The Conceptual Study of Expendable versus Reusable Launch Vehicles is a project given in the KTH course SD2900 Fundamentals of Spaceflight, autumn 2019.
The proposal is that you shall conceptually design two launch vehicles — one fully expendable and one partially or fully reusable — which will launch a 1000 kg satellite to a 600 km orbit and then provide a reasonably detailed comparison between them in terms of performance, cost and environmental impact. (...)
This program simulates two conceptually designed two-stage launch vehicles in a gravity turn that places the payload in the target orbit. One rocket is expendable, similar to the Vega rocket, and the other rocket is reusable, similar to the Falcon 9 rocket. Both ascent and reentry is simulated for both stage.
- The first stage performs a vertical ascent to a specified height with low dynamic pressure.
- At this height the first stage does a programmed turn. At this turn the rocket will be exposed to lift which is why it is done at low dynamic pressure, q∞.
- The first stage is simulated through a gravity turn with a high and constant burn rate. Stage separation is performed when the first stage has burnt up all but a specified percentage of its fuel. The reusable first stage requires spare fuel that is later used for landing.
- The reentry of the first stage is simulated through a gravity turn without thrust. The expendable first stage crashes into the ocean. The reusable first stage performs a ΔV so that is lands with zero vertical speed at ground level.
- The second stage is simulated through a gravity turn. The burn rate is constant until the apogee of the elliptical orbit intersects the target altitude, at that point the burn rate is cut of.
- Once the target altitude is reached the second stage performs a ΔV so that the target orbital velocity is reached. The payload is now in its desired orbit.
- The second stage now performs a second ΔV so that the perigee intersects the the Earth and thus reenters and burns up in the atmosphere.
The following plots are generated from running Expendable_rocket_final_version.m and Reusable_rocket_final_version.m.
To use this program: clone the repository and create a copy of template.m. Design a rocket and enter its parameters into the program by following the instructions in template.m.