tag:blogger.com,1999:blog-192883022973901942.post3926470090540426269..comments2023-10-08T02:46:24.823-07:00Comments on Bootstrapping Space: Reddit is distractingChris Wolfehttp://www.blogger.com/profile/11247630943891521469noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-192883022973901942.post-33778381995775748772016-10-25T11:09:39.009-07:002016-10-25T11:09:39.009-07:00It would be a different ship, which would need to ... It would be a different ship, which would need to be simulated, built, tested independently.<br /> I don't think removing the heatshield material from a baseline hull would be feasible, but it should be possible. Removing the pressurized volume really would be impossible; that's a load-bearing component during atmospheric ascent.<br /><br /> The approach depends on what kind of mission(s) you have in mind. If you want to do a one-off probe or something then use a baseline tanker and hack a payload deployer into the upper section.<br /> If you want to send multiple interplanetary probes a year then it would make sense to build a dedicated exploration version. This would probably use the same hull but with proper payload bay doors. Omit the heat shielding and sea-level Raptors, add extra insulation and cryocooling and add some deployable large-diameter dishes for communication. Dry mass would probably still be around 80-100 tons. (That would include a modest fission power source in an alternate reality where the word 'nuclear' doesn't make people's heads explode.)<br /><br /> Suppose an exploration version is built, masses 120 tons dry, carries 2,400 tons of propellant and has about 500m³ of cargo volume. Further suppose that this is meant for probing the gas giants; it has 100 kW of fission power and 200 kW (@ 1 AU) of PV.<br /> This craft would have about 9.2km/s of dV with 100 tons of payload. 10 tons, 11.1km/s. 500 tons, 6km/s.<br /><br /> Add a supplemental plasma thruster system with Isp of around 3000. Assume we reserve 10% of the propellant mass (240t) to be used in this thruster. (Ideally it would consume the existing methalox or a similarly dense cryogenic propellant.) That changes things a bit... the 100-ton payload case would have 6.5km/s of chemical dV for efficient departure and anywhere from 2.8km/s to 21.7km/s of electric dV. The exact amount for an orbit mission will be somewhere in the middle, since the thruster would be used after departure but before capture. A flyby would get the full benefit, a total mission dV of 28.2km/s.Chris Wolfehttps://www.blogger.com/profile/11247630943891521469noreply@blogger.comtag:blogger.com,1999:blog-192883022973901942.post-66753016850979524222016-10-22T18:31:21.584-07:002016-10-22T18:31:21.584-07:00Wow, that's quite the collection of crunchy da...Wow, that's quite the collection of crunchy data!<br />I'll be reading through those posts for sure.<br /><br />On G+, there has been talk of stripping away the heatshield and aerodynamic habitat modules to turn the ITS into a more sensible solution for non-Mars destinations. Can you confirm if this is even possible?Matter Beamhttps://www.blogger.com/profile/16721504049578296529noreply@blogger.com