Posted by: Szabolcs Nagy
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ISS and the last Dragon-1 (CRS-20) visit
SpaceX has been using its cargo vehicle called Dragon-1 since the beginning to deliver precious cargo supply to and from the International Space Station (ISS). During the first contract between Nasa and SpaceX the commercial company committed to do certain amount of missions to ISS, this contract is called Commercial Resupply Services 1 or CRS-1 missions. Currently the CRS-20 mission is ongoing and on Monday (6th March) it will undock from the Space Station, reenter out atmosphere and for the last time will splash down in the Atlantic Ocean. This will mark the end of CRS-1 contract missions and will start CRS-2 contract mission (including SpaceX, Northrop Grumman and Sierra Nevada Corporation).
The new thing is that SpaceX will use its Dragon-2 spacecraft from the second half of 2020 for both human and unmanned cargo spaceflights too.
So I was desperate to take a decent image of International Space Station and the final mission of the Dragon-1 design. So this post is a longer one focusing on my photographic history of Dragon-1 and the photos I have ever managed to take this week between 23rd and 31st of March. In the first half this article I will summarise the past few days of ISS imaging and also at the second part I will revisit those photos from earlier dates when I was lucky enough to photograph the Dragon spacecraft berthed of flying solo.
23rd March (birthday ISS)
Sky was great, but not the best but this was the first time I could do ISS photography for months! The maximum elevation of this flyby was 56º which is one of my favourites, mainly due the shallow angle we look at the station (more relevance later on the 31st March session). During taking my scope out in front of my balcony I managed to hit the door with the scope’s focuser. This caused some misery in the next few days…. Also for some reason the laptop recorded at 1/4 of the usual frame rate, so lost many many frames. This usually happens when using two Zwo cameras after each other. When I restarted the laptop, frame rate was back to normal.
I could see Dragon CRS-20, but I knew there is so much more in my equipment.
25th March
Much more favourable flyby with a max. elevation of 86º above horizon and much more favourable result too. Even the cylindrical shape of the Dragon trunk is easily visible. These are the best animations made from the sharpest frames.
On a timeline the left hand one happened sooner (Dragon not lit yet fully) and the right hand one few seconds later with Dragon nicely illuminated. We can look inside the trunk of the Dragon spacecraft, where it delivered Bartolomeo payload hosting platform.
26th March
Favourable flyby once again, but the focuser caused some problem just as much as my lack of knowledge about starts. I started panicking that the accident a few days back (hitting focuser) caused some permanent damage. When I placed the Bathinov mask for appropriate focusing, there were too many spikes. Just looked like scope is completely out of focus and misaligned. Approx. 10 mins later I realised my wrong doing – never try to take focus on a double star (in my case Castor)!
This wasn’t the only problem during that evening. Despite the 87º max. elevation, atmospheric conditions were average and my manual tracking wasn’t good at all! So after this event I actively started working on the problem, because my tracking wasn’t accurate at all and due inaccuracy I lost so many good frames. Dragon still visible at the end of the animation, but far from ideal or what I captured on the previous day.
31st March
I honestly totally gave up the possibility of capturing any more images of this historic mission. On the very last day ISS was observable high above the horizon (57º) the station went very close to Moon (half a degree), so I decided to capture that mainly with a 72/420 refractor scope and then using my 10″ scope to capture some close up frames too if possible. This scenario meant that I will miss half of the flyby. Looking back now I should have gone back for the close up only. Atmospheric conditions were amazing!
Stacked frames of 20 gave better overall result – I marked the currently docked/berthed spacecrafts too
My photos of the Dragon-1 cargo spacecraft from the past
SpaceX Dragon CRS-15
My first real photographic experience with a Dragon cargo spacecraft was in July 2018 when I managed to capture the Space Station and the CRS-15 vehicle both crossing the disk of Sun hours before the Dragon spacecrafts was berthed to ISS. More about the event here.
SpaceX Dragon CRS-16
Dragon CRS-16 mission flying solo en route to the International Space Station from December 2018. More about these images here.
SpaceX Dragon CRS-17
During High Beta Angle season the visibility of ISS is a bit unusual, luckily it has nothing to do with the docked spacecrafts. On this animation you will see the Dragon CRS-17 docked to the Space Station in May 2019. More about these images here.
23.03.2020 – 31.03.2020
Equipment:
Skywatcher 250/1200 Flextube dobson scope
Zwo ASI224MC colour camera
TeleVue 2.5x powermate
Bahtinov mask
Some photos with previous Dragon mission – taken by fellow amateur ISS photographers