  A satellite internet provider (e.g., Starlink, OneWeb, O3b mPOWER), despite
possessing the capability to provide internet services to on-ground users in a
global scale, can dramatically change the way space missions are designed and
operated in the foreseeable future. Assuming a scenario where space mission
satellites can access the internet via a space internet system, the satellite
can be connected to the network permanently (24x7) and act as mere terminal
independently from its location. The ability to communicate with the satellite
on-demand has the potential to improve aspects such as real-time tasking,
outage minimization, operation cost, and dependency on the ground. This paper
performs a feasibility study on the concept of connecting space missions to the
network through commercial mega-constellations. This study includes a review of
existing and near-future space internet systems, identification of candidate
space missions for the aforementioned concept, a necessary adaptation of
existing Commercial off-the-shelf (COTS) terminals to be plugged into space
mission satellites, assessment of communication performance, and investigation
of the legal aspects of the radio frequency (RF) spectrum usage. The paper
evidences that the concept is practically possible to implement in the near
future. Among the studied space internet systems (i.e. Starlink, OneWeb, O3b
mPOWER), O3b mPOWER stands out as the most suitable system allowing permanent
coverage of low earth orbit (LEO) space missions with data rates that can reach
up to 21 Mbps per satellite. Although the concept is very promising and can be
implemented in the near future, our investigations show that some regulatory
aspects regarding the RF usage should be solved for future exploitation of
connecting space missions through NGSO constellations.
