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"The current plan for the first-ever attempt at powered, controlled flight on another planet is [...] to take off from Mars' Jezero Crater on Sunday at 10:54 p

"The current plan for the first-ever attempt at powered, controlled flight on another planet is [...] to take off from Mars' Jezero Crater on Sunday at 10:54 pm US eastern time (0254 GMT Monday) and hover 10 feet (3 meters) above the surface for a half-minute, NASA said." Set your alarms :) If the given time is actually take off, we can expect images from the flight at the earliest around 11:10pm (E(S?)T)/ 03:31 AM (GMT) as Earth and Mars are currently at a distance of 15 light minutes from each other. If they don't have a live feed, I would watch their Twitter account just in case. Useful links: https://mobile.twitter.com/NASAPersevere https://mobile.twitter.com/NASAPersevere https://mars.nasa.gov/mars2020/ https://mars.nasa.gov/mars2020/ Edit: see reply by samizdis for another, better link

_joel 6y ago
I'm not sure there will be images that quickly, just the telemetry to confirm if it was successful or not.
- janmo 6y ago
  The bitrate Earth/Mars is very low. It will take a lot more.
  - ape4 6y ago
    I hope there is a movie eventually.
  - _joel 6y ago
    The direct earth to rover comms is slow but it's a lot quicker via MRO as it has a higher gain antenna. https://mars.nasa.gov/mars2020/spacecraft/rover/communications/ https://mars.nasa.gov/mars2020/spacecraft/rover/communicatio...
  - xiphias2 6y ago
    Would setting up 60 Starlink satellites in a line to transmit between the two help?
    - nvahalik 6y ago
      No. It’s not a power or signal quality problem. It’s a speed-of-radio waves problem. Mars is really far away. And unfortunately we don’t have something like an Ansible to make communication instant.
      - maxov 6y ago
        I think this situation is a good illustration of latency vs bandwidth. Latency is unavoidable due to the speed of light, but there’s no physical barrier to bitrate aside from power consumption. Seems like the best bitrate we have from Mars is MRO at ~5 megabits/s which is enough for standard definition video. I’m certain we have the technology to push it higher, but it would be expensive and it seems it’s not really needed for existing projects.
        dredmorbius 6y ago
        Nit, though I'm going a bit (pun status unspecified) beyond my paygrade here: bandwidth is ultimately limited by the frequency of the trandsmission channel, though multiple channels can be multiplexed. This is the heart of Claude Shannon's work. For deep-space transmission, other factors apply, though if you're operating in the right frequencies, the background noise level is low (at least as compared to Earth where there are numerous competing signals of terrestrial origin). And whilst signal/noise ratio does impose limits, there's only so much that boosting volume dB will achieve before you hit the channel limits themselves. To increase bandwith beyond channel limits, you'd have to multiplex channels, which would involve different frequencies, different transmission routes (say, to widely-separated relay systems), or both. For physical media (e.g., fibre) this is relatively easy. For broadcast, given mass and energy budgets of spacecraft, probes, and rovers, the problems are harder. Encoding, redundancy, error-correction, and retransmit protocols can all increase the ultimate reliability of the signal, though these impose other costs, notably on bitrate or at least time until the transmission is confirmed.
        deleted 6y ago
        [deleted]
samizdis 6y ago
According to NASA [1]: Perseverance is expected to obtain imagery of the flight using its Navcam and Mastcam-Z imagers, with the pictures expected to come down that evening (early morning Monday, April 12, in Southern California). The helicopter will also document the flight from its perspective, with a color image and several lower-resolution black-and-white navigation pictures possibly being available by the next morning. [1] https://www.nasa.gov/press-release/nasa-s-mars-helicopter-to-make-first-flight-attempt-sunday https://www.nasa.gov/press-release/nasa-s-mars-helicopter-to...
d--b 6y ago
They’re quite confident. 3m is pretty high. Is there a reason not to hover at 1m? Maybe the lower gravity makes it acceptable...
- birktj 6y ago
  Ground effect? But I would assume with such low atmospheric density the effect is probably not so strong.
- JshWright 6y ago
  What risks would be reduced by dropping the max altitude from 3m to 1m?
  - d--b 6y ago
    Obviously not an expert here. But here on Earth I would happily jump 1m but I'd probably break a leg from 3m. Somebody must have decided that a 3m test flight was the best option. Maybe it's because if something fails, at least they may collect 1 picture at 3m high, and that's better than 1 picture at 1m...
dima55 6y ago
They had a software glitch, and the flight was pushed back a few days while they investigate.

