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Time-in-Space Record Broken
NoFrance writes "Russian cosmonaut, Sergei Krikalev has taken the record for most time spent in space away from fellow Russian Sergei Avdeyev. At 748 days in space, Krikalev has an impressive list of accomplishments to his name, including : back-to-back 6 month tours on mir, he flew on the first joint US-Russian space shuttle mission, and a member of the first crew to live on ISS. He is currently commander of the ISS in a six-month stint that began on 14 April. Most impressive is his ability to deal with the physical hardships in space. In space most people lose around 1.5% of their bone mass per month, even with a disciplined exercise regime. And growing the bone mass lost from a 6 month stint back, can take a long time."
Yeah, I wonder how they prepare themselves psychologically for such a journey. As for the record amount of time spent in space by an American astronaut is Shannon Lucid with 188 days
Calcium suppliments don't help. The problem is your body realises that you have too much muscle mass and that you are too strong for microgravity, so it stops reinforcing your bones until it percieves a need to strengthen your bones. It's not a lack of available calcium. It is the exact same phenomenon that plagues people on bedrest. Even though they are given the best food and nutrition available when they are off bedrest they are weak and frail.
-everphilski-
That's Mrs. Krikaleva. Russian names change depending on gender. /pedantic
http://en.wikipedia.org/wiki/Spaceflight_records#T otal_time_in_space_-_top_50_space_travelers
* Winners compare their achievements to their goals, losers compare theirs to that of others.
Thanks, but this is the record for the most time spent in space cumulatively - if I understand correctly, Lucid's record 188 days were a single stay. :)
Oh, and out of curiosity (sorry for going off-topic here), how'd you manage to post a score 0 comment without either being AC or getting modded down? o.o
quidquid latine dictum sit altum videtur.
Centripetal-force-generated artificial gravity systems, like those envitioned by Arthur C. Clarke shown in the film 2001, have been studied by NASA and the Air Force for decades. Basically, it would require a structure of a few hundred meters radius rotating at a few rpm. The scale of such a habitat would be enormous, and the cost associated has not been shown to be warranted as of yet. However, the commercialization of space will probably bring about such an innovation out of necessity (for comfort).
Links here, here, and here.
According to Space Today, the U.S. space endurance record holder is former ISS commander Michael Foale, with a total of 375 days spent in space (note that it's the record for cumulative time spent in space. The longest time spent in space on a single mission is 438 days).
Man is a slave because freedom is difficult, whereas slavery is easy.
There is no simple artificial gravity solution.
I'm sure every slashdotter has seen multiple sci-fi examples of a huge spinning doohickey that replaces gravity with centrifugal[1] force.
Four problems I can see:
1) If the radial arm is too short, there are tons of biological side effects. Coriolis forces and angular momentum are the two major factors causing these side effects, which can be mediated by intermittent spinning.
2) An engineering nightmare, especially if done intermittenly.
3) A logistical nightmare. If the radial arm is long enough to prevent the side effects, construction and maintenace service would, I believe, be beyond acceptable costs.
4) Would make impossible all the long-term zero-g experiments we need to continue doing.
However, there is currently renewed research into the idea. I was able to find an entry for the Mars Gravity Biosatellite in Wikipedia, but there is not much information there.
Anyone know more info (such as projected launch date) about the MGBS or other artificial gravity experiments?
[1] Yeah, yeah, it doesn't really exist. But it's a useful term.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
Micheal Foale a British born astronaut with dual US/UK citizenship has spent 374 days, 11 hours, 19 minutes in space. I believe this is the extra-Russian record.
872835240
Besides, that last one to show up there wasn't a bus at all. It arrived with a load of freight, and left with a load of trash. In most writings, this is a class of vessel commonly referred to as the 'garbage scow'.
Calcium supplements wouldn't help, but there is work being done that may one day lead to a suppliment that would prevent bone loss.
