Mars landing live

[Clitheroekid]

You can watch it here, but you'll need to be quick, it's due to land in about 20 minutes!

I'm watching a little nervously, as getting all that tech to work perfectly is a hell of a big ask.

https://mars.nasa.gov/insight/timeline/ ... ch-online/

[mike]

Possibly the same feed at

http://www.nasa.gov/live

Landing due 1954 GMT, confirmation due 2001 GMT

[jackdaww]

i think its landed.

[kiloran]

Landed safely and waiting for the dust to settle

Stand by for pictures of little green men

--kiloran

[mike]

They seemed to know it had landed in real time. But signals were taking 7 (?) minutes to get back to Earth due to the distance. The Marco relay cubes don't speed up communcation, just allow for no blind spots.

My only explanation is the timing given of 1954 GMT was the time we would get the signal back on Earth, not the time the probe touched down. But there was the confirmation at ~2001 GMT that they were receiving telemetry.

Any ideas ?

[Gengulphus]

They seemed to know it had landed in real time. But signals were taking 7 (?) minutes to get back to Earth due to the distance. The Marco relay cubes don't speed up communcation, just allow for no blind spots.

My only explanation is the timing given of 1954 GMT was the time we would get the signal back on Earth, not the time the probe touched down. But there was the confirmation at ~2001 GMT that they were receiving telemetry.

Any ideas ?

My impression (not one I'm certain about) is that lots of communication stuff was shut down during the landing, probably to protect it, release power for other systems, etc, and then brought up again afterwards. In particular, there were at least two "carrier detected" moments in the sequence, one as it came out from complete communications blackout from being surrounded by hot plasma during the descent, some time before the moment it was reported as having landed, and one several minutes afterwards, shortly followed by someone saying that it had "phoned home" and reported that it was in good shape.

Based on that and other comments made, I would guess that the first was a low-capacity communications system, probably basically a "command channel" reporting the commands given to motors, etc, and the state of the command systems, while the second was a higher-capacity communications system reporting all sorts of measurements of the state of the lander. If so, the first would give them the basic information that it was still 'alive' and that it had gone through the expected sequence of events for a landing and that together with some information about position and velocity that could be obtained from even a basic radio carrier wave with no modulation to communicate any information would confirm that it had landed (and not so hard as to leave it totally non-functional). But telemetry would involve sending all sorts of measurements - things like whether it was at a angle (and if how, how big an angle), whether it was in sunlight, how well various systems were working, local temperature, etc, and would probably have to wait for the higher-capacity communications system. Such measurements would be needed to establish how good a state the lander was in.

As I said, that's my guess - hopefully a well-informed guess rather than a badly-informed one, but I certainly cannot guarantee it!

Gengulphus