Reliability and robustness analysis of earth-moon mission in presence of uncertainty
- Paper number
IAC-11,A3,2.P,26,x11776
- Author
Mr. Masoud Ebrahimi, K. N. Toosi University of Technology, Iran
- Coauthor
Mr. Ehsan Taheri, K.N. Toosi University/Aerospace Research Institute (Ministry of Science, Research and Technology), Iran
- Coauthor
Prof. Jafar Roshanian, K. N. Toosi University of Technology, Iran
- Coauthor
Prof. Mehran Mirshams, K. N. Toosi University of Technology, Iran
- Year
2011
- Abstract
As the moon is an important place for space explorations, the orbital transfer from Earth to Moon must be efficient and economical. There are some papers in which earth-moon orbital transfer were optimized (minimize the time of flight (T) or the total characteristic velocity (V) of a spacecraft). Almost in all of these works deterministic optimization approaches were used. Nevertheless, in the all space mission design analysts face a lot of uncertainties such as initial velocity, mass and position of the spacecraft, gravity model or the solar radiation, propulsive parameters and … . In the design of a space mission, an insufficient consideration for uncertainty would lead to a wrong decision on the feasibility of the mission. The two major classes of uncertainty-based design problems, robust design problems and Reliability-based design problems have been proposed. A robust design problem is one in which a design is sought that is relatively insensitive to small changes in the uncertain quantities. A reliability-based design problem is one in which a design is sought that has a probability of failure that is less than some acceptable (invariably small) value. In this research reliability and robustness analysis of earth-moon mission is investigated. A restricted three-body problem is used to derive the equations of two-dimensional flight from a Low Earth Orbit (LEO) to a Low Moon Orbit (LMO). Initial LEO may be reshaped because of gravity perturbation (anomaly or model form), the solar radiation, the aerodynamic force and …. As a result, uncertainty in initial velocity and position are considered. Besides, because of mass and propulsive parameters uncertainty, we will have uncertainty in escape point velocity variation. There are similar uncertainties in LMO. Introducing the mean and variance data for each uncertain parameter and implementing Monte-Carlo method, probability density function of time of flight (T), total velocity variation (V) and final LMO characteristic are calculated. Results show some flight’s scenarios can’t receive to LMO in presence of uncertainty. Additionally, although certain flight’s scenarios need more total velocity variation or have more flight time, they are more robust and reliable.
- Abstract document
- Manuscript document
(absent)