The DC-3 of Commercial Space Flight

The metaphor of a DC-3 for commercial space flight has been used and claimed by many projects in the aforementioned sector. But I feel it is also an accurate title for my project. Early in the age of airline travel, the United States lagged many other regions of the world in creating an effective airline network. That is, until the pioneering Douglas Sleeper Transport, DC-2, and DC-3 came along. Those of you in the aerospace industry know the rest of the story.

My DC-3 will be either a very basic large capsule shape with an aerospike nozzle or an air breathing winged version. The first concept (C1) will be very similar in appearance to the old Chrysler SERV concept, which itself was almost an enlarged Apollo capsule. As mentioned, it will use an aerospike engine. This should allow for a hydrogen/liquid oxygen engine to propel it to orbit in a single stage provided light enough materials are used. Additionally, it should be able to fly hypersonic, parabolic routes between intercontinental destinations, much like ICBMs (except less destructive). Using old SERV data, it should have a fairly high Lift to Drag ratio, at least for a vehicle of its configuration, allowing it some low to moderate cross range for diversions and less aerodynamic heating and g-forces during reentry. Alternately, C1 could be equipped with an depoyable parasail similar to the concept advanced for the Gemini capsules in the early 1960s, which would give it more cross-range and an unpowered landing. C1 is the preferred concept due to its relative simplicity. The only stumbling block to it could be an inability to keep the airframe and all components light enough to be carried by the high fuel requirements of SSTO rockets (around 85%-95% of the total takeoff weight will be fuel). Using a high specific impulse aerospike engine should help create a successful solution to the rocket equation as will using lightweight composites and light weight metals in the airframe.

Failing the ability to successful create a feasible C1, C2 shall be an alternate solution. This will use an winged, air-breathing concept probably drawing aerodynamic data from the canceled American National Aerospace Plane and the Soviet TU2000 plane. From stationary to Mach 6, C2 should be able to either rapidly cool atmospheric oxygen to cryogenic temperatures (ala the British LAPCAT) or use ramjet technology. This should increase the specific impulse of the first portion of flight enough to allow the single stage to reach orbit. If this does not work, then a flyback stage could provide fuel for the airbreathing portion as well possibly a few Mach numbers of the pure rocket portion of flight, then separate and fly back to ground station. In this "C2-2" concept, the vehicle should be able to achieve Mach 18-20 without the additional stage, allowing it to complete intercontinental flight without the additional stage.