges on concrete) by mobile crane.

Don't know why they brought the legs over and laid them out on the pad, but I'd wager that's not where the legs were removed.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: LouScheffer on 06/28/2019 01:17 pm
So with these tweaks, we should use an effective g of 9.8 - 0.5 - 1.58 = 7.72 m/s.  Knowing the 370 second coast, the 123 km start altitude, and the 60 km end altitude, then we solve for 123000 + v*t - 1/2*g*t = 60000, to get vertical v = 1257 m/s.  This is within 1% of the correct value of 1265 m/s, as determined by the physics based computation below (in Python).  The estimated peak altitude is 226.6 km as opposed to the correct 225.6 km.  So the few tweaks get a result that is likely more accurate than the input data we are using.

Python makes my head spin! I redid the code in Pascal. Here's my output, which finds the maximum altitude. If I were to do the code though, I would use fourth-order Runga-Kutta to solve the differential equations, plus add in the drag from the thin upper atmosphere. :-)

vx = 3214 m/s. Earth rotation added 407 m/s.
t=  0.0 s, g=9.4950 m/s^2, dr=   0.000 km, y=6479.000 km, alt= 123.000 km
t=163.1 s, g=9.2011 m/s^2, dr= 437.223 km, y=6560.991 km, alt= 225.638 km
t=370.0 s, g=9.6823 m/s^2, dr= 996.027 km, y=6311.894 km, alt=  60.003 km
You are certainly correct that that any number of better integration schemes could be used.  Here I used forward Euler, the fancy name for extrapolation, just to make the  code simple.  This in turn requires a small time step (if you increase dt to 1 sec, you will give km-size errors) and risks roundoff errors (here not a problem since we are computing only a fraction of a smooth orbit.)

But at least the same algorithm (in Pascal or Python) gives the same answers:
vx =  3213.996 Earth rotation added 406.860 m/s
t=163.1 g=9.2011 m/s^2  dr= 437.223 km  y=6560.991 alt= 225.638 km
t=370.0 g=9.6819 m/s^2  dr= 996.027 km  y=6311.894 alt=  60.003 km
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: abaddon on 06/28/2019 01:56 pm
Maybe I'm seeing things... but am I the only one who counts four (!) sets of legs (one set still attached)?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 06/28/2019 02:02 pm
I think the legs are off the left booster, still attached on the right booster.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: stcks on 06/28/2019 02:03 pm
Maybe I'm seeing things... but am I the only one who counts four (!) sets of legs (one set still attached)?

Definitely 3 sets.. one on the concrete at LZ-1, one in the grass/dirt between the LZ and the hangar, one on the booster near the hangar... but wheres the fourth?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: abaddon on 06/28/2019 02:06 pm
Maybe I'm seeing things... but am I the only one who counts four (!) sets of legs (one set still attached)?

Definitely 3 sets.. one on the concrete at LZ-1, one in the grass/dirt between the LZ and the hangar, one on the booster near the hangar... but wheres the fourth?
I'm seeing what look a lot like legs, but they are a darker grey color, not white.  Immediately to the right of the small white building in the center.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: stcks on 06/28/2019 02:10 pm
Maybe I'm seeing things... but am I the only one who counts four (!) sets of legs (one set still attached)?

Definitely 3 sets.. one on the concrete at LZ-1, one in the grass/dirt between the LZ and the hangar, one on the booster near the hangar... but wheres the fourth?
I'm seeing what look a lot like legs, but they are a darker grey color, not white.  Immediately to the right of the small white building in the center.

Yes, I think those are legs. I'm counting those as the ones between LZ and hangar above. Still not seeing 4 sets though

Edit: I think we're in the wrong thread too... updates vs discussion
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: pb2000 on 06/28/2019 03:02 pm
higher res
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: abaddon on 06/28/2019 03:04 pm
Maybe I'm seeing things... but am I the only one who counts four (!) sets of legs (one set still attached)?

Definitely 3 sets.. one on the concrete at LZ-1, one in the grass/dirt between the LZ and the hangar, one on the booster near the hangar... but wheres the fourth?
I'm seeing what look a lot like legs, but they are a darker grey color, not white.  Immediately to the right of the small white building in the center.

Yes, I think those are legs. I'm counting those as the ones between LZ and hangar above. Still not seeing 4 sets though

Edit: I think we're in the wrong thread too... updates vs discussion
Continuing from Updates...

