Mars entry navigation from EKF processing of beacon data

Abstract

A simulation analysis has been preformed to quantify the benefits to Mars entry navigation that can be expected if tracking data from Mars based beacons are used. Two types of Mars in situ beacon configurations are analyzed. The primary configuration is a ground based network consisting of beacons, pre-deployed by a mission's orbiter twin to within 50 km of an upcoming lander's anticipated touch down site. The second consists of the aforementioned surface beacons in combination with a single orbiting beacon either on-board a near circular polar orbiter (such as with the Mars Global Surveyor) or alternately on a Mars body-fixed equatorial synchronous, or more appropriately Areosynchronous, orbiter. In either case the tracking beacons would provide pseudo range and range-rate (Doppler) observations, hi this study, the Mars entry configuration is a Mars Path Finder (MPF) type entry reoriented follow along the equator in East-West crossing. For several beacon configuration scenarios, Extend Kalman Filter (EKF) runs are performed and the corresponding trajectory solution analyzed to quantify the benefit from its tracking. Atmospheric, aerodynamic, and other force as well as measurement models are included in this numerical simulation. In each configuration/solution combination, sensitivities to various sets of reasonable beacon location errors and associated measurement degradations (biases and data 'blackout') are presented.

Multiple Model Adaptive Rank Estimation for Integrated Navigation During Mars Entry

“…The physical parameters of the Mars entry vehicle used in this simulation are set as follows: B* = 0·016 m 2 /kg, L/D* = 0·156 (Lévesque and de Lafontaine, 2007). Furthermore, the number of radio beacons used for the navigation filter has been analysed by Lévesque and de Lafontaine (2007) and Pastor et al (2000). Based on the conclusions of the past research, three radio beacons are adopted in this paper.…”

Supersonic Retropropulsion Thrust Vectoring for Mars Precision Landing

“…In the process of exposing the engines for SRP, a TRN sensor can also be exposed for terrain viewing. Radiometric navigation can also be used to improve state estimates in real time, through the use of orbital or ground beacons [19]. Orbiting beacons (possibly, similar in principle to GPS) may be available once enough orbiting assets are placed around Mars, and ground beacons may be used in cases where existing infrastructure exists on the surface of Mars, like would be the case with Mars sample return or a human mission.…”

Observability analysis of Mars entry integrated navigation

“…The MSB can be pre-deployed by a mission's obiter (Pastor et al, 2000). The relative range measurement is constructed like that: where R i refers to the true range from the entry vehicle to the ith beacon,R i is the measurement range, x i B ; y i B and y i B are the positions of the beacons in MCICF, e i R is the range measurement noise.…”