Long-time readers know that I am not a fan. I believe that the benefits of airbreathing for launch vehicles are overhyped, and the technical risk too high for anyone trying to develop cost-effective space transportation in the short term (i.e., private investors), when properly designed rockets can dramatically reduced launch costs without such technical risk. That doesn’t mean, of course, that it wouldn’t be useful for the government to do focused technology development in this area, which will help with non-space applications, as NACA did to support the aviation industry throughout the first half of the last century.
That said, John Bossard, a fan of such propulsion systems, has a thoughtful essay with which I largely agree, particularly this part:
In the final analysis, the argument about whether or not airbreathers have a place in launch vehicle systems becomes secondary to how we will approach launch vehicle development. Anyone who doubts whether free-market forces can do a better job that government elites in deciding what is the correct approach for something as relatively straightforward as launch vehicle development, need look no further than the current debacle of our home-mortgage industry, or our nationalized car companies. Perhaps no better example exists than to look at our current national launch vehicle concept, a concept chosen by a elite cadre of our nation’s finest aerospace technologists, and compare the success of that program with that of launch vehicles being developed by private companies.
I would claim that if we allow it, nay, if we demand it, we can let free-market forces decide what the right approach is, and whether airbreathing propulsion has a role in launch vehicle development. We can let all-comers try their hand. Let a plethora of concepts take to the field, and let free-market forces separate the winners from the losers. Cheer your champions! Raspberry your competition! But whatever you do, support the process, be an enabler of the free enterprise and entrepreneurism, and do what you can to make the field open to whoever has the fortitude to try.
If NASA will finally start being a good customer, and purchasing transportation services instead of engineering services, the market might finally be able to sort these issues out, even if decades later than it could have.