Questions tagged [power]

Questions regarding energy used to operate a mechanical or electrical device.

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9
votes
1answer
442 views

How much power would an Alpha Centauri probe require for communication?

Project Longshot report (1988) says: A laser with an input power of 250 kilowatts would allow for a data rate of 1000 bits per second at maximum range." Yet Breakthrough Starshot website (2016) ...
3
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2answers
285 views

Temperature of photovoltaic cells vs efficiency - is it ever actively controlled?

The efficiency of photovoltaic cells is surprisingly strong function of junction temperature. Hotter usually means lower efficiency. If one searches for example for images and sites tagged with "...
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2answers
154 views

Has the choice of photovoltaic junction types for newer spacecraft converged on one, optimal solution?

On earth, the photovoltaic cell junction for mass production tends to be just silicon, although there is a variety of material types - single crystal vs multicrystal or polycrystal, or even amorphous. ...
10
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1answer
495 views

Do geosynchronous satellite launches require a tight launch window?

I thought only launches to rendezvous (resupply, repair, space station expansion etc) and direct launches into interplanetary trajectory require precisely timed launch window. Then I read: Geosync ...
2
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3answers
486 views

Would it be possible to power a Venus lander using a temperature differential?

Venus has an average surface temperature of 735K. Would it be possible to harness this extreme temperature and use it to generate electricity? After all, that's the principle a radioisotope ...
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) ...
7
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2answers
595 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 ...
11
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2answers
2k views

Are cubesats deployed with fully discharged batteries? Even those on Sherpa?

I'm pretty sure that at least some large satellites are deployed with their batteries charged so that they can initialize themselves, get their own attitude and position, and possibly establish some ...
14
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2answers
5k views

WHY did Rosetta have to go into hibernation for 2.5 years?

It seems the Rosetta spacecraft was put (put itself) into hibernation 08-June-2011. It spun itself up to stabilize its attitude, then shut down navigation, attitude control, communication systems as ...
3
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2answers
371 views

Can Red Dragon generate electrical power after a Mars landing, or will it rely only on battery power?

Red Dragon will presumably have to shed or re-stow solar arrays before any landing. What will be the source of electrical power after landing?
3
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2answers
115 views

Lessons Learned - What can space power system design teach Antarctic remote sensing systems

I know that a lot of brilliant engineering has gone into developing the space technology that we have. So, what engineering lessons about dealing with extreme cold and portable power sources do you ...
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0answers
69 views

Is there an upper limit for thrust generation by ion propulsion? [duplicate]

I was just reading an article about how the main factor preventing ion propulsion from being more effective is power generated from solar arrays. Solar arrays typically only generate 1-5 kW of power, ...
7
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3answers
1k views

Alternator/generator on launcher engines?

In Kerbal Space Program, most liquid fueled engines include a generator which provides electricity to systems on the rocket, keeping the batteries topped up while on ascent. Do any real rockets (...
1
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1answer
2k views

Why do satellites never run out of power?

Why do the satellites never run out of power do they have batteries that are charged by sunlight everyday? Also they transmit so much information across the globe.
2
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1answer
269 views

What are the challenges in building a supercritical CO2 gas turbine power plant for a Mars habitat of 6 astronauts?

There is abundant $\require{mhchem}\ce{CO2}$ in martian atmosphere, so we could use that in a modified gas turbine. Can this, combined with PV cells (a hybrid power source), be an efficient energy ...
2
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2answers
504 views

Could chemical energy quicken ion propulsion?

Background Tsiolkovski's rocket equation says that change of speed is proportional to the exhaust velocity. Chemical propulsion seems to have a strictly limited and since long achieved maximum ...
9
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7answers
1k views

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 ...
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 ...
5
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1answer
252 views

Is utilizing the high temperature for chemical reactions on Venus a feasible way of generating electricity?

I assume utilizing habitats floating high in the Venus atmosphere as described by Geoffrey Landis. So weight, size etc is a constraint, and we will not be operating at the surface with the crushing ...
14
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2answers
6k views

How powerful are reaction control wheels?

Most (ok, all) of my space exploration experience has been from Kerbal Space Program which has reaction control wheels with greatly exaggerated performance. I'm aware of real life missions (notably ...
6
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1answer
581 views

How much power does the Voyager radio dish draw?

I found here and here that Voyager transmits its main radio signal at 23 watts. In other words, the strength of the signal coming from its radio dish is 23 watts. However, what I want to know is how ...
1
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0answers
82 views

How is New Horizons powered? [duplicate]

My understanding is that New Horizons has an RTG on board, which generates electricity for it's systems. How and when was the RTG manufactured, and how does it work? How exactly does New Horizons ...
17
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2answers
12k views

What powers New Horizons?

What does New Horizons use to keep itself traveling (so far), while keeping all of its monitoring and communication systems active? I did read that it leveraged force from a gravity sling shot from ...
15
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3answers
9k views

How much RF transmit power does DSN need to send commands to Voyager?

I recently looked up how weak the Voyager signals are when they get to Earth from the 22 W transmitters (as of September 2013, it was roughly -245 dBm). But that got me wondering how many watts of ...
6
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1answer
2k views

Total Mass of the ISS Solar Array

This document does a pretty decent job of detailing the ISS solar array. There's one part, however, that is sort of ambiguous and critical to an analysis I'm performing, and so I thought I might ask ...
3
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1answer
342 views

Is the waste heat (sink) system dependent on whether the energy source is nuclear or solar?

A power plant in space causes waste heat which has to be removed from the plant. The need for large heat sinks, and their mass, kind of bogs down some of the advantages of big nuclear power in space. ...
3
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2answers
314 views

What are low-mass ways of supplying power for a 4.5kW ion thruster?

