  Ultra High Energy Cosmic Rays (UHECRs) offer a unique chance to study the
universe at energies inaccessible by man-made accelerators. Observations by
ground based observatories have clarified several characteristics of these
particles, but their origin, nature, and acceleration mechanisms are still
unclear, mostly due to their extremely low flux. Space-based observatories have
the potential for an increase in statistics, up to several orders of magnitude,
and would be able to cover the whole sky, allowing for a direct comparison of
spectra and direction of arrival, but the detector design poses several
formidable technical challenges.
  The JEM-EUSO program has been addressing this problem, trying to open the
road of space-based UHECR observations. Several missions have already been
completed (on the ground: EUSO-TA; with stratospheric ballons: EUSO-Balloon,
EUSO-SPB1 and EUSO-SPB2; in space: TUS\cite{Klimov2017}, MINI-EUSO). Others are
under study (K-EUSO) or proposed for the next decade
(POEMMA)\cite{Olinto_2021}. In this work we report on the status of the
JEM-EUSO program and the technology developed so far.
