According to the official website of NASA, both the United States and Europe have satellites orbiting Mars as well as rovers working on the Martian surface, and these space probes have maintained communication with ground control centers. However, in April, the relative positions of Earth and Mars will cause communication between Earth and these Mars spacecraft to be obstructed or even interrupted.
At that time, from the perspective of Earth, Mars will pass almost directly behind the Sun. When Mars, the Sun, and Earth form such a straight line, the intense radiation from the Sun can easily interfere with or even cut off communication between Earth and Mars. To prevent the Mars probes from receiving incorrect commands, engineers at NASA's Jet Propulsion Laboratory plan to completely stop sending any commands to the Mars spacecraft for several weeks in April, until the angular relationship between the two planets returns to normal.
Both Earth and Mars orbit the Sun. The phenomenon when the Sun fully obscures Mars as seen from Earth is called a 'Mars solar conjunction,' which occurs approximately once every 26 months.
The Odyssey spacecraft has been orbiting Mars since 2001. Chris Potts, the project manager for the Odyssey mission at NASA's Jet Propulsion Laboratory, said: 'This is the sixth time the Odyssey spacecraft has encountered a Mars solar conjunction during its operation. Therefore, we have accumulated rich experience in dealing with such events, although each conjunction is slightly different.' The differences in each Mars solar conjunction generally lie in the degree to which the Sun obscures Mars and the level of solar activity at the time of the obscuration.
Potts stated: 'In fact, the biggest difference in the 2013 Mars solar conjunction is that the Curiosity rover is currently operating on Mars.' In addition to completing their own designated exploration tasks, the Mars Odyssey and Mars Reconnaissance Orbiter have almost taken on the role of relaying all data from the Curiosity and Opportunity rovers on the ground.
The stability of signals sent from Earth to probes operating on Mars will start to decline in early April. When the angle between the Sun and Mars is less than about 2 degrees, communication between Earth and Mars will be almost completely interrupted, occurring from April 9 to 26. In the days immediately before and after this period, communication between the two planets will also be more or less affected.During this period, both orbiters will continue to collect scientific data, but their activity levels will be correspondingly reduced compared to normal conditions. At the same time, these two orbiters will continue to perform their normal data relay work for Mars surface rovers.
Starting from April 4, the Mars Reconnaissance Orbiter will, as planned, enter a mode where it only stores data and suspends data transmission. Project execution manager and NASA Jet Propulsion Laboratory scientist Reid Thomas stated: 'During the entire solar conjunction period, we will only perform data storage.' He expects that by around May 1, when communications are fully restored, the orbiter will need to transmit back to Earth about 40GB of data collected by its own instruments, as well as about 12GB of relay data from the Curiosity rover.
NASA's Opportunity rover will be experiencing its fifth solar conjunction. The Opportunity rover control team will stop sending commands to it from April 9 to 26. During this time, Opportunity will autonomously carry out scientific exploration activities based on the pre-uploaded long-term instructions. Curiosity will also continue operations during the solar conjunction. The Curiosity project science team plans to suspend contact with Curiosity from April 4 to May 1.
