Reply To: Richard Branson – Virgin Pledge

[Brian H]

Aeronaut wrote: Brian,

For 2 tons of mass to equal 2 tons of weight, you need to have done one of 3 things-

1. Persuaded Congress to repeal the Law of Gravity (which would make rockets much smaller), or
2. Beat CERN to discovering the god particle that’s supposed to impart mass to every atom in existence, thereby making an anti-gravity device possible, or
3. Gone off your meds.

To split hairs, NASA routinely ships water to the ISS. 8,000 miles plus a topoff makes almost any point in the world accessible within 24 hours. Granted, the bird of choice would most likely be a C5-A, as the situation would be motivated by political expediency rather than cost-effectiveness.

About water mass, are you calculating volume radially around the vacuum chamber, or 1 meter around the entire machine- cap banks, switches and all?

Duke, here’s a link to a borated polyethylene supplier who lists the TVT of .875 inches of lead as doing the same shielding as 1inch of his material, but around 11 times heavier. Probably costs less in materials and labor, too.

http://www.boratedpe.com/kingplasti-shieldboratedpesheet.html

Maybe we’re not stuck with quite as much weight as we were expecting yesterday….

Rockets? Gravity? Aero, you’ve gone loony. 🙂 %-P We are not discussing how much fuel mass it would take to put an FF into geosynch orbit. A 747 is many orders of magnitude less expensive transportation (fuel-wise, etc.) than a Delta rocket.

Mass and weight are identical, by convention, at sea level, on Earth. Here’s a link to the standard Kilogram used as the defining mass/weight standard for the world:

The kilogram or kilogramme (symbol: kg) is the base unit of mass in the International System of Units (SI, from the French Le Système International d’Unités). The kilogram is defined as being equal to the mass of the International Prototype Kilogram[1] (IPK), which is almost exactly equal to the mass of one liter of water. It is the only SI base unit with an SI prefix as part of its name. It is also the only SI unit that is still defined in relation to an artifact rather than to a fundamental physical property that can be reproduced in different laboratories.

In everyday usage, the mass of an object, which is measured in kilograms, is often referred to as its weight. However, the term weight in strict scientific contexts refers to the gravitational force of an object. Throughout most of the world, force is measured with the SI unit newton and the non-SI unit kilogram-force. Similarly, the avoirdupois (or international) pound, used in both the Imperial system and U.S. customary units, is a unit of mass and its related unit of force is the pound-force. The avoirdupois pound is defined as exactly 0.45359237 kg, making one kilogram approximately equal to 2.2046 avoirdupois pounds.

(And, therefore, 910 kg = about 1 ton, etc., etc., etc. See above.)

Image, with ruler (marked in cm.) for scale: http://tinyurl.com/KilogramSI

So, to repeat, a 747-400F could handle the weight/mass of 140-155 FF reactors, but the volume constraint would limit it to 15-18, depending on packing efficiency.