Understanding Maneuvering

OVERVIEW
An idle spacecraft in orbit is naturally stable.  That is, it will continue to orbit the same way until fuel is expended and thrust is produced.  In the Lost Universe, orbits are simplified to five altitudes.  The absolute altitudes themselves are irrelevant, since the amount of fuel required to transfer between each pre-defined altitude remains the same.  



APOAPSIS & PERIAPSIS
You can identify the highest and lowest points of your orbit relative to a planet by referencing the ship's apoapsis and periapsis respectively, which can be found in the Flagship Monitor in your Flagship LAN.  Apoapsis defines the highest point of your orbit while periapsis defines the lowest.  Either one can be changed without affecting the other.

Your assets can orbit in either fully circular patterns (1-1, for example), or highly elliptical ones (5-1, for an extreme example).  The highest and lowest points of your orbit (both numbers respectively) are all that matter to you, so it is often easiest to picture the ship's orbit as two points along a vertical axis.



MANEUVER COST
The number of altitude changes (and, consequentially, the amount of fuel) required to perform a specific maneuver is expressed as delta-v.  Total maneuver cost is the product of delta v multiplied by the ship's base burn cost.   You can identify the exact cost of burns for your own ship in the Flagship Monitor.

A burn to increase apoapsis from 1 to 2 will result in a delta-v of 1, meaning that an unmodified Phase I flagship will expend 20 units of noble gas to perform said maneuver.  Were the burn to result in a change in apoapsis from 1 to 4 and periapsis from 1 to 2 instead, the net delta-v would become 4 (80 units of noble gas).

Illustrated is a visual representation of the five constant altitudes, as well as all possible elliptical orbits with an apoapsis of 5.  The redder the colour, the greater the ellipse.  It is not necessary to apply this illustration in practise, but it may be a useful visualization for some.

RENDEZVOUS
Rendezvous occurs when your ship matches the circular orbit of another interactive object, and is a necessary maneuver for recovering DRVs, docking at stations, capturing relays, as well as repairing and restocking defensive batteries.



DROP/RETURN VEHICLES
DRVs in the database display five payload values in descending order, corresponding to the delta-v required to complete their mission. If a vehicle is deployed and recovered from altitude 1, zero payload penalty will occur, but a vehicle deployed from altitude 2 and recovered at altitude 4 (total delta-v penalty of 4) will only be able to deliver the fifth and smallest payload.  

To maximize your industrial efficiency, it is highly recommended that you maintain a consistent orbit of 1 whenever possible or deploy longer-term Settler DRVs.  Alternatively, you can choose to spend flagship fuel in lieu of reactive propellant if the flagship is capable of maneuver (not docked or otherwise immobilized).  If all else fails, the DRV can remain on the surface for as long as necessary, but any duration after it has filled itself to capacity is downtime, and it remains vulnerable to enemy attack until it has returned to space.



ARTILLERY
Standard artillery ammunition is limited by the range of the weapon from which it is fired, and is incapable of delta-v during flight. Rocket-assisted ammunition adds an additional 1 delta-v, which may be performed mid-flight to intercept a maneuvering target. However, only the bonus delta-v provided by the rocket can be adjusted, and not the base delta-v of the projectile itself, after the weapon is fired.



PLANEFOLDING
Due to the indubitable impracticality of conventional spaceflight between territories, bridging astronomical gaps at superluminal speeds is made possible by planefolding, specifically the eponymous planefolder module.  Planefolding (or simply 'folding') is a process which jumps the spacecraft from one orbit into the orbit of a distant planet, preserving both apoapsis and periapsis.

If a ship is not equipped with a planefolder, or is otherwise incapable of performing an independent jump, multiple craft may piggyback on the fold conducted by an ally provided all involved parties have rendezvoused.  Planefolder modules typically possess a several-day cooldown between each use and are very power-intensive, so be sure to coordinate maneuvers with your comrades and/or conduct your folds sparingly.