Toward the Grandest Horizon
James Benford and Gregory Benford
Starship Century is a ground‐breaking anthology of science and science fiction based on findings and discussions of the 100‐Year Starship Symposium held in 2011. The anthology includes non‐fiction and science fiction.
It contains fascinating facts and stories about travel to the stars. Turns out we can easily build starships that can travel to the stars in the next century. And it was facinating that the biggest problem to get humans to the stars is the ability to build a self sustaining eco-system. We’re not even close to that. We need to practice a lot on space stations, the Moon and Mars.
Just imagine that we don’t know about an essential fungus or bacteria that is a basis for all life. It’s everywhere and nothing goes wrong with it but after sometime on a starship bio life begins to deteriorate since the lack of the essence is only manifest after years of slow degradation.
Another fascinating essay in the book compares the wealth in the world to the cost of explorations throughout history. We are well on the way to a very wealthy world now believe it or not but it will take some time for the world wealth to reach the required amount to fund starship travel.
Read the book for the ideas and comments.
Check out their website too.
Starship Century | Toward the Grandest Horizon
There is a common misperception that if you get rocket up high enough, say several hundred miles above the ground, there will be no gravity to pull it back down to the earth, and the rocket will be able to maneuver around. This is akin to the captain in the science fiction spaceship calling for an all halt. In space, there is no all stop. This is because, if you are not moving in relation to the planet you are near, you are being pulled down to it by its force of gravity. Even the moon at 240,000 miles from the earth experiences the pull of gravity from the earth. That pull of earths gravity is what keeps the moon from sailing off to orbit the sun.
You can imagine that at a mere 300 miles or less, a space station would be not even ten percent farther away from the center of the earth than someone standing on the ground. In fact, the force of gravity diminishes with the square of the distance. This means that in an orbit of 300 miles from the earth, the force of gravity is about 86 percent of the force of gravity on the earth. Thats still quite a pull on a space station.
The ISS ranges from 205 to 270 miles above the earth. In order to keep gravity from pulling it down, it maintains a velocity in a direction perpendicular to a line from the station to the center of the earth. According to the NASA website (www.nasa.gov), the ISS speeds around the earth once every 90 minutes. If the earth is about 25,000 miles around, at 270 miles up, the length of the orbit is approximately 27,000 miles.
This means the ISS is traveling about 18,000 miles per hour along the path of its orbit. It must travel this fast just to keep from falling back to earth. If it were to slow down, its orbit would decay. It would travel lower and lower until finally, the drag on the station from the thicker air would slow it quickly, and it would probably burn up on re-entry. Whether it would leave debris on the surface of the earth depends upon the density of the station, the metal material, and how much air drag, also called air resistance, slows it down.
When Skylabs orbit decayed in 1979, the station did not burn up completely in descent. Parts of the station landed in Australia. Such is the power of gravity and air resistance.
The L5 point(EML5) is the best location for a space colony
in the Earth-Moon System.
We advocate participation in the engineering details to create that colony.
The Sacramento L5 Society meets on the Second Saturday each month at
2530 Mercantile Drive
Rancho Cordova, CA 95746
Check out our To the Stars page for other groups and events.
It is the business of the future to be dangerous; and it is among the merits of science that it equips the future for its duties.
— Alfred North Whitehead – 1925 —
How do we save the earth and support the private sector, including mom and pop businesses? L. Paul Turner’s book, “The Space Trade, How to Develop Real Estate in Orbit, is the only step-by-step guide that I’ve found. Of course, I wrote it to be just that. The free TOC is at www.TheSpaceTrade.com.
How are we going to get to space? What if Atlantic shipping rates was the price. John Powell’s “Floating to Space” is on Amazon. Be sure to buy it from him, because he includes extra DVDs and is signed by the author.
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