All Questions
18,268
questions
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How to select the right magnetic torquers to desaturate a wheel?
I want to select actuators for a micro-satellite (around 40 kg) orbiting in LEO.
I proceeded in calculating the maximum disturbance torques that affect my spacecraft and selecting proper reaction ...
2
votes
0
answers
87
views
Would the steel frame/skin of Starship be able to endure loss of a heat shield tile during reentry?
STS-27 was able survive reentry without a tile because the was over a metal component with sufficient thermal inertia to serve as a heat sink without melting.
Would the steel frame of Starship be able ...
- 10.5k
17
votes
1
answer
2k
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How did STS-27 survive reentry after losing a thermal tile?
My buddies and I have been arguing about this for a while, speculating about the upcoming Starship test.
STS-27 suffered damage on ascent that knocked off a tile & damaged hundreds more. It only ...
- 10.5k
1
vote
1
answer
136
views
Initial trajectory of Ariane carrying JUICE
Why did Ariane carrying JUICE spacecraft on 14th April 2023, after its initial vertical ascent, flow practically parallel to Eath's surface for some time, before finally departing vertically into deep ...
- 13
2
votes
1
answer
189
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Is Electromagnetic Propulsion Like Radiation Pressure propulsion?
while browsing for new propulsion methods I found the following interesting:
https://en.wikipedia.org/wiki/Radiation_pressure
"Radiation pressure (also known as light pressure) is the mechanical ...
- 41
2
votes
1
answer
140
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Why are some satellite solar arrays arranged in a zig-zag pattern
Some of the solar panel arrays I've seen on satellites are arranged in this weird zig-zag pattern.
Even when they're fully deployed they still have this arrangement. Why? What's the benefit from doing ...
- 133
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votes
0
answers
58
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If we make a Mars or moon station, how would the carbon and water cycle work if the Earth was destroyed? [duplicate]
If it costs 50k to fly 1 pound to space, how much would the machine cost? I'm a 7th grader and I need help on my project. How would the carbon and water cycle machines work? This is hypothetical.
user51001
22
votes
3
answers
4k
views
Why are tunnels not popular considerations for Lunar or Mars colonies?
In many modern movies, books, articles, blogs, renders etc which talk about colonies on Mars or the Moon, I often see things like habitation modules or 3D/SDL printed regolith structures and similar ...
- 343
1
vote
0
answers
29
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Who offers Conjunction Data Messages (CDM)
I know space-track and LeoLabs offers Conjunction Data Messages. Are there other commercial or open-source offerings? How accurate are CDMs if you only used TLEs which do not include covariance.
- 321
5
votes
1
answer
112
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Why does the quality of New Horizon LORRI images vary so much?
I was looking on OPUS for New Horizons images from the Arrowkoth approach, and was surprised at the differences between back-to-back images taken with the same duration exposure. I'd expect them to be ...
- 327
1
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0
answers
34
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How to compute light time correction for eclipse entry/exit timings?
I used a typical geosynchronous orbital parameters and generated lunar shadow penumbra entry and exit timings using OREKIT and GMAT. GMAT has an option to include light-time correction (also for ...
0
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0
answers
94
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Understanding the difference between pointing knowledge, pointing accuracy and pointing stability?
In terms of specifications for satellite Attitude Determination And Control System (ADCS) hardware, my understanding is that pointing knowledge is for attitude determination, whereas pointing accuracy ...
- 41
9
votes
4
answers
4k
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Why don't SpaceX boosters belly flop?
The first F9 booster landing attempts failed because the booster broke up. After that, they began lighting the engines in the upper atmosphere to slow the booster.
It seems to me that their problem ...
- 2,553
3
votes
1
answer
82
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Aerostats in the outer solar system
Having read a lot lately about some preliminary studies of aerostat options on Venus and Earth (Semirigid gas bags filled with N2/O2 to allow for a dual breathable/lifting gas - sorry no source on ...
0
votes
2
answers
300
views
How can Starship belly flop with a full payload?
Starship had an empty weight of under 100 tons. Of this, less than 12 tons is accounted for by the engines. Starship is supposed to be able to make atmospheric entry with a 150 ton payload in the nose....
- 2,553
1
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0
answers
112
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Is it planned to have the NASA astronauts from the Artemis 2 mission fly again to the moon?
Just recently, NASA announced the astronauts who will fly to the moon (Which is pretty AMESOME!).
Is it planned to fly them on another Artemis mission or are the Artemis astronauts only flying once ...
- 4,272
2
votes
0
answers
95
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Do smaller engines have a higher thrust to weight ratio?
