A good review on the state of the technology.
This doesn’t make much sense, though: “…the hardware itself will have to be deorbited when it reaches end-of-life. ‘ESA has a Clean Space Initiative. Anything that we’re sending to space, we have to think about the whole lifecycle, cradle to grave,’ Caplin said.”
It’s loony tunes to think that we’d deorbit something that size from GEO. It will be repurposed in some way in space, or at least go to a graveyard orbit.
It’s loony tunes to think that we’d deorbit something that size from GEO. It will be repurposed in some way in space, or at least go to a graveyard orbit.
When it comes to repurposing or graveyard orbits, maybe we should consider the ISS a test case?
Too low, too draggy.
I beg to differ.
Dave’s First Rule of Rocketry. 🙂
We need to stop thinking of mass, that at great expense has been put in orbit, as garbage. It is a resource that can be salvaged and used for something else.
Used as what, or for what? I have no idea, but I’ll leave that for the future to figure out.
(And I see the FAA is threatening to ground the entire SpaceX Dragon fleet because of an on-orbit anomaly. FAA to “investigate” SpaceX launch failure)
Mass, a couple of starship flights could replicate.
The game has changed, lose the sunk cost fallacy.
We need to build a salvage yard in Earth orbit. Melt down old SPS, and use the resources to build new SPS, build space stations, and spacecraft. We should start that now, with the junk that is already up there. Send the ISS to the Earth-Moon L1 liberation point. Then build a cage around it. Later on, a pressurized ring around it. Place super conducting cables around the ring.
Then send a current through the cables. That will create a magnetic field. Tourist could then visit, and see the ISS. They just wouldn’t be able to go inside the ISS.
Rand, if you are looking at this, what do you think about my proposals?
L1 requires station-keeping. L4/L5 does not.
If L5 is the Boardwalk of CIS lunar space, then L4 could be the Baltic Ave.
Halo orbits. Station-keeping is de minimis, which is why, if I’m not mistaken, SOHO is still out at SEL-1.
EML-1 offers low delta-V access to GEO (less than 2km/s each way IIRC), as well as accessibility to all the LEO inclinations for about the same d-V. As well as 24/7 access to everywhere on the Moon’s surface. Lots more benefits as well. I’m just worried that the Chinese better appreciate its advantages and will set up shop in the best halos before we even figure out what’s going on.
Junkyard orbit.
A 1GW SPS is roughly the equivalent of an 1100 MW nuclear reactor. Good but insufficient. We’d need a fleet of such satellites for the US alone and it’s unclear how much such sats in GEO would interfere with comsats in the same orbits.
Is it not worth doing? I’m tending to think not. In the year 2022 the EIA states that the USA alone generated 4,230,672 thousand megawatt hours of electricity from all forms of utility scale facilities. This is a staggering number.
I don’t see SPS providing a significant fraction of that anytime soon or even in 50 years perhaps not even for a century. So color me skeptical.
You need to make them larger. Say about 5GW of power. And make a few thousand of them. Each one with a mass of 5,000 tons.
If I did my math right you’d need 97 (assume >100 with backup spares, etc.) of these 5GW powersats or >500 kT (your figure) of mass at GEO operating continuously for a year to provide just our needs from 2022.
If EVs replace gas/diesel vehicles I’m sure it’d be a lot higher.
I suspect a few thousand operating world-wide would blot out GEO for COMSAT purposes altogether. Maybe with frequency reallocation to avoid the powersat frequencies you’d do better.
Not saying doable/not-doable, just trying to give a feel for the scale of it. I remain skeptical.
just our needs from 2022.
I should distinguish needs from capacity. This would replicate our capacity from 2022. Assuming we don’t push a lot of unsalable excess utility power, capacity vs needs ignores peaks, etc. But on the whole, assuming things average out in the long run, it’s probably a good match.
The SPS would need their own frequency. We could use one of the AM frequencies, or use a VHF frequency. Like channel 13. So I think it can be done. Late David Criswell proposed building them on the Moon, beam the power to relay satellites in GEO, and beam the power from GEO, to Earth.
After building a salvage yard in LEO, place several SPS in orbit at about 6,000 miles. These can be used to provide power to hypersonic airships. These would fly at mach 5, at an altitude of about 35, to 42 miles above the Earth.
You could travel anywhere in the world in about four hours. Rand could fly from Los Angels, to London in about 2 1/2 hours. He could fly to Washington DC in 1 hour.
The lower the frequency the higher the beam dispersion and the larger the ground antenna needs to be. At microwave frequencies the ground rectifier antenna (often called a rect-tenna) is a few miles wide in an oblate circle for power beamed down from GEO. To avoid such large ground infrastructure and transmission losses it has even been suggested to use lasers at frequencies transparent to the atmosphere to reduce beam dispersion. Even at the lower microwave frequencies there will be some loss due to the atmosphere and the water vapor molecules within. From what I’ve read, probably a practical lower limit.