6 ms·

My guess is lower image size, which means image can get transferred faster.

by POiNTx 6y ago

Azrael3000 6y ago
That is most certainly correct. They also mentioned that these are images from engineering cameras, so they are normally responsible for navigation. The real HD footage will come in over the next hours as the bandwidth just is not large enough. Elon Musk needs to provide some Starlink sats for a better connection.
- _Microft 6y ago
  Starlink would most certainly be of little direct use here. What I could imagine is having Starlink satellites around Mars that allow to route data from rovers anywhere on the planet to a dedicated high-performance communications platform that handles communication with Earth.
  - teraflop 6y ago
    In fact that's exactly what they're doing: the Mars Reconnaissance Orbiter is serving as a communications relay, as it did for previous landers. It's just that since there have never been more than a handful of spacecraft active on Mars at any given time, there's currently no point in spending huge amounts of money to launch a whole constellation of satellites for continuous coverage.
    - m4rtink 6y ago
      Could be still a nice exercise if someone could compute how many Starlinks could a Falcon Heavy throw to Mars transfer orbit & if they could be able to actually capture into Martian orbit by their default means of propulsion (do they actually have any high thrust engines ?).
    - Sharlin 6y ago
      Not only the MRO, but other orbiting assets as well, particularly NASA's MAVEN and ESA's TGO. Even the venerable 2001 Mars Odyssey is still used as needed, I think.
      - m4rtink 6y ago
        Even ESAs Mars Express is still around - since 2003!
    - davidmr 6y ago
      And a photographer! MRO took what might be my very favorite picture of all time: https://www.space.com/16946-mars-rover-landing-seen-from-space.html https://www.space.com/16946-mars-rover-landing-seen-from-spa...
nothis 6y ago
Anyone know the bandwidth they're working with, at least roughly?
- kibwen 6y ago
  Here's a page with data about the Deep Space Network: https://mars.nasa.gov/msl/mission/communications/#data https://mars.nasa.gov/msl/mission/communications/#data "The data rate direct-to-Earth [from Mars] varies from about 500 bits per second to 32,000 bits per second"
  - extropy 6y ago
    That's rover directly to earth, when reconnaissance orbiter is used to relay it's around 2 mbit to orbiter.
  - zokier 6y ago
    Clarification, that is for the old Curiosity rover. The page for Perseverance has some additional information > 160/500 bits per second or faster to/from the Deep Space Network's 112-foot-diameter (34-meter-diameter) antennas or at 800/3000 bits per second or faster to/from the Deep Space Network's 230-foot-diameter (70 meter-diameter) for high-gain antenna, and > Approximately 10 bits per second or faster from the Deep Space Network's 112-foot-diameter (34-meter-diameter) antennas or approximately 30 bits per second or faster from the Deep Space Network's 230-foot-diameter (70-meter-diameter) antenna for the low-gain antenna, which I believe the first two images were sent through https://mars.nasa.gov/mars2020/spacecraft/rover/communications/ https://mars.nasa.gov/mars2020/spacecraft/rover/communicatio...
    - m4rtink 6y ago
      Maybe it was the low gain antenna but via MRO or other orbiter? 30 bits per second seems like a bit too slow to get even the two small images back so quickly.
txg 6y ago
This is the right answer. The camera (and its 8 siblings) are capable of color HD imaging - the sensor has a Bayer filter. This image used a binning mode to produce a downsampled frame that could be more rapidly transferred back over the lower bandwidth comms used during landing. Binning combines the Bayer pattern and so color information is lost. Also doesn't help that there is a (transparent) lens cover in front of the lens obscuring the view.

My guess is lower image size, which means image can get transferred faster.

by POiNTx 6y ago

My guess is lower image size, which means image can get transferred faster.

That is most certainly correct. They also mentioned that these are images from engineering cameras, so they are normally responsible for navigation. The real HD footage will come in over the next hours as the bandwidth just is not large enough. Elon Musk needs to provide some Starlink sats for a better connection.

_Microft 6y ago
Starlink would most certainly be of little direct use here. What I could imagine is having Starlink satellites around Mars that allow to route data from rovers anywhere on the planet to a dedicated high-performance communications platform that handles communication with Earth.
- teraflop 6y ago
  In fact that's exactly what they're doing: the Mars Reconnaissance Orbiter is serving as a communications relay, as it did for previous landers. It's just that since there have never been more than a handful of spacecraft active on Mars at any given time, there's currently no point in spending huge amounts of money to launch a whole constellation of satellites for continuous coverage.
  - m4rtink 6y ago
    Could be still a nice exercise if someone could compute how many Starlinks could a Falcon Heavy throw to Mars transfer orbit & if they could be able to actually capture into Martian orbit by their default means of propulsion (do they actually have any high thrust engines ?).
  - Sharlin 6y ago
    Not only the MRO, but other orbiting assets as well, particularly NASA's MAVEN and ESA's TGO. Even the venerable 2001 Mars Odyssey is still used as needed, I think.
    - m4rtink 6y ago
      Even ESAs Mars Express is still around - since 2003!
  - davidmr 6y ago
    And a photographer! MRO took what might be my very favorite picture of all time: https://www.space.com/16946-mars-rover-landing-seen-from-space.html https://www.space.com/16946-mars-rover-landing-seen-from-spa...

nothis 6y ago

Anyone know the bandwidth they're working with, at least roughly?

kibwen 6y ago
Here's a page with data about the Deep Space Network: https://mars.nasa.gov/msl/mission/communications/#data https://mars.nasa.gov/msl/mission/communications/#data "The data rate direct-to-Earth [from Mars] varies from about 500 bits per second to 32,000 bits per second"
- extropy 6y ago
  That's rover directly to earth, when reconnaissance orbiter is used to relay it's around 2 mbit to orbiter.
- zokier 6y ago
  Clarification, that is for the old Curiosity rover. The page for Perseverance has some additional information > 160/500 bits per second or faster to/from the Deep Space Network's 112-foot-diameter (34-meter-diameter) antennas or at 800/3000 bits per second or faster to/from the Deep Space Network's 230-foot-diameter (70 meter-diameter) for high-gain antenna, and > Approximately 10 bits per second or faster from the Deep Space Network's 112-foot-diameter (34-meter-diameter) antennas or approximately 30 bits per second or faster from the Deep Space Network's 230-foot-diameter (70-meter-diameter) antenna for the low-gain antenna, which I believe the first two images were sent through https://mars.nasa.gov/mars2020/spacecraft/rover/communications/ https://mars.nasa.gov/mars2020/spacecraft/rover/communicatio...
  - m4rtink 6y ago
    Maybe it was the low gain antenna but via MRO or other orbiter? 30 bits per second seems like a bit too slow to get even the two small images back so quickly.

txg 6y ago

This is the right answer. The camera (and its 8 siblings) are capable of color HD imaging - the sensor has a Bayer filter. This image used a binning mode to produce a downsampled frame that could be more rapidly transferred back over the lower bandwidth comms used during landing. Binning combines the Bayer pattern and so color information is lost. Also doesn't help that there is a (transparent) lens cover in front of the lens obscuring the view.