Defense

Defensive technologies for threats deliberate, accidental, and natural are widely varied throughout society. The most common looming threat shared by all spacefaring societies is the inherent danger of high-energy impacts; everything in space is moving rapidly relative to everything else, and forward planning is required to ensure that entities in close proximity to each other do not annihilate one another. Accidents such as a malfunctioning spacecraft, natural phenomena like clouds of particulate matter, and deliberate attacks from even small rogue entities are significant threats that society must contend with.

Read more: Debris

Armor

Impact armor, intended to absorb or deflect impacts, is most commonly used for civilian purposes. The raw power of targeted military strikes completely negates any benefit that thick armor could provide; maneuverability and lightweight construction are far more valuable. Armor can still be effective against low-mass impacts such as particle beams and weaponized debris fields.

For civilian purposes, armor can provide defense against natural and artificial debris alike, particularly for stations that see high volumes of traffic with the potential for free-flying debris in or through their orbit. Stations are also able to more easily accommodate the extra mass of armor since they remain in their designated orbit.

Reflective armor is a different type of armor which can be quite thin, intended to deflect lasers or reflect strong radiation near stars or gas worlds. This type of protection has widespread military and civilian use for the protection of sensitive external equipment.

Radiation Shielding

Radiation is ubiquitous throughout space; virtually all spacecraft require shielding of some kind to protect against it. Biological tissue and electronics alike are adversely affected by prolonged exposure to this radiation, and so require shielding of some kind to ensure their safety. This shielding can be a layer of solid material for reflection or absorption, or a strong magnetic field which can also provide adequate radiation deflection.

While thin reflective foil provides enough defense in some cases, shielding against smaller wavelengths such as x-rays and gamma rays requires notable thickness to the material in order to provide adequate protection. This type of radiation is found in significant intensities as a product of both natural and artificial high-energy events, such as near gas giant worlds or from nuclear propulsion drives.

Energy Shielding

Energy weapons are devastating close-range weapons which can corrode through solid matter. Ionized hull plating, also known as energy shielding, is a powerful defense against plasma weapons where the ions absorb or deflect the plasmatrons, significantly reducing their destructive effect.

Point Defense

Point defense systems are used to destroy incoming projectiles, particularly missiles. Missiles will often perform evasive maneuvers on approach to their target in order to evade point-defense fire. They are vulnerable up to the point of impact or detonation, as a single bullet can detonate the payload or simply knock out the missile’s ability to guide itself. Despite this, divergent relative velocities and powerful proximity missile detonations mostly negate the effectiveness of point defense. Laser-based point defense can be utilized for debris fields.

Atmosphere & Terrain

Planetary bodies provide numerous natural defenses for ample protection against the hazards of space. A significant atmosphere provides a barrier against spaceborne debris which burns up before it’s able to reach the surface, and the surface itself can provide shielding for subterranean structures against debris and radiation even without an atmosphere. A strong magnetosphere will also help to protect a world against cosmic radiation, whether it be from a star, gas giant, deep space, or other source.