Russian Mikhail Pavlinsky ART-XC X-ray telescope onboard Spektr-RG observatory (Roscosmos) and Russian KONUS instrument onboard WIND spacecraft (NASA), residing in two opposite Lagrange points L1 and L2, have provided a detailed study of GRB 221009A — the brightest of all gamma-ray bursts previously registered by Konus and most likely the brightest one in the whole history of mankind.