All Questions

1
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0answers
32 views

Are geostationary orbits impacted by changes to earths magnetic field?

Would geostationary satellites be pushed to different orbits by changes in the magnetic filed or even more so by shifting poles or even a reversal?
1
vote
1answer
77 views

What kind of signal Voyager 1 is sending to us?

I was reading on wiki about Voyager 1 mission and I found very interesting! One thing I did not manage to find: what is the signal Voyager 1 is sending to us? Is it simply a sinewave or something more ...
1
vote
0answers
80 views

What would be payload capacity of reusable Falcon 9 if there was no atmosphere on Earth?

Reading this question and answers, I wondered what would happen if there was no atmosphere, everything else being the same on Earth. What would be the payload capacity to LEO of Falcon 9 in reusable ...
17
votes
2answers
3k views

What are the pros and cons of Aerospike nosecones?

Some rockets, mainly (only?) ICBMs have Aerospike nosecones Why are they preferred in lieu of traditional nose cones? Illustrations: An aerospike nosecone on a trident ICBM Video including the ...
3
votes
3answers
209 views

How good is Stratolaunch vs Falcon9 as a first stage?

With the Stratolaunch flying this week I was interested in seeing how good it was compared to a Falcon9. I figured comparing energy contribution would make sense. The stats as best I can find: ...
6
votes
2answers
249 views

Do we know why communications with Beresheet and NASA were lost during the attempted landing of the Moon lander?

I was watching the livestream of the SpaceIL team when they were attempting to land Beresheet on the Moon. As near as I can remember, at around an altitude of 15km above the surface, the SpaceIL ...
1
vote
0answers
45 views

Operator access to a cube satellite or any educational satellite

I would like to have free or low-cost access to an existing CubeSat (educational satellite) for educational purposes. I wish to familiarise myself with the end to end command & control activities, ...
4
votes
2answers
76 views

Payload Specialist Training

How rigorous was training for Space Shuttle payload specialists? These astronauts were not selected from the normal astronaut pipeline, but instead were people with clout (politicians), PR ...
-4
votes
0answers
58 views

Apollo 11 Mission to the Moon [duplicate]

Where are the stars in the Apollo 11 photographs. It look unnatural without stars with a black celestial background.
5
votes
0answers
541 views

Why does the Event Horizon Telescope (EHT) not include telescopes from Africa, Asia or Australia? [migrated]

The Event Horizon Telescope seems to include these radio telescopes currently: Image by European Southern Observatory (ESO)/O. Furtak; CC-BY 4.0-licensed, see the source on Wikipedia Commons and the ...
3
votes
0answers
54 views

What is the physics behind a rocket landing on a celestial body with an atmosphere?

I would like to know the different physics concept I would need to land a rocket being in orbit. I know the timing is important to leave it, how can one find this out ? Then how to compute the ...
0
votes
1answer
123 views

What is the most promising interstellar propulsion method? [closed]

What interstellar propulsion system has the highest potential for being the safest, most efficient, and can get around to the nearest stars, within a human lifetime (say reach 20–50% the speed of ...
5
votes
1answer
134 views

Can Amateur Rocketeers use Liquid Nitrogen Dioxide as oxidizer?

I was reading similar question as mine here. But no one talked about Nitrogen Dioxide (NO2). Its boiling point is 21C. So easy to store. But how easy it is to handle compared to Hydrogen Peroxide or ...
3
votes
0answers
61 views

Are these two length scales in FH exhaust plumes real, understood, and distinct?

The Ars Technica article We can admit it—we’re dazzled by the controlled fury of the Falcon Heavy includes a beautiful photo of the exhaust plume produced by the 27 engines of a Falcon Heavy launch. ...
2
votes
1answer
166 views
+100

Delta V to get to the Sun-Earth Lagrange Point 1?

For any of these starting positions, GEO, GTO, EM-L2 or EM-L4/5, which would require the least delta-V to get to Sun-Earth L1? How much delta-V would it require? Would this chart help in identifying ...
2
votes
0answers
53 views

LOX as annular heat sink

I'm thinking of my time spent working with cryostats. Liquid helium pot on the inside, and surrounded by a liquid nitrogen jacket. And the whole thing insulated with vacuum and superinsulation. (...
2
votes
0answers
37 views

How large of a mirror would be needed to warm Titan up?

