3 ms·
From the actual paper: “The shortest Earth–to–Mars flight times will be in 2030 and 2050, corresponding to periods of solar max. Current work shows that for the
by cwillu 3y ago
From the actual paper: “The shortest Earth–to–Mars flight times will be in 2030 and 2050, corresponding to periods of solar max. Current work shows that for the previous solar cycle, the smallest effective dose would have been accumulated for a flight starting in 2000, during solar max. For an optimal average shielding of 30g/cm², the effective dose would be 0.5 Sv after a 1.9-years flight and astronaut's career dose limit of 1 Sv would be accumulated after a 3.8-years flight.”
This is talking about the flight time to and from mars, not the time actually spent on mars.
Even ignoring that it's 4 years of flight time, “No one can survive longer than 4 years” is utterly ridiculous: an astronaut who exceeds his career dose limit does not suddenly drop dead of cancer.
- credit_guy 3y agoWhere did they pull the 1.9 years of flight? The SpaceX plans to go to Mars talk about 80 to 150 days, with 115 days average [1]. [1] https://en.wikipedia.org/wiki/SpaceX_Mars_program#Colonization_and_terraforming https://en.wikipedia.org/wiki/SpaceX_Mars_program#Colonizati...
- cwillu 3y agoThey're talking more in terms of “if we wanted to maximize the time spent in transit”: “[…] Several studies considered radiation doses during 500- and 1000-days flights, according to NASA plans (Drake et al., 2009). However, there is still no clear answer about optimal flight conditions that would enable the longest mission duration. In this study, we present the net radiation doses from SEP and GCR radiation as an accumulated dose during a spaceflight, dependent on flight duration and launch date for the time period between 1998 and 2006. […] Our simulations show that for solar cycle 23 and aluminum shielding, the mission duration–assuming a 1 Sv mission limit–should not exceed approximately 4 years.” -- https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021SW002749 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/202... Reference Drake et al, 2009: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021SW002749#swe21195-bib-0006 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/202...
- credit_guy 3y agoI don't get it. Why would they do that, and then "declare Mars unsafe for humans"? It's like saying "you can't finish a Marathon if you start by shooting yourself in the foot". Well, duh?
- cwillu 3y agoThat's my point: the headline is utterly misleading as to the content of the paper it's talking about. The paper is talking about travel time, but the blogspam and its title is making an statement about mars itself.