Four on the left pad, four on the booster on the bottom right, the four grey ones immediately to the right of the building in the center of the image, and then four down a little bit and to the left of those.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat on 06/28/2019 03:15 pm
Guys, you cannot just plug in earth-surface kinematic equations and expect accuracy.
For one example, the value of "g" at 250km is a good 7% less than at the surface.

Rather than try to compensate for each of the oddities, just approach the problem using *orbital* equations?
It should be quite easy to determine the exact shape of an orbit, given known velocity , direction and altitude at a point on this orbit. Just calculate the Apogee of that orbit to know how high the stage will be at max.
The reason you might want to compensate for each of the oddities is that then you can do the computation in one line on a calculator.  The pure physics solution you suggest is called Lambert's problem and has no closed form solution.  All known solutions require iterations and mathematicians have been arguing about the best way to solve it (https://www.esa.int/gsp/ACT/doc/MAD/pub/ACT-RPR-MAD-2014-RevisitingLambertProblem.pdf) for centuries.

Furthermore, the three main tweaks get very close to the right answer.  They are:
  (a) Gravity is weaker higher up, by about 0.5 m/s at 150 km
  (b) The forward velocity generates an additional acceleration of v^2/r in the Earth frame.  For this you need the inertial velocity, not the rotating frame velocity shown in the SpaceX webcast (I made this mistake above).  This means the horizontal velocity is about 400 m/s faster than the SpaceX numbers.  Plugging in 3200 m/s horizontal and Earth's radius gives 1.58 m/s^2.
  (c) The Earth is not flat.  This effect is small (the landing location is about 2 km below a plane defined by the start of coast location).  Since we are guessing the 60 km altitude for start of entry burn anyway, this can be ignored.

So with these tweaks, we should use an effective g of 9.8 - 0.5 - 1.58 = 7.72 m/s.  Knowing the 370 second coast, the 123 km start altitude, and the 60 km end altitude, then we solve for 123000 + v*t - 1/2*g*t = 60000, to get vertical v = 1257 m/s.  This is within 1% of the correct value of 1265 m/s, as determined by the physics based computation below (in Python).  The estimated peak altitude is 226.6 km as opposed to the correct 225.6 km.  So the few tweaks get a result that is likely more accurate than the input data we are using.

import math
Re = 6356000            # Radius of Earth in meters
mu = 3.985744e14        # Gravitational constant of Earth
Erot = 40000000/86400.0*math.cos(28.5/180.0*math.pi)  # Rotation speed of earth at 28.5 degrees north
x = 0;
y = Re+123000           # Initial altitude is 123 km
vy = 1265.0             # Initial vertical velocity (tweak this to get right result)
vx = math.sqrt(3079**2 - vy**2)  # Initial velocity in Earth-rotating frame is 3079 m/s, find X component
vx += Erot                       # Add Earth's rotation to convert to velocity in inertial frame
print("vx = ", vx, "Earth rotation added", Erot, "m/s")
r = math.sqrt(x**2+y**2)
t = 0
dt = 0.1
while t < 370-dt/2:
  a = mu/r**2           # Find the acceleration magnitude
  ax = a * (x/r)        # Find x and y components
  ay = a * (y/r)
  vx = vx - ax*dt       # Update velocity = integral of acceleration
  vy = vy - ay*dt
  x = x + vx*dt         # Update position, integral of velocity (in inertial space)
  y = y + vy*dt
  t += dt
  r = math.sqrt(x**2+y**2)
  theta = math.pi/2 - math.atan(y/x)  # angle from vertical
  dr = Re*theta - Erot*t              # distance downrange, compensation for Earth rotation
  print("t={0:5.1f} g={1:6.4f} m/s^2  dr={2:8.3f} km  y={3:8.3f} alt={4:8.3f}".format(t,a, dr/1000.0, y/1000.0, (r - Re)/1000.0))

Here, I pasted it into repl.it for ya.

Anyone should be able to run and modify it:
https://repl.it/repls/BurlyCylindricalEngineers (name was auto-generated lol)

Side note:

this kind of analysis is our forum at its best. Hats off to y'all. Additionally, Euler's method is terrible but I love it for its absolute simplicity and portability...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: FlokiViking on 06/28/2019 06:10 pm
Did they bring home just the one side, or both sides of the fairing?  Haven't really been able to tell from the pictures...
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 06/28/2019 06:58 pm
Did they bring home just the one side, or both sides of the fairing?  Haven't really been able to tell from the pictures...

