5 m^3 per person is reasonable if the trip lasted a couple of weeks, but this is going to be at least 3-4 months or more.Based on diagrams of the original Mars Direct plan, I had calculated the volume of the Earth Return Vehicle crew cabin for each of the four astronauts: 36 m^3. And for 6 months, that was thought to be too small.ISS total habitable volume is 388 m^3. For 6-7 people (permanent crew, living on the station for months at a time), that is 55-65 m^3 per person.
Quote from: Pipcard on 02/15/2016 02:41 am5 m^3 per person is reasonable if the trip lasted a couple of weeks, but this is going to be at least 3-4 months or more.Based on diagrams of the original Mars Direct plan, I had calculated the volume of the Earth Return Vehicle crew cabin for each of the four astronauts: 36 m^3. And for 6 months, that was thought to be too small.ISS total habitable volume is 388 m^3. For 6-7 people (permanent crew, living on the station for months at a time), that is 55-65 m^3 per person.Musk keeps saying 3 months or 100 days. Some opportunities require a little more energy, but 120 days is fine. So not more than 4 months (except with reduced crew).
Quote from: Robotbeat on 02/15/2016 06:10 pmQuote from: Pipcard on 02/15/2016 02:41 am5 m^3 per person is reasonable if the trip lasted a couple of weeks, but this is going to be at least 3-4 months or more.Based on diagrams of the original Mars Direct plan, I had calculated the volume of the Earth Return Vehicle crew cabin for each of the four astronauts: 36 m^3. And for 6 months, that was thought to be too small.ISS total habitable volume is 388 m^3. For 6-7 people (permanent crew, living on the station for months at a time), that is 55-65 m^3 per person.Musk keeps saying 3 months or 100 days. Some opportunities require a little more energy, but 120 days is fine. So not more than 4 months (except with reduced crew).I'd like to know where and when did he actually say this. Because I'm not finding it.Also, with that fast trajectory, what will the heating loads be as the vehicle gets aerocaptured by the Martian atmosphere? And can that thin atmosphere slow it down enough?
Quote from: Robotbeat on 02/15/2016 06:10 pmQuote from: Pipcard on 02/15/2016 02:41 am5 m^3 per person is reasonable if the trip lasted a couple of weeks, but this is going to be at least 3-4 months or more.Based on diagrams of the original Mars Direct plan, I had calculated the volume of the Earth Return Vehicle crew cabin for each of the four astronauts: 36 m^3. And for 6 months, that was thought to be too small.ISS total habitable volume is 388 m^3. For 6-7 people (permanent crew, living on the station for months at a time), that is 55-65 m^3 per person.Musk keeps saying 3 months or 100 days. Some opportunities require a little more energy, but 120 days is fine. So not more than 4 months (except with reduced crew).For a 100 crew size with a 15m diameter 50m^3 /person is a crew cabin of 30m tall. For 30m^3 it is 17m tall.If it is such a short duration of travel then a crew cabin size of 3000m^3 may work. Even a possible 2000m^3 may work. But for the first missions the MCT crew cabin will be the on surface HAB module as well so if the volume is 2000m^3 then the crew numbers would need to be less than 40 for initial trips. Crew sizes of 25 has been batted around a lot for these missions.
3000m^3 is starting to get too big (IMHO) to be practical (at some point, you're better off lowering the price and sending more people if you have that much room).
Quote from: Robotbeat on 02/16/2016 12:03 am3000m^3 is starting to get too big (IMHO) to be practical (at some point, you're better off lowering the price and sending more people if you have that much room).I am quite sure Elon Musk recently said just that. That 100 people may not be the upper limit forever and they may offer "economy class" trips with more. My guess is that they would need some advances in ECLSS to pull that off.
