There are two very important small orthogonal spaceships:
The G is c/2, the R is 2c/4. There exist G guns for all possible periods p>9. Also for the R there exist guns for all periods p>9. It is unknown if R guns with a period of 9 and 10 exist.
Next to c/2 orthogonal, known spaceship speeds are 2c/6 orthogonal, 2c/19 orthogonal and 2c/12 diagonal, with smallest examples:
The latter two ones appeared naturally in C1 soups and have a synthesis from G's. For all spaceship speed there exist puffers and for all known orthogonal speed also rakes.
- Snowflakes (discussion thread) at the ConwayLife.com forums