I think that one of the key reasons why it's so difficult to solve global problems like #spacedebris#climatechange & #oceanplastic is because we don't experience the harm; it's always someone else who is affected (1/n)
What I mean is that the harm is perceived to be 'out of sight' so it becomes easy to ignore. Even if it is not ignored, it's easy to assume that someone else will tackle it. (2/n)
And even if we aim to tackle it, it's under the assumption that we won't be alone in doing so and the costs/difficulties can be shared. (3/n)
I think that one of the reasons why we should all watch #DrowninginPlastic is because more than anything else @lizbonnin is our ambassador in this dark world we humans have created; we can empathise & fully understand her response (4/n)
@lizbonnin Because she responds as a human being & in a way that you and I would if we were there with her. The honesty & vulnerability connects us in a way that would not be as powerful if the typical rules of reporting were followed (5/n)
@lizbonnin It brings the problem into sight, but more than that it makes us feel the harm so that we can't push it out of mind. From my perspective, #DrowninginPlastic is one of the most powerful films I've seen (6/n)
@lizbonnin (so huge thanks & congrats to everyone involved, but especially @lizbonnin for being bold & brave) (7/n)
@lizbonnin Perhaps as important, #DrowninginPlastic shows us that humans can tackle these global challenges by working together without self-interest if we commit. Yes, it will not be easy, but it will definitely be worthwhile (8/n)
@lizbonnin Because sooner or later we will experience the harm unless we act now. 'Out of sight, out of mind' won't work for us much longer #BeTheChange (9/9)
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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]