The M-ARGO, short for Miniaturised Asteroid Remote Geophysical observer, is a 12U cube satellite developed by the ESA Concurrent Design Facility, which brings together researchers and scientists from different fields for fresh eyes and fresh ideas. M-ARGO was planned to launch in 2021, but was delayed to the 2024/25 launch window.
The 12U size means that is a bit larger than the conventional cube satellite, being twelve times the size of ESTCube-1. However, this increase in size is explained by M-ARGOs special purpose: to reach a mission goal in deep space. It is the first satellite that aims to reach its mission goal in deep space on its own. A larger launch is to be used to reach the Sun-Earth L2 Lagrange point, just like a conventional cubesat. Once there, though, M-ARGO will wait for its own transfer window and use an on board electrical thruster to move into deep space by its own power.
Thus not only is this mission different in terms of how it accomplishes its objective, but also in terms of the objective itself, which is to perform close surveys of a small asteroid (every proposed objective asteroid is sub-50m in diameter) with a very high spin speed, which have never been observed in this way before.
All in all in the M-ARGO mission is very important in showing what cubesats are capable of and through that influencing the costs of these kinds of deep space missions to become lower, so that this kind of research is no longer out of reach for groups with lower budgets.
ESA articles on M-ARGO:
https://www.esa.int/ESA_Multimedia/Images/2017/06/M_Argo
https://www.esa.int/ESA_Multimedia/Images/2019/11/M-Argo
ESA Concurrent Design Facility:
https://www.esa.int/Enabling_Support/Space_Engineering_Technology/CDF/What_is_the_CDF
Paper:
https://www.sciencedirect.com/science/article/pii/S0273117721001782?dgcid=rss_sd_all