January 15, 20224 yr 3 minutes ago, birdguy said: That was only 6 or 7 years ago. To determine long term effects you have study the astronaut's physicals for at least a couple of years. Noel Well yes 7 years ago. Former astronauts get a whole battery of tests for a long time after returning to Earth, I suspect for life, after all, they are among the few human beings that have spent an extended period in space and much can be learnt from them, they are a valuable medical resource. There are loads of regular medical tests they have to go through, even dermatological tests and behavioural tests. I recall its something like 15 astronauts that have spent a long duration in space. All of them are still alive and Ive not heard of any life threatening issues they have.
January 15, 20224 yr Author 10 minutes ago, martin-w said: I recall its something like 15 astronauts that have spent a long duration in space. All of them are still alive and Ive not heard of any life threatening issues they have. Still alive and nothing life threating is not an indication of good health or other non-life threatening conditions. A lot more study for longer periods of time will determine lasting effects of diminished but not life threatening conditions. https://www.aau.edu/research-scholarship/featured-research-topics/study-looks-how-astronauts-body-changed-after-year Noel The tires are worn. The shocks are shot. The steering is wobbly. But the engine still runs fine.
January 15, 20224 yr Actually there's an discrepancy in that article. It states the health of astronauts has long been studied "but" most astronauts travel on missions of 6 months or less, not as long as a trip to Mars. When in fact the duration of a flight to Mars is indeed 6 months with current technology and once there the astronauts are in a gravitational field. Quote Still alive and nothing life threating is not an indication of good health or other non-life threatening conditions. As yet they haven't found any. And they haven't found any in the 15 astronauts who have previously spent up to a year in space either as far as I know. And as for epigenetic changes, as they article states... Quote "However, since we only have two people in our study, we can't say that these changes are due to space travel itself," says Feinberg. "We need more studies of astronauts to draw such conclusions." Quote Overall, they found that about just as many epigenetic changes occurred in earthbound Mark's DNA as occurred in his space-flying twin. There was a less than 5 percent difference in overall methylation between the twins during the mission. Quote "It was encouraging to see that there was no massive disruption of the epigenome in either Mark or Scott," says Rizzardi. "However, with only two people in the study, we're limited in the conclusions we can draw about the effect of space travel on the genome. With only 5% difference between the twins, seems they were quite encouraged by the findings and again, on Mars astronauts will be in a gravitational field, not micro gravity in orbit. What the twins microgravity orbital research does do is point to where science should look for potential issues. Quote "If we know what to expect," he says, "we can anticipate health problems astronauts may encounter and ensure that medicines and other remedies are at hand during a mission." Edited January 15, 20224 yr by martin-w
January 18, 20224 yr A manned round trip to Mars will probably take two to three times longer to return to Earth: A year, or a year and a half... Besides the affects of zero gravity, how can life-sustaining on-board supplies last that length of time?
January 18, 20224 yr Administrators 17 minutes ago, overspeed3 said: A manned round trip to Mars will probably take two to three times longer to return to Earth: A year, or a year and a half... Besides the affects of zero gravity, how can life-sustaining on-board supplies last that length of time? Why would the trip back take longer? If that is the case then they better count on a one-way trip with resupply missions! 🚀 Charlie AronAVSIM Board of Directors-ADMIN/Moderator-RegistrarJust going to run a Chromebook and not upgrade to a Windows computer. Too many problems with the new Sims! 😱Trying to keep peace and harmony and the will of Landru on the site seems to be a full time job!
January 18, 20224 yr Author Doesn't a trip to any planet have to be scheduled when the planet is in the right alignment or position vis-a-vis earth? And when that window has passed doesn't the trip take longer? If that is correct then going to Mars when the planetary alignment is optimum then after being on mars for a time that window will close so the trip back would be longer. Is the window for the return trip the same as the window for the arriving trip? How many times a year is the alignment between Earth and Mars optimal? I ask this not knowing a damned thing except some vague recollections of what I might have heard somewhere because I am not a space travel buff. So if I am wrong about all of this I'm sorry. Noel The tires are worn. The shocks are shot. The steering is wobbly. But the engine still runs fine.
