To install a module, you'll need a minimum of four astronauts: two EVA, one spacewalk coordinator, and one person to operate the SSRMS. Ideally, you'd have five so somebody could work the RMS on the Shuttle as well. With two crew at the station, you'd have to send up two or three more on Soyuz. That means it is indeed doable with one Soyuz flight, although it's the absolute barest minimum to support that. Conceivably, this could be worked in with a Soyuz taxi flight, saving even more money, although the Russians might get miffed as they generally have plans for those flights.<br /><br />Shuttle assembly flights with heavy payloads (like Destiny) have gone up with five crew. NASA generally considers this the minimum for a station assembly flight, because they will not have the commander or pilot of the Shuttle performing the EVA, and they want one backup person available for EVA as well. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>