▁emb ry o ▁space ▁colon ization . ▁ ▁The ▁most ▁common ▁role ▁of ▁sle eper ▁ships ▁in ▁fiction ▁is ▁for ▁inter stell ar ▁or ▁inter gal actic ▁travel , ▁usually ▁at ▁sub - light ▁speed . ▁Tra vel ▁times ▁for ▁such ▁jour ne ys ▁could ▁reach ▁into ▁the ▁hundreds ▁or ▁thousands ▁of ▁years , ▁making ▁some ▁form ▁of ▁life ▁extension , ▁such ▁as ▁susp ended ▁animation , ▁necessary ▁for ▁the ▁original ▁crew ▁to ▁live ▁to ▁see ▁their ▁destination . ▁Sus p ended ▁animation ▁is ▁also ▁required ▁on ▁ships ▁that ▁cannot ▁be ▁used ▁as ▁generation ▁ships . ▁ ▁Free zing ▁the ▁astr onaut s ▁would ▁probably ▁involve ▁whole - body ▁vit r ification ▁and ▁would , ▁most ▁likely , ▁be ▁fro zen ▁at ▁ 1 4 5 ▁k el v ins ▁to ▁reduce ▁the ▁risk ▁of ▁f ract uring . ▁ ▁Sus p ended ▁animation ▁can ▁also ▁be ▁useful ▁to ▁reduce ▁the ▁consumption ▁of ▁life ▁support ▁system ▁resources ▁by ▁crew ▁members ▁who ▁are ▁not ▁needed ▁during ▁the ▁trip , ▁or ▁by ▁an ▁author ▁as ▁a ▁plot ▁device , ▁and ▁for ▁this ▁reason ▁sle eper ▁ships ▁sometimes ▁also ▁make ▁an ▁appearance ▁in ▁the ▁context ▁of ▁purely ▁inter plan et ary ▁travel . ▁ ▁Ex amples ▁in ▁fiction ▁ ▁There ▁are ▁numerous ▁examples ▁of ▁sle eper ▁ships ▁in ▁science ▁fiction ▁literature ▁and ▁films . ▁Some ▁of ▁the ▁best - known ▁examples ▁are : ▁ ▁" F ar ▁Cent aur us ", ▁published ▁in ▁Dest ination : ▁Un iverse ! ▁by ▁A E ▁van ▁Vog t ▁