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

[GWR64]

The launch was to 440 km altitude, not 350 km. i had confused.

2nd line 3rd field from the left.

yes,

On TLE from day 146 RAAN was about 165 deg.

3 TLEs from space-track

2019-029A
1 44235U 19029A   19146.23811933  .00001584  00000-0  45153-4 0  9990
2 44235  53.0009 165.1862 0006365 272.1524  87.8751 15.42688051  1556
2019-029B
1 44236U 19029B   19146.23794529  .00001625  00000-0  45907-4 0  9995
2 44236  53.0007 165.1834 0005819 272.7499  87.2839 15.42817023  1558
2019-029C
1 44237U 19029C   19146.23807623  .00001595  00000-0  45357-4 0  9991
2 44237  53.0009 165.1850 0006247 272.3109  87.7179 15.42720938   446

comparison with previous TLEs

TLEs from day 179 shows about 5 deg, for the Objects with the 440 km orbit. Starlink AQ for example
60° negative drift in 33 days, just under 2° per day.
The satellites with 550 km orbit had a RAAN of 10-15 deg on day 179.
Probably depending on when they have started increase the orbit.
With the higher orbit the RAAN-drift gets slower.

more precisely, this would have to be explained by a professional.
 

[gongora]

This is a visualization from Celestrak at
https://celestrak.com/cesium/orbit-viz.php?tle=/satcat/tle.php?INTDES=2019-029&satcat=/pub/satcat.txt&orbits=64&pixelSize=3&samplesPerPeriod=9
...

They're in one plane.

[spacenut]

Does anyone know when the next Starlink launch will be? 

[gongora]

Does anyone know when the next Starlink launch will be?

Ben Cooper's schedule is showing a late September launch with no payload specified, that's a possibility.

[jketch]

Does anyone know when the next Starlink launch will be?

There is information in L2.

[strawwalker]

Is there any difference in RAAN?
Are all in the same plane or are they trying to put some in a slightly different plane to test that condition?

The 60 Starlink satellites including the unresponsive and deorbiting ones, based on the latest elements available from SpaceTrack (all now within the last 7 days), and adjusted forward to 2019-06-29 ~18:00 UTC so that the RAAN values are all concurrent.

