> <i><font color="yellow">but the main problem for private is not technological... I don't think that a little company will never take a so great risk (for astronaut's and company's life) without a giant NASA or ESA logo on the manned vehicle</font>/i><br /><br />I don't expect a company to go straight to manned orbital flight. There are probably two paths. The first path is establishing a firm sub-orbital flight business with a combination of tourists and commercial zero-G experiments (I believe the market for this latter category is estimated at well over $100 million a year). Using the experience gained and the dollars acquired from this first market, the company would eventually move into orbital market. This is the Virgin Galactic model.<br /><br />The second path is to provide unmanned orbital services (satellite, cargo/supplies to ISS). If revenue and capability are sufficient, then the payload becomes a manned vehicle of some type. This is the SpaceX model.<br /><br />Implicit in these assumptions is that there will be a market for humans beyond sub-orbital flight. Will ISS open up for non-government or non-government-sponsored personnel? Will NASA or any other government buy manned access for their people on a commercial service? Will Bigelow's orbital facilities succeed?<br /><br />If dollars show up, someone will figure a way to take it. The key is to take small steps, with each new step building the knowledge, technology, and revenues gained from previous steps.<br /><br />I believe President Reagan first announced that NASA would build a space station the same month that Apple announced the first Macintosh -- with a single floppy, no hard drive, 128K of memory, 8 KHz processor, small black and white screen. Today, for about the same price as that original Mac, you can get a Mac with four 2.5 GHz CPU cores, 1 Gig of memory, 250 GB hard disk, and a 30" color monitor. These systems <b><i>far</i></b> exceed the Cray supercomputers of 1984.</i>