NASA already has major budget issues so it’s a damn good thing the agency didn’t turn to AT&T to provide the wireless data coverage for the Lunar Reconnaissance Orbiter. Because AT&T charges $0.0195 per kilobyte over a 5GB cap, it would cost roughly $231,883 for the daily data transmission of the 461GB. That’s $83,709,763 per year assuming AT&T didn’t come up with some charge for interplanetary roaming. All joking aside, this Moon satellite has an impressive data transmitter.
Somehow electrodes in a vacuum tube boosts microwave signals to high levels that are idea for transmitting large amounts of data. This amplifier can send data at a 100 megabytes a second back to Earth, more than 238,800 miles away. Similar designs were used on Kepler and Cassini, but the LRO’s system is the most powerful. And it has to be if it’s taking high-res photos of the Moon’s surface.
Knowing AT&T, they will first have to disapprove of all Lunar Orbiter apps that undercut their bottom line.
“All joking aside, this Moon satellite has an impressive data transmitter.”
461GB per day = 5.336 Mbps, Hmmm… Is this before or after compression? Does the figure include the likes of error correction overhead? Missing info CG.
“Somehow electrodes in a vacuum tube boosts microwave signals to high levels that are idea for transmitting large amounts of data.”
Man CG… You need a grammar checker. This is likely a Traveling Wave Tube (TWT); very common on spacecraft when you need high transmit power. Wikipedia has a nice page on TWT’s.
“This amplifier can send data at a 100 megabytes a second back to Earth, more than 238,800 miles away.”
Well, that’s not exactly how it works. There is a complete chain of equipment involved in the transmission link including: coder, modulator, up converter, power amplifier, transmit antenna, free space loss, atmospheric and rain loss, receive antenna, low noise receive amplifier, down converter, demodulator, decoder, etc.
100 Mbps from the moon is rather impressive at first glance. They’re likely using a VERY large antenna on the Earth. But again, it is not stipulated whether 100 Mbps is before or after compression is applied and whether the figure includes the likes of error correction overhead.
Sorry I failed you, Drone. Be sure to link in here your blog post that explains the process better than mine.