SpaceX F9 : Starlink v0.9 : May 23, 2019 - DISCUSSION

[PM3]

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

Then, a Falcon 9 will launch from pad 40 with the first Starlink satellites on mid May at the earliest.

[gongora]

0694-EX-ST-2019

This STA is necessary to gate on-orbit testing of satellites for the upcoming SpaceX Starlink Mission 1488.
STA is required to verify the end to end functionality of the system.

Operation Start Date:   05/15/2019

Hawthorne  North  33  55  17  West  118  20  36, Mobile within the SpaceX factory

[PM3]

SpaceX still needs to get some sort of modification or STA approved before they can do anything with the sats they're intending to launch first, they just don't match the existing license.

Is it confirmed that SpaceX will start the constallation at 550 km orbits, and not - surprise - at 340 km (which is already licensed)?

[gongora]

SpaceX still needs to get some sort of modification or STA approved before they can do anything with the sats they're intending to launch first, they just don't match the existing license.

Is it confirmed that SpaceX will start the constallation at 550 km orbits, and not - surprise - at 340 km (which is already licensed)?

They've specifically said they're starting (or want to start) at 550km.  The altitude isn't the only difference.  They also want to use different frequencies to communicate with their gateways on these first <=75 sats.

[Steven Pietrobon]

Is it confirmed that SpaceX will start the constallation at 550 km orbits, and not - surprise - at 340 km (which is already licensed)?

I believe the plan is to deploy the satellites at 340 km, with the satellites then manoeuvring to 550 km. This way, if a satellite is DOA, its can quickly decay without becoming a space debris hazard.

[gongora]

Is it confirmed that SpaceX will start the constallation at 550 km orbits, and not - surprise - at 340 km (which is already licensed)?

I believe the plan is to deploy the satellites at 340 km, with the satellites then manoeuvring to 550 km. This way, if a satellite is DOA, its can quickly decay without becoming a space debris hazard.

The insertion altitude has changed a few times.  It was briefly 350km, then changed to 430km.  The VLEO constellation is 335-346km (if they get around to building it).

[PM3]

Satellite "go" from FCC:

SpaceX Statement

Today, the Federal Communications Commission (FCC) approved SpaceX’s request to fly more than 1,500 of its Starlink satellites at an altitude of 550 kilometers. ...

(0694-EX-ST-2019 still pending, and additional FAA license needed)

[oldAtlas_Eguy]

Also reported by SpaceX is that all sats for the launch are at CC.

The question remains how many? What orbit parameters for release?

[vaporcobra]

Also reported by SpaceX is that all sats for the launch are at CC.

The question remains how many? What orbit parameters for release?

Can't say how many per mission but the plan for the 1584 going to 550km is to launch them to ~350km and use their Hall thrusters for the last 200km. Major benefit is that faulty satellites would re-enter extremely quickly at such a low altitude, while healthy sats should easily be able to raise themselves ~200km.

[Nehkara]

Can we get a source/confirmation on the insertion altitude?  Is it currently 430 km or 350 km?

[gongora]

Can we get a source/confirmation on the insertion altitude?  Is it currently 430 km or 350 km?

This was my source for 430km:

March 18, 2019
...
SpaceX also noted that its initial version of satellites will likely be injected into orbit at an altitude of 430 km, slightly above the 350 km injection used for the collision risk analysis in its response.

[ZachS09]

For these Starlink launches, will Stage 2 directly insert itself into the payload deployment orbit, or will it do a parking orbit and circularization at apogee?

[codav]

For these Starlink launches, will Stage 2 directly insert itself into the payload deployment orbit, or will it do a parking orbit and circularization at apogee?

As they will launch a larger batch of sats, with at least the weight of the Iridium launches if not more, I'd bet on coast phase plus apogee burn.

[DreamyPickle]

This is probably a dumb question but: Why not Vandenberg?

Iridium launched from there and I was under the impression that Starlink will have a similarly large inclination.

[gongora]

This is probably a dumb question but: Why not Vandenberg?

Iridium launched from there and I was under the impression that Starlink will have a similarly large inclination.

Starlink isn't using polar orbits.  The initial orbital planes are only inclined a couple degrees more than the ISS.

[envy887]

This is probably a dumb question but: Why not Vandenberg?

Iridium launched from there and I was under the impression that Starlink will have a similarly large inclination.

Starlink isn't using polar orbits.  The initial orbital planes are only inclined a couple degrees more than the ISS.

53.8 degrees should be accessible from VAFB, but there will be a performance penalty for the dogleg on ascent. Using the Canaveral pads allows more payload and/or margin.

[gongora]

They are also set up for much higher throughput at Cape Canaveral.  Two launch pads with newer TEs, multiple payload processing bays, core refurbishment facilities.  If a payload can be launched from the Cape then it would make little sense to launch it from Vandenberg unless the Cape schedule gets a lot more congested in the future.

[PM3]

Pad is cleared for Starlink!

[scr00chy]

Pad is cleared for Starlink!

Quickest turnaround on SLC-40 is 16 days. This might beat that.

[smoliarm]

Pad is cleared for Starlink!

Quickest turnaround on SLC-40 is 16 days. This might beat that.

Actually the shortest turnaround on SLC-40 was 13 days:
Apr 14, 2015 --- Dragon CRS-6
Apr 27, 2015 --- TurkmenSat 1
Although this was for Falcon 9 v1.1; don't know if it makes things easier or not.