Tianwen-1 At Mars |
Tianwen-1 At Mars |
Feb 8 2021, 03:04 PM
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#31
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Member Group: Members Posts: 219 Joined: 14-November 11 From: Washington, DC Member No.: 6237 |
For those who haven't already seen, there is excellent work independently tracking and predicting the trajectory of Tianwen-1 by radio amateurs (using that word only technically, since they are very much pros).
The latest is predicting orbital insertion at 8 seconds before 1200 UTC on Wednesday 10 February, with a 386 km periapsis - burn starts a few minutes before that if you, like me, are planning your peanut consumption carefully this week. Plenty of details to be found at these links (even a GMAT script and Jupyter notebook, and some doppler data, for the astrodynamically inclined). https://destevez.net/tag/tianwen/ Daniel Estévez recent twitter thread with MOI images Scott Tilley recent twitter thread |
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Mar 5 2023, 08:31 AM
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#32
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Solar System Cartographer Group: Members Posts: 10191 Joined: 5-April 05 From: Canada Member No.: 227 |
http://jdse.bit.edu.cn/sktcxb/cn/article/d....2096-9287.2023.
This is a link to China's Journal of Deep Space Exploration, and a notice of a forthcoming paper on Phobos observations by the TW-1 orbiter. There is an English language summary with interesting details. It will probably be another 3 or 4 months before the actual paper is released. More observations than the one shown above have already been made. summary: ----------------------------------- Orbit Design and Analysis of the Phobos Close Approach Exploration Mission for Tianwen-1 Mars Orbiter ZHENG Huixin1, 2 , , XIE Pan1, 2 , , Li Haiyang1, 2 , ZHU Xinbo1, 2 1. Shanghai Institute of Satellite Engineering, Shanghai 201109, China 2. Shanghai Key Laboratory of Deep Space Exploration Technology, Shanghai 201109, China Abstract: In this paper, the mission orbit design and analysis of a potential extended mission, Phobos close approach exploration, is carried out. The state at the end of the main mission is used as the input of the extended mission in this paper. Through analysis, it is concluded that Mars perturbation force can be used to adjust the argument of perigee, and the intersection frequency is related to the value of semi-major axis and eccentricity. Orbit descent maneuver should be performed to increase the number of intersections. As a result, the possibility of conducting aerobraking in order to reduce fuel consumption is analyzed. Finally, phase adjustment maneuver is calculated to complete the Phobos Close Approach Exploration Mission. The orbit design results and the velocity increment are given by simulation. The results of this paper can provide reference for the orbit design of Tianwen-1 orbiter extended missions. Key words: Phobos close approach exploration / Orbit design / Tianwen-1 Mars Orbiter Highlights - Under the condition that the remaining fuel of Tianwen-1 Mars Orbiter is considerably limited and the Orbiter cannot be directly transferred to the orbit of Phobos, this paper utilized Mars perturbation force in adjusting the argument of perigee to make the orbit of the orbiter intersect with the orbit of Phobos. - The intersecting frequency between the orbit of Tianwen-1 Mars Orbiter and Phobos is related to the value of semi-major axis and eccentricity. The intersecting frequency can be maximized by designing appropriate orbital parameters. - In order to complete the close approach detection of Phobos, the Orbiter has to maneuver from the remote sensing orbit to the extended mission orbit. The Mars aerobraking is adopted as the orbital descent maneuver strategy, which can reduce fuel consumption by 80%. - By designing an appropriate phase adjustment orbit period, the phase adjustment velocity increment can be controlled within 10m/s under the worst conditions of approach detection phase. ----------------------------------- Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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