Questions tagged [solar-power]

Questions on obtaining electrical energy from the light of the Sun through either direct photovoltaic conversion or thermal conversion.

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53
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4answers
6k views

Why wasn't an RTG used on the Juno spacecraft?

When I first heard about the Juno spacecraft, I was surprised that it would be using solar panels to generate power throughout the mission. Why wasn't a radioisotope thermoelectric generator (RTG) ...
22
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3answers
4k views

Why didn't Gemini, Apollo or STS use solar panels?

Short-duration flights (Vostok, Voskhod, Mercury) use several-kWh batteries. Space stations use photovoltaic cells for their high power-to-weight ratio. The longest mission duration accomplished with ...
21
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1answer
1k views

Function of the separated, individual solar cells on Telstar 1 and 2? Why were they “special”?

The image below shows a part of a backup satellite for Telstar 1 and 2. In addition to the many small and highly segmented solar panels, there are what look like individual elements of the same kind ...
19
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1answer
3k views

Brushing clean a Mars lander's solar panels

A comment by SF. regarding the InSight Mars lander caught my attention: I really, really wonder why they didn't just include a small compartment with a duster brush grippable by the robotic arm. ...
18
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2answers
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How far from the Sun can solar power be used as a reliable energy source?

Space probes headed for the far reaches of our Solar System rely on radioisotope thermoelectric generators for power (Cassini–Huygens, Voyager 1, Voyager 2). Presumably this is because solar power ...
17
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1answer
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What inspired the circular panels on the Phoenix Lander and InSight rover?

The solar panels on the Phoenix Lander and InSight rover seem to take on an iconic new look of circular solar panels. As far as I could see solar panels on landers and rover took up the maximum ...
16
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1answer
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Can ISS fold its solar panels?

The solar panel modules of ISS use an extending central truss structure to stretch two "ribbons" of solar panels. Can that structure be re-folded in space, if need arose (for whatever reason), or is ...
15
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2answers
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Why does Curiosity use an RTG rather than solar (as Spirit and Opportunity do) for power?

Why did Curiosity choose to go with nuclear power? While solar panels have issues with Martian dust, this was a known factor before the 2004 Spirit and Opportunity mission. Why then did the 2004 ...
14
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2answers
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Do solar panels on satellites gather dust and need cleaning?

As a follow-up to Does cosmic dust pose a problem for long-term satellites, telescopes and probes?, assuming satellite's long duration stay in Earth's orbit – let's for the sake of argument assume a ...
14
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2answers
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Curiosity is still dirty! How will the ExoMARS Rover keep its solar panels dust-free and collecting sufficient power?

update: Current events makes this question even more poignant sols 5183 to 5189, Aug. 23, 2018 - Aug. 29, 2018: Team Continues to Listen for Opportunity Curiosity selfie has been released just a few ...
14
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1answer
301 views

How long could Solar Impulse fly in the Venerean atmosphere?

Extremes of temperature, and pressure serve to effectively constrict the life-span of a PV cell on the Venerean surface. Despite the cloud cover, the Venus' proximity to Sol makes for upto 1km ...
14
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1answer
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How does the efficacy of solar cells on Mars compare with Earth?

Mars gets less than half the light that we get on Earth and there are dust storms, but the atmosphere is much thinner and there are no clouds. After all factors have been considered, how effective are ...
12
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2answers
996 views

Making propellants on Mars: Why not just LH2/LOX instead of methane?

In this cool video of a presentation about SpaceX's GPU-based computational fluid dynamics, there is a slide early on about making rocket fuel on Mars - specifically using water from the ground and ...
12
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2answers
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Lightest possible solar array?

I'd like to know what is the lightest possible solar array per unit power with current or near future technology. The arrays I have been able to find: Vanguard Space THINS 400-500 W/kg (2014; thin ...
11
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6answers
2k views

Can a satellite work like a radiometer?

Like a Crookes Radiometer, could a satellite have a stiff vain to maneuver? With a white side to let light pass and the black side capture light radiation be enough provide radiation pressure to keep ...
11
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2answers
2k views

Why latest Landsat satellites have solar panel on only one side?