Name	Epoch	Semimajor	Inclination	RAAN
OBJECT BK	2019-06-29 01:49:04	6929.1	53.01	7.95
OBJECT E	2019-06-28 22:47:11	6930.0	53.01	7.93
OBJECT BJ	2019-06-28 01:58:11	6928.1	53.01	7.90
OBJECT BF	2019-06-28 13:12:30	6928.2	53.01	7.85
OBJECT U	2019-06-29 13:18:28	6932.2	53.01	7.83
OBJECT BL	2019-06-28 19:42:25	6928.3	53.01	7.81
OBJECT AD	2019-06-28 19:39:41	6928.2	53.01	7.80
OBJECT G	2019-06-28 19:40:53	6928.1	53.01	7.78
OBJECT A	2019-06-29 13:17:10	6928.2	53.00	7.77
OBJECT L	2019-06-28 13:25:58	6927.0	53.00	7.75
OBJECT BH	2019-06-28 18:00:48	6928.2	53.01	7.75
OBJECT BE	2019-06-29 00:40:24	6928.2	53.00	7.66
OBJECT C	2019-06-29 03:53:12	6927.9	53.00	7.63
OBJECT M	2019-06-28 23:09:39	6928.2	53.00	7.63
OBJECT Z	2019-06-28 13:36:04	6928.2	53.00	7.63
OBJECT V	2019-06-28 19:57:07	6928.3	53.00	7.62
OBJECT AC	2019-06-28 23:11:39	6932.6	53.01	7.62
OBJECT R	2019-06-29 11:57:34	6927.6	53.01	7.58
OBJECT AF	2019-06-28 18:32:23	6928.1	53.00	7.51
OBJECT AP	2019-06-29 00:56:24	6928.1	53.00	7.49
OBJECT K	2019-06-29 00:57:57	6928.1	53.00	7.46
OBJECT N	2019-06-28 21:48:33	6928.5	53.00	7.44
OBJECT BC	2019-06-28 18:38:59	6928.2	53.00	7.42
OBJECT BA	2019-06-28 18:42:04	6928.3	53.00	7.41
OBJECT AE	2019-06-28 20:16:16	6928.2	53.00	7.40
OBJECT BB	2019-06-29 04:17:22	6926.2	53.00	7.38
OBJECT AT	2019-06-29 12:18:14	6928.1	53.00	7.35
OBJECT BD	2019-06-29 12:22:44	6932.3	53.00	7.35
OBJECT AX	2019-06-28 15:34:28	6928.8	53.00	7.33
OBJECT AK	2019-06-28 20:59:16	6928.6	53.00	7.28
OBJECT W	2019-06-29 01:14:44	6927.9	53.00	7.27
OBJECT X	2019-06-29 11:48:02	6928.5	53.00	7.24
OBJECT AU	2019-06-28 22:06:22	6928.3	53.00	7.24
OBJECT AY	2019-06-27 04:43:58	6928.3	53.00	7.21
OBJECT AS	2019-06-28 19:00:24	6927.9	53.00	7.16
OBJECT AG	2019-06-29 12:35:50	6928.0	53.00	7.14
OBJECT AM	2019-06-29 12:37:37	6928.2	53.00	7.14
OBJECT AL	2019-06-28 22:23:20	6928.1	53.00	7.13
OBJECT AJ	2019-06-28 12:32:05	6932.3	53.00	7.11
OBJECT AN	2019-06-29 12:40:50	6927.7	53.00	7.07
OBJECT B	2019-06-28 22:21:46	6929.4	53.00	7.04
OBJECT H	2019-06-29 12:47:01	6928.0	53.00	7.01
OBJECT BM	2019-06-29 12:45:23	6928.1	53.00	7.01
OBJECT AH	2019-06-28 20:54:10	6928.2	53.00	6.98
OBJECT T	2019-06-24 21:20:07	6928.2	52.98	6.95
OBJECT D	2019-06-29 00:09:01	6928.3	53.00	6.94
OBJECT S	2019-06-28 12:57:56	6927.8	52.98	6.94
OBJECT P	2019-06-28 19:25:28	6928.3	53.00	6.89
OBJECT Q	2019-06-28 20:06:54	6907.1	53.00	6.80
OBJECT AR	2019-06-26 01:42:56	6928.7	53.00	6.68
OBJECT AW	2019-06-29 12:31:06	6928.4	53.00	6.59
OBJECT AB	2019-06-28 00:42:25	6929.9	53.01	6.20
OBJECT F	2019-06-29 11:45:17	6925.4	53.01	5.94
OBJECT BG	2019-06-28 13:14:04	6885.9	53.00	5.82
OBJECT AZ	2019-06-29 12:30:33	6876.6	53.02	5.54
OBJECT AA	2019-06-24 03:18:50	6876.8	53.01	5.52
OBJECT Y	2019-06-28 16:32:00	6862.2	53.00	4.36
OBJECT J	2019-06-28 17:41:09	6816.9	53.00	1.25
OBJECT AQ	2019-06-28 21:56:09	6813.7	53.00	1.09
OBJECT AV	2019-06-29 11:47:31	6775.1	53.00	0.26

The bulk of the constellation are well within 2 degrees of the same plane. The 15-30 degree spread is not real, it is because you are looking at RAANs over a wide spread of days with different precess time between satelliltes. Stuff in Space is another resource comparable to the Celestrack visualizer to help you see what the orbits look like. Eventually the stray orbits will disappear, and the remaining ones will tighten up.

[speedevil]

Is there any difference in RAAN?
Are all in the same plane or are they trying to put some in a slightly different plane to test that condition?

The 60 Starlink satellites including the unresponsive and deorbiting ones, based on the latest elements available from SpaceTrack (all now within the last 7 days), and adjusted forward to 2019-06-29 ~18:00 UTC so that the RAAN values are all concurrent.

Interesting.
Is there any archive of old elements that would enable one to work out the peak delta-v per day for any satellite?

