  Policy Brief on "Long Term Space Data and Informatics Needs", distilled from
the corresponding panel that was part of the discussions during S20 Policy
Webinar on Astroinformatics for Sustainable Development held on 6-7 July 2023.
  Persistent space data gathering, retention, transmission, and analysis play a
pivotal role in deepening our grasp of the Universe and fostering the
achievement of global sustainable development goals. Long-term data storage and
curation is crucial not only to make the wide range of burgeoning data sets
available to the global science community, but also to stabilize those data
sets, enabling new science in the future to analyse long-term trends over
unprecedented time spans. In addition to this, over the long-term, the
imperative to store all data on the ground should be ameliorated by use of
space-based data stores --maintained and seen to be as reliable as any other
data archive. This concept is sometimes referred to as Memory of the Sky.
Storing the data must be accompanied by the ability to analyse them. Several
concepts covered below acknowledge roots and inspiration based in the Virtual
Observatory effort. Within this policy document, we delve into the complexities
surrounding the long-term utilization of space data and informatics, shedding
light on the challenges and opportunities inherent in this endeavour. Further,
we present a series of pragmatic recommendations designed to address these
challenges proactively.
  The policy webinar took place during the G20 presidency in India (2023). A
summary based on the seven panels can be found here: arxiv:2401.04623.