January 18, 20224 yr Moderator 11 minutes ago, charliearon said: Why would the trip back take longer? It's a matter of orbital mechanics. The position of Mars' orbit isn't static relative to Earth. So while the outbound voyage to Mars is planned to arrive when it is closest to Earth, the return voyage will take longer because by then the distance from Earth has increased significantly.... Fr. Bill AOPA Member: 07141481 AARP Member: 3209010556 Avsim Board of Directors | Avsim Forums Moderator
January 18, 20224 yr Administrators OK, that explains the longer travel time for a short stay on Mars. Maybe plan a longer stay until the distance shortens again! Charlie AronAVSIM Board of Directors-ADMIN/Moderator-RegistrarJust going to run a Chromebook and not upgrade to a Windows computer. Too many problems with the new Sims! 😱Trying to keep peace and harmony and the will of Landru on the site seems to be a full time job!
January 18, 20224 yr 26 minutes ago, charliearon said: Maybe plan a longer stay until the distance shortens again! The closest distance occurs about every two years, I believe, but, if the journey takes four years one way, eight years return journey, you'd have to stay on Mars for two years to make the journey worthwhile, so ten years total time off Earth. Edited January 18, 20224 yr by dmwalker Dugald Walker
January 18, 20224 yr Author I think your math is off Dugald. Outbound 4 years, inbound 8 years, layover 2 years adds up to 14 years total off earth time. That's a long time to be away from your loved ones. Noel The tires are worn. The shocks are shot. The steering is wobbly. But the engine still runs fine.
January 18, 20224 yr 34 minutes ago, dmwalker said: if the journey takes four years one way, eight years return No. Its also dependant on fuel burn. SpaceX are saying that with orbital refuelling the journey time there is 6 months. Quote Several types of mission plans have been proposed, including opposition class and conjunction class,[5] or the Crocco flyby.[7] The lowest energy transfer to Mars is a Hohmann transfer orbit, which would involve a roughly 9-month travel time from Earth to Mars, about 500 days (16 mo) at Mars to wait for the transfer window to Earth, and a travel time of about 9 months to return to Earth.[8][9] This would be a 34-month trip. Shorter Mars mission plans have round-trip flight times of 400 to 450 days,[10] or under 15 months, but would require significantly higher energy. A fast Mars mission of 245 days (8.0 months) round trip could be possible with on-orbit staging.[11] In 2014, ballistic capture was proposed, which may reduce fuel cost and provide more flexible launch windows compared to the Hohmann.[12] https://en.wikipedia.org/wiki/Human_mission_to_Mars
January 18, 20224 yr Administrators Dang! was also thinking that 4 years outbound and then 8 years inbound was awfully long! Charlie AronAVSIM Board of Directors-ADMIN/Moderator-RegistrarJust going to run a Chromebook and not upgrade to a Windows computer. Too many problems with the new Sims! 😱Trying to keep peace and harmony and the will of Landru on the site seems to be a full time job!
January 18, 20224 yr 2 minutes ago, birdguy said: I think your math is off Dugald. You are probably right. However, the reason the return journey would be longer is that, by the time you get there, the window of the closest distance will have passed. That would be the case if you return as soon as you get there. I presume that, if you time the length of stay on Mars to catch the beginning of the next window, the inbound journey would be the same as the outbound journey. Dugald Walker
January 18, 20224 yr Author I've done the short Mars trips in deployment to war zones here on earth. Now I'm wondering which one would be more dangerous. Noel The tires are worn. The shocks are shot. The steering is wobbly. But the engine still runs fine.
January 18, 20224 yr 51 minutes ago, martin-w said: SpaceX are saying that with orbital refuelling the journey time there is 6 months. That sounds pretty good. That's one reason why I didn't become an astrophysicist. Edited January 18, 20224 yr by dmwalker Dugald Walker
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