  Multi-messenger observations of transient astrophysical sources have the
potential to characterize the highest energy accelerators and the most extreme
environments in the Universe. Detection of neutrinos, in particular tau
neutrinos generated by neutrino oscillations in transit from their sources to
Earth, is possible for neutrino energies above 10 PeV using optical Cherenkov
detectors imaging upward-moving extensive air showers (EAS). These EAS are
produced from Earth interacting tau neutrinos leading to tau leptons that
subsequently decay in the atmosphere. We compare neutrino detection
sensitivities for generic short- and long-burst transient neutrino sources and
sensitivities to the diffuse neutrino flux for the second generation Extreme
Universe Space Observatory on a Super Pressure Balloon (EUSO-SPB2)
balloon-borne mission and the proposed space-based Probe of Extreme
Multi-Messenger Astrophysics (POEMMA) mission.

High Energy Astrophysical Phenomena