[Erik Boehm]

simulation11 wrote:

Here is a site for scifi writers that has some interesting information.

http://www.projectrho.com/rocket/rocket3c2.html#table

It states that we may expect a Hydrogen-Boron rocket engine to have an exhaust velocity of 980 km/sec, thrust of 61 kN and engine mass of 300 metric tons.

We expect an FF engine to have a mass closer to 3 tons, but perhaps the other numbers are in the ballpark. If so, our spacecraft will have a top speed of 980 km/sec or 0.33% of the speed of light. I think that relativistic effects will be minimal.

With a top speed such a small fraction of the speed of light, extra-solar missions will be limited to robots, sleepers or generation ships. However, it should do fine for getting around the solar system, even out to the brown dwarf, Barbarossa, thought by some amateur astronomers to be orbiting the Sun, currently at about 218 AU.

http://www.metaresearch.org/msgboard/topic.asp?TOPIC_ID=770&whichpage=33

The critical factor then is the thrust. At 61 kN, our 100-metric ton ship will have an acceleration of 61 cm/sec^2. It would hit top speed in a few weeks, but it would still take 13 months to accelerate, coast/cruise, and decelerate to Barbarossa. A larger ship, with the 2,000 ton mass of the Space Shuttle, would take 25 months for the same journey.

The brown dwarf Barbarossa is not to be confused with the asteroid of the same name. Barbarossa may be the Dark Star Marduk/Nibiru that author Andy Lloyd is looking for.

http://www.darkstar1.co.uk/solution.html

Thank u so much. It’s quite interesting info. Barbarossa, wow it is the same name with my sister. 😉

simulation rachat credit

It seems to me based on the Nomograms from that site:

http://www.projectrho.com/rocket/dvNomogram01.pdf

With Hydrogen-Boron Fusion, you could get to 1,300 km/s with a mass ratio of 4 (your ship weighs 4x as much when full of propellent, than when empty),
Now given that the speed of light is 300,000 km/s, this is 0.43% the speed of light….
Still not fast enough to colonize the galaxy in a short amount of time (23 million years to cross the galaxy?)
Ignoring acceleration time, its still too long to make it to the nearest star in one life span.

But….. if a focus fusion reactor capable of fusing hydrogen to Iron were developed, and a mass ratio of 10 were used, you could get over a third the speed of light.
Just H->He fusion max, with a mass ratio of 8 (for comparison, the saturn V was 22), could get to 0.2 C, a fifth the speed of light, you could cross the galaxy in under a million years.
Given the history of life on Earth (roughly 4,000 million years) in terms of the geologic timescale, colonizing the galaxy would take but the blink of an eye to a species that has mastered fusion.

I’m not sure how those nomograms were generated.
Especially the max values.
Any reaction could get the highest possible “exhaust velocity” by just powering a big laser…
Doesn’t use much propellant, but then what do you do with spent fuel? makes no sense to keep it, and it doesn’t make sense to jettison it/send it off at low velocity, when you dump all the energy into a huge laser.
So I suspect that those values are calculated based on the maximum amount of extractable energy per unit weight of fuel, assuming all the extracted energy is used to accelerate spent fuel as propellant.

If we can get proton boron fusion now, then in a millennia, with larger reactors, if we could get close to the maximum for H->He fusion, He could be all over the galaxy in a million years.
as a species: 1 million years to reach earth orbit, another million years to reach the other side of the galaxy.

Incidentally, the age of the earth, its lack of alien colonization, and the speeds at which fusion would allow travel, convince me that the “Rare Earth Hypothesis” is most likely valid.

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