Mythos Space: Hyperspace

HYPERSPACE (Plane)
Hyperspace (also called the Astral Plane) is an alternative region of space co-existing with our own universe

Two merchant vessels entering hyperspace.

which may be entered using an energy field or other device. Hyperspace is most succinctly described as a "somewhere else" within which the laws of general and special relativity decidedly do not apply, especially with respect to the speed of light being the cosmic speed limit.
Hyperspace is a great, endless "sea" of clear silvery sky, both above and below. Hyperspace has subjective directional gravity. It is also timeless. Age, hunger, thirst, poison, and natural healing do not function in Hyperspace, though they resume when the traveler leaves Hyperspace. Travel through Hyperspace for Starships is relatively easy once an Interstellar Gate is used. Ships find this route between stars quite useful. Unfortunately Hyperspace is haunted by a number of aggressive and dangerous species.
HYPERSPACE TRAVEL
Ships equipped with a Hyperdrive can enter hyperspace once they are out of a planets gravity well, typically ten miles out (GM's discretion). Wormholes, Warp-Gates and some psychic powers can also allow access to hyperspace, but these are pretty rare.
Travelling between solar systems using Hyperspace can be accomplished via a successful Navigation check. Success indicates that the course has been successfully set through the Silver Void. Failure results in the ship running off course to a destination of the DMs choosing.
Ships using Hyperspace to travel to distant star systems take 7d10 ship days to reach their destination, regardless of travel distance. During this time the crew need not eat, drink or sleep, though many still do to repel the sheer alien-ness of the Starry Void.

HYPERSPACE ENCOUNTERS
Hyperspace is a busy place, especially where vessels enter and leave the Starry Void. Every time a ship enters or leaves Hyperspace, there is a chance that something is drawn to the disturbance.

Roll d100 -- and be sure you have numbers and behavior ready.

     1    Terror From Beyond (Solitary)
     2    Fire Vampire Swarm (2d6)
     3    Mi-Go Clutch (1d8)
     4    Nug-Soth Explorers (2d4)
     5    Tove Colony* (5d10)
     6    Nightgaunt*
     7    Space Patrol -- 2d8 Starfighters
     8    Space Patrol -- 1d4 Couriers
     9    Merchant Frigate -- GM's choice. 

    10    Moon Beast Slavers(1d4 + 2d6 Lengites) 

    11    Asterion Star Mother (Solitary)
    12    Asterion Star Warrior Gang* (1d8)
    13    Asterion Starlord Command* (1d4)
    14-20 Asterion Starling Clutch* (2d6)
    21    Dimensional Horror*
    22    Astral Angler (Solitary)
    23    Phase Spider*
    24    Examiner Cluster* (1d6)
    25    Thuum'ha Trade-Freighter (2d12)
    26    Arkhamer Researchers -- GM's choice.
    27    Spirit -- DM's choice.
    28    Sawsnark Cruiser -- GM's choice.
    29    Giant Robot -- GM's choice.
    30    Color Out of Space -- 
    31    Wenelian Pirates*

    32    Tove Colony* (5d10)
    33    Byakhee Swarm* (1d12)
    34    Elderian Travellers (2d4)
    35    Space Pirates -- GM's choice.
    36-00 No encounter 
* Appears in an unocupied section of the nearest ship or space station. The only exception to this rule is a Boojum ship like the Sawsnark Cruiser. 

This material is using the Grit and Vigor roleplaying Game by John Stater. John has been kind enough to allow me to see the playtest version of the rules, and this gives me more than enough to begin work on the Mythos Space setting.