  Low latency and high synchronization among users are critical for emerging
multi-user virtual interaction applications. However, the existing ground-based
cloud solutions are naturally limited by the complex ground topology and fiber
speeds, making it difficult to pace with the requirement of multi-user virtual
interaction. The growth of low earth orbit (LEO) satellite constellations
becomes a promising alternative to ground solutions. To fully exploit the
potential of the LEO satellite, in this paper, we study the satellite server
selection problem for global-scale multi-user interaction applications over LEO
constellations. We propose an effective server selection framework, called
SpaceMeta, that jointly selects the ingress satellite servers and relay servers
on the communication path to minimize latency and latency discrepancy among
users. Extensive experiments using real-world Starlink topology demonstrate
that SpaceMeta reduces the latency by 6.72% and the interquartile range (IQR)
of user latency by 39.50% compared with state-of-the-art methods.
