A product of the now sadly defunct Game Designers Workshop, Space: 1889 is
(From the Space: 1889 rulesbook.)
In this alternate Victoria-era reality, Thomas Edison invented the Ether Flyer in 1868 and in 1870 made the first manned Ether Flyer flight. His destination was Mars, where he found intelligent inhabitants and an ancient civiliation based along canals and using liftwood for aerial wind- & muscle- powered craft. By 1889 (the conventional starting date for gaming in this setting) many Earth nations have a presence on Mars, but the British and the Belgians have the most extensive colonies. Venus also is colonized, primarily by the Germans.
The themes of Space: 1889 include exploration of space and other planets, interaction with the inhabitants of those planets and investigation of their mysterious cultures and history, political intrigue between nations, Earth-based and otherwise, and the invention and use of steampunk science and technology.
There is a Space: 1889 mailing list.
Heliograph, Inc. reprinted the Space: 1889 books in 2000 and 2001, although no more development is planned.