It is normal for satellites to have solar panels on both sides of the body. But Landsat satellites, from Landsat 4, seems to have the solar panel on only one side. Are there any specific advantages ...
11
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1answer
205 views

28V vs. 124V on the ISS

Apparently the US segment of the ISS runs on 124v DC, while the Russian segment is on 28v DC. Why the difference? I understand it is often safer to have several different voltages rather than one, but ...
10
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1answer
962 views

How can the Parker Solar Probe survive passing within 4 million miles of the sun's surface?

There is a lot of information on the internet about NASA's Parker Solar Probe mission, including several multi-hundred page scientific reviews and in-depth studies - here's one. But could someone take ...
10
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1answer
314 views

Why does DSCOVR appear to be missing solar cells?

In recent photos of DSCOVR I've noticed it appears to be missing eight solar cells in its array. In photos from the original "unboxing" from storage it appears to have all its cells. Why is this?
10
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1answer
224 views

Why the MASCOT lander has no solar panels?

The MASCOT lander carried on Hayabusa2 just landed on Ryugu, completed it's mission and finshed operation as it has a non-rechargeable battery and no means to generate power. See this answer for more ...
9
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7answers
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How could a fast powerful rover on Mars be powered electrically?

Background The rovers on Mars are slow and weak. If I am to believe what I read, MSL Curiosity only produces 1/6th of a horsepower electric effect, 125 watt. In order to perform tasks like deep ...
9
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1answer
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How much light is there on the way from Earth to Proxima Centauri?

I want to know how much light is there for a spacecraft that flies from earth to Proxima Centauri. I know there's the sun but what happens after the spacecraft leaves the solar system? Are there stars ...
9
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1answer
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What are the sources of light at L2? How will the James Webb telescope be powered?

The James Webb space telescope will be positioned very close to L2. According to JPL, Webb will have a large solar-array to power itself. I don't understand how this works, since L2 is positioned "...
9
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3answers
2k views

How will Dragon v2's solar panels be protected during launch on top of Falcon 9?

When Elon Musk unveiled Dragon v2 last year, we got our first truly good look at what SpaceX's crew vehicle is like. Apart from the ability to propulsively land, one of the big changes was the lack of ...
9
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1answer
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What is the average intensity of sunlight on the Venerean surface?

A follow-up to How much more power does a PV cell generate in Venerean orbit? NASA writes to say about Venera 8 ... measured the light level as being suitable for surface photography, finding it ...
9
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1answer
303 views

Do Orion's solar panels have adjustable sweep?

In this video overview of NASA's proposed EM-1 mission, the solar panels on the Orion spacecraft are initially shown extending perpendicular to the spacecraft (at around 3:46). Shortly after that, as ...
9
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1answer
559 views

Manufacturing solar cells on the Moon

How practical is it to manufacture solar cells on the Moon? I understand there is a lot of silica there, and in theory if we could robotically make and deploy solar cells on the Moon, then we would (...
9
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1answer
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Peltier cell as solar cell in space

There's a related question: In space can the difference in temperature between the inside and outside, provide useful energy? The problem with that one is that it relies on the concept of "hot inside"...
8
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2answers
571 views

How quickly do the Van Allen radiation belts degrade solar panels?

I heard the other day that to take cargo from Earth to a Lagrange point or the Moon using solar electric propulsion would be a problem because the Van Allen radiation belts would degrade the solar ...
8
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2answers
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Solar flux on (not at) Earth

I'm trying to find out if there are reliable values for the solar flux received on Earth. I realise this will change with location, time of day, season, weather etc. but I'm surprised that I can find ...
8
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1answer
1k views

How are solar panels protected from the Sun?

In 2003, JAXA sent a probe, Hayabusa, to an asteroid named Itokawa. On the way to the asteroid, there was a large solar flare which damaged the probe's solar cells. I've been searching through the ...
8
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1answer
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Why does the ISS not use the most efficient solar panels available?

In this question, Geoffc's answer stated that the ISS solar arrays are about 14% efficient. Higher efficiency panels were available when these arrays were manufactured. Given the high cost per pound ...
8
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1answer
472 views

What is the difference in solar panel efficiency between Solar Impulse & ISS?

Solar Impulse is on target to circle the world. Presumably Solar Impulse has the most current and efficient solar cells available, while those on the ISS range between 5 and 10 years old. How do the ...
8
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1answer
727 views

How much more power does a PV cell generate in Venerean orbit?

