25

First you lock on to energy at (or near) the expected frequency. That’s carrier lock. Then you start to look for patterns in how the phase changes. The transmitter is coding groups of bits as phase-change “symbols”, and you want to find the time-pattern of those: symbol lock. But those are not yet bits because the coding works in blocks of bits. Once you ...


21

Hobbes' answer explains why live broadcast is currently not feasible from the Mars side. I'd like to complement it with why this is currently not feasible from the Earth side. Mars power budgets are not generous, so by the time spacecraft transmissions get back to Earth they are incredibly faint. The only equipment used to reliably receive these signals is ...


12

The JPL Mars Helicopter Scout transmitter can send data at up to 250 kb/s, an order of magnitude short for HD video. Communications with the rover are through a radio link called Zig-Bee, a standard 900 MHz chipset that will be mounted in both the rover and helicopter.[10] The communication system is designed to relay data at 250 kb/s over distances of ...


4

According to this specs page, Mars 2020 Rover will have three kinds of antenna: Ultra-High Frequency Antenna, X-band High-Gain Antenna, X-band Low-Gain Antenna. The one used to send data to Earth are the first two: UHF and the High Gain antenna, the Low Gain Antenna is used for receving data from Earth and it is the slowest of all. UHF has transmission ...


4

Doing a scaling process from the performance of the telecommunications ("telecom") system of NASA's Cassini spacecraft at Saturn, I estimate the system you describe could support a data rate of a bit under 7 kbps, if the signal is received at a NASA DSN station's 34-m (diameter) antenna. If a 70-m antenna were used instead, that rate would jump to ...


3

No experience of satellites here, but I used to do real-time software development. I believe that the point is to discover "normal" from "abnormal". You would have several different "functions" that monitor parts or the whole system. One typical solution for monitoring software is one or many watchdog timers. The software is supposed to reset the watchdog ...


2

Space politics is complicated - at a bare minimum you need approval from the regulatory body that has jurisdiction over the region that you plan to transmit/receive over. Depending on the launch location, you may need additional approval. Typically these requests are handled in tandem by the FCC and the International Telecommunications Union (ITU) and/or the ...


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