The GO sister ships haven't made port yet.  They would be the ones carrying the other fairing half.

https://twitter.com/SpaceXFleet/status/1144681621162987523
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Paul_G on 06/28/2019 08:55 pm
During the booster boostback burn there was something "flying around" with a gaseous "tail" in the plume interactions. It can be seen in the IR view from T+02:45 to 02:50 (from 27:43 in the Youtube video). Does anyone know what it was?
I'm not suggesting that anything went wrong, I'm just curious.

I noticed that - it definitely looked (to the untrained eye) like something spinning around and gassing out - in my snapshot it doesn't look much, but for the second or so that it is visible in the video stream, it looked significant. Perhaps it was something from the side booster ejection mechanism - during the pre launch chat on the video stream, the separation mechanism was described as using high pressure gas.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 06/28/2019 09:08 pm
Are you sure you're not just looking at the exhaust from the center engine on the core that's still burning?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Paul_G on 06/28/2019 09:17 pm
Are you sure you're not just looking at the exhaust from the center engine on the core that's still burning?

It doesn't look like the exhaust - in the video stream it definitely looks an object spinning, rather than the core engine thrust impinging on the boosters. Perhaps its just the result of the Infra Red video.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Robotbeat on 06/28/2019 11:31 pm
Are you sure you're not just looking at the exhaust from the center engine on the core that's still burning?

It doesn't look like the exhaust - in the video stream it definitely looks an object spinning, rather than the core engine thrust impinging on the boosters. Perhaps its just the result of the Infra Red video.
it’s a phenomenon in the exhaust itself.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 06/28/2019 11:49 pm
Are you sure you're not just looking at the exhaust from the center engine on the core that's still burning?

It doesn't look like the exhaust - in the video stream it definitely looks an object spinning, rather than the core engine thrust impinging on the boosters. Perhaps its just the result of the Infra Red video.

gongora is correct, it is a downstream Mach disk formed by the interaction of the exhaust plumes  from the core stage. There is an excellent explanation of this phenomenon in the video 'The flames of the rockets, part 2 of 2' by 'French Space Guy' starting at: https://youtu.be/yJceyvBKxc0?t=164
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: intrepidpursuit on 06/29/2019 08:54 am
During the booster boostback burn there was something "flying around" with a gaseous "tail" in the plume interactions. It can be seen in the IR view from T+02:45 to 02:50 (from 27:43 in the Youtube video). Does anyone know what it was?
I'm not suggesting that anything went wrong, I'm just curious.

It's basically the high altitude version of a Mach diamond. It's normal and can be seen with many kerolox rockets, here's an example on a Saturn V (https://www.esa.int/spaceinimages/Images/2009/06/Apollo_11_Saturn_V_in_flight)

Recent F9 launch seen pretty much from sideways, starting at around 30 seconds in: https://www.youtube.com/watch?v=GDinkcft23Y

This guy must be from LA. If the boosters landed in Vandenberg now THAT would be impressive.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ugordan on 06/29/2019 11:16 am
https://www.youtube.com/watch?v=R11GKrDWq44
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mlindner on 06/29/2019 05:29 pm
Here is a plot of the second stage telemetry. It took a while to process the 350,000 odd frames from the webcast, but it is interesting to note the low acceleration implied by the raw data, less than 1g for all burns. This distortion would have been caused by the high yaw angle used for the plane changes, which resulted in a much lower measured ΔV than actually occurred.

Correction for those reading the plot here, 980 cm/s^2 is 1g so all the burns were all over 1g.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: mark_m on 06/29/2019 06:49 pm
Here is a plot of the second stage telemetry. It took a while to process the 350,000 odd frames from the webcast, but it is interesting to note the low acceleration implied by the raw data, less than 1g for all burns. This distortion would have been caused by the high yaw angle used for the plane changes, which resulted in a much lower measured ΔV than actually occurred.

Correction for those reading the plot here, 980 cm/s^2 is 1g so all the burns were all over 1g.

I took it to mean the raw data implied a (misleading) less-than-1g set of burns, which became the final greater-than-1g values after accounting for the high yaw angle.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alexphysics on 06/29/2019 08:57 pm
23 objects tracked now, including Falcon upper stage. LightSail should still be inside Prox-1, and Tepce may not have split yet, so this could be all.

DSX and PSat-2 are identified.

