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-2
votes
0answers
193 views

How long would it take to get to Kepler 189f? [on hold]

I just read a news story about a planet that might be Earth-like called Kepler 189f. It is 500 light years away. How long would it take to travel there in a space ship, from the travelers reference ...
1
vote
1answer
44 views

Why must spacecraft reach escape velocity to escape Earth (or any other big object)?

I think I have learned in physics that escape velocity is defined as the speed at which objects going ballistic in the opposite direction of the main gravitational force are able to finally overcome ...
4
votes
3answers
317 views

What properties would the ideal material for spacecraft construction possess?

Assuming we develop the capability to send a robot to study Gliese 518, or any of the Earth-like planets discovered in the neighbourhood; the spacecraft would need to travel through the Solar System ...
2
votes
1answer
103 views

Mars Circular Intercept Orbit

I've been trying to simulate a spacecraft entering a circular capture orbit about Mars using Mathematica, but am having a little trouble. The simulation starts when the spacecraft enters Mars' sphere ...
2
votes
2answers
147 views

Magnetic Levitation For Space Travel

At 1 G, we feel at home. At 5 G's, normal people can stay awake. At 9 G's, trained pilots with G-suits can stay awake. At 25 G's, R.I.P. Unfortunately, these numbers are limiting for space travel, ...
6
votes
3answers
100 views

Would approaching a distant star at near the speed of light unfold its entire history in “fast-forward”?

The light we detect today in our telescopes from distant stars is really old. If we could travel fast (lets say, 90% the speed of light) towards a star a million lightyears away, all the time looking ...
2
votes
3answers
687 views

Spaceships travelling through space and debris

How can a spaceship travel through space if there is space debris flying around at very high speeds? Wouldn't even a small rock crack through the spaceship?
5
votes
0answers
67 views

What is the cheapest way to land a grain of sand on the moon?

I have a payload that is the size and density of a grain of sand. I want to land it intact on the moon, but I am not particular about location beyond that. What is the least expensive way to get it ...
0
votes
0answers
532 views

Could Space Travel be achieved using a very strong magnetic field to warp space?

An Alcubierre Warp Drive could theoretically achieve faster than light space travel but requires exotic matter or negative energy to compress space in front of the spaceship and expand space behind ...
1
vote
1answer
72 views

How much power would a space craft's magnetic shield require? [closed]

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 ...
16
votes
4answers
760 views

How would we see a near-lightspeed object emitting light?

Consider an object travelling near the speed of light relative to us (let it be a spaceship or a star), which is emitting light (consider it monochromatic resulting from a two level electronic ...
0
votes
2answers
121 views

Can a wormhole be created in space?

Is wormhole a practical concept? If not what did the scientists do, to theorize it? Does it have any limitations pertaining to speed of light?
2
votes
0answers
53 views

What is the interstellar density of mm sized “dust” particles?

If you assume an interstellar spacecraft of 100 m in diameter traveling to the nearest star - that ship would plow through 3 x 10^20 m^3 of interstellar space. At 0.5 c the energy release of such a ...
2
votes
1answer
79 views

Term for “atmospheric ricochet” due to wrong “angle-of-attack”

I watched "Apollo 13" yesterday, and they had the "angle-of-attack" problem that had to be manually solved, to prevent the ship from "ricochet[ing] off the atmosphere like a rock skipping off a pond". ...
2
votes
1answer
62 views

What are the steps and energetic requirements for getting from the HST to the ISS?

There have been several general critiques of the realism some of the physics depicted in the movie "Gravity" notably regarding the the orbital mechanics of the transition from the Hubble Space ...
8
votes
1answer
236 views

Graphene as optical and UV mirrors

One usually hears about graphene as a good thermal conductor, and good light absorber due to its tunable bandgap properties. But i haven't heard about its aplicability as an optical mirror. In fact, ...
0
votes
3answers
119 views

Inertia and Rocket Propulsion

We were taught in school that the law of inertia indicates that an object tend to stay the way it is, so if you throw something in space it will tend to go on forever and ever. The reason an object ...
2
votes
1answer
386 views

How does Lunar Orbit Injection (LOI) work?

