In previous article was able to show that the re-entry with lifting power can reduce the overloads and thermal effects of atmospheric braking. But what other advantages does having aerodynamic quality give a spacecraft? And how can we increase the aerodynamic perfection of the spacecraft ?
The appearance of a ship with a supporting hull
The simplest version of a ship with a supporting hull is a cone with a blunted bow. The blunted bow creates a detached jump at a safe (for hull thermal protection) distance, and the overpressure from air braking forms a lifting force on the hull. To calculate such a layout, there are fairly simple analytical dependencies, allowing with patience and any available calculation tool to obtain a set of aerodynamic characteristics (N.S. Arzhanikov, G.S. Sadekova, "Aerodynamics of Aircraft", Chapter 11)
The main constraint on the appearance of our returned spacecraft will be the usable volume (which must be no worse than 10.4 m 3 Apollo cabin ).
Square of midsection, m 2
Maximum quality, –
* with a midship diameter of 3 meters such a ship can be accommodated by Falcon-9 (midship diameter is 3.7 meters)
Appearance of the descent vehicle
Green line – planning without side maneuvers, red line – maneuver of 100 s, blue line – 800 s
Since the maneuver in the track plane is accompanied by a decrease in altitude (see graphs just above) and increased drag in the denser layers of the atmosphere, it is possible to reduce the atmospheric section time (and duration of thermal exposure) by "snaking" with one or more roll sections in opposite directions.
Although the aerodynamic quality of 1 – 1.5 provides high flying qualities for hypersonic flight in the upper atmosphere, but it is not enough for a soft landing without a parachute or brake engines. A possible solution to the problem is retractable wings in the aerodynamic shadow and/or hidden in the hull.
When transonic speeds are reached, the wings open up and increase the bearing surface and aerodynamic quality.
An alternative would be a "gliding" wing or paraglider landing.
The repo with the model program and source data lives at my github You can poke it with a wand, you can fork it – in case someone else wants to play around