Science Forums 2

[Moontanman]

Originally Posted by Gardamorg

Nano Assembly would allow the spacecraft to be both strong and light.

With light fuel, and a light haul/craft, the craft will zip through space, as opposed to a craft with light fuel and a heavy craft producing drag.

We wouldn't need it to be any stronger than high class titanium or diamond.

First of all what do you hope to achieve by making the space craft super light? Read this link, all of it.....

BRUCE BEHRHORST ARTICLE LIST

Once you get to a certain point lowering the weight just increases the risk of failure. When the space craft is already much lighter than the fuel, engine, and payload, to go even lighter just makes it weaker with no real increase of speed or acceleration.

In space you have no drag dude, mass simply resists acceleration but the gain of a couple of percent in acceleration isn't worth the risk of failure. Hydrogen is already as light as reaction mass is going to get, the Saturn five rocket was very light in comparison to it's fuel and payload weight but it was also on the ragged edge of failure. A reusable space craft needs to be more durable than that. The Saturn five was much lighter than it should have been to make up for the small Isp of it's engines. It would be very difficult to make a space craft any lighter. It's fuel tanks weren't much more than metal balloons as it was.

You seem to have a strange idea of what strong is, diamond is not strong, it's hard, there is a difference. I can smash diamonds quite easily, titanium is strong but it will bend and deform.