Just what the title states. I read that LOI was used by the Apollo program (and possibly others) to achieve escape velocity. How does it work? Is it merely a matter of centrifugal/centripetal force?
0
votes
1answer
71 views

What if we were to travel against the speed of our galaxy?

The Earth (and its inhabitants) is rotating and moving along with the Milkyway at approximately 600 000 m/h (not the of the Earth's rotation). Now let's say I'm in my spaceship in earth orbit watching ...
-4
votes
2answers
65 views

How many years would it take the Pioneer space probe to travel to Proxima Centauri with its current speed? [closed]

Pioneer space probe moving at a speed of $30km/s$. Assuming its heading for Proxima Centauri, which is situated at $4.2ly$ from earth, calculate how long it would take to get there in years, to the ...
7
votes
1answer
251 views

Antimatter Propulsion System

Is there a possibility ( in theory ) to build a antimatter propulsion system, if so how can we control the collision of matter-anitmatter, will humans be able to control this force just like ...
1
vote
1answer
224 views

Quantum Thrusters and Warp Drives

Any reservations about the potential of this (given in the link below/title above)? Does it seem like a helpless attempt or something which might have the potential of developing into something real? ...
1
vote
0answers
32 views

The magnitude of spacecraft anomalous velocities?

That Voyager and several other spacecraft have had anomalous changes in speed is known. According to the news reports, the differences are unsettling. But just how large are these anomalies really? ...
6
votes
5answers
4k views

Why can't a spaceship accelerate for ever? Since there is no friction in space

I have seen many answers like: because we don't have infinite energy, because of gravity, because it is impossible, because of physics. But they don't really answer my question.. I mean if there is ...
1
vote
1answer
73 views

What is most infeasible about a sky hook (as in space travel not Batman)?

We need to get things into space but it costs too much. Lots of people talk about space elevators but no one talks about the skyhook idea. I'm referring to this: Skyhook (Wikipedia), not the thing in ...
3
votes
2answers
144 views

Orbit reversal in a gravitational well

A friend recently asked me this, and without wishing to spend a huge time thinking about it, I wondered if anyone knew the answer (or at least had an informed guess), or was familiar enough with these ...
6
votes
2answers
231 views

Physics and math behind flight through solar system: Where to start?

I wrote a first program that simulates a solar system. I was able to calculate the locations for every planet on its elliptical route for any given time. In a second program i managed to simulate ...
2
votes
0answers
97 views

Can flux pinning be used for propulsion in Earth's magnetic field?

I was wondering if the following steps would result in a net displacement on a spacecraft operating in Earth's magnetic field: Turn on a superconductor Use a linear actuator to shift some mass Turn ...
0
votes
2answers
704 views

If acceleration causes relative time dilation does the eventual deceleration reverse it?

If acceleration causes relative time dilation does the eventual deceleration reverse it? For example: traveling to Alpha Centauri Based on me reading this site: ...
3
votes
5answers
3k views

If a space ship accelerated constantly, would its astronauts constantly feel the forward movement?

I know that if a space ship suddenly traveled very fast, its astronauts would be fly against the back wall, potentially getting hurt. If the space ship suddenly stopped, they would also fly against ...
0
votes
1answer
49 views

What routine tasks have to be performed on the outside of spaceships/stations? [closed]

What kind of routine tasks have to be performed on the outside of spaceships or space stations? Repairs, I presume. Anything else? Is there anything that needs to be cleaned off from the outside, ...
1
vote
0answers
68 views

Plasma Propulsion system - Maximum Velocity [closed]

What is the maximum velocity that can be achieved using plasma propulsion if we could make a propulsion system as powerful as lightning ?
6
votes
0answers
192 views

What exactly is the composition of radiation in interplanetary space?

The articles I found on radiation in the solar system mostly dealt with solar wind, I wonder about other types. Is there a breakdown that tells me, withhin an order of magnitude, at least what ...
12
votes
4answers
272 views

Why are spacecraft made to “spin” after launch?

At some point after launch, usually just before or after separation from the last booster stage, spacecraft are often made to "spin" (about the axis of their trajectory)? See e.g this You Tube video. ...
32
votes
6answers
32k views

Could someone jump from the international space station and live?