Spacecraft in terrestrial Solar System typically use PV cells to power their instruments. As the referenced Wikipedia article writes, Photovoltaics (PV) is a method of generating electrical power ...
8
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1answer
342 views

Could dusters be installed on solar panels on a mars lander? [duplicate]

I see on the interwebs that the lander Insight is about to land on Mars and the NASA PR describes the solar panels as producing 600-700W now and 200-300W when covered in dust. Is there any reason why ...
8
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1answer
257 views

Does Juno use MPPT?

MPPT aka Maximum Power Point Tracking is an active mechanism to collect maximum power a PV cell may deliver. This is typically achieved by varying the resistive load connected to a cell. Juno will ...
7
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5answers
3k views

How could a satellite follow earth around the sun while staying outside of earth's orbit?

I'm wondering if its possible for a satellite to follow earth around the sun while staying outside of its orbit. I wondering for the sake of space based solar infrastructure or just something ...
7
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3answers
1k views

Optimal trajectory for solar electric propulsion?

Consider using solar electric propulsion for, e.g. Earth-Mars trip, or for asteroid retrieval mission. Is there a benefit to first entering an eccentric orbit so that part of the time is spent ...
7
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4answers
2k views

Why aren't solar collectors in space solar power concepts placed closer to the sun?

I've been thinking about space solar power for quite some time, as to how it could be more profitable than ground based solar power. From all the concepts that I have seen the main problem I always ...
7
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2answers
588 views

Solar cells in series

Most of space-based hardware operates on solar panels composed of lots of photovoltaic cells connected in short series that produce around 28V; lots of these are connected in parallel to produce ...
7
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2answers
766 views

How does ROSA unroll? (Roll Out Solar Array)

The upcoming SpaceX launch with the apparently first re-use of a dragon capsule will bring with it the Roll Out Solar Array (ROSA). (See also: More science, reused Dragon capsule featured on CRS-11) ...
7
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3answers
285 views

Will space-based energy beamed to earth increase heat on earth?

A Japanese paper on beaming energy from solar installation on the moon to earth via laser and microwave recently made the rounds in the media. Would this, or any space-based energy system cause a net ...
7
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2answers
668 views

Could a space based solar power system be used as a weapon?

Space based solar power systems that beam power back to terrestrial receivers have been discussed for decades. However, I've always had a nagging concern that such a system, once built, could be ...
7
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1answer
300 views

How are the orientations of the ISS' eight independent solar arrays optimized?

I've noticed that in various photos and videos the orientation of the ISS' eight independent solar arrays are often moving, and usually some are different than others. 0th-order naive thinking would ...
7
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0answers
234 views

Were solar concentrators on HS-702 just a stop-gap measure until triple-junction PV cells were available?

According to Gunter's Space Page discussion of early versions of the Hughes HS-702 Bus: The first version of the 702 used solar arrays with concentrators. These concentrators tended to early ...
6
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2answers
829 views

Why aren't landers designed to point their solar panels and radio antennas to Sun and Earth?

Opportunity, the rover on Mars, is on its tenth year. Wow! But its solar panels are fixed flat on top of it. As are those of all interplanetary landers which I know of. Why aren't they designed to ...
6
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2answers
718 views

The Orbital Mass Accelerator Engine Theory

Can 2 satellites equal in weight traveling on the same orbital path in the opposite directions intersect and propel each other to gain altitude in orbit? Can orbital perturbation be negated during ...
6
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2answers
1k views

What is a typical satellite solar panel mass?

Does anyone know a reliable source to find the mass of solar panels on satellites (in particular GEO satellites)? I know they will vary but I am struggling to even find one data point let alone a ...
6
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1answer
449 views

Are the ISS US Segment solar arrays double-sided?

Some answers on this site claim that the ISS US Segment solar arrays are double-sided (i.e. cells on both sides of the blanket). I tend to doubt this, but a search of my references did not turn up ...
6
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2answers
521 views

When there is more power than needed, are satellite photovoltaics shunted or open circuit?

I saw the word "shunts" in this answer about DSCOVR's upgraded photovoltaic arrays when it was unmothballed and readied for space. Reading it, I get the idea that shunts are used to dissipate the ...