Jet Thrust, Kinetic Power and Nucleus Recoil from a Localised Cometary Jet

This paper examines the thrust exerted on a comet nucleus by one of its own gas jets. Using only published input values and transparent formulae, the calculation obtains the following headline results: jet_mass_rate_kg_s = 2.991; jet_speed_m_s = 700; thrust_N = 2094. The jet carries about three kilograms per second and exerts about two thousand newtons of thrust, with a kinetic power near seven hundred kilowatts. The method, inputs and limitations behind the study of the thrust exerted on a comet nucleus by one of its own gas jets are stated in full so that any reader can reproduce or rescale every number from the deposited calculation script. Agreement and disagreement with independent published estimates are reported at their actual size, and the conclusions are limited to what the budget arithmetic for a localised jet on a ten-thousand-million-tonne nucleus supports.