_joel 6y ago

I'm not sure there will be images that quickly, just the telemetry to confirm if it was successful or not.

janmo 6y ago
The bitrate Earth/Mars is very low. It will take a lot more.
- ape4 6y ago
  I hope there is a movie eventually.
- _joel 6y ago
  The direct earth to rover comms is slow but it's a lot quicker via MRO as it has a higher gain antenna. https://mars.nasa.gov/mars2020/spacecraft/rover/communications/ https://mars.nasa.gov/mars2020/spacecraft/rover/communicatio...
- xiphias2 6y ago
  Would setting up 60 Starlink satellites in a line to transmit between the two help?
  - nvahalik 6y ago
    No. It’s not a power or signal quality problem. It’s a speed-of-radio waves problem. Mars is really far away. And unfortunately we don’t have something like an Ansible to make communication instant.
    - maxov 6y ago
      I think this situation is a good illustration of latency vs bandwidth. Latency is unavoidable due to the speed of light, but there’s no physical barrier to bitrate aside from power consumption. Seems like the best bitrate we have from Mars is MRO at ~5 megabits/s which is enough for standard definition video. I’m certain we have the technology to push it higher, but it would be expensive and it seems it’s not really needed for existing projects.
      - dredmorbius 6y ago
        Nit, though I'm going a bit (pun status unspecified) beyond my paygrade here: bandwidth is ultimately limited by the frequency of the trandsmission channel, though multiple channels can be multiplexed. This is the heart of Claude Shannon's work. For deep-space transmission, other factors apply, though if you're operating in the right frequencies, the background noise level is low (at least as compared to Earth where there are numerous competing signals of terrestrial origin). And whilst signal/noise ratio does impose limits, there's only so much that boosting volume dB will achieve before you hit the channel limits themselves. To increase bandwith beyond channel limits, you'd have to multiplex channels, which would involve different frequencies, different transmission routes (say, to widely-separated relay systems), or both. For physical media (e.g., fibre) this is relatively easy. For broadcast, given mass and energy budgets of spacecraft, probes, and rovers, the problems are harder. Encoding, redundancy, error-correction, and retransmit protocols can all increase the ultimate reliability of the signal, though these impose other costs, notably on bitrate or at least time until the transmission is confirmed.
        deleted 6y ago
        [deleted]

samizdis 6y ago

According to NASA [1]: Perseverance is expected to obtain imagery of the flight using its Navcam and Mastcam-Z imagers, with the pictures expected to come down that evening (early morning Monday, April 12, in Southern California). The helicopter will also document the flight from its perspective, with a color image and several lower-resolution black-and-white navigation pictures possibly being available by the next morning. [1] https://www.nasa.gov/press-release/nasa-s-mars-helicopter-to-make-first-flight-attempt-sunday https://www.nasa.gov/press-release/nasa-s-mars-helicopter-to...

d--b 6y ago

They’re quite confident. 3m is pretty high. Is there a reason not to hover at 1m? Maybe the lower gravity makes it acceptable...

birktj 6y ago
Ground effect? But I would assume with such low atmospheric density the effect is probably not so strong.
JshWright 6y ago
What risks would be reduced by dropping the max altitude from 3m to 1m?
- d--b 6y ago
  Obviously not an expert here. But here on Earth I would happily jump 1m but I'd probably break a leg from 3m. Somebody must have decided that a 3m test flight was the best option. Maybe it's because if something fails, at least they may collect 1 picture at 3m high, and that's better than 1 picture at 1m...

dima55 6y ago

They had a software glitch, and the flight was pushed back a few days while they investigate.