# More on milli G acceleration and space travel:

sonhouse
Science 02 Aug '09 17:42
1. sonhouse
Fast and Curious
02 Aug '09 17:429 edits
I did the math a bit more, space trips at 3 Milli G's (0.096 Feet/second squared or 0.294 Meters/second squared):

For a 50 million mile trip (80 million kilometers) (typical Mars journey) takes 38.38 days for an average velocity of 15.07 Miles per second, 24.11 Kilometers per second and peak velocity of 30.1 miles per second, 48.1 kilometers per second.

For a 500 million mile trip (Around Jupiter distance), takes 85 days for an average velocity of 68 miles per second, 109 Kilometers per second and peak velocity of 136 miles per second, 217 kilometers per second.

For a 5000 million mile trip or 8000 million Kilometers (Around Pluto) takes 271 days for an average velocity of 213 miles per second, 340 Kilometers per second and a peak velocity of 426 miles per second, 680 kilometers per second.

For a 10,000 million mile trip or 16,000 million Kilometers (the furthest so far discovered minor planet Eris, about 3000 Kilometers in diameter)
takes 383 days for an average velocity of 301 Miles per second, 482 Kilometers per second and peak velocity of 601 miles per second, 964 Kilometers per second.

For a 100 billion mile trip, 160 billion Kilometers (the distance to the first usable solar foci) takes 3.3 years for for an average velocity of 953 miles per second, 1525 kilometers per second and peak velocity of 1906 miles per second, 3051 kilometers per second.

For a 4.3 light year trip, (Alpha Centauri) takes 52.4 year for an average velocity of 15,058 miles per second, 24,093 kilometers per second and peak velocity of 30,116 miles per second or 48,187 kilometers per second. That represents a peak velocity of 0.16 C! and average velocity of 0.08 C!

Those are pretty impressive figures for a constant acceleration of 3 milli G's, eh! I wonder if you could even feel that?
My problem I posed BTW, how long would it take to get from the front of a spacecraft to the back which is 10 meters away at 3 milliG's, is about 25 seconds!

For comparison, a trip to Mars now in present day spacecraft takes about 6 months, for an average and peak velocity of about 3.2 miles per second, 5.1 Kilometers per second.
2. 03 Aug '09 03:321 edit
Originally posted by sonhouse
I did the math a bit more, space trips at 3 Milli G's (0.096 Feet/second squared or 0.294 Meters/second squared):

For a 50 million mile trip (80 million kilometers) (typical Mars journey) takes 38.38 days for an average velocity of 15.07 Miles per second, 24.11 Kilometers per second and peak velocity of 30.1 miles per second, 48.1 kilometers per second.
, for an average and peak velocity of about 3.2 miles per second, 5.1 Kilometers per second.
I would guess that even with milli g acceleration, it would take a tremendous amount of energy to maintain a low acceleration of 3 milli g's once the velocity was getting up there. Would nuclear power be enough to go 1906 miles per second accelerating at 3 milli g's?Also I wonder if the space ship hit a rice sized piece of space debris if it would be like a howitzer round going off inside, or if it would just zip right through punching holes in the life support systems?
3. 03 Aug '09 06:17
Originally posted by sonhouse
For a 4.3 light year trip, (Alpha Centauri) takes 52.4 year for an average velocity of 15,058 miles per second, 24,093 kilometers per second and peak velocity of 30,116 miles per second or 48,187 kilometers per second. That represents a peak velocity of 0.16 C! and average velocity of 0.08 C!
I am curious. What time period would be needed if we chose not to slow down at the far end but let our spacecraft accelerate all the way to Alpha Centauri.

Could we use Alpha Centauri as a slingshot to get us to the next star we wish to visit?

I assume that nuclear power is the only real option for sustained acceleration in interstellar space, so what amount of mass of nuclear fuel would need to be expended to keep up that acceleration for the 52 years?
4. sonhouse
Fast and Curious
04 Aug '09 20:37