How large of a mirror would be needed to warm Titan up to ~290K? Paul Birch in his paper "Terroforming Mars Quickly" calculated a mirror size of: Support Mirror: 2.5 x 10^7m radius 3x 105m wide ...
3
votes
3answers
234 views

Why SpaceX have the T+0 second in the countdown while the Space Shuttle 'skip' the T+0 second?

Does the space shuttle countdown skip the first second after launch (T+0) and if yes why? You can see this effect in videos like this one: In comparison with an ...
-2
votes
1answer
122 views

How would molten or liquid metal be transported in open space? [closed]

How to transport a ball of liquid, molten metal nearest to the Sun possible? It must be close to the Sun for the metal to stay molten. However, to stay safely cool enough, the spacecraft must always ...
1
vote
2answers
178 views

What is the shielding capability of liquid metal compaired to solid metal?

For simplicity, consider a spherical metal shape for shielding materials (people) inside. A problem I see is that it is going to be hard to forge a sphere of metal big enough like that and it is ...
13
votes
2answers
597 views

Can the Right Ascension and Argument of Perigee of a spacecraft's orbit keep varying by themselves with time?

I came across the orbital data for a low Earth orbit spacecraft and one thing which I am not able to understand is why does its Right Ascension of ascending node and Argument of Perigee keep changing ...
21
votes
1answer
5k views

ELI5: Why do they say that Israel would have been the fourth country to land a spacecraft on the Moon and why do they call it low cost?

In the news they say that Israel hoped to become the fourth country to land a spacecraft on the Moon. Only government space agencies from the former Soviet Union, the US and China have made ...
8
votes
1answer
164 views

What is known about these early Falcon XX concepts?

I came across this page with the following picture from 2010: I must say the Falcon X, Falcon X heavy and Falcon XX look rather interesting. Does anybody know of resources that explain the intended ...
7
votes
1answer
197 views

What would the damage radius be if a Falcon 9 booster impacted the Earth without a landing burn?

Apologies in advance if this is the wrong stack exchange for the question, but I figured it would fit here; if not let me know and I'll delete/move it. I'm trying to figure out what the damage radius ...
-2
votes
1answer
128 views

NASA Apollo 11 fuel used to land on the moon [duplicate]

To land on the surface of the moon required the lander to descent onto the lunar surface. How much rocket fuel was used to descend to the surface of the moon?
4
votes
0answers
44 views

How many laptops onboard ISS?

About how many laptops are there on board the ISS? I saw the header image in this article: https://www.nytimes.com/2019/04/11/science/scott-mark-kelly-twins-space-nasa.html?partner=rss&emc=rss and ...
7
votes
1answer
229 views

Are turbopumps lubricated?

It is easy to find data about rocket engine propellant, but quite difficult to find information about other fluids used in rocket engine. For engine using a turbopump, this pump turns at quite high ...
1
vote
0answers
34 views

Was any data actually transmitted between OSCD and ISARA in the recent CubeSat lasercom test?

Two CubeSats (the OCSD and ISARA CubeSats) recently demonstrated technology for on-orbit sat-sat laser communications. All the information I have been able to find doesn't indicate if the test ...
1
vote
0answers
39 views

What is the estimate price for small ion thrusters on cubesats?

I can't find much about price for ion thruster and I read from somewhere that most ion thruster are off the rack product. I just need the rough estimate price for a small ion thruster and the closest ...
2
votes
1answer
146 views

Would it be practical to add side payloads on top of Falcon Heavy's side boosters?

Those side payloads / side fairings, would be strapped on central core second stage, on top of side boosters. The idea is to increase payload volume without (that much) changing drag during the lift ...
2
votes
1answer
105 views

Titan crude oil equivalent in Gbbl?

