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It's awesome that they've been involving the public so much in the details of how the rover mission really works. I'd actually been wondering about this exact q

by ryusage 14y ago

It's awesome that they've been involving the public so much in the details of how the rover mission really works. I'd actually been wondering about this exact question, since it seems to be one of the limiting factors for the quality of images and such. From a physics standpoint, sending data is clearly a lot more complicated than I'd previously assumed.

keithpeter 14y ago
Yes, the clue is in the comparison to 'home modems'. The technology was finalised 2004, which means design around 2000 or so? I'm impressed with the reception technology that allows 'direct to home' communication at all given the power levels available.
- rubberbandage 14y ago
  Absolutely, this seems like one of the most amazing in a long string of incredible things. There’s only enough energy to power two 60w light bulbs, and yet it can transmit all the way to earth while also powering the computer running the thing.
  - jeza 14y ago
    This probably has more to do with the massive antenna (also known as a radio telescope) here on earth that are used to pick up the signal. Fortunately a few such antenna exist around the globe, so Mars should be in view of one of these antennas at all times. According to Wikipedia (http://en.wikipedia.org/wiki/Deep_Space_Network http://en.wikipedia.org/wiki/Deep_Space_Network), radio telescope complexes used by NASA are located at: Goldstone Deep Space Communications Complex near Barstow, California, USA Robledo de Chavela near Madrid, Spain Canberra Deep Space Communications Complex near Canberra, Australia
  - TheAmazingIdiot 14y ago
    You'd be amazed what you can do just with a watt of radio power. If a transmitter and a receiver is in space, what's the furthest distance the receiver can go away from and have a 1 watt signal still above the noise floor? Assume the transmitter is a perfect omnidirectional. About 9200 miles.
    - zokier 14y ago
      9200 miles is not very much in space. That's like 0.006% of the distance between Earth and Mars.
      - TheAmazingIdiot 14y ago
        I well realize that. I was assuming absolute worst conditions, at 1 watt PEP. With hardware noise reduction, we can drop easily to .1 watt and still keep everything else consistent. Next, if we choose a directional antenna, we can also greatly magnify directed output. No sense in directing energy in the ground, is there? We can also have receiver systems (dish arrays) that can provide great gains in reception and transmitting.
Achshar 14y ago
> It's awesome that they've been involving the public so much in the details of how the rover mission really works. It must be mission critical to spread awareness since their budget cuts are getting worse and one way to correct that is to get people excited about space exploration. They now put a considerable effort in PR, involving people in the mission, sharing most of the information and making professional videos. And i believe this is why we see twitter accounts of most astronomers, satellites, rovers and other NASA properties. The NASA's ustream has been very popular lately and they have presence on every major social network. And curiosity was named after an essay written by a student in a competition organised by NASA for school students.
- hrayr 14y ago
  "And curiosity was named after an essay written by a student in a competition organised by NASA for school students." Nasa has been doing this for some time now, Sojourner[1], and MERs (Spirit & Opportunity) have also been named by student competitions. [1] http://mars.jpl.nasa.gov/MPF/rover/name.html http://mars.jpl.nasa.gov/MPF/rover/name.html
  - deleted 14y ago
    [deleted]
ericHosick 14y ago
In general, space travel is very risky. It's not like they can iterate. Pulling something off like landing on Mars is very impressive. Keeping this in mind, I feel it was actually quite risky that NASA streamed the landing live. I think NASA should receive big kudos for taking that real risk.

by ryusage 14y ago

keithpeter 14y ago

Yes, the clue is in the comparison to 'home modems'. The technology was finalised 2004, which means design around 2000 or so? I'm impressed with the reception technology that allows 'direct to home' communication at all given the power levels available.

rubberbandage 14y ago
Absolutely, this seems like one of the most amazing in a long string of incredible things. There’s only enough energy to power two 60w light bulbs, and yet it can transmit all the way to earth while also powering the computer running the thing.
- jeza 14y ago
  This probably has more to do with the massive antenna (also known as a radio telescope) here on earth that are used to pick up the signal. Fortunately a few such antenna exist around the globe, so Mars should be in view of one of these antennas at all times. According to Wikipedia (http://en.wikipedia.org/wiki/Deep_Space_Network http://en.wikipedia.org/wiki/Deep_Space_Network), radio telescope complexes used by NASA are located at: Goldstone Deep Space Communications Complex near Barstow, California, USA Robledo de Chavela near Madrid, Spain Canberra Deep Space Communications Complex near Canberra, Australia
- TheAmazingIdiot 14y ago
  You'd be amazed what you can do just with a watt of radio power. If a transmitter and a receiver is in space, what's the furthest distance the receiver can go away from and have a 1 watt signal still above the noise floor? Assume the transmitter is a perfect omnidirectional. About 9200 miles.
  - zokier 14y ago
    9200 miles is not very much in space. That's like 0.006% of the distance between Earth and Mars.
    - TheAmazingIdiot 14y ago
      I well realize that. I was assuming absolute worst conditions, at 1 watt PEP. With hardware noise reduction, we can drop easily to .1 watt and still keep everything else consistent. Next, if we choose a directional antenna, we can also greatly magnify directed output. No sense in directing energy in the ground, is there? We can also have receiver systems (dish arrays) that can provide great gains in reception and transmitting.

Achshar 14y ago

> It's awesome that they've been involving the public so much in the details of how the rover mission really works. It must be mission critical to spread awareness since their budget cuts are getting worse and one way to correct that is to get people excited about space exploration. They now put a considerable effort in PR, involving people in the mission, sharing most of the information and making professional videos. And i believe this is why we see twitter accounts of most astronomers, satellites, rovers and other NASA properties. The NASA's ustream has been very popular lately and they have presence on every major social network. And curiosity was named after an essay written by a student in a competition organised by NASA for school students.

hrayr 14y ago
"And curiosity was named after an essay written by a student in a competition organised by NASA for school students." Nasa has been doing this for some time now, Sojourner[1], and MERs (Spirit & Opportunity) have also been named by student competitions. [1] http://mars.jpl.nasa.gov/MPF/rover/name.html http://mars.jpl.nasa.gov/MPF/rover/name.html
- deleted 14y ago
  [deleted]

ericHosick 14y ago

In general, space travel is very risky. It's not like they can iterate. Pulling something off like landing on Mars is very impressive. Keeping this in mind, I feel it was actually quite risky that NASA streamed the landing live. I think NASA should receive big kudos for taking that real risk.