Many organizations have proposed air launch Reusable Launch Vehicles (RLVs) due to a renewed interest generated by NASA's 2 nd Generation Space Launch Initiative. Air launched RLVs are categorized as captive on top, captive on bottom, towed, aerial refueled, and internally carried. The critical design aspects of various proposed air launch RLVs concepts are evaluated. It is found that many concepts are not possible with today's technology. The authors introduce a new air launch concept that is possible with today's technology called SwiftLaunch RLV.
The advantages and disadvantages of the various methods for air launching expendable or reusable space launch vehicles are described. Many different air launch scenarios are modeled and simulated using trajectory optimizations. The trajectory optimization is conducted using POST, a numerical integration program based on the three-degree-of-freedom equations of motion of a flight vehicle. Results in terms of change in velocity gains are reported as a function of launch conditions and launch vehicle aerodynamics. Air launch benefits are presented for a range of air speeds, altitudes, and flight path angles. The most beneficial launch vehicle parameters are in the following order; launch velocity, launch flight path angle, and launch altitude. Increasing launch vehicle size had the largest effect on payload size. There is an optimum launch flight path angle that maximizes the benefit from air launching. The results show that once above about 15000 meters (49,200 feet), added launch altitude has little additional benefit.
NomenclatureA e = Nozzle exit area a = Angle of attack β = Launch azimuth DV = Change in velocity D = Drag force g = Flight path angle F = Vacuum thrust fps = feet per second g = Gravitational acceleration LEO = Low Earth Orbit LV = Launch Vehicle m = Mass of vehicle M = Mach number nmi = nautical mile p = Atmospheric pressure psf = pounds per square foot φ = Latitude t b = Engine burn time T = Thrust force T/W = Thrust to weight ratio V carrier aircraft = Carrier aircraft's flight speed V earth rotation = Earth rotation velocity increment _________________________
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.