'Curiosity' - NASA Mars Rover - Due to land 5th Aug 2012
Discussion
FurtiveFreddy said:
Bedazzled said:
That's pretty poor in comparison to the amount of data they are collecting. Nasa are planning a Laser Communication Relay mission, details here, if that works we could get a live video feed from Mars!
Live apart from the 14 minute delay, of course!TheHeretic said:
mrmr96 said:
If you had a big enough telescope to look directly at mars with the naked eye, there would still be a 14min delay as that's light speed of course. So I DO think it's fair to describe such a transmission as being 'live'.
Nothing you see, or hear is actually 'live'. 
So apparently this:
website below said:
During tonight and tomorrow's communications passes, sol 4, they should get a few of the full-resolution frames down from Mars. But only 10 or 20 will make it down before they begin the big flight software upgrade on sol 5. That effort will take at least 4 sols, and no science data will be returned during that time. So it'll be some time -- at least a week, more like two -- before the whole thing is available in full resolution. Even then, it won't include the top of the mountain. The panorama was planned and sequenced before the landing, so its pointing was pretty much random. Malin said that in the coming couple of weeks they have other preplanned image mosaics but that they will be able to adjust some parameters, shifting pointing slightly to better frame the pretty vistas in the distance, and the intriguing geology they contain.
One reason that the communications have been slow is that they are still limited to pretty low data rates; the maximum they have achieved so far is 256kbps. Within the next week or two, they should be able to move in to the data transmission mode with Mars Reconnaissance Orbiter that will allow rates of up to 2 Mbps. One thing I hadn't understood until I chatted with Watkins this morning was that the 2 Mbps is a maximum achievable during a single pass in which they can actually use an adaptive data rate, lower at the beginning and end of the pass when the geometry is not as good, and highest when the orbiter is most overhead. That's pretty spiffy.
http://www.planetary.org/blogs/emily-lakdawalla/20...
It's amazing that they're 14 light minutes away and they're going to get 2Mbps down. Obviously a 28 minute ping means it won't be any good for gaming though.One reason that the communications have been slow is that they are still limited to pretty low data rates; the maximum they have achieved so far is 256kbps. Within the next week or two, they should be able to move in to the data transmission mode with Mars Reconnaissance Orbiter that will allow rates of up to 2 Mbps. One thing I hadn't understood until I chatted with Watkins this morning was that the 2 Mbps is a maximum achievable during a single pass in which they can actually use an adaptive data rate, lower at the beginning and end of the pass when the geometry is not as good, and highest when the orbiter is most overhead. That's pretty spiffy.
http://www.planetary.org/blogs/emily-lakdawalla/20...
Curiosity to the Orbiter is maximum 2Mbps.
Orbiter to earth is up to 6Mbps but it depends on how far it is from earth at any given time so that rate can be as low as 0.5Mbps.
The distances involved here are vast. The closest MRO gets to earth is about 60 million miles and the furthest is 250 Million miles!
In those circumstances, even 0.5Mbps is pretty good.
Mars is currently about 155 Million miles from earth, so I guess the data rate will be around 3Mbps?
Orbiter to earth is up to 6Mbps but it depends on how far it is from earth at any given time so that rate can be as low as 0.5Mbps.
The distances involved here are vast. The closest MRO gets to earth is about 60 million miles and the furthest is 250 Million miles!
In those circumstances, even 0.5Mbps is pretty good.
Mars is currently about 155 Million miles from earth, so I guess the data rate will be around 3Mbps?
Edited by FurtiveFreddy on Thursday 9th August 23:57
This article explains the comms systems well, but essentially the direct link from Curiosity to earth is for commands and backup as it can't match the MRO relay data rates.
http://www.space.com/16893-mars-rover-curiosity-br...
http://www.space.com/16893-mars-rover-curiosity-br...
Bedazzled said:
Those bandwidth figures via the orbiter sound a bit more like it for uploading hi-res pics etc. What's the lower capacity direct link used for, navigation/system signals etc?
Quite a good tour of the Curiosity rover here, click on the left/right arrows to see each subsystem. It's got a drill, a laser, and... a sundial?!
That's an interesting link. Thanks.Quite a good tour of the Curiosity rover here, click on the left/right arrows to see each subsystem. It's got a drill, a laser, and... a sundial?!
garyhun said:
Regarding the orbiter that's taking photos and being used as the radio relay, is this part of this latest mission or is it orbiter from a previous Mars mission?
I cannot seem to find details on the JPL NASA site.
Well, technically its part of this mission but its been there years doing lots of other stuff (its own photo mission and relay for Spirit and Oppurtunity), IIRC there are current 2 or 3 orbiting probes at Mars all doing different things.I cannot seem to find details on the JPL NASA site.
Actually NASA and ESA have a shed load of stuff "out there" (ie- not just the stuff in orbit here) and for each probe there is at least one final stage following or ahead of it on the same orbit/path.
scubadude said:
garyhun said:
Regarding the orbiter that's taking photos and being used as the radio relay, is this part of this latest mission or is it orbiter from a previous Mars mission?
I cannot seem to find details on the JPL NASA site.
Well, technically its part of this mission but its been there years doing lots of other stuff (its own photo mission and relay for Spirit and Oppurtunity), IIRC there are current 2 or 3 orbiting probes at Mars all doing different things.I cannot seem to find details on the JPL NASA site.
Actually NASA and ESA have a shed load of stuff "out there" (ie- not just the stuff in orbit here) and for each probe there is at least one final stage following or ahead of it on the same orbit/path.
NASA overview - http://mars.jpl.nasa.gov/odyssey/mission/overview/
There are two orbiters which have been assisting in this mission so far.
1. Mars Reconnaissance Orbiter (MRO) which is the primary link for data to/from Curiosity and also provides the very high resolution images of the surface of Mars we have seen via its 'HiRise' camera. That camera and the images it produces was the primary reason it was sent to Mars in the first place.
2. Odyssey was used briefly during the landing to act as another radio uplink to verify the MSL had landed safely. However, Odyssey is not in top health at the moment, so may be of limited use from now on.
1. Mars Reconnaissance Orbiter (MRO) which is the primary link for data to/from Curiosity and also provides the very high resolution images of the surface of Mars we have seen via its 'HiRise' camera. That camera and the images it produces was the primary reason it was sent to Mars in the first place.
2. Odyssey was used briefly during the landing to act as another radio uplink to verify the MSL had landed safely. However, Odyssey is not in top health at the moment, so may be of limited use from now on.
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