Iliad-07 travels through space using a technology that allows it to constantly accelerate through space. Don't ask me how it works, the physicists blame some kind of trick with fusion energy based propulsion that the Krasnovians figured out, and ISTO copied after obtaining a collision between the INT-Jules Verne and the KNV-Graf Zeppelin left the Zeppelin's drive section embedded in the Verne.

It's apparently still 1) top secret, and 2) possibly something so stupid that physicists at the time were ashamed to admit it actually worked.

Space travel using constant accelleration introduces some strange and non-intuitive effects. The most immediate effect is that the crew has gravity. Normal, completely indistinguishable from if they were on the surface of the Earth, gravity. This is down to the Equivalence Principle laid down by Albert Einstein.

The second strange thing that happens is that time slows down tremendously on the Vessel, at least with respect to the Inertial Frame of Reference. (i.e. Earth). And the farther you travel in this way, the more time is dilated.

Some quick examples (assuming 1 g of accelleration):

(Light Years)
Time on Ship
Time on Earth
0.03 0.7 0.7 Inner Edge of the Oort Cloud
3 6.2 9.1 Outer Edge of the Oort Cloud
4.234 7.1 11.7 Proxima Centauri
4.5 7.3 12.3 Alpha Centauri
6 8.1 15.4 Barnard's Star
8.6 9.2 20.7 Sirius
45.7 15.1 95.2 18 Scorpii
26500 39.6 52984 Center of the Milky Way
25000000 66.2 49999843 Andromeda Galaxy