  The development of large constellations of satellites (i.e., so-called
megaconstellations or satcons) is poised to increase the number of LEO
satellites by more than an order of magnitude in the coming decades. Such a
rapid growth of satellite numbers makes the consequences of major fragmentation
events ever more problematic. In this study, we investigate the collisional
risk to on-orbit infrastructure from kinetic anti-satellite (ASAT) weapon
tests, using the 2019 Indian test as a model. We find that the probability of
one or more collisions occurring over the lifetime of ASAT fragments increases
significantly in a satcon environment compared with the orbital environment in
2019. For the case of 65,000 satellites in LEO, we find that the chance of one
or more satellites being struck by ASAT fragments of size 1 cm or larger is
more than 25% for a single test. Including sizes down to 3 mm in our models
suggests that impacts will occur for any such event. Finally, we apply our
methods to examine the November 2021 Russian ASAT test, also finding a
significant collision probability over the lifetime of the fragments. The heavy
commercialization of LEO demands a commitment to avoiding debris-generating
ASAT tests.
