  NRAO and SpaceX have been engaged in coordinated testing efforts since Fall
2021, including conducting experiments on different interference avoidance
schemes for the Karl G. Jansky Very Large Array (VLA) in New Mexico, and the
Green Bank Telescope (GBT) inside the National Radio Quiet Zone (NRQZ) in West
Virginia. The Starlink system is capable of avoiding direct illumination of
telescope sites with their adaptive tasking to place downlink beams far away.
Nevertheless, even satellites operating in this mode can potentially present
strong signals into the telescope's receiver system if they pass close to the
telescope's main beam at the boresight. For additional protection, Starlink
satellites can either momentarily redirect or completely disable their downlink
channels while they pass within some minimum angular separation threshold from
the telescope's boresight, methods that are referred to as "telescope boresight
avoidance". In two separate experiments conducted since Fall 2023, NRAO and
SpaceX arranged to have the GBT observe a fixed RA/Dec position in the sky,
chosen to have a large number of close-to-boresight Starlink passages.
Preliminary analysis from these two experiments illustrate the feasibility of
these avoidance methods to significantly reduce, if not eliminate, the negative
impact of close-to-boresight satellite passages. Importantly, these experiments
demonstrate the value of continuing cooperative efforts between NRAO and
SpaceX, and expanding cooperation between the radio astronomy and satellite
communities more generally.
