Author Topic: SpaceX F9 : USA 328-331 / Globalstar FM15 : SLC-40 : 19 June 2022 (04:27 UTC)  (Read 72320 times)

Online JayWee

  • Full Member
  • ****
  • Posts: 646
  • Liked: 591
  • Likes Given: 983
Why do you dump the fuel when the stage is doomed anyway? Btw, looking at the picture - any guesstimate how much fuel is that?

Online Herb Schaltegger

Why do you dump the fuel when the stage is doomed anyway? Btw, looking at the picture - any guesstimate how much fuel is that?

Common (and best) practice is to passivate the stage - venting down residual propellants ensures no pressure stabilization can occur during entry. Pressure stabilization can change the survivability probabilities and larger tank structures might survive deeper into the atmosphere and thus change the debris impact zone predictions. In addition, with no or minimal LOX and RP1 left in the stage, there will be no chance of energetic, potentially propulsive combustion during entry/breakup which might also affect the entry impact predictions. Typically you also want to de-energize any batteries, vent down COPVs, and discharge any capacitors.
Ad astra per aspirin ...

Offline daveglo

  • Full Member
  • ****
  • Posts: 446
  • "a big enough engine, even a water tower can fly"
  • St. Louis, MO, USA
  • Liked: 455
  • Likes Given: 414
Anyone want to explain what this "parking orbit" has to do with launching a Globalstar sat?  ::)
Looks like the mission profile could be:

1. Direct injection into a 533 x 533km orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km (ΔV about 174 m/s)
4. SES3 to circularise at 1200 x 1200km (ΔV about 170 m/s)
5. Release Globalstar.
If the two orbits were the same inclination, then SES2 and SES3 would be equally long, but SES3 is twice the length.
The most straightforward explanation is the SES3 also includes an inclination change, in addition to circularizing. So the two orbits have slightly different inclinations.

EDIT:  SES3 was about twice as long as SES2, and should have provided twice the delta-V.  If we assume SES2 was in-plane, then SES3 provided about 340 m/s, where only 170 m/s of that was needed to circularize.  So the sideward delta-V was about sqrt(340^2-170^2), or about 290 m/s.  Orbital speed at that altitude is about 7256 m/s, so the change in inclination should be about atan(290/7256), or about 2.3 degrees.   According to Alexphysics the launch azimuth indicated a 54o orbit, whereas GlobalStar uses 52o.  So this is consistent with the mystery orbit being 533x533x54o.

This makes our best guess:
1. Direct injection into a 533 x 533km x 54o orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km x 54o  (ΔV about 174 m/s)
4. SES3 to circularize/plane change at 1200 x 1200km x  52o (ΔV about 170 m/s for circularization, 290 m/s for plane change, 340 m/s total)
5. Release Globalstar.
6: SES4 for the second stage disposal burn.  At least 300 m/s to get to a 100 x 1200km or lower orbit.

This might explain why, when I saw the SES-3 burn earlier today, the direction of the burn was at an approximate 30-45 degree angle to the flight path.

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 4152
  • Canada
  • Liked: 1221
  • Likes Given: 1113
So what previous DoD/NRO missions utilized the 530km x 530 km x 52 degrees orbit?

Online FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 26096
  • UK
    • Plan 28
  • Liked: 49057
  • Likes Given: 16640
https://twitter.com/waynehale/status/1538525140824346625

Quote
A remarkable achievement by #SpaceX   Truly seems like we are on the way to ‘airliner like operations’ for spaceflight.

Online FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 26096
  • UK
    • Plan 28
  • Liked: 49057
  • Likes Given: 16640
https://twitter.com/johnkrausphotos/status/1538516888392814593

Quote
Falcon 9 heads to orbit with Globalstar FM15 early this morning, capping off an impressive sprint of three launches in about 36 hours with SpaceX launching two missions from Florida and one from California.

See more of my newest photos → johnkrausphotos.com/New

Offline Mariusuiram

  • Full Member
  • *
  • Posts: 116
  • Liked: 105
  • Likes Given: 118
Maybe everyone is overthinking the info available?

The Globalstar quote above referencing launching the spare also says current and future subscribers “and other customers”

What if DOD / SDA or similar wants to test using commercial sat comms and is paying to launch this spare.

They would be the customer making it secretive and also paying for a direct insertion.

So there is a government client but it’s a commercial spare payload.

Online Rekt1971

  • Full Member
  • *
  • Posts: 115
  • Liked: 304
  • Likes Given: 1133
Maybe everyone is overthinking the info available?

The Globalstar quote above referencing launching the spare also says current and future subscribers “and other customers”

What if DOD / SDA or similar wants to test using commercial sat comms and is paying to launch this spare.

