Posts by Zad

Each module has its own memory and processor, the cameras can do their own JPEG compression, subsampling etc. before handing it over to be transmitted back.

e.g. "Each camera has an 8 gigabyte internal buffer that permits it to store over 5,500 raw frames"

http://mars.jpl.nasa.gov/msl/mission/instruments/cameras/mastcam/

As I understood it, the 5 Mbit / 40Mbit thing - that wasn't link speed, but total downloaded data in particular passes.

Why re-invent the wheel?

If I only got 30m GPS accuracy, I would throw it in the bin.

Why are people re-inventing the wheel? GPS works perfectly well up into orbit, is cheap, light, low power, durable, flexible, and capable of being interfaced with similar cheap, light, low power (etc) systems like the Arduino, Mbed, PIC micros, in fact anything which has a serial interface.

Adafruit have a $39 unit which measures 23x35mm and weighs 8.5 grammes. It is not altitude capped, and has an internal data logging capability. It draws a maximum 20-25mA whilst actively tracking. It also supports 10Hz updates.

This is a problem that was solved a long time ago.

They can start by not calling it ICT. Number fiddling or not, IT is what rest of the world (i.e. the universe outside UK schools) calls it.

Kids should know how to use basic functions in Word etc by the time they are 11 anyway. It must take all of an hour to teach it.

Disappearing off the radar...

Amazingly, as soon as you put a tracker car inside a welded steel crate, the signal can't get out. Who would have thought it!

The words "disappear off the radar" in the original article are really going to get some stupid people jumping to conclusions, and was a very poor choice of phrase. Then again I would expect nothing less from someone who has written a report stating the blindingly obvious. Incidentally, military P-code systems use a different frequency with a much wider signal spread based around a different centre frequency and wouldn't be blocked with these jammers.

The interesting stuff will be when someone hacks together some FPGA gubbins and a transmitter and generates fake location info. That will really put the cat among the pigeons. It will royally mess up road charging because you could make your car believe it was hundreds of miles away. For that matter you could make other people's cars believe they were in the London charging zone, or suddenly doing 90mph. Sideways.

Let's off-road!

From what I can tell, the extraction methods seem to be along the lines of mashing the throttle to the floor for a few minutes, and then taking a photo. Somewhat reminiscent of the less experienced drivers out there in the snow.

Now, I'm sure they have considered this (actually, I'm not sure they have, because I'm posting this) but how about rocking the wheels? 1 actuator rotation forward, 2 back, 3 forward... etc etc. This would compact the dusty sand beneath the wheels and offer better traction. The little "wiggle room" it generates helps a small amount of momentum to build up and reduces wheelspin. It also allows any sand that falls in to drop under the wheel and raise it slightly.

On the matter of construction cost. I believe the major reason these 2 wee beasties have been so successful is down to how they were designed and built. There was no time (18 months) and very little money to get these rovers together so the engineers used spares and existing designs from a previous mission, with relatively few modifications. Having already extensively tested and space-rated the components and subassemblies meant that huge chunks of time (and money) were saved. This relatively minimal approach to the project meant that management interference was much reduced and the engineers could get in with what they do best.

Throttling...

Be/O2 do not artificially throttle. The important word there is artificially. Every real-world system has a maximum bandwidth limit and, if extra transport bandwidth isn't brought in, there will always be a load level at which latency suddenly shoots up. My latency goes from around 28ms to 100ms in the space of 15 minutes, although spookily, as I write this it has just dropped back down to the daytime baseline again. My theory is that as their core system has saturated, it is sending data via a (long distance) temporary backup path.

This is no excuse for the appalling lack of communication though. Before the O2 takeover, there were regular comments from the Be staff. These seem to have totally ceased now. Maybe this is the point when Be/O2 "Jumped the shark".

Space - The final front ear

Still, I guess perchlorate is a good source for liberating oxygen though? Ammonium perchlorate might be the best form, having nitrogen and hydrogen.

I hope they are now doing tests on the earth based rover model, to see what responses it has, and if they might have detected it at the other locations. Before they performed this analysis, I believe they performed a baseline analysis to see what contaminants were present.

I trust they will name this sample location Errol!

Woah! No brakes!

The big advantage the Harrier had was that if could VIFF - vector in forward flight. Pointing the engine thrust forwards allowed it to decelerate much faster than any other aircraft, forcing any attacking aircraft to overshoot the Harrier and put it right in the middle of it's gun (well rocket) sights. The Harrier also has the massive advantage that it doesn't look like it is straining to have a poo when in hover.