Questions tagged [power]
Questions regarding energy used to operate a mechanical or electrical device.
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1answer
142 views
How exactly does Curiosity's floating bus work, and how does it continue to operate when voltage drops from 11 to only 4 volts?
@Hobbes's answer calls attention to Emily Lakdawalla's book The Design and Engineering of Curiosity : How the Mars Rover Performs Its Job which led me to reading excerpts in several Planetary Society ...
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1answer
99 views
Why satellite’s solar panel wattage is often listed in specifications?
What is the purpose of listing the power output (Wattage) from solar panel, without the energy/power specification of batteries or other electrical storage devices?
Do satellites often use the power ...
10
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2answers
215 views
How did the Mir crew recover from the power outage following collision with Progress 34?
There are several accounts about how and why the collision between Mir and Progress 34 happened and that it ended in Mir being completely dark and silent:
"'For the first time I experienced a ...
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1answer
63 views
How feasible is wind energy generation on Mars? [duplicate]
Spacecrafts and rovers tend to have dust settled on their panel which leads to reduced power generation.
If wind turbines could power the instruments, then the seasonality of solar power generation ...
3
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0answers
47 views
What are the tradeoffs of circularly unfurling solar panel over linearly deploying solar panels?
Martian landers like Phoenix and Insight uses circularly unfurling solar panels. The regular satellites make use of linearly unfurling panels.
What are the primary reasons why linear unfurling ...
4
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4answers
132 views
Radioisotope thermoelectric generator behavior on reentry
The RTG has become a major source of power in places where solar power just wont cut it. but there has always been an issue with sending them into space. if the launch fails, radiation comes raining ...
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0answers
54 views
Use or tests of multimode optical fiber for cubesat battery charging or datalink while in storage, or waiting to launch?
the idea of POF or power over fiber is to couple a moderate amount of solid state laser light, say a few hundred milliWatts or even several Watts (or potentially more, but it gets more challenging), ...
1
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1answer
63 views
power system redundancy in launch vehicles
Is the power supply system redundant in launch vehicles?
If so, how is it achieved? For example, is there redundancy at the battery pack level or converter level?
How much battery packs will there be,...
2
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1answer
107 views
How will JAXA's space elevator-testing cubesat experiment work?
The Infobae article Japón inicia hoy el ambicioso proyecto de construir un ascensor espacial which translated from Spanish into English by Google says
Japan begins today the ambitious project to ...
3
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0answers
55 views
Have inflatable solar arrays ever been used in practice?
Was trying to find some "experimental" solar panel designs, and came across a rather fascinating design idea, inflatable solar panels. I feel like something this compact would work stupendously for a ...
5
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2answers
157 views
In what ways could a US-based commercial space company legally use nuclear power?
At the moment, commercial usage of space seems to be the next big 'thing' in space exploration. Much of this (tourism, commercial launch companies, etc) will likely use solar power or fuel cell ...
4
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1answer
159 views
Generating power in zero-g
When generating electricity, energy is lost to friction in mechanical bearings (e.g. turbine or generator bearings) and as heat, through resistance in transmission wires.
If you were generating ...
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0answers
166 views
What kind of power does “…most powerful all-electric propulsion communications satellite ever produced” refer to?
The Florida Today article On second flight, SpaceX Falcon 9 rocket to launch 'brute' of a satellite from Cape describes the upcoming SpaceX launch of SES-12. Next to this tiny image of (presumably) ...
6
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1answer
302 views
Why was the ISS' DC vacuum cleaner replaced with an AC version? Are there “wall sockets” throughout the ISS where it's plugged in?
The question Why did Apollo spacecraft use both AC and DC equipment? Still used in present and future designs? and especially the answer there reminded me of something I'd seen in the YouTube video ...
3
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1answer
222 views
Cosmic rays can be new energy source [closed]
Space is filled with cosmic rays that are high-energy particles. If we could convert that energy into electric (or any other) energy, then we could use it to power a rocket anywhere in the universe. ...
6
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2answers
191 views
Using Kilopower without shielding
The KRUSTY reactor (the first actual test under the Kilopower project) is shown in this image.
As can be seen, about half of the mass is shielding. Suppose we were using the reactor on an umanned ...
0
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2answers
238 views
If we make a “Ring around the earth” in orbit - a wire ring in orbit - could we use it generate electricity?
