10 years ago I visited my local GP surgery for some vaccinations. Two days later, finding myself in excruciating & unrelenting pain, I was back for some prescription pain relief. It didn't work & it's been that way ever since #MEawarenesshour
Just a few days later, I found myself unable to lift myself out of a chair & experiencing extremely rapid declines in energy. These episodes seemed to come without cause or warning. They happened in the middle of the day & also at night #MEAwarenessHour
A few days later, I was signed off work & told not to return until I had made it through two weeks without any symptoms. That was the beginning of my first #SelfIsolation. For the next 3 months I really only left my house for food shopping. #MEAwarenessHour
I got used to being at home & not going out. I got used to speaking to friends on the telephone rather than seeing them in person. I reconnected with friends I had lost touch with & we shared our experiences with illness #MEAwarenessHour
So the prospect of another period of isolation at home does not worry me. It is familiar. Like wearing comfortable clothes. #MEAwarenessHour
I understand that it might be difficult for some to remain housebound when they would rather be out, enjoying the company of friends & family, a good meal, a drink with colleagues, or a trip to the beach. Trust that this period of isolation will come to an end #MEAwarenessHour
Trust that you will be able to return to your lives, your family, your friends & your colleagues. Trust that the beaches, the forests, the mountains & the rivers will be there waiting for you to relish once again. Trust that you will get through this period #MEAwarenessHour
Then remember that some will not have the same opportunities to return to the world. Some will continue to be isolated from the outside, as they were before the world knew of COVID-19. Unable to go back to lives they once enjoyed but unwilling to remain #MEAwarenessHour
I am one of the lucky ones, able to go back into the world. Yet I have lost the the wealth of opportunities open to most of the world. I am still tied to my house, anxious to leave it for long or to go far from its comforts. #MEAwarenessHour
When you emerge, remember those lost in an isolation imposed by an unforgiving & relentless illness #MEAwarenessHour
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Welcome to this month's look at #Starlink conjunction risk mitigation manoeuvres. Through 30 April 2023, I estimate that Starlink satellites have made a total of > 45,000 manoeuvres to mitigate the risk of colliding with other space objects [1/n]
A better relationship to consider is the one between the (cumulative) number of manoeuvres and the (cumulative) number of Starlink satellites launched. The growth is a non-linear function of the number of Starlink satellites [2/n]
Here, I looked at the manoeuvre estimates/reports in 6-monthly intervals, corresponding to the reporting periods used by SpaceX. Additionally, I added a prediction to the end of 2024 based on an exponential fit through 30 April 2023. [3/n]
I've been thinking about the new proposed @FCC "five-year rule" for #SpaceDebris mitigation & wanted to share some analysis & thoughts. Whilst I think the intentions are good I believe the implications of the change are poorly understood. Let me explain... [1/n]
As @brianweeden's excellent thread explains, "The new proposed ruling would require all FCC licensed satellites that end their life in LEO to re-enter the atmosphere within 5 years, and ideally ASAP." [2/n]
Latest analysis for #Starlink & #OneWeb shows these two constellations accounted for 42% of all close approaches within 5 km predicted by #SOCRATES at the end of August, with Starlink alone accounting for 29%. [1/n]
On average, #SOCRATES predicts that each #Starlink satellite will now experience 1 close approach within 5 km with a non-Starlink object every day, and each #OneWeb satellite will experience 3.4 close approaches with a non-OneWeb object every day. These rates are increasing [2/n]
Here's the same data from [2/n] plotted with respect to the number of satellites in each constellation in orbit, clearly showing #SOCRATES predicts that #OneWeb satellites experience more close approaches (within 5 km) per satellite than the #Starlink satellites [3/n]
A follow-on from yesterday's thread with a note about averages. In a #SOCRATES report from 30 June 2022 the average collision probability for each #Starlink conjunction was 3.7E-6 but the range of values can be broad (chart shows data since 2019) [1/n]
#SOCRATES predicted some events with a collision probability > 1E-2 (1-in-100) & some with a probability < 1E-7 (1-in-10,000,000). The average value might seem to be almost negligible & you might think all conjunctions would be similar, but that's not the case [2/n]
In addition, some #Starlink & #OneWeb satellites experience more conjunctions than others. Most satellites experience relatively few encounters but a few satellites are involved in a relatively large number (charts shows data for 7 days from 30 June 2022) [3/n]
Welcome to my (delayed) monthly analysis of @CelesTrak#SOCRATES conjunctions. Since 1 March 2019, SOCRATES has predicted about 9 million unique conjunctions within 5 km involving active or derelict payloads. This is a thread focused on those involving #OneWeb & #Starlink [1/n]
#OneWeb payloads have accounted for ~500,000 unique conjunction predictions since 1 March 2019 (5.5% of all predictions made), while #Starlink payloads have accounted for ~1.1 million (12.5%) [2/n]
On 1 March 2019 #SOCRATES predicted ~3860 unique conjunctions within 5 km. On 30 June 2022 the corresponding number was ~10,160, an increase of ~160%. #Starlink accounted for ~2570 (25%) & #OneWeb accounted for ~1250 (12%) [3/n]
In advance of my monthly analysis of #Starlink conjunction data I wanted to share some additional analysis undertaken over the last few days. It's a work in progress but here's a thread looking a little deeper at the #SpaceX approach to #Starlink orbital space safety [1/n]
My focus has mostly been on understanding the implications relating to the choice of the probability threshold for collision avoidance manoeuvres. With the #SOCRATES#Starlink data now running across nearly 3 years we can gain some insights that may be useful [3/n]