5 ms·

On the one side, you have a point, but on the other... as the article mentioned, a moon round trip can be done in the span of a week, they can set the craft on

On the one side, you have a point, but on the other... as the article mentioned, a moon round trip can be done in the span of a week, they can set the craft on a trajectory so that it has a free return even if the thing becomes uncontrollable. Not so for Mars trips, after a few hours they're committed to the trip. The article then mentions everything that can go wrong. I'm confident that if they tried to launch a Mars mission with current-day technology now, the crew wouldn't make it. Nobody's ever been in space for that long, to start - yet Musk wants to deorbit the ISS, the only viable platform at the moment to even try and simulate a two year space trip.

Robotbeat 2y ago
“Current day technology” is sort of poorly defined because you can make new technology in one day. “Current tech” is a fake constraint, because even preparing for a launch in two years, you’d be developing new technology all along the way. The annoying thing is that we could’ve been simulating long duration partial gravity using artificial gravity for decades, but NASA has refused to do so. For inexplicable reasons. If I had to guess, it’s due to the microgravity research community fiefdoms who have made a career of microgravity health effects and so don’t like the idea of directly addressing them using artificial gravity as it makes a whole career’s worth of work largely obsolete.
- Retric 2y ago
  > you can make new technology in one day. Not if you want it dependable enough to entrust a multi billion dollar project and several people’s lives to it. People talk about the moon mission like some massive conquest of space, but we needed to get the fuck off the moon much past sunrise or astronauts would have cooked. It was based on extremely limited oxygen supplies and involved significant radiation exposure that was only ok because again we ran away from an extremely inhospitable environment before things went wrong. Even today the ISS benefits from earths magnetic field, its space light not a true replica of a mars mission.
  - Robotbeat 2y ago
    Note that Mars’ surface has a similar radiation dose as ISS, as measured by the Curiosity rover. (This includes the quality factor.)
    - Retric 2y ago
      A significant part of that is because it’s much further from the sun. A hypothetical 500 day mars mission is ~1 Sv optimistically which is something like 5% fatal cancer risk. A 3 year mission you’re well above that even before considering solar storms etc. I think many would sign up for a mars mission especially as treatment improves, but there’s only so much wiggle room here.
    - idlewords 2y ago
      It does not; see the paper cited in my other reply to you. GCR dose is 1.5-2x on Mars compared to ISS. The mention of "quality factor" here just begs the question. The reason we need research on biological effects of high-Z ion exposure is that it has a different mechanism of damage, not captured by that paradigm.
      - Robotbeat 2y ago
        GCR /alone/, maybe, but it’s, um, strange to pretend the substantial trapped radiation dose on ISS doesn’t exist, as you’re doing here (Table 2 in your linked paper shows the trapped dose at ISS is about equal to the GCR dose at ISS, so ignoring trapped dose makes your estimate off by approximately a factor of 2). It is the total effective dose (including quality factor) which matters, not cherry picking one particular source.
        idlewords 2y ago
        The 2-3x uncertainty in tumor risk comes entirely from the heavy ion component of GCR. Please go back and re-read that section of my post if you need to.
        2y ago
- iab 2y ago
  I think this shows a fundamental, widespread misunderstanding of space flight in general: > you’d be developing new technology all along the way Aerospace does not work like this. Hardware does not evolve until launch, it is frozen in time to allow for testing and flight qualification for subsystems, and systems as a whole.

Robotbeat 2y ago

“Current day technology” is sort of poorly defined because you can make new technology in one day. “Current tech” is a fake constraint, because even preparing for a launch in two years, you’d be developing new technology all along the way. The annoying thing is that we could’ve been simulating long duration partial gravity using artificial gravity for decades, but NASA has refused to do so. For inexplicable reasons. If I had to guess, it’s due to the microgravity research community fiefdoms who have made a career of microgravity health effects and so don’t like the idea of directly addressing them using artificial gravity as it makes a whole career’s worth of work largely obsolete.

Retric 2y ago
> you can make new technology in one day. Not if you want it dependable enough to entrust a multi billion dollar project and several people’s lives to it. People talk about the moon mission like some massive conquest of space, but we needed to get the fuck off the moon much past sunrise or astronauts would have cooked. It was based on extremely limited oxygen supplies and involved significant radiation exposure that was only ok because again we ran away from an extremely inhospitable environment before things went wrong. Even today the ISS benefits from earths magnetic field, its space light not a true replica of a mars mission.
- Robotbeat 2y ago
  Note that Mars’ surface has a similar radiation dose as ISS, as measured by the Curiosity rover. (This includes the quality factor.)
  - Retric 2y ago
    A significant part of that is because it’s much further from the sun. A hypothetical 500 day mars mission is ~1 Sv optimistically which is something like 5% fatal cancer risk. A 3 year mission you’re well above that even before considering solar storms etc. I think many would sign up for a mars mission especially as treatment improves, but there’s only so much wiggle room here.
  - idlewords 2y ago
    It does not; see the paper cited in my other reply to you. GCR dose is 1.5-2x on Mars compared to ISS. The mention of "quality factor" here just begs the question. The reason we need research on biological effects of high-Z ion exposure is that it has a different mechanism of damage, not captured by that paradigm.
    - Robotbeat 2y ago
      GCR /alone/, maybe, but it’s, um, strange to pretend the substantial trapped radiation dose on ISS doesn’t exist, as you’re doing here (Table 2 in your linked paper shows the trapped dose at ISS is about equal to the GCR dose at ISS, so ignoring trapped dose makes your estimate off by approximately a factor of 2). It is the total effective dose (including quality factor) which matters, not cherry picking one particular source.
      - idlewords 2y ago
        The 2-3x uncertainty in tumor risk comes entirely from the heavy ion component of GCR. Please go back and re-read that section of my post if you need to.
        2y ago
iab 2y ago
I think this shows a fundamental, widespread misunderstanding of space flight in general: > you’d be developing new technology all along the way Aerospace does not work like this. Hardware does not evolve until launch, it is frozen in time to allow for testing and flight qualification for subsystems, and systems as a whole.