Felix Baumgartner just completed his breathtaking free-fall skydiving jump from $120,000\,\text{feet} = 39\,\text{km}$ above the Earth, breaking the speed of sound during the process. I was wondering ...
0
votes
5answers
1k views

How a spacecraft travelling near light speed avoid asteroids?

How would a spacecraft traveling near light speed avoid a (relatively dense group of) asteroids? Or suppose such spacecraft is designed, how would the physics work for steering it inside such a ...
5
votes
2answers
613 views

What is the fastest a spacecraft can get using gravity-assist?

Assuming normal spacecraft and space objects (no neutron stars, black holes, etc). To what speed can a spacecraft accelerate using gravity-assist? For example, if a spacecraft is moving at ...
-2
votes
1answer
138 views

Based on what does Hawking give 1000 years of time for humans to escape the planet earth? [closed]

I read it news that: Hawking Gives Humans 1,000 Years to Escape Earth How did he arrive at this figure? Whats gonna make human race extinct in 1,000 years?
4
votes
2answers
575 views

What kind of cooling mechanism could be used in outer space?

This question arises out of this question on Quora - Apollo 11: 1969 Moon Landing: Did Neil Armstrong really land on the moon? I'm convinced with most of the explanations provided in the first ...
1
vote
0answers
249 views

What happened in Philadelphia Experiment(1943 October 28)? [closed]

The Philadelphia Experiment was an alleged naval military experiment reported to have been carried out at the Philadelphia Naval Shipyard in Philadelphia, Pennsylvania, USA sometime around October 28, ...
4
votes
0answers
116 views

What can be the lightest possible moon launch vehicle? [closed]

I tried calculating this, but it gets too complicated. Assume, we have a Moon orbit station and ISS on Earth orbit. We have a Moon base. We want to send a tourist for a week on the Moon and back. We ...
3
votes
2answers
95 views

What is stopping us from stick building a space station?

I want to understand why we do not build space stations in a similar way that we build a home, piece by piece. Instead we construct modules on the ground and fly them up. Are there some technical ...
3
votes
1answer
135 views

What's wrong with this reactionless drive?

I think this is analogues for the Woodward effect, but macroscopic: We assume a spacecraft consisting of a broomstick, a donut and lots of gear for storing and transfering mechanical energy. Take the ...
1
vote
1answer
140 views

How do they point a camera on a space probe?

When a probe like Voyager 1 is sent into deep space they are able to point the camera at the planet and its moons and take pictures. How is the camera pointed at the object? Is the camera fixed to ...
5
votes
1answer
307 views

Finding interplanetary flight trajectory using calculus of variations?

Consider two orbits $x(t),\space y(t)$ representing the origin and destination for some spaceflight of interest. These could be, for example, cycloids describing LEO and another orbit circling, say, ...
1
vote
0answers
79 views

What is approximately critical Q for the space shuttle? [closed]

Everything is in the title, I wonder what was approximately the critical dynamic pressure the space shuttle (RIP) could handle, as I am trying to create a simple space flight simulator. I don't need a ...
23
votes
8answers
4k views

Why don't modern spacecraft use nuclear power?

The Voyager 1 & 2 spacecraft launched in 1977 with Plutonium as their source of electricity. 34 years later they claim these two spacecraft have enough power to last them until at least 2020. That ...
2
votes
2answers
299 views

What equations do I use to do basic time dilation problems?

I understand the concepts of relativity, but I don't know where to go to set up equations to do any actual calculations. For example, what equations would I use to find out the following: A ship ...
11
votes
2answers
87 views

How are interplanetary trajectories found?

How are interplanetary trajectories that involve gravity assist maneuvers found? Examples: the MESSENGER spacecraft made flybys of Earth, Venus, and Mercury before getting into orbit the Juno ...
5
votes
3answers
3k views

How do they produce air on the ISS?

How do they provide air on the ISS? I know it is produced by electrolysis but is that all they breathe, hydrogen and oxygen? The air here on Earth contains other things like nitrogen. Do the people ...