NORAD  Name      NSSC ID    Type  Country Period Incl.   Apo  Peri

44339  OBJECT A  2019-036A  TBA     TBD   99.13  24.00   725   709
44340  OBJECT B  2019-036B  TBA     TBD   99.12  24.00   725   708
44341  OBJECT C  2019-036C  TBA     TBD   99.12  24.00   725   708
44342  OBJECT D  2019-036D  TBA     TBD   99.11  24.00   725   707
44343  OBJECT E  2019-036E  TBA     TBD   99.10  24.00   725   707
44344  DSX       2019-036F  PAYLOAD US   316.92  42.21 12035  6005
44345  FH R/B    2019-036G  R/B     US   306.86  42.24 11936  5449
44346  OBJECT H  2019-036H  TBA     US    96.27  28.52   853   307
44347  OBJECT J  2019-036J  TBA     US    96.24  28.53   850   307
44348  OBJECT K  2019-036K  TBA     US    96.23  28.52   852   304
44349  OBJECT L  2019-036L  TBA     TBD   99.10  24.00   724   707
44350  OBJECT M  2019-036M  TBA     TBD   99.10  24.00   724   707
44351  OBJECT N  2019-036N  TBA     TBD   99.09  24.00   724   706
44352  OBJECT P  2019-036P  TBA     TBD   96.23  28.53   849   307
44353  OBJECT Q  2019-036Q  TBA     TBD   99.09  24.00   724   706
44354  OBJECT R  2019-036R  TBA     US    96.19  28.53   847   305
44355  OBJECT S  2019-036S  TBA     US    96.19  28.53   847   305
44356  OBJECT T  2019-036T  TBA     US    96.15  28.52   847   301
44357  PSAT2     2019-036U  PAYLOAD US    96.17  28.53   845   306
44358  OBJECT V  2019-036V  TBA     US    99.09  24.00   725   705
44359  OBJECT W  2019-036W  TBA     US    96.14  28.52   847   300
44360  OBJECT X  2019-036X  TBA     US    96.12  28.53   848   297
44361  OBJECT Y  2019-036Y  TBA     US    96.12  28.52   848   297


Now it seems the FH second stage ended up in a bit different orbit than the DSX after all so it could probably be that the earlier orbit estimate was not very good and now with a better estimate it really shows some difference between both orbits. If that's the case, maybe there was a propulsive passivation after all.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: OneSpeed on 06/30/2019 02:00 am
Here is a plot of the second stage telemetry. It took a while to process the 350,000 odd frames from the webcast, but it is interesting to note the low acceleration implied by the raw data, less than 1g for all burns. This distortion would have been caused by the high yaw angle used for the plane changes, which resulted in a much lower measured ΔV than actually occurred.

Correction for those reading the plot here, 980 cm/s^2 is 1g so all the burns were all over 1g.

My mistake. I should have said 'for all of the first burn' (SES2). From the telemetry, the ΔV was 7022 - 6963 = 59m/s, over a 23 second burn. That's an average of 2.6 m/s², or 0.26g, much less than the Merlin engine could deliver with that gross mass. E.g. if the engine was actually producing a 4g burn, then the yaw angle must have been cos-1(0.26/4) = 86.27°.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ThatOldJanxSpirit on 07/01/2019 11:25 am
23 objects tracked now, including Falcon upper stage. LightSail should still be inside Prox-1, and Tepce may not have split yet, so this could be all.

Now it seems the FH second stage ended up in a bit different orbit than the DSX after all so it could probably be that the earlier orbit estimate was not very good and now with a better estimate it really shows some difference between both orbits. If that's the case, maybe there was a propulsive passivation after all.

I’m estimating that to be a 145 m/s manoeuvre at around apogee. If they lit the engine it would have consumed about 200kg of propellant which would seem to be a very tight margin. Most likely they just dumped everything through the nozzle as shown in the animation. Assuming the same Isp as an N2 CGT (70s) then a tonne of propellant would have been vented, so this seems quite credible.

Likely that cruising for an extra two and a half hours then demonstrating that the vehicle was still controllable and fluids could still flow was an adequate demonstration to the USAF that it was capable of relighting for GEO insertion.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 07/04/2019 03:03 am
https://twitter.com/spacex/status/1146546495241371649 (https://twitter.com/spacex/status/1146546495241371649)

Quote
View from the fairing during the STP-2 mission; when the fairing returns to Earth, friction heats up particles in the atmosphere, which appear bright blue in the video
Super cool
The reentry seems remarkably stable
The fairing looks almost empty in the distorted view of the fisheye lens.
What’s that ring that appears faintly around 0:15 and strongly at the end?
The video is under one minute.
Is it sped up, edited?
The chute just appears. Any deployment action is hard to see.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Vettedrmr on 07/04/2019 03:06 am
The video is under one minute.
Is it sped up, edited?
The chute just appears. Any deployment action is hard to see.