They would be the customer making it secretive and also paying for a direct insertion.

So there is a government client but it’s a commercial spare payload.

It's possible, but wouldn't really explain three 2nd stage burns.

Online gongora

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8976
  • US
  • Liked: 11124
  • Likes Given: 4979
Maybe everyone is overthinking the info available?
The Globalstar quote above referencing launching the spare also says current and future subscribers “and other customers”
What if DOD / SDA or similar wants to test using commercial sat comms and is paying to launch this spare.
They would be the customer making it secretive and also paying for a direct insertion.
So there is a government client but it’s a commercial spare payload.

Why would DoD/SDA pay for a launch of one spare satellite for an already operational constellation, one of many existing constellations, for "testing"?  That's an awfully expensive test of an existing capability.  Also it wasn't a direct insertion.  It stopped at another orbit on the way.

Online Comga

  • Senior Member
  • *****
  • Posts: 6056
  • Liked: 3918
  • Likes Given: 3570
Anyone want to explain what this "parking orbit" has to do with launching a Globalstar sat?  ::)
Looks like the mission profile could be:

1. Direct injection into a 533 x 533km orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km (ΔV about 174 m/s)
4. SES3 to circularise at 1200 x 1200km (ΔV about 170 m/s)
5. Release Globalstar.
If the two orbits were the same inclination, then SES2 and SES3 would be equally long, but SES3 is twice the length.
The most straightforward explanation is the SES3 also includes an inclination change, in addition to circularizing. So the two orbits have slightly different inclinations.

EDIT:  SES3 was about twice as long as SES2, and should have provided twice the delta-V.  If we assume SES2 was in-plane, then SES3 provided about 340 m/s, where only 170 m/s of that was needed to circularize.  So the sideward delta-V was about sqrt(340^2-170^2), or about 290 m/s.  Orbital speed at that altitude is about 7256 m/s, so the change in inclination should be about atan(290/7256), or about 2.3 degrees.   According to Alexphysics the launch azimuth indicated a 54o orbit, whereas GlobalStar uses 52o.  So this is consistent with the mystery orbit being 533x533x54o.

This makes our best guess:
1. Direct injection into a 533 x 533km x 54o orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km x 54o  (ΔV about 174 m/s)
4. SES3 to circularize/plane change at 1200 x 1200km x  52o (ΔV about 170 m/s for circularization, 290 m/s for plane change, 340 m/s total)
5. Release Globalstar.
6: SES4 for the second stage disposal burn.  At least 300 m/s to get to a 100 x 1200km or lower orbit.

This might explain why, when I saw the SES-3 burn earlier today, the direction of the burn was at an approximate 30-45 degree angle to the flight path.

(My bolding above)
290 m/s “sideways” vs 190 m/s prograde is very close to a 60 degree angle to the flight path.
Are there effects that would cause it to appear to be “an appropriately 30-45 degree angle to the flight path”?

Also, if these suppositions are correct, wouldn’t the constrain pretty tightly the drop-off orbit for our mystery payload(s)?
After all that secrecy….
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline TimTri

  • Member
  • Posts: 7
  • Germany
  • Liked: 9
  • Likes Given: 7
This user filmed the 3rd S2 burn from multiple angles.



He confirmed to me in the comments that an object on the exact same trajectory was visible a few minutes earlier, which could be our mystery payload. It also appeared to be venting (maybe an early propulsion test of some sort?).

I also had a look at the trajectory over Europe after SECO-1 (around the time the secret payload might have been deployed). Seems to be almost identical to an ordinary Starlink launch, except with a circular orbit already nearly at operational height (about 540km).
Starlink-3287 flew over Europe in the exact same trajectory with an almost identical orbit at the exact same time (verified on Heavens Above and CelesTrak). Maybe this could help us develop rough viewing opportunities for the secret payload. Other nearby sats include Starlink-1183 (1-2 minutes later) and Starlink-2446 (2-3 minutes earlier).

Edit: Here‘s the mystery object a few minutes prior to the Stage 2 flyover.
« Last Edit: 06/19/2022 03:39 pm by TimTri »

Offline Paul_G

Maybe everyone is overthinking the info available?

The Globalstar quote above referencing launching the spare also says current and future subscribers “and other customers”

What if DOD / SDA or similar wants to test using commercial sat comms and is paying to launch this spare.

They would be the customer making it secretive and also paying for a direct insertion.

So there is a government client but it’s a commercial spare payload.

