  ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of
metal creation from the epoch of cosmic dawn. Using high-spectral resolution in
the soft X-ray band, ORIGIN will be able to identify the physical conditions of
all abundant elements between C and Ni to red-shifts of z=10, and beyond. The
mission will answer questions such as: When were the first metals created? How
does the cosmic metal content evolve? Where do most of the metals reside in the
Universe? What is the role of metals in structure formation and evolution? To
reach out to the early Universe ORIGIN will use Gamma-Ray Bursts (GRBs) to
study their local environments in their host galaxies. This requires the
capability to slew the satellite in less than a minute to the GRB location. By
studying the chemical composition and properties of clusters of galaxies we can
extend the range of exploration to lower redshifts (z ~ 0.2). For this task we
need a high-resolution spectral imaging instrument with a large field of view.
Using the same instrument, we can also study the so far only partially detected
baryons in the Warm-Hot Intergalactic Medium (WHIM). The less dense part of the
WHIM will be studied using absorption lines at low redshift in the spectra for
GRBs.
