SpaceX to launch 60 Satellites in one go

[2hats]

Realistically, the last chance saloon for the UK, but there's a risk of cloud around by mid-evening.

Tonight start looking by 2055BST under and around Venus. They will arc from the west to the SE via the SW. Will be more drawn out than yesterday (the imagery above).


(This map for SE UK; the track will run a little closer to the horizon as one moves north, slightly earlier and closer to the zenith if you are west of there).

 

[2hats]

Starlink satellites now appear to be running about 1 minute early compared to the chart one post above. Always best to go out early.

 

[Maggot]

Proper cloudy here

 

[smmudge]

Aye same here, but will give it a go, maybe there's a gap.

 

[2hats]

Success from light polluted central London. Initially they were quite dim, perhaps around mag +4 , but a fine sight easily spotted in binoculars (handy they came close to conjunction with Betelgeuse and then Procyon, making it easy to lie in wait for them). As they travelled to the SE they brightened to around mag +2 (similar to the main stars in the Plough) and could be seen naked eye, though by that time they were starting to suffer from extinction behind a thin cloud layer. I counted 35+ of them chasing each other over about 10-15 degrees of sky. In binoculars some appeared to have a hint of red-orange. That could have been because they were closing towards orbital sunset at the time though. But since some were still white it might have been a consequence of experimenting with different coatings, insulation or different orientations for some of them (for signature reduction).

Same pass this evening seen from Germany:

 

[smmudge]

Nothing for me, though I could see a few stars, it wasn't really clear enough I don't think.

 

[2hats]

The next Starlink launch coming up is Starlink 8 which is targeting 0325 BST on Thursday 4 June (given clear cloud that should be visible in the pre-dawn sky).

The mission is notable for several reasons...

- both first stage recovery barges are going to be in the Atlantic at the same time:


(current manifested west coast launches will all be return to launch site for the time being),

- a test of VisorSat, a satellite with a sunshade visor to reduce optical signature,

- use of hitchhiking rideshare slots: three small Planet Labs' SkySat imaging satellites will ride the second stage to orbit with the Starlink cluster,

- the first stage will be on its fifth reflight.

 

[HAL9000]

The next Starlink launch coming up is Starlink 8 which is targeting 0325 BST on Thursday 4 June (given clear cloud that should be visible in the pre-dawn sky).

The mission is notable for several reasons...

- both first stage recovery barges are going to be in the Atlantic at the same time:


(current manifested west coast launches will all be return to launch site for the time being),

- a test of VisorSat, a satellite with a sunshade visor to reduce optical signature,


- use of hitchhiking rideshare slots: three small Planet Labs' SkySat imaging satellites will ride the second stage to orbit with the Starlink cluster,

- the first stage will be on its fifth reflight.

Why are two first stage recovery barges present? I asusme only one is needed

 

[Crispy]

Why are two first stage recovery barges present? I asusme only one is needed

One is returning to shore with the booster from the Dragon launch

 

[2hats]

That next Starlink launch (officially Starlink 8) now targeting 0225BST on Thursday. Satellite release is due just a few seconds before 0240BST and then the extended object will be visible over Europe several minutes later.

Here for the southern UK the first ascent pass will be visible (cloud permitting) starting 0244BST, passing from W to E directly overhead.

 

[20Bees]

After weeks of clear sky the forecast is... meh

 

[paul mckenna]

why do they use barges at all? Surely it's worth sacrificing a bit of fuel capacity to avoid the faff?

 

[Crispy]

why do they use barges at all? Surely it's worth sacrificing a bit of fuel capacity to avoid the faff?

The payload hit is not small. ~13t payload with a barge landing, ~9.5t when returning to land.
They only return to land when the payload is small enough

 

[paul mckenna]

surprises me that it'd need so much fuel to boost part of the way back round, once already in space. I assume they're geostationary when payload released so just a quick squirt (and possibly a bit of a wait) then drop back down innit

 

[2hats]

The payload hit is not small. ~13t payload with a barge landing, ~9.5t when returning to land.
They only return to land when the payload is small enough

Also for some mission profiles and payload combinations the fuel margins are not that high (bear in mind they are super chilling/cooling the propellants to squeeze every last drop out of them). Crew Dragon, for example, requires the sea barge to recover the first stage as there isn't sufficient fuel margin to bring it back to land (per your numbers above), let alone provide for some in-plane steering to facilitate rendezvous with the ISS. This is one reason why such missions target instantaneous launch windows (the propellant chilling also limits time on the pad). The shuttle had margins to permit plane corrections and so allow for several minute long launch windows (actually, typically, two phasing windows that overlapped during a 10 minute planar window to the ISS). Atlas V has margins for up to a 30 minute window to the ISS (well they do throw pretty much all of the hardware away in the process; the latest F9 would have similar margins if they didn't bother with recovery).

