Not in a good way!  Next post dealing with grass skirts, living in a cave or plastics and not about Microwave transmission, will result in closure!

If you feel obsessed with commenting about the off-topic things, then PM each other with your replies!

One of the concerns is how long these satellites could last in orbit without significant deterioration and how much maintenance they would need in order to do so. The current lifetime seems to be generally 30-35 years.

47 minutes ago, dmwalker said:

One of the concerns is how long these satellites could last in orbit without significant deterioration and how much maintenance they would need in order to do so. The current lifetime seems to be generally 30-35 years.

 Did I mishear, or was it mentioned that the array might be a mile or more in diameter?

I'm not even sure I can imagine the heavy lift capability necessary for something like that,  much less building several of them.  Which doesn't even mention the ground facilities to receive the microwaves.....

5 minutes ago, HiFlyer said:

Did I mishear, or was it mentioned that the array might be a mile or more in diameter?

Nothing is finalised but the proposed designs seem to vary from 2,000  tons and 2 km in diameter for circular arrays to 10,000 tons and12 km in length for a linear array.

5 hours ago, HiFlyer said:

The alternative is to stop and think. 

 

Which is what they have done. They are complying with all recommendations regarding power density. As I said, they have been at this since the 70's. There's no evidence of recklessness. 

2 hours ago, dmwalker said:

One of the concerns is how long these satellites could last in orbit without significant deterioration and how much maintenance they would need in order to do so. The current lifetime seems to be generally 30-35 years.

 

As I mentioned, this tech isn't just about power beaming from space. There are numerous applications, like providing power where cables can't be laid, military applications, keeping drones aloft indefinitely 

3 hours ago, charliearon said:

 

If you feel obsessed with commenting about the off-topic things, then PM each other with your replies!

 

Why is it necessary for a topic to stay slap bang on topic? Some of the most interesting conversations drift into other areas.

 

21 minutes ago, martin-w said:

There are numerous applications, like providing power where cables can't be laid, military applications, keeping drones aloft indefinitely 

These would be land-based line-of-sight transmitters using conventional energy to power the transmitters, would they? These would be completely separate from orbiting transmitters and would not be part of the justification to put transmitters in orbit.

27 minutes ago, martin-w said:

 

Why is it necessary for a topic to stay slap bang on topic? Some of the most interesting conversations drift into other areas.

 

Rules set down by the site owner!  If you feel that the topic is done, then start a new topic.  This forum is not a cocktail party, as others have suggested from time to time.

9 hours ago, charliearon said:

Rules set down by the site owner!  

 

Fair enough, just wondered. 

I moderated a well known flight sim forum for years, and there's was no issue with topics evolving, as long as the OP didn't mind. Didn't cause any issues. But fair enough, you're the boss.

10 hours ago, dmwalker said:

These would be land-based line-of-sight transmitters using conventional energy to power the transmitters, would they? These would be completely separate from orbiting transmitters and would not be part of the justification to put transmitters in orbit.

 

Well yes, several different applications. Nothing to do with beaming energy from orbit in order to power a land based grid. Orbital power generation is just one possible application for the technology.

Depends what you mean by conventional energy. Any source of electricity of course. 

Transmitting power where cables can't be run, like across a valley. Powering swarms of drones for various tasks like atmospheric monitoring or ground monitoring, they could stay aloft indefinitely. Providing power quickly for the armed forces without having to lay cables. Powering spacecraft from the ground. Transmitting power across stretches of ocean rather than laying undersea cables. And yes, for beaming power from solar arrays in space. 

 

Edited October 6, 20232 yr by martin-w

4 hours ago, martin-w said:

Transmitting power across stretches of ocean rather than laying undersea cables

It does have to be line of sight, doesn't it? So relay satellites would be needed.

5 hours ago, martin-w said:

Powering swarms of drones for various tasks

Each drone would need its own dedicated power transmitter, would it not?

I found one article on microwave powered drones where a 500kW 28GHz gyrotron was used to send a 0.4kg drone into the air for 30 seconds, reaching a height of 0.8m above the source of the microwave beam.

“The researchers measured the efficiencies of the power transfer through the beam (4 per cent); the capture of microwaves by the drone (30 per cent); the conversion of microwaves to electricity for propulsion (40 per cent), and other relevant processes.”

“Based on this information and an analytical formula, they calculated the overall power transmission efficiency in their experiment was around 0.43 per cent.”

“The researchers hope that although microwave-powered rocket propulsion is still in its early stages, it could someday become a superior way to launch rockets into orbit given the high onboard-fuel demands of conventional propulsion techniques.”

It's hard for the layman to imagine the process becoming efficient enough to power a rocket into orbit but, if it can be achieved, it would be “one giant leap for mankind”. 

https://eandt.theiet.org/content/articles/2021/07/wirelessly-powered-drone-achieves-flight-with-microwave-beam/ 

2 hours ago, dmwalker said:

It does have to be line of sight, doesn't it? So relay satellites would be needed.

 

No relay satellites. It would be line of sight. Just as an example, island to island in an archipelago. The islands where I live for example. They aren't talking about beaming energy thousands of miles around the planet. Beaming up to a satellite and back down again would introduce too many loses I would have thought.  

 

2 hours ago, dmwalker said:

Each drone would need its own dedicated power transmitter, would it not?

 

No... a receiver. Why a power transmitter? they wouldn't be transmitting anything. 

 

2 hours ago, dmwalker said:

I found one article on microwave powered drones where a 500kW 28GHz gyrotron was used to send a 0.4kg drone into the air for 30 seconds, reaching a height of 0.8m above the source of the microwave beam.

 

I wonder what the new technology in the video I posted could achieve. Early days. 

 

Quote

 

“These results show that more work is needed to improve the transmission efficiency and thoroughly evaluate the feasibility of this propulsion approach for aircraft, spacecraft and rockets,” Shimamura said. “Future studies should also aim to refine the beam-tracking system and increase the transmission distance beyond that demonstrated in our experiment.”

The researchers hope that although microwave-powered rocket propulsion is still in its early stages, it could someday become a superior way to launch rockets into orbit given the high onboard-fuel demands of conventional propulsion techniques.

 

 

 

Edited October 6, 20232 yr by martin-w

2 hours ago, dmwalker said:

It's hard for the layman to imagine the process becoming efficient enough to power a rocket into orbit

 

Microwave and thermal propulsion has been considered, where the beam heats up hydrogen propellant carried by the spacecraft. Microwaves would be better than lasers because they aren't absorbed by cloud as much and are cheaper to generate. 

 

 

Edited October 6, 20232 yr by martin-w

2:47 for the launch.

 

 

Edited October 6, 20232 yr by martin-w