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Hi,
I've been reading a ot of books about proposed missions to Mars, but none talk all that much about the communications systems.
I'm wondering specifically whether a special focusing antenna is NEEDED to relay communications, or if an astronaut could theoretically face Earth, yell in its direction, and eventually be heard.
What frequency would such a Mars mission be likely to use? Would there be any way that non-NASA people could pick up signals from the mission with, say, a ham radio?
As you can tell by my questions, I'm a bit of a novice when it comes to radio engineeering. What I'm wondering is: could an astronaut, separated from the main Mars lander, relay a message directly to Earth (if possible, without an antenna or special equipment), without going through the lander?
Thanks very much for any help you can provide,
Pete
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Hi Petey,
Theoretically possible, at certain times, with the 2,3 biiiig antenaes on Earth... But impractical to monitor I think...
They'll probably work with relay sats in Mars orbit which will boost the suits signal before relaying to Earth etc... So smaller antenaae can pick up the signal?
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Petey
You can go to the "Martian Politics" and the "Laser Communication-Earth/Mars" section and it goes over communication of the future and what we will probably be using.
Larry,
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Thanks for the help, guys.
Pete
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http://www.gate.net/~tomk/mgs/mr_report.html]1.3 watt beacon reception
What if you tried to take your cordless phone to Mars ?
At 2.4 ghz the maximum path http://flakey.info/wirelesstools/]loss is 211 db.
Add 5 meter http://home.online.no/~jensts/Satellite … htm]dishes for total of 80 db gain and the loss is now approx 130 db.
Cordless phone puts out tenth of a watt (20dbm=100mw), received signal is -110 dbm.
http://wirelessreview.com/ar/wireless_e … ise/]Noise is -130 dbm for 300K. (receiver and sky noise will be less than 100K)
Carrier/Noise ratio = 20 db (signal 100 times stronger than noise.)
Use your cordless phone handset from Mars, and keep your Earth phone number ?
(For wideband FM, only 12 db carrier/noise, http://www.rwt.co.uk/satspecs.htm]threshold extension, gives good reception.)
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http://people.qualcomm.com/karn/mpf_budget.html]Mars Pathfinder Radio link information
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