For a given chamber pressure and shape,
thrust is proportional to nozzle area, which is proportional to the square of dimensions
mass is proportional to the volume, which is proportional to the cube ...
- 2,553
5
votes
1
answer
2k
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Are there any studies about "ping pong" cyclers between gas giants?
Imagine arriving at Saturn, jettisoning your passenger cargo, and then utilizing the massive gravitational pull of the gas giant to slingshot back towards Jupiter.
Due to the immense mass of these ...
- 317
-1
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1
answer
370
views
What would be the least expensive technological solution (considering all costs) to put on Lagrange Point 1 to affect global warming?
For example, I did read about an exploding asteroid at Lagrange Point 1 to block some of the Sun's light. Just two degrees change in Earth's overall temperature can trigger an Ice Ages.
2
votes
1
answer
71
views
International treaties and national laws on management of space trash
For the worldbuilding of a story I'm currently writing, I am considering drafting a UN treaty on managing space trash (meaning derelict spacecraft and debris of such). So I have a few questions.
First,...
1
vote
0
answers
114
views
How close are we to a space elevator, materially? [duplicate]
Under the most advanced design of the SE, what are the values of the (tensile) strength and other qualities of the materials needed? What are those of the best materials we have in our hands now?
- 139
3
votes
1
answer
166
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How easy would it be for an interstellar probe to identify planets in another star system?
Would sending an interstellar probe be the only way to completely map another star system or would it be eventually possible to map it from Earth, beyond any reasonable doubt?
If a probe is necessary, ...
- 131
3
votes
1
answer
276
views
Calculating and Drawing the orbit of a body in a 2D gravity simulation in python
I'm making a space exploration game and its in a 2d plane so no z axis, and I'm using Newton's law of universal gravity, I would really like to calculate anddraw the predicted trajectory of a body, ...
- 31
5
votes
0
answers
79
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Orion ESM jettison imagery
The Orion, among others, had a camera inside the CMA (Crew Module Adapter) looking up at the heat shield to image the separation of the ESM (European Service Module). Has any footage or imagery from ...
- 910
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1
answer
177
views
Deep Space Optical Communications (DSOC) - from what distance could a flashlight be detected by a space-based telescope
Flight laser transmitter - for Psyche mission has Mass 29 kg (100 W).
It also requires pointing up to 3 degrees of the Sun (towards the receiver telescope).
My question is about really small probes (...
2
votes
1
answer
232
views
Calculate position of planet on fictitious orbit each day
I'm a software developer but my degree with in mathematics. I'm trying to develop a game/simulation of a fictitious randomly generated solar system, and trying to work out how to model and calculate ...
- 23
4
votes
1
answer
217
views
How bright would Earthlight be from the surface of the Moon? Can you read under the light of the Earth?
In the lunar sky, the Earth would certainly outshine the Moon from its place in the sky of Earth. However, I can find very little about what it would actually be like.
I am wondering about the size of ...
- 201
5
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3
answers
314
views
What is the reason for a LACE rocket to dump fuel?
The concept of LACE sounds awesome, especially the part "fuel is hard to come by in the atmosphere but there's some oxidizer available".
The inefficiency due to the heat exchange ...
- 365
2
votes
0
answers
79
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6U , 12U Deployer / Dispenser, helpful criteria we might use for selection?
as a member of a group of students that builds 6U and 12U Cubesats for different projects I am interested in knowing the average cost of a 6U and a 12U deployer.
Also, beyond cost, what are some other ...
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8
votes
1
answer
734
views
Rocket Turbopump Energy Balance
The exhaust velocity of a rocket is given by:
$v_e = \sqrt{\frac{2k}{k-1} \cdot R \cdot T_c \cdot (1-(P_e/P_c))^{\frac{k-1}{k}}}$
The velocity tends to a finite asymptote as $P_c$ increases. Therefore,...
2
votes
0
answers
102
views
Do rocket exhausts produce an electromagnetic signature?
Rocket exhaust contains ions, the composition of which varies depending on temperature and fuel. https://arc.aiaa.org/doi/10.2514/3.27825 and https://www.eucass.eu/doi/EUCASS2017-434.pdf
Figure 12 : ...
- 15.3k
7
votes
1
answer
250
views
What would Venus look like without acid clouds?
Despite its unpleasant surface conditions, Venus is undoubtedly one of the most beautiful worlds in the solar system when viewed from space. It’s huge clouds of sulphuric acid make the planet ...
- 71
27
votes
2
answers
5k
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How much technical information is given to astronauts on a spaceflight? How much of it is left to the control center?