Despite the cost, what is the crude oil that is hydrocarbons energy equivalent which Titan could provide as referred to crude oil Gbbl compared to Earth? (Joules as common denominator) Here is what ...
0
votes
0answers
17 views

Relation between beamwidths of E-plane and H-plane

Is there any relation between E-plane and H-plane beamwidths of an antenna when steering in azimuth and elevation directions?
2
votes
0answers
205 views

What part of the EM spectrum was used in the black hole image? [migrated]

The EHT has published the first image of a black hole. It is the event horizon of the singularity in M87 against its accretion disk. I've been through the reports in the popular press but none ...
0
votes
1answer
282 views

Apollo 11 space mission Lunar Orbit Insertion

I'm doing a basic analysis of the trip to the Moon. I've estimated the speed as follows: ...
0
votes
2answers
188 views

If Starman (Roadster) had a “Starman Cam” could it see Mars? (as more than just a dot)

Our own Ben Pearson's new article in Ars Technica Starman is out there, but we probably won’t see him again until 2047 points out: A much closer pass will happen at Mars on April 22, 2035. The ...
1
vote
0answers
135 views

SpaceX Falcon 9 Heavy Launch 4/11/19

Will it be possible to see the launch from the Dominican Republic as to goes into space? Staying there the next few days/nights. What is the track out of Cape Canaveral?
1
vote
1answer
37 views

Data Rates and Radios with Satellites [closed]

I am new to using radios and was wondering why do data rates matter when you use a radio to pull info from somewhere else. Also what does it mean when a satellite sends a wide band signal. Thank you ...
0
votes
0answers
15 views

Same philosophy of astronomers of 1st image of black hole as paleontologists on Jurassic World? [migrated]

The historical first image of a black hole is captured from eight different telescopes, where each saw the hole through its own prism. Then, scientists took these data and combined them to make the ...
4
votes
1answer
159 views

What set of units does the Orion capsule cockpit instrumention use?

Shuttle was English, ISS is metric. What's Orion? For example: What units are inertial velocity displayed in?
-2
votes
0answers
79 views

How does mass exchange affect the mutual orbit of two bodies?

If a pair of bodies orbit around their center of mass, and then mass is removed from one of them and transferred to the other, this will change their orbits. Total mass is conserved, but the ...
5
votes
1answer
98 views

Going to the Lunar gateway during the upcoming solar maximum! What will the radiation environment be like?

EarthSky.org's What will the sun do next? says: On December 6, 2018, the Center of Excellence in Space Sciences India (CESSI) reported that two of its scientists have made a prediction for the ...
11
votes
1answer
216 views

How much does it cost to train an astronaut?

What are the total costs to train an astronaut from selection until they are ready to go to space? How much time does it take? And is it possible to break down the costs by category (salary, training, ...
1
vote
2answers
183 views

Could an Igloo work on Mars?

Could ice make a good habitat like an igloo for colonists or as cold storage for fuel? Could the cavern be sealed and then carbon dioxide melted to create pressure inside the cavern to grow plants or ...
1
vote
0answers
49 views

How does temperature affect a solar sail?

Is there an ideal temperature which solar sail material operates at? Does a colder reflective surface create more thrust? Related: How will JWST manage solar pressure effects to maintain attitude and ...
4
votes
1answer
111 views

What is a mixture ratio of propellant?

I am a little confused, is the mixture ratio of a propellant Fuel/Oxidizer or Oxidizer to Fuel ratio?
1
vote
0answers
48 views

What have been the most common causes of mishaps or failures with various cubesat mechanisms & components?

I am keen to know more about common CubeSat mechanisms & components (antenna / solar array deployments / thruster / momentum wheel / robotic arm problems) that have worked well in the past and ...
2
votes
1answer
68 views

What would be the performances of chlorine trifluoride as an oxydizer?

Inspired by this comment Assume that a particularly deranged moustache-twirling villain with way more time and resources than is reasonable decides to build a satellite-launching rocket using ...
1
vote
1answer
78 views

What are the top most used satellite control system, flight dynamics solution at the moment ? Approx costs?

I am looking for a list of top most used satellite control systems, flight dynamics solutions by space agencies, private companies etc. the moment? How much do they cost approx for use by 1 person? Is ...
1
vote
0answers
30 views

what are various best practices/processes associated with orbit change manoeuvres of LEO / GEO satellites?

Suppose a satellite was supposed to burn X% fuel reduce Y% mass to gain delta V and change to different orbit in time t. But something is faulty with its propulsion system so it's burning more fuel to ...
12
votes
1answer
1k views

How was Skylab's orbit inclination chosen?

As referenced in this question, there were a number of early spaceflight missions at higher inclination than may be expected (given limited payload capability, higher inclination further limits ...

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