In a previous post (link below), the structure that we can see at the top of the stack is similar, but not identical to the structure we saw in Transporter-2, which had some Starlinks on it that can be seen deploying at the T+1:28:53 mark () - this implies that *something* was up on this structure, and deployed before the Globalstar payload. But the Starlinks that are being deployed now need the stage to be spun in order to deploy - is it feasible that if there were some kind of Starlink says on this mission that the stage could be spun up to deploy them, then spun down to allow for the 3rd firing of the 2nd stage to get Globalstar to where it needs to be., or could a revised deployment procedure be used?

Some have suggested that SpaceX could be testing their Starship heat tiles on re-entry - wouldn’’t this need some kind of NOTAM like we see for Stage 2 disposal?

It seems that something was up on top of the stage, and deployed prior to SECO-2, as shortly after SECO-2, we did get a view of the now empty support structure on top of the stack.

Looks like the same deployer for Starlink on the Transporter missions
https://twitter.com/GewoonLukas_/status/1538395956848349185

Online gongora

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8976
  • US
  • Liked: 11124
  • Likes Given: 4979
Everyone keeps mentioning the deployment structure at the top of the T2 stack.  It was also on the T3 stack, the flight that had four payloads show up later.

Online JayWee

  • Full Member
  • ****
  • Posts: 646
  • Liked: 591
  • Likes Given: 983
I also had a look at the trajectory over Europe after SECO-1 (around the time the secret payload might have been deployed). Seems to be almost identical to an ordinary Starlink launch, except with a circular orbit already nearly at operational height (about 540km).
Starlink-3287 flew over Europe in the exact same trajectory with an almost identical orbit at the exact same time (verified on Heavens Above and CelesTrak). Maybe this could help us develop rough viewing opportunities for the secret payload. Other nearby sats include Starlink-1183 (1-2 minutes later) and Starlink-2446 (2-3 minutes earlier).

If you wanted to hide secret megaconstellation, mixing it with Starlink would be a perfect way to do it. Also would expain the secrecy - you don't want to let people know that there are military/intelligence assets snucked into a commercial constellation...

Offline Skyrocket

  • Extreme Veteran
  • Senior Member
  • *****
  • Posts: 2489
  • Frankfurt am Main, Germany
  • Liked: 743
  • Likes Given: 148
Everyone keeps mentioning the deployment structure at the top of the T2 stack.  It was also on the T3 stack, the flight that had four payloads show up later.
This is interesting - i had not noticed that before.
There appear to be Starlink-shaped satellites on top of the structure.
This might have interesting implications, what USA 320, ..., 323 might be.
« Last Edit: 06/19/2022 04:18 pm by Skyrocket »

Online gongora

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8976
  • US
  • Liked: 11124
  • Likes Given: 4979
In a previous post (link below), the structure that we can see at the top of the stack is similar, but not identical to the structure we saw in Transporter-2, which had some Starlinks on it that can be seen deploying at the T+1:28:53 mark - this implies that *something* was up on this structure, and deployed before the Globalstar payload. But the Starlinks that are being deployed now need the stage to be spun in order to deploy - is it feasible that if there were some kind of Starlink says on this mission that the stage could be spun up to deploy them, then spun down to allow for the 3rd firing of the 2nd stage to get Globalstar to where it needs to be

It's certainly feasible to spin up and spin down the stage for a deployment, but was the stage spinning in the T2 Starlink deployment you linked?
« Last Edit: 06/19/2022 04:12 pm by gongora »

Offline Paul_G


It's certainly feasible to spin up and spin down the stage for a deployment, but was the stage spinning in the T2 Starlink deployment you linked?

Yes, the video shows the stage was spun up to deploy the Starlinks.

Online LouScheffer

  • Senior Member
  • *****
  • Posts: 2934
  • Liked: 5115
  • Likes Given: 648
Looks like the mission profile could be:

1. Direct injection into a 533 x 533km orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km (ΔV about 174 m/s)
4. SES3 to circularise at 1200 x 1200km (ΔV about 170 m/s)
5. Release Globalstar.
If the two orbits were the same inclination, then SES2 and SES3 would be equally long, but SES3 is twice the length.
The most straightforward explanation is the SES3 also includes an inclination change, in addition to circularizing. So the two orbits have slightly different inclinations.

EDIT:  SES3 was about twice as long as SES2, and should have provided twice the delta-V.  If we assume SES2 was in-plane, then SES3 provided about 340 m/s, where only 170 m/s of that was needed to circularize.  So the sideward delta-V was about sqrt(340^2-170^2), or about 290 m/s.  Orbital speed at that altitude is about 7256 m/s, so the change in inclination should be about atan(290/7256), or about 2.3 degrees.   According to Alexphysics the launch azimuth indicated a 54o orbit, whereas GlobalStar uses 52o.  So this is consistent with the mystery orbit being 533x533x54o.

