I believe TSATF was adapted for large VSF games set on Mars and Venus at the Northwest Historical Miniatures Gaming Society's Enfilade convention in Olympia, Washington, but I don't know if there was a published variant used.
Usually the first place to look for The Sword and the Flame variants is the Jackson Gamers' web site on Angelfire. The author, Larry Brom, was long associated with the gamers in Jackson, Mississippi, and I think that's where both The Sword and the Flame and "Brom's Standard Rules" (for larger actions) where developed. They don't list a VSF variant, but maybe some ideas from other variants might be useful, especially the WW2 variant:
http://www.angelfire.com/games3/jacksongamer/TSATF_variants.htmBy the way, there are some interesting games pictured on the Jackson Gamers' web site, so it's worth browsing around.