  The Cosmic Microwave Background (CMB) radiation offers a unique window into
the early Universe, facilitating precise examinations of fundamental
cosmological theories. However, the quest for detecting B-modes in the CMB,
predicted by theoretical models of inflation, faces substantial challenges in
terms of calibration and foreground modeling. The COSMOCal (COsmic Survey of
Millimeter wavelengths Objects for CMB experiments Calibration) project aims at
enhancing the accuracy of the absolute calibration of the polarization angle
$\psi$ of current and future CMB experiments. The concept includes the build of
a very well known artificial source emitting in the frequency range [20-350]
GHz that would act as an absolute calibrator for several polarization
facilities on Earth. A feasibility study to place the artificial source in
geostationary orbit, in the far field for all the telescopes on Earth, is
ongoing. In the meanwhile ongoing hardware work is dedicated to build a
prototype to test the technology, the precision and the stability of the
polarization recovering in the 1 mm band (220-300 GHz). High-resolution
experiments as the NIKA2 camera at the IRAM 30m telescope will be deployed for
such use. Once carefully calibrated ($\Delta\psi$ < 0.1 degrees) it will be
used to observe astrophysical sources such as the Crab nebula, which is the
best candidate in the sky for the absolute calibration of CMB experiments.