Edited, yes.  But it doesn't look like it runs at anything other than normal speed.

Have a good one,
Mike
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: ThatOldJanxSpirit on 07/04/2019 07:01 am
https://twitter.com/spacex/status/1146546495241371649 (https://twitter.com/spacex/status/1146546495241371649)

Quote
View from the fairing during the STP-2 mission; when the fairing returns to Earth, friction heats up particles in the atmosphere, which appear bright blue in the video
Super cool
The reentry seems remarkably stable
The fairing looks almost empty in the distorted view of the fisheye lens.
What’s that ring that appears faintly around 0:15 and strongly at the end?
The video is under one minute.
Is it sped up, edited?
The chute just appears. Any deployment action is hard to see.

I also note there is a lot of thruster activity during entry.

Is it me, or have they mounted the fairing sideways. Both the entry and Ms Tree videos seem to show it flying sideways on. Iirc in all previous videos it has flown pointy end first.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 07/04/2019 11:51 am
I also note there is a lot of thruster activity during entry.

Is it me, or have they mounted the fairing sideways. Both the entry and Ms Tree videos seem to show it flying sideways on. Iirc in all previous videos it has flown pointy end first.

There's further discussion in the fairing reuse thread: https://forum.nasaspaceflight.com/index.php?topic=37727.msg1962801.msg#1962801

I agree the landing is "sideways" but the re-entry video seems to be looking aft from a nose-mounted camera re-entering nose first. To me, at least.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: matthewkantar on 07/10/2019 02:25 pm
Rewatching the fairing reentry video, this time on a desktop instead of my phone. Definitely one of the best space vids I have ever seen.

I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Alvian@IDN on 07/10/2019 03:20 pm
I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?
The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: codav on 07/11/2019 10:53 am
I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?
The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)
I strongly disagree and say it's the latter, for two reasons.

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

Second, SpaceX only recently added this extra metal protection to the tip to fairings which were planned to be recovered. The recent RADARSAT launch, for example, didn't sport the thermal protection cap. And in the reentry video, you can clearly see sparks coming from the tip, which is the area where air compression is highest as the fairing is moving very fast horizontally as it hits the upper atmosphere tip-first. The camera has a large field of view, it's a fisheye lens, so it is not clearly visible.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: cscott on 07/11/2019 01:30 pm
I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?
The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)
I strongly disagree and say it's the latter, for two reasons.

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

Second, SpaceX only recently added this extra metal protection to the tip to fairings which were planned to be recovered. The recent RADARSAT launch, for example, didn't sport the thermal protection cap. And in the reentry video, you can clearly see sparks coming from the tip, which is the area where air compression is highest as the fairing is moving very fast horizontally as it hits the upper atmosphere tip-first. The camera has a large field of view, it's a fisheye lens, so it is not clearly visible.
I agree in so far as the bright sparks at the end of the re-entry vehicle do look like aluminum.  But surely there must be better ablative materials?  Maybe it's a combination of high pressure on ascent combined with high heating on re-entry?  I'd expect something like RCC, but maybe a small block of sacrificial aluminum wins the trades when SpaceX does them.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 07/11/2019 01:40 pm
RADARSAT fairing had protection at the tip, it just wasn't bare metal.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: envy887 on 07/11/2019 02:07 pm
I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?
The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)
I strongly disagree and say it's the latter, for two reasons.

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

Second, SpaceX only recently added this extra metal protection to the tip to fairings which were planned to be recovered. The recent RADARSAT launch, for example, didn't sport the thermal protection cap. And in the reentry video, you can clearly see sparks coming from the tip, which is the area where air compression is highest as the fairing is moving very fast horizontally as it hits the upper atmosphere tip-first. The camera has a large field of view, it's a fisheye lens, so it is not clearly visible.

Your reasoning is logical, but I recall one of the SpaceX folks on a broadcast (perhaps the GPS launch?) said it was for ascent heating.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: soltasto on 07/11/2019 05:27 pm
I have a question, not sure if it has been answered here: Is the little bit of thermal protection we have seen on the tip of the fairing protection for the ascent, or for the descent?
The former. Although the fairing reenter even faster than the center core, it's (relatively) lightweight, the air pushes the fairing like a piece of paper falling down instead of like a pencil (okay, maybe not that light, because it still need parafoil)
...