[strawwalker]

Interesting.
Is there any archive of old elements that would enable one to work out the peak delta-v per day for any satellite?

You can get the complete history of elements for any satellite from Space-Track either by copying them from their website or through their API. There is a lot of noise in the Starlink data, though.

[gongora]

The 60 Starlink satellites including the unresponsive and deorbiting ones, based on the latest elements available from SpaceTrack (all now within the last 7 days), and adjusted forward to 2019-06-29 ~18:00 UTC so that the RAAN values are all concurrent.

Name	Epoch	Semimajor	Inclination	RAAN
OBJECT BK	2019-06-29 01:49:04	6929.1	53.01	7.95

The bulk of the constellation are well within 2 degrees of the same plane....

Of course the SpaceX documentation shows planes at 0 and 15 RAAN.  Which of those would this be?

[Barley]

Of course the SpaceX documentation shows planes at 0 and 15 RAAN.  Which of those would this be?

At that altitude RAAN precesses fairly quickly, on the order of magnitude of a degree per day.  So the actual RAAN is not a good identifier of the plane.  I suspect the document you are looking at is using some sort of notional RAAN either at a fixed epoch or for illustration.

[Danderman]

So.... We have differing opinions on whether a couple of satellites are significantly out of plane.

The difference in altitude between 440 and 550 km does not seem to be sufficient to provide for very quick plane change for satellites that remain at 440 km altitude.

[strawwalker]

The difference in rate of precession between the two objects at the top and bottom of my list above, in their orbits from June 29, is about 0.4 degrees per day.

[Rik ISS-fan]

My oppinion is that a 95% reliability for the Starlink satel items is totally unacceptable. With 3 failed satellites out of the 60 launched. This was the first deployment with 60 test satellites, so a higher failure rate was to be expected.
But with the next deployment at most 1 Sat might fail directly or within half a year. That's 98.33% reliability. For the whole constellation SpaceX should reach 99.9% reliability.
In my oppinion the FAA should stop allowing starling deployment if SpaceX doesn't reach these reliability statistics.
It's fortunate that SpaceX delivered these sats to only 550km altitude, now they will deorbit within 5years. At 800km this would be >200years and at 1200km they practical stay up indefinitely. That's why, with this insanely large Starlink constellation,  SpaceX has to reach very reliability. This to prevent Kesseler Syndrome.
I also think the Starlink  satellites are laying in debris avoidance capability. So in my oppinion SpaceX shouldn't be allowed with Starlink before they prove higher reliability.

[kevinof]

Think you're out of order with your "english" comment. This is a world wide site and takes comments and contributions from anyone no matter what their English is like. Would also add that Rik ISS-fan is a long time contributor on this site and deserves better.

Now he has a point. 95% at the level of deployments that SX is talking about is too low. Hopefully they will know what caused the failures so far and take steps to improve the reliability on future launches.

My oppinion is that a 95% reliability for the Starlink satel items is totally unacceptable. With 3 failed satellites out of the 60 launched. This was the first deployment with 60 test satellites, so a higher failure rate was to be expected.
But with the next deployment at most 1 Sat might fail directly or within half a year. That's 98.33% reliability. For the whole constellation SpaceX should reach 99.9% reliability.
In my oppinion the FAA should stop allowing starling deployment if SpaceX doesn't reach these reliability statistics.
It's fortunate that SpaceX delivered these sats to only 550km altitude, now they will deorbit within 5years. At 800km this would be >200years and at 1200km they practical stay up indefinitely. That's why, with this insanely large Starlink constellation,  SpaceX has to reach very reliability. This to prevent Kesseler Syndrome.
I also think the Starlink  satellites are laying in debris avoidance capability. So in my oppinion SpaceX shouldn't be allowed with Starlink before they prove higher reliability.

My opinion is that you should learn to type in English properly, also what would SpaceX ‘laying’ to the FCC accomplish? And how would SpaceX prove increased reliability without launching more satellites?

[hkultala]

My oppinion is that a 95% reliability for the Starlink satel items is totally unacceptable. With 3 failed satellites out of the 60 launched. This was the first deployment with 60 test satellites, so a higher failure rate was to be expected.

