Design and analysis of parachute triggering algorithms for re-entry vehicles

Design and analysis of parachute triggering algorithms for re-entry vehicles

Ording, B.E.

Brouwer, G.F. (mentor)
Sudars, M. (mentor)

Aerospace Engineering

Space Systems Engineering

2010-08-31

Most re-entry vehicles utilize a Descent and Landing System (DLS) for a safe descent through the lowest part of the atmosphere. It usually requires deployment in a certain suitable range of flight conditions, which has to be estimated by limited means of navigation. The investigation performed is a comparison of currently used trigger methods and triggering algorithms which are based on correlation between in-flight measurements and the DLS triggering conditions for a ballistic re-entry vehicle, where the correlations have been extracted by multiple Monte Carlo campaigns. This approach gives an improvement of the estimation of the deployment conditions of a factor of two over direct measurements of the Mach number. The Mach number is determined to be the most critical parameter for the parachute deployment, because its opening range is the smallest compared to the dynamic pressure and the altitude. Furthermore a sensor sensitivity analysis is performed for a lifting entry trajectory in order to support an upcoming ESA re-entry mission. The velocity drift appears to be the dominant dispersion by a factor ten for the Mach estimation, if the Mach estimation is performed by estimating the drag using axial deceleration measurements. Such a method is the preferred method for the estimation of the deployment conditions, because it has an expected error of less than Mach 0.1. For the lifting-re-entry mission, a strategy was developed to have redundant parachute deployment triggering if a certain system on the vehicle fails. This strategy involves the use of an Inertial Measurement Unit, Global Positioning System measurements and as last resort, a static pressure probe. Furthermore it appeared that the vehicle can estimate its state using no inputs from the guidance navigation and control system for four minutes. Finally a case study has been performed to investigate the possibility to reduce the footprint by a dynamic parachute opening window. This has found to be ineffective on Earth, but could be effective for Mars re-entry using a parachute able to deploy beyond Mach 2.5, which would reduce the footprint 15 to 25 kilometers if the NASA MER missions are used as a reference; this would be a reduction of 30 to 50 % of the footprints of current missions. A higher opening velocity is already desired in order to be able to land on the Martian highlands. Modified parachute designs can be developed to incorporate both benefits.

re-entry
parachute

http://resolver.tudelft.nl/uuid:aca06712-b096-4de3-9e2a-f385d6b97337

2010-09-10

Student theses

master thesis

(c) 2010 Ording, B.E.