Icarus

The Icarus possesses an Anti-Gravity Drive, allowing it to hover with almost no power consumption, and to alter its altitude independently of forward thrust. The Drive works by inverting the polarity of gravitational energy, and loses effectiveness as it rises from a gravity well; thus, the Icarus has a maximum operating altitude of 113 miles (about 600,000 feet), within the range of Low Orbit. Icarus cannot achieve a true orbit, as it cannot attain the necessary velocity, but its ability to move laterally while maintaining altitude through anti-gravity allows an approximation of orbit.

Its lateral engines function through gravitational redirection. At low altitudes, this drive is at maximum effectiveness, but the ship's acceleration is limited by air resistance. At high altitudes, friction is reduced to virtually zero, but the effectiveness of the drive is reduced; however, while acceleration suffers, maximum velocity is much higher.

Highest acceleration is experienced between 30,000 and 50,000 feet, deemed "cruising altitude". At this altitude, Icarus can achieve lateral acceleration of 0.75g, although this is only recommended when all crew members are securely braced and all loose items in the cabin are stowed. At these altitudes, its maximum velocity is approximately 700 miles per hour.

Icarus' lateral acceleration may be in any vector, though the ship's design is intended primarily for forward acceleration; in that vector, the ship's aerodynamic properties are ideal, and all stowage and crew seating is intended to brace primarily in that direction.

Flight Times

For trips with flight duration as the most important factor, different modes of flight are employed.

Short Range

A "short range" flight is less than 100 miles. At this range, limitations on acceleration and velocity due to air resistance are less important than time spent climbing and descending. For short range flights, the optimum altitude is 50-500 feet, with a maximum velocity of about 500 miles per hour.

Medium Range

A "medium range" flight is between 100 and 2,000 miles. At this range, maintaining optimum cruising altitude and a maximum velocity of over 700 miles per hour is the best option. Though the ship can reach higher velocity at orbital altitude, the climbing and acceleration time is prohibitive.

Long Range

A "long range" flight is any over 2,000 miles. At this range, it is more sensible to achieve orbital altitude, and accelerate for long periods of time to reach supersonic airspeed. In this scenario, Icarus ascends slowly, accelerating to supersonic velocity at around 110,000 feet, and continuing to accelerate as altitude increases. Achieving orbital altitude takes just over an hour, though acceleration continues past that point. To decelerate, Icarus descends into the atmosphere, allowing the ship's drag to do most of the work.