Summary
September saw a higher number of general collision risks than the usual monthly average, the vast majority of which were very low probability. We saw a reduced number of re-entry and space weather events and we expect these re-entry numbers to continue to reduce from the high we saw in August. All NSpOC warning and protection services functioned as expected throughout the period.
Uncontrolled Re-Entry Early Warning
This month saw 50 re-entering objects; a reduction in the number of objects re-entering Earth's atmosphere compared to August, when the numbers were particularly high due to planned re-entry campaigns. Re-entered objects of note included the Polaris Dawn trunk re-entry on 29 September which re-entered over the Atlantic Ocean. This trunk was from the crewed Polaris Dawn mission launched earlier in the month taking 4 astronauts to complete the first private spacewalk.
Chart showing number of re-entries monitored by month. January: 13, February: 24, March: 25, April: 22, May: 56, June: 48, July: 44, August: 89, September: 50
In-Space Collision Avoidance
We warned UK-licensed satellite operators of 3,041 potential collision risks in September representing a 42% increase on August. Heightened solar activity and multiple operators in similar orbits might have contributed to the increase in risks. Our warnings allow operators to take critical collision avoidance decisions.
Chart showing number of collision risks to UK-licensed satellites monitored by month. January: 1,690, February: 1,943, March: 1,903, April: 1,899, May: 2,560, June: 1,881, July: 1,795, August: 2,137, September: 3,041
Fragmentation incidents
NSpOC has been monitoring the Atlas 5 Centaur rocket body break-up. Objects are still being analysed but we expect the debris count to be over 20 objects.
Space weather
Below is a summary of the key space weather events during this reporting period.
September - A moderate radiation storm occurred on 9 September where satellites may have experienced a modest increase in single event upsets to electronic systems.
12 September - Two coronal mass ejections (CMEs) arrived on 12 September, leading to a moderate geomagnetic storm with possible impacts to satellites.
14-16 September - A Strong wide-area blackout affected the sunlit side of Earth on 14 September, with the subsequent CME arriving at Earth late on 16 September producing a strong geomagnetic storm and an associated moderate radiation storm. Satellites may have again experienced a modest increase in single event upsets to electronic systems.
30 September - A moderate solar flare occurred which may have slightly impacted satellite communications on the sunlit side.
You can find more information on space weather and NSpOC here.
Number of Objects in Space
There was a total increase of 571 registered space objects during September which was slightly lower than in August. Just over 300 of these objects were additional debris pieces catalogued from the LM-6A (CZ-6A) fragmentation which occurred at the beginning of August.
Additionally, SpaceX deployed a further 82 Starlink satellites during September.
Note that numbers in the registered space objects catalogue can fluctuate over time as data is continually verified.
Chart showing number registered space objects by month. January: 28,014, February: 28,172, March: 28,478, April: 28,752, May: 28,850, June: 28,931, July: 28,917, August: 29,297, September: 29,678
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The National Space Operations Centre combines and coordinates UK civil and military space domain awareness capabilities to enable operations, promote prosperity and protect UK interests in space and on Earth from space-related threats, risks and hazards.
