Quita's Ship

Length	48m
Width	49.5m
Empty Weight	68479kg
Maximum Weight	131229kg
Story Weight	120000kg

Quita's ship is designed for interstellar travel. It can accommodate a crew of 5 with 2 additional passengers for up to 6 months at a time. It can operate in atmospheres and land on dry surfaces. It carries a variety of science equipment including a 1.2m telescope and can accommodate small to medium sized live and inert samples. It doesn't have artificial gravity, but does have a faster than light drive.

The interstellar drive operates on the principle of local/remote volume exchange. It exchanges the contents within a 47m radius around the drive with the contents of an identical volume anywhere from 178 km to 1.041 billion km away. The jump is instantaneous and can't be felt or heard. Jumps can be made as frequently as once every 0.6 seconds allowing for a travel rate of up to 1.51 light years / hour. Energy spent is not related to the distance traveled

The jump accuracy is not perfect. Location errors can be as high 939km per jump so errors accumulate pretty rapidly for long distances.

The drive can change the ship's location, but not it's momentum. Upon arrival, regular Newtonian thrust will be required to change the ship's velocity to match its destination. Accounting for differences in star motion, planet motion, and ship motion, this difference can be over 100,000 m/s, but is usually much less. When Albert Einstein rewrote the laws of motion, the laws of momentum survived. I figure if momentum can survive Einstein, who am I to change it?

This drive, of course, is pure fantasy. There is no faster than light travel. If there was, such a drive could be used to change potential energy and, therefore, create energy. I don't believe this is really possible. Energy can be created from matter (E=mc²), but not from nothing!

________________________________________

Imagine a vertical cylinder wound with wire. The wire is connected to a battery charger. In the middle of the cylinder, near the top rests a heavy bar magnet that had been hoisted up by an electric winch.

When we unlock the winch, gravity pulls the magnet down. In physics, we say the magnet has potential energy which, when released, is converted to kinetic energy (motion). As it falls, the wires are exposed to a changing magnetic field which induces a current. The kinetic energy is converted to electrical energy. The electrical energy is then stored in the battery by changes in its chemistry.

When the magnet reaches the bottom, it should be possible to use the battery to winch the magnet back up to the top. This way our perpetual machine can run indefinitely! Not so fast. Some of the energy at each part of the process is lost. There's air resistance, wire resistance, internal resistance in the battery, etc. All these loses convert some the energy into heat which is another type of energy.

When we use the battery to pull the magnet back to the top, it doesn't make it all the way. Energy is conserved, but some is lost to heat and can't be recycled.

Now let's try adding a worm hole. Worm holes are defined as having ends that occupy the same location and different locations at the same time. This way, an object can 'travel' through a worm hole and not travel at all. It could jump to another location without spending any energy.

This should fix our perpetual motion machine. We'll place one end at the bottom and the other at the top. As the magnet is released, it falls into the wormhole entrance at the bottom and emerges at the exit above. The magnet keeps falling since it now has new potential energy. It'll keep falling over and over while continually generating electrical energy. Where is this energy coming from?

This is why I don't believe in the various science fiction faster than light drives. They are useful for story telling, but just can't exist in the real world.

The second propulsion type is based on observed physical laws. It's what I like to call a momentum engine. These engines work by ejecting mass at high velocity. The higher momentum of the expelled material (mass time it's velocity), the greater the acceleration for the ship. The problem momentum engines have is the ship has to carry the fuel that gets ejected. A heavy ship can't accelerate as much.

All we really care about is the momentum. Less mass ejected at a higher velocity yields the same momentum, but with a lighter ship. The trick is to speed up the ejection as much as practical. Quita's ship uses a principle similar to that of particle accelerators. It uses very powerful magnetic fields to eject a relatively small amount of iron to provide thrust. It gets its energy from fusion reactors that split water and fuse the hydrogen atoms into helium atoms.

Quita's ship literally runs on water and iron dust! I choose iron because it has minimal impact on biology when introduced into an environment, is relatively common, and responds well to magnetic fields even when cold.

________________________________________

At full thrust, each second, 173.2g of iron are accelerated to 15,000,000 m/s (0.05c). This provides a 2G acceleration for a 130000kg ship. 19.32g of water are required to provide this energy (3.88 teraJoules / second) so at max thrust, the ship is using total fuel load of 192.6g / second.

A total fuel capacity of 4500kg of iron (573L) and 500kg of water (500L) provide enough fuel for over a dozen typical planet visits (with reserve).

There are two main momentum engines in the rear, two gimbaled engines below for hovering, and several small engines to provide attitude adjustment in space.

With no anti-gravity, there are two remaining ways for the ship to land. It can accelerate to match a planet's velocity very closely and then gently descend to the landing site, or spend less fuel and use atmosphere friction to help slow it down. Like Earth reentry vehicles, a heat shield protects it during rapid entries. In my story, Quita and her ship mates choose the latter option so they get a ride to Earth very similar to what our astronauts experience.

Quita's Ship

Description