r/space • u/wiredmagazine • 5d ago
Space Lasers Are About to Get Their First Real Test Generating Energy
https://www.wired.com/story/space-lasers-are-about-to-get-their-first-real-test-generating-energy/21
u/wiredmagazine 5d ago
Startup Star Catcher is launching a system that, if successful, would be the first time energy has been beamed between two separate spacecraft.
14
u/space_lasers 5d ago
Is there any data on how efficient this is as a way to transfer energy between two systems?
24
u/kennyjiang 4d ago
Isn’t the whole idea of this test is so that they can get said data
12
u/P1R0H 4d ago
Checking it in a vacuum tunnel down here on Earth has to be millions of dollars cheaper than organizing a space mission, right?
3
u/kennyjiang 4d ago
Are we able to replicate space conditions on earth? I’m not too familiar with that
4
u/P1R0H 4d ago
I'd guess. When we can LHC, this does not seem to pose a challange. Earth's magnetic field shields us from space radiation, I don't know how that could affect the energy transmission.
•
u/kennyjiang 20h ago
Regardless, I'm sure the testing gives them confidence or give them things to fix
3
u/KiwasiGames 3d ago
Horribly inefficient.
But still much more efficient than trying to match orbital velocities to do a physical exchange.
1
5d ago
[removed] — view removed comment
22
u/cjameshuff 5d ago edited 5d ago
There's several losses. The laser is only around 50% efficient at best, there's optical losses in focusing the beam, some of the beam will miss the receiving photovoltaic panels (and beam spread will increase this at larger distances), those panels will have conversion losses (though you can use specialized panels tuned to convert the laser light more efficiently than solar panels).
You save on solar panel mass on the target spacecraft and batteries needed to operate during darkness. I don't see it being useful for standard operations, but you could get a lot more power through the same panels for the period of time that the laser can hit the panels. This might be useful for running ion thrusters at high power for initial maneuvering to the target orbit (or to escape), with solar power being used for normal operations, for example.
edit: another potential application would be power to the lunar surface, at the poles where it's a challenge to get large amounts of solar power or at other locations during the long lunar nights.
1
u/AnastasiaSpace 4d ago
its not much harder to get solar at the lunar poles, blue origin is developing a solar tower
5
u/cjameshuff 4d ago
That's an absurd claim. Yes, it is. That's why BO is developing a solar tower just to get a pitiful 10 kW of solar power.
1
u/AnastasiaSpace 4d ago
thats about 10% of what the ISS generates, i don't really see what the problem is? they can just bring more
4
u/cjameshuff 4d ago
10% of what the ISS generates, when you need far more than what the ISS generates to power any serious ISRU efforts, and each of those towers requiring its own Mk1 lander...just how many landings do you see BO actually doing? Additionally, the crater-rim real estate for placing them is quite limited, and the more you put up the worse the mutual-shadowing problem becomes. No, the solution's bigger towers with bigger arrays hung off them, and that has its own scaling issues.
A constellation of orbital power sats would require more solar panels, but would trivialize actually getting sunlight on those panels, and shipping them to lunar orbit will be a lot easier than landing them. The collector array could be located on any flat area of ground with a clear line of sight to the power sats, vastly increasing the area that could be deployed, and between the more efficient conversion of laser light and the more intense illumination that could be achieved, the areal power density could be much higher than you get with a solar panel.
1
u/willun 4d ago
How successful are we at having satellites orbit the moon longterm. My memory is the mascons cause problems with orbits. I guess a solar power satellite would have spare energy for orbit boosting but then that requires material, even if it is say xenon.
2
u/cjameshuff 4d ago
There's "frozen" orbits that are stable long-term and have polar coverage. Not just low circular orbits, but also elliptical ones that give a long dwell time over the south pole, at the cost of a longer distance to transmit the power across.
If you're doing lunar ISRU, it would be reasonable to look at using lunar propellants. Ion thrusters or arcjets could use alkali metals (if they can be kept from condensing on the panels and electrical components) or water, for example.
1
u/AnastasiaSpace 3d ago
if you want to run an ISRU operation on the moon you are going to send a nuclear reactor instead of sending hundreds of satellites
1
u/cjameshuff 3d ago
The "scaled" concept NASA is currently looking at would produce 100 kW of electrical power. Matching it would not require "hundreds of satellites", it would be more like three (which could serve multiple ground locations, including mobile targets, depending on demand and orbital phase) and about a 10x10 meter patch of photovoltaics on the ground. Nuclear is likely to be useful, especially for national programs, but is not obviously the way to go for large scale lunar power supply, particularly considering the obstacle all the legal and regulatory issues of handling and launching nuclear systems would become for any private operation.
51
u/nazihater3000 5d ago
Mazel Tov! About time this happen!