 

[2hats]

The launch of the next batch is due this evening (2139BST). Ascent pass in twilight would be at 2200BST based on current orbital calculations and estimated targeted launch time.

From SE UK:

 

[2hats]

Now postponed a day - targeting 2118BST Friday. Twilight will be really bright so a stretch to see.

 

[2hats]

SpaceX F9 launch of Starlink 4-27 this evening features an atypical early release of the stack and the possibility of seeing the upper stage manoeuvring from NW Europe in twilight. Launch now scheduled for 20:21:20BST, which is just before sunset in S England. Stack deploy scheduled for 20:36:40BST. The pass will be around 2040-2044BST.

So, given a clear sky, one should be able to see them fairly tightly bunched in binoculars. with lighting improving as they move to the east. UKV forecast model cloud cover suggests a fair chance of viewing.
We might get to see some sort of upper stage collision avoidance burn (and resulting exhaust cloud), and/or de-orbit setup disposal burn, venting. Finder chart provided is for the London area; there will be considerable variation in viewing angles across the south of the country as we are all close to the ground track.

​

People with a clear view down to their W/SW horizon might have a second chance to see them, slightly more spaced, around 2213-2215BST low in the W before they go into eclipse on the next orbit.

​

 

[Crispy]

What do you use to generate those charts 2hats? I'll be in the countryside this evening so will have a good chance to see them...

 

[2hats]

I either use SatFlare or roll some Python code to make various finder charts.

Launch weather forecast was looking a bit hit and miss for today but appears to be improving and there are currently no launch weather criteria violations.

​

Clouds gradually thinning out where I am.

 

[2hats]

Bright sky but I lay in wait near Vega. Saw the Starlinks all closely stacked together - like a rectangle of light on the sky (around mag -1), with the fainter upper stage trailing.

Now to wait for the next pass...

 

[AverageJoe]

I was there. Went to Kennedy Space Centre and didn't realise there was a launch!Ive got a video of the launch but can't upload it

 

[2hats]

Telescope view from the London area. Roughly as I saw it but with significantly more detail.

Next pass, low in the SW, coming up in 20 minutes.

 

[2hats]

And now starting to spread out. Much less bright on this pass (perhaps mag +5; lower elevation) though conditions are generally very good (can easily see down to better than mag +9 in binoculars closer to the zenith).

 

[AverageJoe]

They were lucky to launch. The launch was 3.14 US time and at 5 O'clock US time the heavens opened and their was the largest storm I've ever seen. Lots of flooding, even with storm drains. Its still going now with loads of lightning.

 

[2hats]

Starlink 4-20 launch this morning and the fading upper stage/payload deploy attitude setup burn plume, further separation and attitude setup burns, disposal burn and venting of residual propellant were all caught over Cornwall before sunrise, about 110 minutes after launch.

Nascent Starlink train (magenta arrow), upper stage (orange) and tumbling retaining rods (green) plus (most likely) the Boeing Sherpa-LTC2/Varuna-TDM rideshare payload and/or adapter (cyan) also visible.

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ƝateLB_UK 🌈🇪🇺 (@KmunityOfEquals)

Video 1/2 - #SpaceX #Falcon9 #Starlinks flying over #Cornwall, #UK - 5:05am ... Sorry for the jerky track, I had real problems with the mount, and tangled data and power cables!!

nitter.it

Then seen a few minutes later off the southern coast of Spain.

Marineros de La Caleta avistan una extraña luz sobre la costa de la Axarquía

En torno a las 06:05 de esta madrugada de lunes, marineros de un pesquero de cerco que faenan de noche en la costa de la Axarquía avistaban una extraña luz sobre el cielo, concretamente a la altura de Chilches. Ests marineros aseguraban que "nunca hemos visto nada igua". Además señalaba que "si...

www.correodelaaxarquia.com