Thursday July 27th the planet Mars will be at solar conjunction, on the opposite side of the Sun from the Earth. Mars will reappear on the west side of the Sun as a morning planet next month and gradually will become more visible in the morning skies.
So while Mars is out of sight for observers it is also out of ‘radio sight’ for all of the spacecraft at Mars – either on the surface or in orbit. Between July 22nd to August 1st mission controllers will stop sending messages to the spacecraft at Mars, however the orbiters will continue their science observations and collecting data. The rovers on Mars on the other hand will not rove until after the radio silence period, but will still be able to carry on with some investigations.
Click here to read more about how NASA prepares for the radio silence.