I'm in the process of designing a spacecraft for a project, and I'm at the stage of choosing the propulsion system. I'm going to use a Boeing 702 ion thruster (requiring 4.5kW) for propulsion, to ...
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2answers
2k views

Generator in space [closed]

If you spin a generator in weightless space could you generate infinite power? Of course the friction would be a issue but couldn't there be ways to reduce this in a weightless environment?
6
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1answer
442 views

Will the CST-100 recharge its batteries?

Since the CTS-100 uses lithium-ion batteries to supply its electrical power, and lithium-ion batteries self-discharge over time, will the CST-100 need to recharge its batteries at the ISS? If so how ...
3
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2answers
182 views

Is it feasible for a future Rosetta type mission to use wireless transfer of power to Philae?

While listening to the latest updates it seems like there is a limited 60 hour battery capacity left for Philae. There seems to be some information on the web on wireless power transfer using lasers. ...
5
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3answers
464 views

Could Earth's electric grid be used to power rocket launches via cable?

If our regular huge power plants on the ground could be used to power part of a rocket launch, launch mass would be smaller since fuel would not have to be carried on board. I wonder what are the main ...
9
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2answers
781 views

Can the reaction wheels also be used to store energy?

My understanding is that the parts of a typical flywheel energy storage are pretty much the same as the parts of a typical reaction wheel subsystem -- both have a flywheel, electric motor/generator, ...
6
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1answer
619 views

Can electricity be generated from solar storms

If a satellite covered with a thick layer of copper, were to go straight through a solar storm in the opposing direction, would the satellite produce electricity, provided the copper(or other suitable ...
6
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1answer
579 views

Could a solar thermopile be enough to power a small satellite?

It seems that a nuclear thermoelectric generator was used to power spacecrafts for some exploration missions. Can a thermopile that harvest the light/shade temperature difference on Earth's orbit be ...
13
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1answer
796 views

Are the power systems on the US and Russian segments of the ISS similar/compatible?

Clearly there is some method of power transfer between the US Segment with the honking big arrays, to the Russian segment. But since the Russian segment is basically Mir 2 (Zvezda, and an FGB tug ...
-5
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1answer
240 views

Send a wind turbine to space [closed]

Would it be viable to send a wind turbine which will be propelled by wind during a lift to space? Will it be able to produce significant amount of electricity while in space?
32
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3answers
33k views

How much power would a spacecraft's magnetic shield require?

I've read over the decades that a magnetic shield might protect a spacecraft from cosmic radiation. Its a fascinating idea that might only be theory or science fiction at the moment. In regards to ...
9
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3answers
6k views

Does the ISS need more heating or more cooling?

While reading the recent question 'Do exercise machines on the ISS generate electric energy?', I got thinking all of the exerciser machines generate heat (heat energy). So yes all exercise machine ...
6
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2answers
1k views

Do exercise machines on the ISS generate electric energy?

I'm just curious, do exercise machines for weight lifting and cycling have electric generators built in them to charge International Space Station batteries, or it's all going to waste?
12
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1answer
755 views

Can the Van Allen radiation belts serve any useful functions for space flight?

Most discussions of the Van Allen radiation belts focus on the necessity to shield sensitive electronics and biomass from radiation hazards. But are there any possible uses for this cache of highly ...
9
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2answers
324 views

Could electricity propel Curiosity on Venus?

To-date the humans have dispatched surface missions to Mars Luna Venus Mars has a thin atmosphere. Luna lacks one. Venus has a soup-thick atmosphere. Landing a static craft on Venus is one thing. ...
13
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1answer
844 views

Could Jupiter's tidal forces be used to generate energy?

Let's say we have a colony on Europa (or any other Jovian moon really). Jupiter exerts a lot of tidal forces on its satellites. Could this force be used to generate energy for our colonists?
16
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1answer
1k views

What is the power requirement of a spacesuit?

A spacesuit is a fairly easily identifiable piece of equipment in spacecraft. It's purpose is to keep it's interior distinct from the exterior in terms of the pressure, and temperature differentials ...
12
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1answer
426 views

What is the typical power redundancy built into a spacecraft?

NASA's Juno page says The Juno spacecraft launched aboard an Atlas V-551 rocket from Cape Canaveral, Fla., on Aug. 5, 2011, and will reach Jupiter in July 2016. The spacecraft will orbit Jupiter 32 ...
5
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1answer
470 views

What is the proper way to charge Lithium Ion batteries?

Lithium Ion Batteries are becoming more and more popular in spacecraft, due to their high power per mass ratio. There are several companies, such as Quallion, advertising their space rated batteries. ...
8
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4answers
856 views

Would it be practical to use the electrical charge of the Lunar surface as an energy source?

This question discusses the charges that exist on the Lunar surface. Would it be possible or practicable to use the differential between the surface and subsurface or different locations on the ...
12
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1answer
871 views

Is there an alternative to nuclear reactors for high-power spacecraft?

Many of my favorite ideas for space exploration, such as large outer solar system probes, or the Mars Direct human Mars exploration proposal, require nuclear reactors to supply the high-power ...
11
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2answers
1k views

How do space missions preserve their batteries for so long?

If I have a set of rechargeable batteries, I count myself lucky if I can get them to last for more than 2 years. Yet there are many spacecraft out there, which use their batteries much more regularly ...
25
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1answer
1k views

How long will communication with the Voyager probes continue?

Voyager 1 and 2 are the most distant man made objects. How long will we be able to still communicate with them? What will be the first thing that prevents communication? RTG exhaustion? Signal ...
9
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2answers
4k views

What power source options provide reliable and sustainable power generation for a Martian Colony

In order to maintain a Colony on Mars, we will need to be able to provide consistent, safe, and sustainable power on the planet. The extremely cold temperature means that the need to maintain ...