You must log in or register to comment.

Lafuente_Astro t1_j1bzxfq wrote

Nice. Is it one of those rollable solar panels?


Erinalope t1_j1c87g4 wrote

Yes, the iROSA, improved rollout solar arrays. They attach to the old motors and fill in some of the empty space.


IWasGregInTokyo t1_j1do7ky wrote

Wondering how efficient they are compared with the much larger original arrays. I'm assumng there's been some improvement in the years since the originals were installed.


danielravennest t1_j1erg85 wrote

30% vs 12% in the original arrays when they were new. That's why the new ones are so much smaller.

The Space Shuttle ran off fuel cells, which meant a limited time on orbit. They had a goal of 30 day science missions, so a project was started for a "Power Extension Package" that had fold-out solar arrays.

That never flew on the Shuttle, but when the Space Station project started in the 1980's, it was adapted for the Station's main solar arrays. State of the art at the time was 12% efficient silicon cells.

Current state of the art are Gallium Arsenide + two other layers to capture more of the solar spectrum. So new satellite arrays get ~30% efficiency. Multi-layer cells are mostly too expensive for ground use, but silicon has been constantly improving, to where panels on Earth can convert up to 20-22% of incoming sunlight today.


AWildDragon t1_j1dwa0g wrote

That and degradation of the old ones due to space exposure.


Erinalope t1_j1dz42a wrote

I think I remember them being marginally more efficient, but all solar arrays start losing efficiency at first light, especially in the harsher environment of space. They’ll be way more powerful just by being newer.


danielravennest t1_j1ernmg wrote

See my other comment in this chain. New space solar is 30% efficient, compared to 12% for the old Station arrays when new. That's why the new roll out arrays can be so much smaller.


Nemo_Shadows t1_j1d8rzg wrote

I wonder just how much sun and warmth is blocked by all that space junk?

Certainly seems like an expensive way to go about cooling the planet from all that Global Warming, nice thing is it went from -10 to +10 here in 24 hours BUT it snowing now.

And there is a better way to do all of it.

N. Shadows


ChefExellence t1_j1dctk6 wrote

A negligible about. Particulates in the atmosphere can block more noticeable amounts of sunlight, but you'd have to put some real effort into blocking sunlight from space


Nemo_Shadows t1_j1difr1 wrote

It is sort of surprising just how much is really up there, but it was actually meant as a humorous look at the weather coming in from Siberia, MAN it is COLD HERE.

10 degrees is a heat wave at the moment and holding steady and I pity the poor fools in the Midwest dealing with -30 and 80 mph winds.

N. S


Erinalope t1_j1e0rtp wrote

Zero. It won’t change a thing because the size and distance. The moon is the moon big and even it’s shadow doesn’t cover the planet. If shadows like that had an effect on climate change we’d know. The number of sunspots have a greater effect on atmospheric temperatures.

Also, it’s climate change, not global warming. The fact that the climate is changing from its balance is what’s causing crazy weather swings. We are not looking to take direct action against climate change from space. It’s just not feasible unless we put a GIGANTIC solar array at L1, like moon big.


danielravennest t1_j1etlvi wrote

"Global Warming" is a thing, but it has been around as long as Earth has been a water planet. The average temperature across the Moon is -15C, and the Earth would be too but for water being a greenhouse gas. So the average temperature actually is +15C.

But the oceans are all water, and even much of the land has water as ice or soil moisture. So the atmosphere is saturated with water, and any excess falls out of the sky (rain, snow, fog, etc.)

The reason CO2 and other greenhouse gases are a problem is they are not saturated, and accumulating.


Speedly t1_j1dooz1 wrote

Should... should I call someone? You okay?


danielravennest t1_j1esqk4 wrote

The thousands of SpaceX Starlink satellites cover about 40 acres. The Earth's cross section, the area available to capture sunlight, is around 32,000,000,000 acres. It is utterly trivial.

About 30-35% of sunlight is reflected back to space, mostly due to clouds, and doesn't warm the Earth. That is a much much bigger factor.

Note: you don't have to sign your posts if it is the same as your username. It already appears at the top of every post.


Nemo_Shadows t1_j1i4rck wrote

Thanks but I'm kind of old school and those headers can still be be falsified in this day and age, plus it is and always has been a courtesy where I come from not arrogance or anything else.

N. S