I envision a conductive wire that is extruded out of a satellite as it completes it orbit, and then goes past it's start point a bit before stopping the extrusion. Then the satellite is sent to grab ...
4
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1answer
735 views
How does SpaceX Falcon Heavy Starman live feed transmitter work?
I'm curious to find out answers to the following questions:
Where is the antenna for the live feed transmitter of starman located in the payload?
How is the transmitter being powered?
Related to 2nd ...
5
votes
1answer
158 views
What is the distribution of ∆V amongst different stages of rocket flight?
How is rocket energy (or fuel consumption) is distributed between
gaining orbital velocity
gaining orbital height
fight aerodynamic drag
-2
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1answer
55 views
'Space Transit Habitat' source(s) of energy
What are the sources of energy for a Space Transit Habitat(manned) in terms of both propulsion( after passing over the Low Earth Orbit) and required electric facilities)through a 6-8 month voyage to ...
7
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5answers
3k views
How does a solar eclipse affect satellites?
Satellites are somewhat closer to the Moon than the Earth is (Or rather, can be), and might well have the sun blocked from them. Furthermore, they can move somewhat more than the Earth, and thus have ...
0
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1answer
188 views
heat recovery thermodynamics in space
Let me try ask it this way. How efficient is current power generation thermodynamic cycles in space? Is it even used? My info is that most spacecraft use PV solar panels, is the heat turned to energy ...
4
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1answer
4k views
What is the maximum speed an ion engine can propel a spacecraft at?
I read that with our current ion propulsion technology it is possible we could send a craft moving the maximum of 100km per second, or around 62 miles.
However we seem to be limited by how strong of a ...
17
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1answer
729 views
Why did Apollo spacecraft use both AC and DC equipment? Still used in present and future designs?
Why did the Apollo spacecraft use both DC and AC power, requiring heavy inverters? Was it impractical to design everything to run on DC power only? Why?
Are both AC and DC power still used in present ...
2
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1answer
219 views
How can satellites serve a large number of devices on earth?
Say we have a LEO satellite. There are 5000 low power devices on earth (They are in the close vicinity, can be served by same satellite) which needs to be communicated with the satellite.
Now my ...
16
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3answers
2k views
Potential high temperature power sources for a Venus lander
What power sources are viable on a 'long term' Venus lander?
An RTG relies on a temperature differential, and is not likely to be doable with a 457C 'cold side'.
Based on this answer there is not ...
4
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2answers
246 views
How to transport gigawatt-level power across a 100km distance?
I'm investigating the idea of transporting gigawatts of electrical power to the first stage booster of an electrical rocket.
The first stage booster, like Falcon 9's recoverable first stage, stages ...
11
votes
5answers
4k views
Can cosmic background be harvested for energy?
I know it would be awfully weak, but it's present even where all other power sources would be unavailable - could cosmic level radiation be used to power minimal set of systems of a probe, say, a ...
1
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1answer
528 views
What is the relation between the rocket equation and work, energy and power?
Say, I'm given the data typical to the Rocket equation in its many variants: $\Delta v, I_{sp}, m_f, m_0, ρ, T$ (thrust) and the likes. And someone asks me "What's the horsepower of the space shuttle ...
4
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2answers
389 views
Tritium as energy source for probes?
There's this ingenious little hack video: "How to make tritium nuclear battery at home".
The idea is very simple: "tritium keychain lights" - tubes with tritium and luminophor - placed between solar ...
8
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3answers
243 views
What kinds of nuclear reactors are suitable for operations in space? (Beyond thermionic and RTG)
If we want a nuclear power plant in space with a capacity similar to that of a conventional water boiling turbine nuclear power plant on Earth today, what kinds of fundamental design changes would ...
15
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1answer
1k views
Why are RTGs different colors?
This is an image of the radioisotope thermoelectric generator (RTG) for Cassini:
This one was for one left on the Moon:
And this one is for the Multi-Mission RTG, used by Curiosity on Mars:
One is ...
3
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2answers
175 views
Power requirements for solar electric interplanetary vehicle
I am interested in electric propulsion for manned interplanetary craft. There must be a lot of models for a craft able to travel to Mars, for instance. I am wondering what the power requirements seem ...
9
votes
1answer
385 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) ...
4
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2answers
218 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
128 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.
...
8
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1answer
404 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
343 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
569 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 ...
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2answers
363 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
106 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
60 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, ...
8
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3answers
794 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 (...
0
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1answer
1k 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
219 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
396 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 ...