Quote from: oldAtlas_Eguy on 02/15/2016 08:15 pmQuote from: Robotbeat on 02/15/2016 06:10 pmQuote from: Pipcard on 02/15/2016 02:41 am5 m^3 per person is reasonable if the trip lasted a couple of weeks, but this is going to be at least 3-4 months or more.Based on diagrams of the original Mars Direct plan, I had calculated the volume of the Earth Return Vehicle crew cabin for each of the four astronauts: 36 m^3. And for 6 months, that was thought to be too small.ISS total habitable volume is 388 m^3. For 6-7 people (permanent crew, living on the station for months at a time), that is 55-65 m^3 per person.Musk keeps saying 3 months or 100 days. Some opportunities require a little more energy, but 120 days is fine. So not more than 4 months (except with reduced crew).For a 100 crew size with a 15m diameter 50m^3 /person is a crew cabin of 30m tall. For 30m^3 it is 17m tall.If it is such a short duration of travel then a crew cabin size of 3000m^3 may work. Even a possible 2000m^3 may work. But for the first missions the MCT crew cabin will be the on surface HAB module as well so if the volume is 2000m^3 then the crew numbers would need to be less than 40 for initial trips. Crew sizes of 25 has been batted around a lot for these missions.Right, I'm sure the crew size would be much less than 100 at first. And I used to be pretty sure 500m^3 was about the right size for cabin for MCT, squished, yes, but doable for the short trip. And I still stand by that as a possible minimum size per person, at least if you're really clever with how you utilize the space (with sleep schedules rotating, everyone having their own small personal space that they spend at least 12 hours a day in), but I no longer think SpaceX is thinking as small as 500m^3. Probably 1000m^3 or perhaps more. 2000m^3 is perhaps on the high end of what I think SpaceX is thinking of, but I wouldn't argue too much with it until we get more information.3000m^3 is starting to get too big (IMHO) to be practical (at some point, you're better off lowering the price and sending more people if you have that much room).
According to NASA, 5m^3 over a few months is about the size volume where trained astronauts will go bonkers and kill each other, the survivors turning into Reavers who will prey on hapless interplanetary vessels. I've stayed in a capsule hotel before - that's 2.7m^3 of space per capsule, and that's really not a lot.http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070023306_2007019854.pdfThe only way 5m^3 will work is if the passengers are in hibernation or some advanced form of VR or other disruptive future tech. 10m^3 *might* be doable. Nuclear submarines have 10m^3 per person with hot bunking. Certainly you will want shifts so the passengers don't get in each other's faces too much.
A horizontally manufactured large diameter tank would be differently designed and possibly weigh more than a vertically manufactured tank like the SLS. Given the problems with getting the vertical manufacturing setup to stay in alignment it may be easier to do the manufacturing horizontally (lower floor weight support required, easier to maintain alignment).
The only way 5m^3 will work is if the passengers are in hibernation or some advanced form of VR or other disruptive future tech. 10m^3 *might* be doable. Nuclear submarines have 10m^3 per person with hot bunking. Certainly you will want shifts so the passengers don't get in each other's faces too much.
Sorry, wrong link.http://msis.jsc.nasa.gov/sections/section08.htm#Figure 8.6.2.1-1http://ston.jsc.nasa.gov/collections/trs/_techrep/TM-2011-217352.pdfhttp://ston.jsc.nasa.gov/collections/trs/_techrep/TM-2015-218564.pdfI'm being flippant when I talk about the passengers/crew wigging out, but this is something crews on nuclear subs have to be carefully screened for. The British still do hot bunking - it's just the junior crew who have to suffer through it. About 1/3 of submariners are discharged for psychological reasons after their first tour. It may be lower (I didn't check the figures) but it's still a terrible psychological toll. Put your average hipster in there and you may find a gibbering mess coming out.
Well too bad, Boomers. The young folk are going to be the ones going to Mars. Maybe you would've gotten the chance if you hadn't been messing around with drugs in your youth (then racking up a big national debt and environmental damage in your adult lives)
Well too bad, Boomers. The young folk are going to be the ones going to Mars. Maybe you would've gotten the chance if you hadn't been messing around with drugs in your youth (then racking up a big national debt and environmental damage in your adult lives) instead of building spaceships like these fantastically hard-working and bright young engineers at SpaceX (and other Newspace companies), you would've been able to go. You can just deal with it. (You aren't all bad, Boomers, but if you're going to dish it out, you better be able to take it...)