84
votes
Accepted
Can Voyager 1 reach the Andromeda Galaxy?
Technically, yes
While Voyager 1 lacks the velocity necessary to escape the Milky Way galaxy, it doesn't actually need to. Because the Milky Way galaxy itself will collide and begin to merge with the ...
- 896
83
votes
Time at 1 g acceleration to travel 100 000 light years
Nonrelativistic solution
The variables used will be
$x$ for the distance travelled
$v$ for velocity
$a$ for acceleration ($1~\mathrm{g}$)
$t$ for the time
$c$ for the speed of light.
Non braking
...
- 3,566
76
votes
Can Voyager 1 reach the Andromeda Galaxy?
no.
Voyager 1 is currently orbiting the center of the Milky Way, which has an escape velocity of $550 \ \text{km}\ \text{s}^{-1}$ at the Sun's position, while the Sun orbits at $\sim 220 \ \text{km}\ \...
- 3,095
39
votes
Accepted
Speed to maneuver with flaps and ailerons in interstellar dust
It is not only how fast the airfoil has to travel, but also how large the airfoil must be to even have fluid-dynamics-like behavior. Because of the low density of particles in the interstellar medium, ...
- 1,950
38
votes
Accepted
Do things get dirty in space?
Spooky
This one is subjective. To some, just finding an abandoned spaceship would be spooky. I'll say there's probably not a lot that has to happen to evoke this feeling.
Rusted
Actually, unless ...
- 23.8k
32
votes
Accepted
Interstellar Travel Thought Experiment
Does this logic make sense? Has anyone thought of this before?
Yes, it's been considered. In the literature it's known as the "incentive trap".
There are a couple of academic papers on it, ...
- 167k
30
votes
Accepted
How feasible would this mission to Proxima Centauri be?
Unless I am mistaken, the amount of speed a gravitational slingshot can add is less than twice the orbital speed of the planet being used. Mercury's orbital speed is the fastest, at a little over 47 ...
- 10.3k
28
votes
Accepted
What processes create an object with an interstellar velocity?
The answer to 'how can it come blazing in with enough energy to exit again' is that if it started outside the solar system it would have been unusual for it to NOT leave again, since it would have ...
- 21.4k
25
votes
Accepted
Why didn't the Pioneer probes maintain communications with Earth as long as the Voyagers have?
Why the Pioneers didn't last as long:
The Pioneers were a low-budget mission just to test if flying to the outer planets was feasible
They used a smaller radio transmitter (8 W vs. 23 W) and antenna ...
- 126k
24
votes
Collecting antimatter from Van Allen radiation belts
The total antimatter in the van Allen belts is estimated to be 160 nanograms. Annihilating that with matter would produce a whopping 8 kW-hr of energy. A quarter of a gallon of gasoline has that much ...
- 58.5k
24
votes
Accepted
What is the most fuel efficient way out of the Solar System?
The most fuel efficient way to leave the solar system at present, is to launch into a trajectory that (like that used for Gallileo) may well involve one or several gravity assists from Earth or Venus, ...
- 19.4k
23
votes
Accepted
Overcoming the speed of light thanks to ion thrusters
The expression $v_e = \sqrt{\frac{2Vq}{m}}$ is a non-relativistic approximation. This is quite valid when the exhaust velocity is small compared to the speed of light, which is the case for ion ...
- 73.2k
19
votes
Accepted
What limits the speed at which rocket fuel is expelled?
The core of your question is about real, "normal" engine exhaust velocities. The fastest we get so far from practical, in-production engines is about 4,440 m/s, Space Shuttle main engines with liquid ...
- 18.2k
18
votes
Accepted
Where is Voyager 1 now (2021)?
Voyager 1 and 2 are still in the "neighborhood" of our solar system and very close to our Sun compared to any other star. They are roughly three times farther from the Sun than Neptune and ...
- 148k
16
votes
How much light is there on the way from Earth to Proxima Centauri?
No, the power collected by solar panels is reduced by the square of the distance from the light source.
At the Earth's distance from the sun, the energy of sunlight is about 1300 watts per square ...
