Commercial on-orbit refueling is common
The space infrastructure in Earth orbit will continue to grow as launch costs continue to decrease. With more congestion, regulations will be passed that require operators to better maintain and decommission their assets. Businesses will finally find it more economical to repair or resupply spacecrafts rather than ditch and build/launch anew. These trends will drive the demand for on-orbit servicing to inspect, reposition, life-extend, and/or decommission spacecraft. These services will be performed by spacecraft that live on orbit.
Launch will be inexpensive enough, and demand for on-orbit services will be sufficient to send propellant to on-orbit “fuel depots”. Commercial service spacecrafts will be able to replenish their depleted propellant rather than dispose of a “spent” craft, further lowering the cost of their services.