the point is that you can actually live inside the rockets when they first land, you don’t need to build extra housing immediately. this significantly simplifies the mission requirements, at least for the first few years.

tank volume is about 1000 m³, which stores about 5000 kg of oxygen assuming 5 bar of pressure, which lasts a crew of 10 for about half a (martian) year, or about as long as the winter sand storms threaten to reduce solar panel production, so you have enough oxygen to breathe through this time.

it is a myth and misleading to assume that energy supply has to be constant. it is good enough if you can intermittently replenish your live support resources.

    • gandalf_der_13te@feddit.orgOP
      1·
      8 days ago

      yeah i’m well aware of that, rockets are 90% fuel by mass, but not by volume. so there’s still a lot of volume around. also you need the live support system anyways for the travel there, why no still use it once you land?

      • NaibofTabrEnglish
        2·
        7 days ago

        Ok, well in the specific case of Mars, the planet lacks a magnetic field, plus the atmosphere is thin, which means there’s a lot of radiation exposure. Yes you’d definitely want to live inside the metal body of the ship in the short term, vs. say an inflatable habitat. But you’d want to make that very short term, like less than a week, and get yourself into an underground shelter for sleeping as soon as possible. Hopefully have some automated equipment dig it out for you before you arrive. You want several feet of rock between you and the radiation.

        • gandalf_der_13te@feddit.orgOP
          1·
          6 days ago

          this myth with the radiation seems to be very enduring. it comes up on literally every discussion about mars settlement, even though it’s not true. idk what to do about this, probably NASA will give out a statement in 5 years and declare that radiation is not actually that big an issue and then people will stop complaining about it.

          • NaibofTabrEnglish
            1·
            6 days ago

            What are you talking about?

            The radiation exposure on the surface of Mars is much harsher than that on the surface of the Earth for two reasons: Mars lacks a global magnetic field to deflect energetic charged particles (1), and the Martian atmos- phere is much thinner (<1%) than that of Earth, providing little shielding against the high energy particles that are incident at the top of its atmos- phere. This environmental factor, for which there is no analog on Earth, poses a challenge for future human exploration of Mars

            […]

            Combining our measurements with those obtained during the cruise phase (22), we estimate a Total Mission dose equivalent of ~1.01 Sv for a round trip Mars surface mission with 180 days (each way) cruise, and 500 days on the Martian surface for this current solar cycle (Table 2).

            https://www.science.org/cms/asset/b9057f23-375b-447a-ba62-65a4e7f691a4/pap.pdf

            This is based on data collected by Curiosity. This value was confirmed by a more recently published study:

            the accumulated dose equivalent is about 1.02 ± 0.13 Sv. This is quite consistent with the value obtained by Hassler et al. (2014), who estimated a value about 1.01 Sv based on RAD’s cruise measurement and the first 300 sols of surface measurement under similar solar modulation conditions.

            https://www.researchgate.net/publication/354731398_Radiation_environment_for_future_human_exploration_on_the_surface_of_Mars_the_current_understanding_based_on_MSLRAD_dose_measurements

            1 Sievert (Sv) is 20x the DOE annual radiation limit for workers (5 rem), and 10x the average dose received on an ISS mission (10 rem). It’s also about 20% of a lethal dose (~500 rem).

            https://www.scribd.com/document/100083925/DOE-Ionizing-Radiation-Dose-Ranges-Rem-Chart

            This information was super easy to find. It’s not a myth, and the health risks are currently considered too high for human exploration of Mars.

            • gandalf_der_13te@feddit.orgOP
              1·
              4 days ago

              i was referring to this NASA webpage: https://science.nasa.gov/resource/radiation-measurements-on-mars/

              where it says that average radiation intensity is around 200 μGy/day which is about 73 mGy/year (365 days).

              and this XKCD radiation dose chart: https://xkcd.com/radiation/

              where it says “maximum dose permitted by US radiation workers: 50 mSv/year” and “lowest dose clearly linked to increased cancer risk: 100 mSv/year” so yeah we’re right in the middle between these two. still, i’m not sure by how much the risk is increased but i assume it means “above detectable threshhold” which i assume is still pretty small. so i don’t think that radiation alone will stop people from taking the risk and going there. contrary to what the newspapers present. europeans first going to america didn’t face a no-risk journey either and they were still willing to go.