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Nokia selected by NASA to build cellular network on the moon

reuters.com

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Re: Nokia selected by NASA to build cellular network on the moon

#201

Post by bouncycastle »

bluGill wrote: post #154
ehnto wrote: post #82

Earlier quoted context omitted.

Given the nature of space travel, it will likely be a very old model indeed. Unless they have FTL!

If they don't have FTL (including no time effects) they will never come. Space is too large to go anywhere useful. The nearest start is ~4 light years away, at 1/10th the speed of light (vastly faster than we know how to go) it is 40 years to get here! We have done a lot of searching for life and haven't found it, the closer the planet is, the more likely we are to find it, thus I think it is safe to concluded there…

Interesting! I did the calculation and it's actually worse than that...

Alpha Centauri is just 4.37ly away. With an acceleration of 0.00227g, mass of 1t, and max velocity of 0.1C (10% of C), it will take 86.33 years to reach Alpha Centauri for those on the spaceship, assuming you also want to stop at the destination. (Calculator: https://www.omnicalculator.com/physics/space-travel#space-tr...)

Re: Nokia selected by NASA to build cellular network on the moon

#204

Post by fulafel »

Seb-C wrote: post #97

Is anyone aware of a date/time representation system that would work universally (including extraterrestrial places)? I just have been curious about this question for long. Sure, we could keep an earth referential on a moon base, but then what about Mars? As a software developer it is already difficult to always get dates/times properly with timezones, now imagine places which does not have 24 hours per day or the sa…

Time dilation undoes hopes of making any measure work universally. (Unless you include a bunch of other things besides one number in the measure...) But for subjective time there's UT1 (UTC minus leap seconds).

Re: Nokia selected by NASA to build cellular network on the moon

#205

Post by 0xffff2 »

whoisthemachine wrote: post #194
0xffff2 wrote: post #173

Earlier quoted context omitted.

Comfort won't be much of a factor since most NASA centers are completely work from home for non-mission-critical work for the indefinite future. Nonetheless, we do have a ton of these kinds of things going on all the time. The bigger problem is that NASA's culture is so meeting heavy that it's hard to justify these kinds of low importance events on my calendar.

> The bigger problem is that NASA's culture is so meeting heavy that it's hard to justify these kinds of low importance events on my calendar. Not sure if you are speaking from experience, but if that is the case, and this is true, then NASA as an organization seems to be a poor judge of what's important.

Yes, from experience. It's not that we don't know what's important, it's that it's all important and I have to find time to actually write code every now and then too. The real problem is just that we're all very busy and it's not really possible for everyone in the agency to have even a cursory awareness of everything that's going on.

Even now with everything being virtual, I get invites to brown-bag type events probably 3-4 time per week. I can go to one or two, but there's no way I can fit every single one into my schedule.

Re: Nokia selected by NASA to build cellular network on the moon

#206

Post by kristopolous »

matmatmatmat wrote: post #193

Am I the only one wondering what the point of this is?

Imagine you need robots and machines to work remotely on the moon without a human inside a cabin controlling things, without a line of sight and in a low power, low footprint form factor

Now you have 2 options:

1. Use off the shelf Quectel and Qualcomm devices and off the shelf existing embedded hardware. Then test and develop using common terrestrial networks and harden it for radiation. Pack and deploy.

2. Use something else that requires custom design, exotic hardware, untested interoperability, custom built terrestrial towers etc...

I'm going to vote on option 1 for saving time and money...

Re: Nokia selected by NASA to build cellular network on the moon

#207

Post by [deleted] »

fulafel wrote: post #204
Seb-C wrote: post #97

Is anyone aware of a date/time representation system that would work universally (including extraterrestrial places)? I just have been curious about this question for long. Sure, we could keep an earth referential on a moon base, but then what about Mars? As a software developer it is already difficult to always get dates/times properly with timezones, now imagine places which does not have 24 hours per day or the sa…

Time dilation undoes hopes of making any measure work universally. (Unless you include a bunch of other things besides one number in the measure...) But for subjective time there's UT1 (UTC minus leap seconds).

[deleted]

Re: Nokia selected by NASA to build cellular network on the moon

#208

Post by cozzyd »

snypher wrote: post #53
timdux wrote: post #43

All terrestrial base stations (1) require GPS signal for time synchronization. Most of them can run for 4 hours - 24 hours without GPS, but that's it, after that holdover period it's dead. There is no GPS signal on the moon. That's a problem. (1) except micro base stations

It's a problem being worked on, but it should be possible to use the existing GPS satellites on Moon. Also, given it is just being used as a time source and not for navigation, it should be possible to make a moon-based time signal with less hardware units? https://www.nasa.gov/feature/goddard/2019/nasa-eyes-gps-at-t...

There's only like an extra 25 dB of path loss to the moon than Earth since GPS satellites are at orbits of 20,000 km. Of course the GPS antennas are probably oriented facing the Earth, but you'd still see GPS satellies on the far side (with a bit more path loss). Since GPS has a 43 dB processing gain from the modulation scheme, and thermal noise levels on the moon are similar to Earth (I think?), that means you need -150 dBm or so at the receiver. I believe newer GPS satellites have an EIRP of 50 dBm or so, so receiving GPS signals on the moon might work without even using a high gain antenna. Use of a high gain antenna would probably completely compensate for the increased path loss to the moon.

Re: Nokia selected by NASA to build cellular network on the moon

#209

Post by edem »

Seb-C wrote: post #97

Is anyone aware of a date/time representation system that would work universally (including extraterrestrial places)? I just have been curious about this question for long. Sure, we could keep an earth referential on a moon base, but then what about Mars? As a software developer it is already difficult to always get dates/times properly with timezones, now imagine places which does not have 24 hours per day or the sa…

Ultraepoch? Milliseconds since the Big Bang?
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