First, rocket speeds through ascent aren't high enough to really heat up the fairing tip so much that it needs any additional protection. No other rocket using expendable fairings have this extra protection.

...

The Delta IV fairing might disagree:

Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 07/12/2019 09:19 pm
https://twitter.com/AF_SMC/status/1149786098135998465
Quote
DSX has deployed its booms! Thank you to the incredible team behind the success ensuring that everything goes according to plan!
DSX will perform 3 primary experiments: wave particle ineraction, space weather and space environmental effects!

#SpaceStartsHere #SMC #AFRL #STP2
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: tyrred on 07/13/2019 09:46 am
Is Lightsail 2's delayed solar sail deployment a concern?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Pete on 07/13/2019 01:37 pm
Is Lightsail 2's delayed solar sail deployment a concern?
The status seems to be sat alive but
"The team is concerned with readings from the attitude control system on LightSail 2 and is conducting additional tests.They are currently configuring the control system and conducting a possible software update for the craft’s flight operating system."
and
"the ground team needs to wait at least until the 21st of July to perform the operation."
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Comga on 07/13/2019 07:44 pm
https://twitter.com/exploreplanets/status/1149789931453030400

Quote
From #LightSail2, with love <3

I wonder if the Planetary Society has their FCC license in place for operating a remote sensing satellite.
Someone might use this to discover North America.

Lovely image, actually.
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 07/13/2019 07:56 pm
I wonder if the Planetary Society has their FCC license in place for operating a remote sensing satellite.
Someone might use this to discover North America.

Lovely image, actually.

"The imaging system was developed by the Aerospace Corporation PICOSAT Project Group for
use in the LightSail program. LightSail 2 is equipped with two 2MP cameras, designed to take
images of the solar sail. The imaging system will verify the deployment of the solar sail and
validate the design of the system. "
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: SkipMorrow on 07/25/2019 04:35 pm
How can I try to spot this? Do any of the online satellite viewing sites have a track on this?
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 07/25/2019 04:44 pm
How can I try to spot this? Do any of the online satellite viewing sites have a track on this?

It's in the catalog, every site should have it.
Catalog ID 44420
International Designator 2019-036AC
Name "LIGHTSAIL" or "LIGHTSAIL 2" depending on the site
24.01deg inclination, 709km perigee, 726km apogee

Can check on Celestrak.com, stuffin.space, or whatever else you use
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Be Free on 08/18/2019 07:37 pm
My launch video.

https://www.youtube.com/watch?v=BF2I22McGQs
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: gongora on 02/08/2021 05:10 pm
COSMIC-2/FORMOSAT-7

All satellites reached their mission orbits.
https://www.taipeitimes.com/News/front/archives/2021/02/09/2003752028
Title: Re: SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION
Post by: Yiosie on 10/18/2021 09:43 pm
COSMIC-2/FORMOSAT-7

All satellites reached their mission orbits.
https://www.taipeitimes.com/News/front/archives/2021/02/09/2003752028

Now fully operational:

COSMIC-2 Achieves Full Operational Capability (https://www.nesdis.noaa.gov/news/cosmic-2-achieves-full-operational-capability) [dated Oct. 12]

Quote
The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC-2) is a network of six small satellites, each about the size of a standard kitchen oven, designed to improve weather prediction and model accuracy as well as space weather monitoring capabilities.

<snip>

Following launch on June 25, 2019, the satellites underwent an initial seven-month instrument and data evaluation process to make sure they were working properly as they were moved into their proper orbit. This was then followed by a period of software updates to enhance performance. During this time, a series of reviews were held to make sure that numerous specific milestones were being met by the spacecraft and the associated ground systems. These determined that:

• The six satellites were located where they were supposed to be in orbit
• The ground stations were functioning properly
• The data collected by the satellites was validated and correct
• The data processing centers in Taiwan and the U.S. were operational
• The backup ground station that has commanding capability will work in case the primary ground station cannot send signals to the satellites
• The data could be properly archived

On September 14 and 15, 2021 a board of scientists, engineers, and senior leadership from NOAA, USSF, UCAR, and NSPO held the Full Operational Capability (FOC) review, which verified that space weather data from COSMIC-2’s main instrument were properly calibrated and validated. This was the final major review remaining to achieve FOC status, and the review board praised the program and the team for a very detailed and meticulous presentation.