Gemini is the first oblique spaceship to be constructed, and was created by Andrew J. Wade in 2010. It displaces itself by 5,120 cells vertically and 1,024 cells horizontally every 33,699,586 generations, and is therefore an ibisship. It derives its name from the latin, gemini, meaning twins, describing its 2 identical halves, each of which contains three Chapman-Greene construction arms. A tape of gliders continually relays between the two halves, instructing each to delete its parent and construct a daughter configuration.
It is the largest spaceship in terms of its diameter and bounding box, but has a much smaller population than the Caterpillar.
The pattern marks the thirteenth explicitly-constructed spaceship velocity, but facilitates an infinite range of related velocities. For example, Dave Greene has reduced its period by eight generations, whilst maintaining its displacement. Theoretically speaking, a Gemini-esque spaceship could be constructed with any velocity slower than (but not equal to) (1,1)c/580. In June 2010, Greene also constructed slope-2 and slope-3 versions of the spaceship.
Gemini was voted Pattern of the Year 2010 on the ConwayLife.com forums.