This makes our best guess:
1. Direct injection into a 533 x 533km x 54o orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km x 54o  (ΔV about 174 m/s)
4. SES3 to circularize/plane change at 1200 x 1200km x  52o (ΔV about 170 m/s for circularization, 290 m/s for plane change, 340 m/s total)
5. Release Globalstar.
6: SES4 for the second stage disposal burn.  At least 300 m/s to get to a 100 x 1200km or lower orbit.
This might explain why, when I saw the SES-3 burn earlier today, the direction of the burn was at an approximate 30-45 degree angle to the flight path.
(My bolding above)
290 m/s “sideways” vs 190 m/s prograde is very close to a 60 degree angle to the flight path.
Are there effects that would cause it to appear to be “an appropriately 30-45 degree angle to the flight path”?

Also, if these suppositions are correct, wouldn’t the constrain pretty tightly the drop-off orbit for our mystery payload(s)?
After all that secrecy….
From the video just below your post, the angles look consistent with a 60 degree angle.  If it was purely circularization, it would be in line with the flight path.  If it was purely plane change, it would be at right angles.  It looks to me as closer to a right angle than straight ahead, so 60 degrees seems plausible.

Offline TimTri

  • Member
  • Posts: 7
  • Germany
  • Liked: 9
  • Likes Given: 7
Everyone keeps mentioning the deployment structure at the top of the T2 stack.  It was also on the T3 stack, the flight that had four payloads show up later.

You might be onto something here. The grid-shaped structure looks basically identical to the one seen on the Globalstar launch, and there are clearly some Starlink satellites on top of it. The deployment isn‘t shown. And I don‘t know if they ever acknowledged the existence of Starlink satellites on that launch. These USA 320 etc. sats are in 540km orbits, similar to the one our secret payload was deployed in.

Offline jcm

  • Senior Member
  • *****
  • Posts: 3428
  • Jonathan McDowell
  • Somerville, Massachusetts, USA
    • Jonathan's Space Report
  • Liked: 1016
  • Likes Given: 636
Looks like the mission profile could be:

1. Direct injection into a 533 x 533km orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km (ΔV about 174 m/s)
4. SES3 to circularise at 1200 x 1200km (ΔV about 170 m/s)
5. Release Globalstar.
If the two orbits were the same inclination, then SES2 and SES3 would be equally long, but SES3 is twice the length.
The most straightforward explanation is the SES3 also includes an inclination change, in addition to circularizing. So the two orbits have slightly different inclinations.

EDIT:  SES3 was about twice as long as SES2, and should have provided twice the delta-V.  If we assume SES2 was in-plane, then SES3 provided about 340 m/s, where only 170 m/s of that was needed to circularize.  So the sideward delta-V was about sqrt(340^2-170^2), or about 290 m/s.  Orbital speed at that altitude is about 7256 m/s, so the change in inclination should be about atan(290/7256), or about 2.3 degrees.   According to Alexphysics the launch azimuth indicated a 54o orbit, whereas GlobalStar uses 52o.  So this is consistent with the mystery orbit being 533x533x54o.

This makes our best guess:
1. Direct injection into a 533 x 533km x 54o orbit (1:34:51 period)
2. Release payload 'X'
3. SES2 to raise apogee to a 533 x 1200km x 54o  (ΔV about 174 m/s)
4. SES3 to circularize/plane change at 1200 x 1200km x  52o (ΔV about 170 m/s for circularization, 290 m/s for plane change, 340 m/s total)
5. Release Globalstar.
6: SES4 for the second stage disposal burn.  At least 300 m/s to get to a 100 x 1200km or lower orbit.
This might explain why, when I saw the SES-3 burn earlier today, the direction of the burn was at an approximate 30-45 degree angle to the flight path.
(My bolding above)
290 m/s “sideways” vs 190 m/s prograde is very close to a 60 degree angle to the flight path.
Are there effects that would cause it to appear to be “an appropriately 30-45 degree angle to the flight path”?

Also, if these suppositions are correct, wouldn’t the constrain pretty tightly the drop-off orbit for our mystery payload(s)?
After all that secrecy….



This is interesting but I really wish people would do some error estimates.
What is the uncertainty on the "54 degrees" measured from the launch info?  Plus or minus 0.1 deg? or plus or minus 1 deg? or what?
-----------------------------

Jonathan McDowell
http://planet4589.org

Tags:
 

Advertisement NovaTech
Advertisement SkyTale Software GmbH
Advertisement Northrop Grumman
Advertisement
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1