Discussion: Antares ISS resupply launch from Wallops,VA early Sunday morning

There's an ISS resupply launch from Wallops this Sunday, Nov 6 at 5:50 AM EST (note Standard time - this is right after the time change early Sunday morning so be aware). This launch time is 50 minutes before our local sunrise, so its just about perfect for plume lighting! I don't have any telemetry for Antares launches - altitude vs time, but I may try to gin something up for a lighting prediction tonight. Given the timing though, the lighting should be excellent for anyone on the eastern seaboard.

Unfortunately it looks like we might have cloud cover in MD, and low ceiling is a concern for launch as well, so keep an eye out for the launch status. Here's a viewing press-release from Wallops:

https://www.nasa.gov/wallops/2022/feature/watch-th...

The bleachers at Wallops will be open for viewing, and I assume the closer boat launch site on Pierce Taylor Rd. will also be available:

https://www.google.com/maps/@37.8431414,-75.526356...

Ok, I scraped together something like a launch profile from the replay of the previous NG-17 launch back in Feb. There was good velocity and alt data from 1:20 to SECO, but nothing before that so I just eyeballed the profile for the first 1:20. Ground track estimate from ISS orbital elements should be good. Here's the lighting prediction for tomorrow morning's launch:



First blush of sunlight on the plume should be 2.5 mins after launch and it will be fully sunlit after that. I don't have any telem on the spent 1st stage, but it should follow a ballistic trajectory and be illuminated all the way down to the ocean. Look for it as a single bright dot falling slowly below the path of the burning 2nd stage.

Weather still 80% favorable for launch, with low cloud ceiling being the only concern. Looks like 80% cloudcover in Baltimore, but this might be bright enough to at least glow through the clouds.

From Philly through Boston or NC south to Charleston and inland, the vehicle will clear your horizon just before it enters sunlight and be lit thereafter. This should be a good show all along the NE coast of the US, weather permitting.

I made a kml file with the launch profile. I don't have a place to post it online, but I can e-mail it to anyone interested. You can use it in Google Earth to predict the viewing circumstances from your location. Here's the view from my site N of Baltimore:



Magenta portion is in shadow (burning 1st stage engine will be visible, but not the plume). Yellow portion is sunlit, so engine plus exhaust plume illuminated. Track ends 1 min after second engine cutoff. The vehicle will still be in sunlight but will look like a single dot flying away from the end of the exhaust plume.

Note there should be a 40s gap between first stage cutoff and 2nd stage ignition, between T+3:20 and 4:10. Stage and fairing separation will occur in this gap and be in full sunlight, so look for multiple white dots during this time between the end of the 1st stage plume and the start of the 2nd stage plume. Binoculars would be helpful to see the white dots.

Currently on schedule for launch, with weather 90% favorable. Wallops livestream is up, and there is also live coverage at Spaceflight Now.
NASA TV will also have coverage starting at 5:30 AM. Overcast in Baltimore, but looks decent closer to the coast.

Arg. Well, this is a new one:

SCRUB. The Antares launch director reports there was a fire alarm at the Cygnus spacecraft's mission control center in Dulles, Virginia. The control team won't be able to get back inside the building to support a launch attempt today.

I went out in the rain and took pictures....of the clouds. Next attempt will be tomorrow, Mon Nov 7 at 5:27 am EST. Here's the lighting chart for tomorrow's attempt:



With only a 23 minute shift earlier, the lighting situation is still pretty good. The vehicle will now enter sunlight during the coast phase - after the first stage burn is complete - but the second stage burn will be fully sunlit.

So now we'll see just the bright orange dot of the first stage burn, which will go out at T+3:25. Everything will be dark for 20-30s, then both separated stages will enter sunlight and show up as 1-2 bright dots, followed 20s later by fairing separation and 2nd stage ignition in full sunlight which should be pretty spectacular.

I went out this morning. Overcast when I left the house, but it broke up a bit. Mars is bright in the mornings, and close to Aldebaran, making for two orange "eyes" overhead. Still a low cloud deck towards the east. The launch was delayed to the end of the window (about 5 mins late) due to one the range patrol boats that had an engine problem.

I took 10s exps during the climb, getting one shot right at MECO, then there was the expected coast phase. I looked with binocs during this time but did not see the spent 1st stage illuminated. Second stage lit up and the plume was larger, but a few seconds later it blew up like a balloon in the sunlight! The expansion was very rapid, just took a second or two to reach full size. It was pretty large - almost perfectly round and about 10 deg across (fist held at arms length), with the burning engine visible in the middle. I fumbled with the cable release and the camera was buffering at this time, so I only got a couple of poor shots before it dropped behind a cloud. It was then visible again below that cloud and then the glow was visible for a while after.

The sunrise illuminating the contrail was the real prize. It was amazing! I took a series of photos for about 30 mins after the launch until it was too bright to see the trail. Had some problems with the lens fogging - pretty wet out there. Had to keep bumping the exptime down as the sky brightened.

Really happy with the lighting prediction and track. Will have to look at the replay to see if it was much different than the Feb launch I used for telem. I was a little surprised to see the 2nd engine smaller plume before it blew up into a bigger ball. Not sure if that means it was lower at second engine start or if it was something to do with the throttling. The coast phase might have been shorter than in Feb. But all-in-all the event timing was very close to the prediction.

A few quick-look photos attached. I'll make a long mp4 of the whole sequence. The one shot I got of the 2nd stage plume was short, but shows some interesting structure. Not sure if this is from the engine or clouds along the line of sight. Probably the latter. I would have expected the plume to be pretty symmetric that high up. Image 2120 is 2nd stage ignition, and the next shot I got of the plume was 2122. The big blow-up was between these two.






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