In many space exploration movies, we see that the control center, most notably the Mission Control Center has a team of engineers and scientists communicating with the astronauts regarding a variety ...
- 425
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1
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1k
views
Data on satellites and/or space junk
I am hoping to develop a program capable of predicting when a satellite will fly through the path of a telescope observation. The aim is to make it possible to block or mitigate the light from the ...
- 489
2
votes
1
answer
174
views
Can rocket engines produce high voltages?
I was reading Michael Collins' account of the Apollo 11 TLI burn [1], and I wonder wheter the "flashes", "lightning", "sparks flying" and "insistent fireflies" ...
- 191
2
votes
0
answers
54
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Data of chemical element ambundance on celestial objects?
For worldbuilding purposes, I'm trying to find data on chemical element abundance on different celestial bodies, and I'm interested in numbers or percentages by mass. I have found something about ...
0
votes
0
answers
88
views
Why Aren't they Building Cosmodromes on Mountains? [duplicate]
Why Aren't they Building Cosmodromes on Mountains? Constructing a road leading 10000 feet or more up-hill should potentially save a lot of fuel.
- 370
3
votes
1
answer
146
views
TEME state vector to TLE orbital elements
I was looking at time series of some TLE parameter(semimajor axis, inclination, etc..) and I wanted to how those parameters evolve between measured time points.
So i decided to feed TLE element to ...
6
votes
0
answers
178
views
Why was the ExoMars Rover to use such as complex parachute system?
American Mars landers use a single, supersonic main parachute. The European/ Russian ExoMars rover was to use a much more complex 4 parachute system consisting of a drogue, a main and a pilot for each ...
- 910
18
votes
1
answer
3k
views
How did NASA avoid a repeat of the Mars Polar Lander failure?
One of the most likely causes of the MPL (Mars Polar Lander) crash landing on Mars was the deployment of the legs being mistaken by the onboard computer as touchdown. Phoenix (and later InSight) ...
- 910
2
votes
0
answers
71
views
GEO station keeping in GMAT
I am currently trying to implement station keeping maneuvers for a geosynchronous satellite in orbit around Earth using the General Mission Analysis Tool (GMAT) but I am not managing.
I know there are ...
- 21
5
votes
2
answers
131
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Insights into the Mylar heat welding technique used to weld the Echo II balloon seams?
I am working on a 50-micron BO-PET film (basically Mylar) which will need welding. I don't know if I'll be able to obtain an ultrasonic/HF welding machine and since the project will need extensive low-...
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10
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2
answers
4k
views
What causes a satellite's orbit to decay?
Why do orbits of satellites orbiting at sufficient speed, far beyond the Earth's atmosphere, decay if there is no atmospheric drag? What drag is applied on the satellites at that altitude?
- 3,758
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2
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390
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Given the current state of technology, what would make bullet-sized interplanetary spacecraft technically impossible?
[Image: original source https://www.quora.com/How-many-types-of-bullets-do-we-have]
For example, if a spacecraft does not need a control module, propulsion or means of communication. All it is tasked ...
0
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0
answers
68
views
Inserting optical elements into a ring laser gyroscope to sense all three axes
Ring laser gyroscopes (RLGs) leverage the physics of ring laser interferometers and the Sagnac effect to sense rotation in a single plane. My understanding of RLGs is that they are independent systems ...
- 501
23
votes
3
answers
8k
views
Why aren't the radiators on the ISS straight?
The radiators look like a highly stretched paper accordion. Is it just because of how they decomposed, or is there a deeper reason?
- 841
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votes
1
answer
756
views
What is a Mars 5-sol orbit? [closed]
I need to calculate the delta-v for descent from 5-sol orbit to the surface of Mars and then ascent back to 5-sol orbit from the surface of Mars. What is a "5-sol orbit?"
0
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1
answer
136
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Did Relativity's Terran 1 booster survive the fall to the ocean for recovery?
There is no plan to recover the booster of the Terran 1 rocket launched yesterday. Did the booster survive (not necessarily intact) the fall to the ocean and the impact with the surface of the water? ...
- 849
4
votes
1
answer
122
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How much ice is there in the inner asteroid belt?
After asking this question (How long would it take before we use up all the ice in the asteroid belt?)I did some research to find out how much ice there is in the inner asteroid belt (Not the Kuiper ...
- 4,272
0
votes
0
answers
109
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Why did the May 2016 Falcon 9 launch have a radar glitch?
Looking at a chronicle of booster landing failures, in May 2016 the landing legs appear to have had a radar glitch. This then damaged them. So, my question is why did this happen?
