  Single spacecraft missions do not measure the pristine solar wind
continuously because of the spacecrafts' orbital trajectory. The infrequent
spatiotemporal cadence of measurement fundamentally limits conclusions about
solar wind-magnetosphere coupling throughout the solar system. At Mars, such
single spacecraft missions result in limitations for assessing the solar wind's
role in causing lower altitude observations such as auroral dynamics or
atmospheric loss. In this work, we detail the development of a virtual solar
wind monitor from the Mars Atmosphere and Volatile Evolution (MAVEN) mission; a
single spacecraft. This virtual solar wind monitor provides a continuous
estimate of the solar wind upstream from Mars with uncertainties. We
specifically employ Gaussian process regression to estimate the upstream solar
wind and uncertainty estimations that scale with the data sparsity of our real
observations. This proxy enables continuous solar wind estimation at Mars with
representative uncertainties for the majority of the time since since late
2014. We conclude by discussing suggested uses of this virtual solar wind
monitor for statistical studies of the Mars space environment and heliosphere.
