Possibly the real reason: Money.
<delurk>1) Scott Kelly's spaceflight is tied for fifth place for longest duration, with his crewmate Mikhail Kornienko. Four Russians have previously made longer spaceflights, between 1987 and 1998. They are all still alive. However "devastating" the effects of a year-long LEO spaceflight are, they apparently aren't bad enough to kill you within 20-30 years. Beyond-LEO radiation may be another story, but that's not what this article was about.2) ISS centrifuge was designed for small mammals at most, not humans. Would have been only of indirect use to the human research program, and would have been expensive to get it to work without excessive vibration loads on the rest of ISS. Cancellation was the right call, IMO.<lurk>
Do we know if NASA and Russia are planning a new long duration mission?
HOUSTON—There is a strong desire within NASA’s human research community to launch more U.S. astronauts on “one-year” International Space Station missions. But more of the potentially record-setting flights—intended to reveal physical and psychological challenges associated with the agency’s human deep space exploration aspirations—are not planned until commercial crew operations are ...
NASA took advantage of the unique opportunity of having a set of twin brothers as astronauts by studying each to take a closer look at the effects on the human body after spending a year in space. For those in the dark on the U.S. space agency's study, astronaut Scott Kelly and his twin brother, Mark Kelly, took part in NASA's "Twin Study." The study looked at what a year in space did to Scott Kelly while Mark Kelly spent the year on Earth. "By measuring large numbers of metabolites, cytokines, and proteins, researchers learned that spaceflight is associated with oxygen deprivation stress, increased inflammation, and dramatic nutrient shifts that affect gene expression," NASA reports in its preliminary findings."After returning to Earth, Scott started the process of readapting to Earth's gravity. Most of the biological changes he experienced in space quickly returned to nearly his preflight status. Some changes returned to baseline within hours or days of landing, while a few persisted after six months."
When I was at IAC 2017 in Adelaide, I attended the microgravity research symposium among others. Very interesting sessions.One thing I feel its worth pointing out that the general consensus of the NASA, ESA and Russian researchers there was that some form of spin gravity will be required in the future for long duration (>3 year) manned missions. They may not have a lot of sway to influence the HSF programs yet, but I am fairly sure it will happen eventually. Why do many biologists seem to hold this view in spite of the relatively quick recoveries of long-duration astronaut stays in space? The reason for this in my opinion is because of an understanding of the way biological systems respond to stress. Biological systems are (generally) heavily redundant, and if some fundamental process needs to happen, but cannot occur using the usual pathway (e.g. because a gravity induced osmotic-gradient is missing), some other process can be hijacked to take the load. But these backup processes are not adapted for these tasks, so this alternate process results accumulative inefficiencies that lead to thresholds beyond which they break down.Sleep deprivation may be a good analogy here (different time-scales obviously). We can all go without sleep if we need to. We do not understand all the processes that occur during sleep, but there are obvious, accumulative changes that occur the longer it continues. We also know that even a little sleep can go a long way to "recharging the batteries" so to speak.We do know that many biological processes make use of gravitational potential energy to achieve certain tasks, but that in the absence of gravity at least some of these tasks can still be achieved. But because these are non-standard processes, we assert there must be some threshold, somewhere beyond the 438 days that Valeri Polyakov achieve, where those processes will break down. Ergo, we need spin-gravity. And if it is as big an engineering challenge as they say, we should get started on it.
Should the thread title be modified to "'Astronaut Scott Kelly on the devastating effects of 11 months & 3 days in space" ? 😉
Pedantry noted but I think the title of the thread is taken from the title of an external article.
QuoteNASA astronaut Scott Kelly spent a year in space. His recollections of this unprecedented test of human endurance, and the physical toll it took, raise questions about the likelihood of future travel to Mars.http://www.theage.com.au/good-weekend/astronaut-scott-kelly-on-the-devastating-effects-of-a-year-in-space-20170922-gyn9iw.htmlEdited extract from Endurance: A Year in Space, A Lifetime of Discovery by Scott Kelly (Doubleday, $35), published on October 19.Article paints a pretty bad picture about the effects of long term microgravity on people. May not be a showstopper for short Mars missions but I am growing increasingly convinced that a true colonization will simply require natural gravity. Actual colonies with people living on them located on rotating space stations, Moon/Mars/asteroids for industry/science only. Thoughts?
NASA astronaut Scott Kelly spent a year in space. His recollections of this unprecedented test of human endurance, and the physical toll it took, raise questions about the likelihood of future travel to Mars.
Possibly the real reason: Money.A conspiratorial reason: The Zero-G scientists don't want to research artificial gravity because it will put them all out of jobs.
BFS/BFR, if it lives up to its expectations, could be a real test to see there's any truth to this. Low cost LEO AG experiments could surely be done utilizing BFS.
Quote from: mike robel on 11/21/2017 03:50 amPossibly the real reason: Money.It's always about the money, even when it's "not about the money." Especially when it's "not about the money."
I note with some bemusement that mainstream media is trying to say that the Kelly brother's DNA no longer matches after the long duration flight. I'm no biologist or geneticist, but I would have thought that actually isn't possible?! I mean; it's not like he's been exposed to huge levels of gamma radiation and is going to Hulk-out at any moment...
Scientists studying Scott found that much of his gene expression changed while in space, and about 93 percent of his expression levels went back to normal when he got home. However, 7 percent of his genes related to the immune system, DNA repair, bone formation, and more were still a little out of whack when he returned. These genes are referred to as the “space genes,” according to NASA.