Quote from Knight Hawks:

Energy Sensors detect the radiating energy of chemical rockets, atomic rockets and any other source of extreme heat. This includes stars, nuclear explosions, volcanic activity and even large geysers, but not ion engines. Energy sensors can detect very strong sources of heat, such as stars, at ranges up to 100 light years. The radiating energy travels at the speed of light, so the information detected from a source 20 or 30 light years away will be 20 or 30 years old.

I look at it this way.

Every ship needs a navigational array (Nav-Array).  This allows the ship to locate other ships in normal space and travel around a planet without running into another ship.  Under normal conditions every ship within the range of the Nav-Array should show up on their navigational screens.  They also allow them to travel around in normal space without running into an asteroid or planet.

Astronavigation equipment (or Astronav) is used to plot new courses through space and is not required on all ships.  It’s an additional package the player may or may not opt for.  The Astronav is standard on research vessels.

Tactical Arrays are used on military ships and are similar to nav-arrays but have the ability to detect ships that are attempting to evade civilian nav-arrays.   They have the computer packages which allow them to predict target’s movement, aide in targeting ships, evading incoming weapons (Missiles and torpedo) and identifying the type of ship firing on them.  This is standard equipment on military ships.  On civilian and research vessel it is an optional piece of equipment and quite expensive.

Scanners and Sensors are used by both military and scientific vessel but are not necessary on civilian ships.  They are quite expensive as well.  There main use is aiding in research so they are considered bonuses to the operator skills.  And yes, they can tell the player what they have found sort of like a detect magic spell in D&D.

Game systems in general tend to over complicate equipment.  A ship carrying passengers and cargo from Point A to Point B doesn’t need to calculate Point B if it is a standard route.  These standardized routes are built into a nav computer or avionics’ package of the ship.   As long as the ship remains in good condition, there shouldn’t be a problem with navigating these routes.  Only smugglers, pirates, military and research ships need an astronav, since they are the ones looking for different ways to evade, find or locate planets and authorities by going off the beaten path.

As far as arming ships, the weapon system comes with its own targeting systems and built in to the price of the weapon system.  Evasion programs are rather useless on a ship design to carry cargo.  It is better just to slap some decoys on the ship to stop incoming weapons and deceiving the enemy of your location. Converting a cargo ship over be a smuggler or pirate ship is another matter which involves replacing a lot of the standard features on a ship to make it much more capable of handling the rigors of combat.

Since stealth has come up with in this thread, I’ll through my thoughts out on the matter.

Stealth as we know it is about two things:  Reducing your signature (EM emission) and camouflage.  A ship doesn’t have to hide its IR signature or engine output.  It only needs to blend in with the background radiation and light sources within a solar system.

Look at how submarines hid in the ocean and you’ll get a feeling about I’m talking about here.  They mask their engines reducing the sound they transmit into surrounding water.  They use variations in water temperature to deflect sound or mask their presence to an enemy submarine.  The same could be done in space using the solar winds.

Star Frontiers uses two items which conform to this vision. The Masking Screen is camouflage which makes the ship appear to be an asteroid or comet.   Since Ion engines are low power and throw out particles they mimic the solar winds.

Granted, a ship is going to be easier to find in open space, rather than in an asteroid belt, ort cloud or planetary ring.   Therefore it is reasonable to assume enemy ships are not going to just pop into normal space where there is nothing to hide in.  They are going to look for places where their reduced signature and camouflage is going to work best.

They also better their chances of evading detection by jumping further away from known detection sources.  A ship jumping in at 1 AU from a planet has about eight minutes to reduce its signature, apply its camouflage and change course before it is detected by planet or ship based equipment.  We then have to add the civilian and military response time to the 8 minute head start.  This coupled with travel time to the last know plot of the ship’s course, the intruder may have several hours to days before the actual hunt begins for the enemy ship. If said jump takes place outside a dense asteroid belt, it then becomes a cat and mouse game.

They don’t have to be high tech devices either.

The Stealth fighter uses its shape to defect incoming radar signals and baffles in the engines to reduce its IR signature.  It does have Radar absorbent material as well, which is high tech stuff.  So if were to advance just these ideas a few hundred years our stealth starship uses baffles in their exhaust and hull plating to defuse the IR signature. Scanner absorbent material which lowers it EM signature and finally, they pulse their drives to mimic solar activity.   Instead of them being a starship, they now appear to be an uncharted chunk of rock.

Finally, you have to look at the traffic and military preparedness of the planet an enemy ship jumps into.  If it is a busy system with low military presence or they are lacking in their monitoring of the system, a ship will have a much easier time entering the system than one that is on high alert.  Failures in system monitoring and preparedness can allow a ship to enter the system unnoticed.

Fun Fact:

Sometime around the beginning of the 80’s people in the Southwest United States began seeing triangular shape object in the night sky.  UFO enthusiasts believe they had something big.  Then in 91 at the beginning of Gulf War we learn about F117 Nighthawk.  Its triangular shape and faceted fuselage stunned us.  We also learned about fly-by wire and other technologies incorporated into the aircraft.    According to the inter web, development of the Stealth Fighter began 1975.  A full 15 years before they were made public in 1990.  The first test flight took place in Dec. 1977.

The Stealth Fighter changed our perception of what could fly and how it could be done.  Fly by wire (as my brother and I joked) could make a brick fly.  The second thing it did was to introduce us to concept of stealth.  And finally, it proved the government could keep a secret.

Under our present level of technology, stealth is not possible in space.  It doesn’t mean it can’t be done, it’s just means we don’t have the technical know-how or scientific wear with all to do it at the present time.

By the way, triangular shaped UFO are still all the rage in the UFO community, just watch History Channel’s Hanger One…

I made my last comment with a bit of tongue and cheek.  The point I was trying to make was the stealth fighter change our perception and how it was mistaken for aliens from another planet.

Nor do we have to reduce our IR signature to absolute zero.  It just has to blend in with surrounding space.  Exhaust particles or energies from our SF drives mimic solar winds.  Instead of it looking like a starship on our screens, it’s now seems to appear like an asteroid, comet or dust orbiting the star.  Our intention is to fool the operator and the device intended to locate the craft into believing it is something else.  We’re not attempting to mask or hide the ship, we’re just lowering its signature to the point it doesn’t register on the devices intended to detect it.

It brings us back to our perception of things that can and can’t be done.

Abub:  I believe the game designers wanted it to stay out of the hands of your average player.  Military characters sure, but not the civilian characters.  You don't want your civilian population on par with your military and the same goes with your characters...