Warp drive is a fantasy. But we need to invest in a practical means of inexpensive propulsion, making space flight cost effective. When an inexpensive means of propulsion is attainable, the private sector will be less at risk and therefor more of an attainable concept.
Launch costs aren't high because we need "an inexpensive means of propulsion." SpaceX vehicles have lox/kerosene gas generator engines. Falcon Heavy, which should fly in a couple years, will be a thousand dollars a pound. Falcon 9, which just flew to ISS, is about $2500.
“Launch costs aren’t high because we need “an inexpensive means of propulsion.”” ?
Chemical propulsion is too expensive. The expense is a function of the actual cost of the chemical propellant & infrastructure enabling it’s use. And most of all, what do you do after the chemical reaction is used up?
If we go beyond a “low Earth orbit”, where are the gas stations beyond that? You will need a “Space Station” like vehicle in orbit to send the “extra fuel”. -OR- have a means of producing fuel going beyond Earth orbit.
Ion drive may be used to accelerate, but you may need more power either chemical or other means to overcome gravity of a destination planet & return (if required).
Different set of logistics are required if the mission is simply a mining expedition. In either case, if we can develop a means of propulsion not needing a chemical reaction, that will greatly reduce the cost required for any chemical reaction device for thrust.
The concept being any chemical propulsion system has cost attributed to massive containment & limited use in acceleration time. Not to mention infrastructure necessary to “create” more chemical fuel on route.
SpaceX vehicles are a first step, but keep in mind they are heavily subsidized through NASA. Without U.S. Government intervention, how long do you suppose they would remain in business? Maybe through China, their program is progressing.
No, we need to get away from chemical propulsion systems, if space travel is to be less expensive in monetary costs. But cost has many faces.
This is my opinion, and not that of NASA.