- 167k
15
votes
Travel Speed in Space
Currently functional and proven technology is limited to basically no interstellar travel at all. To reach one of our stellar neighbors (like Proxima Centauri), one of the fastest space probes we have ...
- 18.1k
14
votes
Is it pure luck that the voyager 1 survived to travel beyond our solar system in interstellar space?
It can't be pure luck, seeing as how both Voyager spacecraft are still operating today. If it were just one, you might chalk it up to luck. Both still working means they must have been built really ...
- 58.5k
14
votes
Can we speed up spacecraft to suitable interstellar travel speed using oscillating gravity assists on planets on opposite sides of the solar system?
Accumulating 0.1c (30000 km/s) with gravity turns alone within the bounds of Solar system isn't possible. Reason is: system escape velocity (sometimes referred to as third cosmic velocity) is about ...
- 387
14
votes
How long could it take us to reach Alpha Centauri with current technology?
Current technology can't get us anywhere close to the speed of light (c); the Voyager probes are moving at something on the order of 1/17500 c. At speeds like that, it's about 75,000 years to Alpha ...
- 167k
13
votes
Cyclotron engines as a means of thrust for interplanetary travel?
A cyclotron is a type of Ion engine. Cyclotrons (in the classical sense of the word) haven't been used because they have a very low power-to-weight ratio (tons of magnet to accelerate tiny amounts of ...
- 126k
13
votes
Accepted
How might Earth's location be referenced in stellar terms?
Like the lower left part of the image below.
Define a set of pulsars through describing proportions between their frequencies. Define distances from each of them. This uniquely identifies a point in ...
- 54.9k
13
votes
What limits the speed at which rocket fuel is expelled?
The nozzle is the part of a rocket that limits the speed of the exhaust velocity. (It's also the part that converts the pressure and temperature of the expanding propellant into velocity.)
The speed ...
- 10.1k
13
votes
If a spacecraft travels at 10% c will it be destroyed by interstellar dust and particles?
Based on this answer:
$$E \approx \frac{1}{2} m v^2 = \frac{1}{2} m c^2 \left(\frac{v}{c}\right)^2$$
The mass of a proton $m_P c^2$ is about 938 MeV, so if an innocent atom of hydrogen or bare proton ...
- 148k
12
votes
Accepted
Interplanetary space debris
Space is in general an empty place, and debris is only a problem in Earth orbit. Even there, the amount of debris is only considerable in popular orbits like GEO. The reason is in part that there have ...
12
votes
If the Alcubierre Warp Drive was used to travel to Alpha Centauri, how much time would pass on Earth?
The Alcubierre bubble could get to Alpha Centauri in less than 4 years according to outside observers, not just observers riding inside the bubble--the exact time depends on the exact 'shape' of the ...
- 221
12
votes
Are we actually that close to techniques of accelerating probes to speeds like a quarter $c$?
Given that the interstellar medium (ISM) has a density of about 1 atom per cubic centimeter and given that laser propulsion could, in theory, accelerate a spacecraft to 30% of the speed of light in ...
- 23.8k
12
votes
Accepted
Which spacecraft will be the first for which the Sun would become the second brightest object in the sky?
As a reference, part of this question I answered at Astronomy.SE. The closest point at which the Sun would not be the brightest object in the sky is if we headed directly towards Sirius A, at a ...
- 121k
12
votes
Could a Falcon Heavy assembly or something similar be useful for deep space missions?
A Falcon Heavy on the launch pad masses about 1400 tons. Its payload to low orbit is about 64 tons (fully expendable) (both figures from wikipedia). So it would take, not 2, but about 22 Falcon Heavy'...
- 19.4k
12
votes
What processes create an object with an interstellar velocity?
This is a very generic answer: A gravitationally bound system has a tendency to become more compact. As this happens, the gravitational potential energy becomes more negative. The energy that is lost ...
- 3,844
11
votes
Accepted
Can we not get outside the Local Galactic group?
Your math is fine, but the speed of the fastest probe we have now is no indication of what is possible. 238 km/s is less than a thousandth of the speed of light.
Laser- or maser-powered light sails ...
- 21.3k
Only top scored, non community-wiki answers of a minimum length are eligible