Total Recall: Blue Sky on Mars

There are presently plans to create permanent colonies on Mars so that humanity will have a second home. These colonists will need search, email, entertainment, and indeed most services provided on the modern web. The primary challenge is network latencies, since the two planets are anywhere from 4 to 24 light minutes apart. A recent article sketches out how we might develop search technologies for Mars based on physically transporting a cache of the web to Mars, to which updates are applied via predictive models. Within this general framework, we explore the problem of high-recall retrieval, such as conducting a scientific survey. We explore simple techniques for masking speed-of-light delays and find that "priming" the search process with a small Martian cache is sufficient to mask a moderate amount of network latency. Simulation experiments show that it is possible to engineer high-recall search from Mars to be quite similar to the experience on Earth.