My patience is infinite, my time is not.
what else makes the bone mass come back?
I can answer that. Although this comes as a surprise to many people, bone is actually living tissue. It undergoes two continuous processes. On the one hand bone is continually reabsorbed by the body, and the minerals (mostly calcium and phosphate) end up in the blood stream. And on the other hand, new bone is always created as well. Those self same minerals are taken out of the bloodstream and deposited to make new bone.
Now the problem occurs because of the following. One of the main factors that determines where and how new bone is deposited is the constant traction against the bone by tendons. These tendons are attached on one end to the bones, and on the other to muscles. So muscle activity, which puts tension on the tendons, actually favors bone formation along the stress lines in the bone.
The only problem is that there is just so much muscle activity that you can get from an excercise program. This pales in comparison to the CONSTANT activity that your support, or anti-gravity muscles are doing all the time, 24hrs a day, in an involountary fashion. Now in space, the effects of gravity are gone. So the anti-gravity muscles stop working. So you end up losing the most part of the stimulus that promotes new bone formation. Hence, you get bone loss. The rate of reabsorbtion is now greater than the rate of formation.
How does it come back? Only through time, excercise, GRAVITY, calcium supplements, vitamin D, and in extreme cases, PTH (parathyroid hormone). Although the physiological function of this hormone is to promote bone reabsorbtion (ie loss), no one is sure why it actually does the opposite when used as a drug. Remineralizing a bone is a slow process however. This astronaut will NEVER get back to where he was when he left Earth.
Seven puppies were harmed during the making of this post.
Exercise generally does squat to retain or build bone mass. NASA research has been indicating that it's the vibrations which occur while you're exercising that actually stimulate the bone growth.
w eak_knees.html
http://www.nasa.gov/lb/vision/earth/everydaylife/
http://my.webmd.com/content/article/34/1728_85890
http://www.galileo2000.nl/home/Eng-galileo.htm
Astronauts will still have to do exercise to keep from losing excessive muscles but in the future we'll just vibrate them a bit while they're in orbit to keep them from losing bone density.
Yes, I see:
Javascript + Nintendo DSi = DSiCade
Orion (actually, Medusa - Orion is dated and inefficient) is hardly the only high ISP/high thrust nuclear propulsion method available. In addition to nuclear thermal (not as high ISP, but no EMP and little to no radioactive waste, so can theoretically be used in Earth orbit), there are the antimatter catalyzed microfission and microfusion engines, and fun things like nuclear saltwater engines (dirty, but no EMP - you have subcritical fissile salts in water kept in neutron-absorbing capillaries; the water is injected into the engine, where it goes critical)
There are lots of neat currently-achievable nuclear low-thrust methods as well.
Kneel Before Christ!
Our experiments with space tethers thusfar have had less than spectacular results, and we're talking about putting a heck of a lot more force on them. About half of the experiments thusfar have ended with a broken tether. One problem was on a charged tether: gas bubbles in the insulation turned to plasma and cut the tether. On another, the shock of the tether deployment stopping led to the failure of the cable. One problem not yet experienced but known to be a risk factor is orbital debris, so a hoytether would be needed.
Basically, it needs more research and tests, but the funding isn't there. But the benefits are potentially great - not just for artificial gravity, but for magnetospheric orbital boost as well.
One problem, by the way, of artificial gravity using rotation: uneven centrifugal forces. Your feet experience more force than your head, inversely proportional to the radius of the circle traced out by the floor and proportional to your height. If you have a narrow circle, you won't have as much blood going to your head, and it'd get uncomfortable. So, you'd want a wide circle.
Also, centrifugal craft/stations for which any docking needs to be done are more complex. You need either the craft that is going to dock to be rotating synchronously, or to have a stationary central hub on your craft/station which connects to the rotating segment. Retaining an airtight craft/station with such a hub would be no simple task. Alternatively, you could stop and restart the rotation of the craft/station, but if this is going to be done regularly, you want a propellantless method to do this (such as two sections rotating in opposite directions - but then, you have complications in travelling between the two)
Kneel Before Christ!
