Why No Video Streams of Space Missions?

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Discussion Overview

The discussion revolves around the reasons for the lack of video streams from space missions, exploring technical, logistical, and conceptual aspects. Participants consider the feasibility of live video feeds from satellites and space probes, as well as the implications of such technology for scientific observation and public engagement.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that video encoding hardware is inexpensive and capable of producing high-quality images, questioning why only still images are transmitted from space missions.
  • Others argue that the long exposure times required for still images would result in unexciting video feeds, particularly from orbiting cameras.
  • It is noted that the distance of space probes like Cassini limits the ability to transmit HD video due to bandwidth constraints, likening it to outdated modem speeds.
  • Some participants propose that a live feed from the ISS could provide interesting data about Earth, despite bandwidth limitations.
  • One participant calculates the potential time required to transmit video data from a satellite, suggesting that even minimal video could inspire scientific interest.
  • There is a discussion about the practicality of pointing cameras in space and the lack of demand for such feeds, with some participants expressing skepticism about the utility of random space footage.
  • Another participant mentions that Cassini is already capturing images that can be viewed in sequence to create a video-like experience.
  • Some contributions highlight existing satellite observations of Earth and the availability of real-time weather data, suggesting that there are already systems in place for monitoring the planet.

Areas of Agreement / Disagreement

Participants express a range of views on the feasibility and desirability of video streams from space missions. There is no consensus on whether such technology is practical or necessary, with some advocating for it and others questioning its value.

Contextual Notes

Limitations include the dependence on bandwidth, exposure times, and the specific capabilities of existing space probes and satellites. The discussion also reflects varying assumptions about the demand for video feeds from space.

luma
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Video encoding hardware is cheap and inexpensive. Even the tiniest trickle of bandwidth is enough for crisp, sharp, colourful moving images.

http://www.boston.com/bigpicture/2010/05/checking_in_on_saturn.html

Browsing these images you really wonder our cameraman in space is just taking static portraits. Why not amazing video? Even 3D polarised video is now available for moviemaking.

Imagine.
 
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luma said:
Video encoding hardware is cheap and inexpensive. Even the tiniest trickle of bandwidth is enough for crisp, sharp, colourful moving images.

http://www.boston.com/bigpicture/2010/05/checking_in_on_saturn.html

Browsing these images you really wonder our cameraman in space is just taking static portraits. Why not amazing video? Even 3D polarised video is now available for moviemaking.

Imagine.

Well I believe the exposure time required to take one still is a few minutes. All you would end up with in a 'live-feed' is a static image that changes every few minutes... Not so exciting. It would be even worse if it were from a 'camera' in orbit around earth. Exposure times would be a lot more. As well the images are HUGE and highly detailed.

I suspect if you put a regular old 'webcam' into orbit and aimed it into outer space you wouldn't see much. I don't even think you'd be able to see the stars... maybe every now and then you'd see some peace of debris wizz by, or the moon or something but ... not too exciting...
 
It's mostly the phone bill.
Cassini is currently about 1bn miles away and unless you have a vast antennae and lots of power it's hard to send HD video over that sort of distance. I'm guessing Cassini's bandwidth is closer to a 1980s acoustic modem.

Even for stills the imagers on Cassini and all other space probes are mono with a set of color filters. To get a single color image takes 3x as long as a mono image and takes 3x the bandwidth to send home.
 
mgb_phys said:
It's mostly the phone bill.
Cassini is currently about 1bn miles away and unless you have a vast antennae and lots of power it's hard to send HD video over that sort of distance. I'm guessing Cassini's bandwidth is closer to a 1980s acoustic modem.

Even for stills the imagers on Cassini and all other space probes are mono with a set of color filters. To get a single color image takes 3x as long as a mono image and takes 3x the bandwidth to send home.

It would still be cool to set up a live feed on the ISS or any satellite really, just to watch the motion of the Earth or sun.
 
Mu naught said:
It would still be cool to set up a live feed on the ISS or any satellite really, just to watch the motion of the Earth or sun.

True. A decent HD 1080p camera on the ISS just looking down (say a Canon 5Mkii) could produce some interesting data simply because the repeated passes over the same area could tell you a lot about micro-weather / pollution / waves etc.
Bandwidth is probably still too much to have more than webcam quality, but returning astronauts could sneaker-net back a bunch of 1Tb drives.
 
24 seconds video encoded without audio to Ogg Theora. 720x576

No loss - 5 MiB
Video quality 8/10 (no noticeable change) - 2.4 MiB
Video quality 4/10 (slightly grainy) - 829 KiB

Let's say 4 MiB for a grainy HD video of a minute. It could be smaller since colour could realistically be transmitted for just a single frame and that image sampled for the other monotone frames by CGI here on earth.

Typical acoustic speed is about 300 bits/second

4 MiB * 8 bits / 300 bits = 4, 000, 000 * 8 / 300 ~ 110 Ksecs (rounding up)

Thirty hours.

A satellite could swing around in orbit transmitting for a single day what could inspire thousands of new scientists. Images of an alien planet.

Motion is the life that characterises our universe. Video was our window to other cultures decades ago. And now... other worlds?
 
Picture #15 on that site is amazing. (saved)
It's like your standing on one moon (Enceladus) looking at another moon (Titan) with Saturn's rings in between.
 
luma said:
A satellite could swing around in orbit transmitting for a single day what could inspire thousands of new scientists. Images of an alien planet.

Sorry, what exactly would you be pointing this video at?
 
DaveC426913 said:
Sorry, what exactly would you be pointing this video at?

Record for a min, transmit for a day.
 
  • #10
luma said:
Record for a min, transmit for a day.

You didn't answer my question.

Oh, OK. You're talking about a camera on one of our interplanetary probes that visit solar system planets. Didn't get that.
 
  • #11
And that already happened. Cassini is taking pictures constantly, sending them back, and anyone playing them in sequence has a video.
 
  • #12
I think he's talking about like having a camera on the iss and having it point out into random space. I honestly don't see a real demand for that so that's probably why it hasn't happened.
 
  • #13
There is already plenty of satellite observation of the earth.
http://www.ssd.noaa.gov/

One can get real time information on weather patterns, particularly storm systems, by simply contacting NOAA and getting the data. Meterological models are developed and verified against these data.

http://www.goes.noaa.gov/WINDS/index.html
http://www.osei.noaa.gov/

NASA is watching the Earth as well - http://eospso.gsfc.nasa.gov/
The Earth Observing System (EOS) is a coordinated series of polar-orbiting and low inclination satellites for long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans. EOS is a major component of the Earth Science Division of NASA's Science Mission Directorate. EOS enables an improved understanding of the Earth as an integrated system. The EOS Project Science Office (EOSPSO) is committed to bringing program information and resources to program scientists and the general public alike.
and ESA - http://www.esa.int/esaEO/index.html
for example - http://www.esa.int/esaEO/SEM9UI19Y8G_index_0.html

And NASA is constantly watch the Sun
http://sohowww.nascom.nasa.gov/
 
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