I saw this film from 1918 recently at our local Helsinkian film archive. It seems that the Danish Film Institute has reconstructed it in 2006 to celebrate the 100th anniversary of Nordisk filmcompany, which was one of the largest in the world in the early 20th century. I believe there are several copies with English translations circulating around Europe at the moment.
I found the film fascinating and the trip to Mars well thought out. The plot line is certainly original, but I really don't want to reveal any more of it at the moment, as now the danger of spoiling things for you really exists ;-).
The film is also available on DVD, query the Danish Film Institute (Det Danske Filminstitut) web pages at dfi.dk with 'Himmelskibet' to get more info.