See, it's very simple. The man who spent 438 days in space on a single mission is Russian, while the man who has spent 375 days in the space altogether is an American. The American single mission record is 193 days.
Man is a slave because freedom is difficult, whereas slavery is easy.
We need to figure out how to get rid of the fallout though
;-)
Supposedly, they have. Pratt and Whitney only need a buyer before they start constructing the engines. The engine is a tri-mode jobbie that can do high Isp thrust in space, and low (for NTR) Isp afterburning for high thrust, atmospheric work. Once in space, the engine can idle to produce ship's power.
Nice engine, eh? I want one.
Javascript + Nintendo DSi = DSiCade
I do bone density measurments for a living so here are some comparisons.
If he has been loosing 1.5% of his bone mass a month (this is measured from a baseline prior to flight) he's down around 36%. This would put him 6-7 standard deviations below what's normal for his age. While this is very very serious consider these two things.
1. The younger you are the better your bones are at avoiding fracture regardless of bone mass. Low bone mass doesn't help of course, but he's still probably better off than a 75 year old woman.
2. People with various diseases like celiac sprue are seen to have densities this low and recover very well when the cause is eliminated. Thus when he returns to normal g he should see rapid bone remineralization. However
This process will take two or more years. So if you wanted to know what "a long time" means. There it is. After two years at 1 g, I suspect his bone mass will be 95% of what it was at baseline.
In the meantime he has a hugely increased risk of fracture and will/should probably have to wear all sorts of special padding just in case he falls over.
As Re-entry can easily hit 5g, I think that would be the scariest part of the whole ordeal.
I would be interested to know if he will be put on an anti-resorptive thearapy such as Fosamax or even Forteo, though they would probably only do that if he wasn't regrowing bone on his own.
-Ian, CDT.
Both you and thc69 asked basically the same question. As just a plain old GP I have no idea how to give you a specific, definitive answer.
:)
I know that this kind of equipment already exists - harnesses that you can slip onto certain joints, connected to electric motors and computers. These units cause continual passive movement at the joint, and they are used by orthopedists and rehabilitation specialists for just that purpose - rehabilitation after an injury, after a long period of inactivity (casts, extended stays in intensive care) or to slow down muscle loss/atrophy after damage to the nervous system.
There are also electrical units that stimulate the muscles causing them to contract constantly.
However my understanding is that although these units are reasonably good at maintaining or even improving muscle tone and flexibility at the joint, they are not so good as far as stimulating bone growth is concerned. There's just not enough force involved. You don't just need a muscle contraction, you need muscle pulling a bone against the resistance of gravity. You have to have an opposing force, to create stress in the bone. It's the stress in the bone, not moving the bone, that causes new layers of minerals to be added.
I guess you could design something that also provides an opposing force - with a couple additional problems. First, you have to make sure that the stress lines you create line up with how gravity would cause them to be lined up, or you would get really weird bone deformities after a while. The shape of a bone is not only defined by genetics but also by its relation to surrounding structures, and the forces it is subjected to. The body is really neat in this way - a design that adjusts all on its own for use or lack of use, or weight changes in the organism. Second, it would be quite a bulky unit. Third, there's no real way you can get to and exercise the vertebrae properly in this manner, and compression fractures of vertebrae are a big problem in osteoporosis and potentially astronauts!
For more detail you'd have to ask a specialist though
Seven puppies were harmed during the making of this post.
Actually the SR-71 doesn't leak to cool the skin of the aircraft; it leaks because at operating speeds the parts come together due to thermal expansion. If it were built to be air/water/fuel-tight in the hangar, thermal expansion would cause way more problems for the airframe than a bit of lost fuel.
Ita erat quando hic adveni.
Of the 33 top place getters, 31 are Russian.