No, it's very acceptable.  If they have satellites whose cost of something like 10-50% of the cost of other satellites, they can afford to lose few and still get the working ones for MUCH CHEAPER.

And other satellites in the same plane can maneuver into positions of the "failed one" so some percentage failing and launching few percent more is not a problem for them.

But with the next deployment at most 1 Sat might fail directly or within half a year. That's 98.33% reliability. For the whole constellation SpaceX should reach 99.9% reliability.

99.9% reliability makes no sense for unmanned non-reusable device which can be easily replaced. No other spacecraft are even close to this kind of reliability.

[su27k]

My oppinion is that a 95% reliability for the Starlink satel items is totally unacceptable. With 3 failed satellites out of the 60 launched. This was the first deployment with 60 test satellites, so a higher failure rate was to be expected.
But with the next deployment at most 1 Sat might fail directly or within half a year. That's 98.33% reliability. For the whole constellation SpaceX should reach 99.9% reliability.
In my oppinion the FAA should stop allowing starling deployment if SpaceX doesn't reach these reliability statistics.
It's fortunate that SpaceX delivered these sats to only 550km altitude, now they will deorbit within 5years. At 800km this would be >200years and at 1200km they practical stay up indefinitely. That's why, with this insanely large Starlink constellation,  SpaceX has to reach very reliability. This to prevent Kesseler Syndrome.
I also think the Starlink  satellites are laying in debris avoidance capability. So in my oppinion SpaceX shouldn't be allowed with Starlink before they prove higher reliability.

1. FAA doesn't care about space debris, currently FCC is acting as gatekeeper for space debris mitigation
2. 95% reliability or even lower is totally acceptable at 550km attitude. NASA study suggests a post mission disposal success rate of 99% within 5 years is sufficient to mitigate space debris issue caused by large NGSO constellations. At 550km the worst case natural decay time just happens to be 5 years, so it's all taken care of. Even if all SpaceX satellites failed at 550km, it's still not a problem.
3. And now you should realize SpaceX didn't pick 550km at random, it's not "fortunate" that the orbit for these initial batch are 550km, it's all planned. They realized they'll have some failed satellites when iterating the designs, so they chose an orbit where failure is an option.
4. BTW, the satellites are not delivered to 550km, they're delivered to 440km and will need to raise to 550km by using their own propulsion. It's very likely the failed satellites are lower than 550km, may be even lower than 500km, which will result in even faster natural decay.
5. SpaceX is planning deploy 1,584 satellites to 550km, per point 2/3/4, there's no reason to prevent them from doing so based on reliability concerns. I agree that they should show higher reliability (or have some other means of deorbiting failed satellites) if they want to deploy satellites to 1,150km, but they have plenty of time to improve the reliability while filling up the 550km orbit.

[abaddon]

It's fortunate that SpaceX delivered these sats to only 550km altitude, now they will deorbit within 5years.

It's not "fortunate", it's by design.  For this very reason.  And they were delivered to 440km, not 550km.

If you're going to make something so dramatic as an appeal to the FAA to stop SpaceX from launching Starlink satellites, it'd help you to get the very obvious and basic facts right first.

[ThatOldJanxSpirit]

4. BTW, the satellites are not delivered to 550km, they're delivered to 440km and will need to raise to 550km by using their own propulsion. It's very likely the failed satellites are lower than 550km, may be even lower than 500km, which will result in even faster natural decay.

The three unresponsive satellites never moved from the 440km deployment orbit so they will deorbit in much less than 5 years.

[gongora]

4. BTW, the satellites are not delivered to 550km, they're delivered to 440km and will need to raise to 550km by using their own propulsion. It's very likely the failed satellites are lower than 550km, may be even lower than 500km, which will result in even faster natural decay.

The three unresponsive satellites never moved from the 440km deployment orbit so they will deorbit in much less than 5 years.

I only see two listed in the deployment orbit.

[Danderman]

I don’t understand the replacement strategy for Starlink,  assuming planes of 66 sats. I don’t see how SpaceX can insert the required 10 or so satellites necessary to go from the current 56 working sats to 66.