A few days ago, media reported that China’s first Mars probe, “Yinghuo-1,” would be launched this October aboard a Russian rocket to begin its journey to Mars. However, we surprisingly received news today: Anatoly Perminov, head of the Russian Federal Space Agency, stated on the 29th that to further ensure the reliability of the project, Russia has decided to postpone the launch of the “Phobos-Grunt” Mars probe to 2011.
China’s Mars probe is “hitchhiking” on the Russian rocket. Since the Russian officials have postponed it, and we currently do not have the capability to fund Mars exploration independently, we also have to wait until 2011 for the launch.
Quoted content:
“Phobos-Grunt” was originally scheduled to launch this autumn. It is a significant Russian Mars exploration project that will land on Phobos to collect soil samples. Perminov explained that Russian experts hope to further understand the surface characteristics of Phobos to more accurately design the equipment used for soil collection. “If the soil on the surface of Phobos is too hard, an incorrect collection method could result in this expensive expedition yielding nothing.”
Furthermore, the Russian side currently cannot guarantee 100% stable communication between the probe and the ground during flight, so further testing of its components is required.
Therefore, having missed this year’s launch window, we can only wait another two years for the next optimal launch time.
A Small Calculation: Why is there an optimal launch opportunity every two years?
Launching a Mars probe is a massive undertaking because the distance between Mars and Earth is quite large (at current speeds, it takes at least 10 months to reach Mars). When launching a Mars probe, the route must be precisely selected to strive for the minimum time, the shortest distance, and the least fuel consumption. Thus, when Mars and Earth “meet” (i.e., when Mars and Earth are on the same side, with Mars, Earth, and the Sun aligned in a straight line), the distance between them is minimized. What is the period of this encounter?
The orbital period of Mars is 687 days, and Earth’s is 365 days. Since they move in the same direction, the encounter period is: \frac{1}{\frac{1}{365}-\frac{1}{687}} \approx 780
Therefore, it takes at least two years to encounter such an optimal launch opportunity!
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