The key to commercial success in space

[fwyesterday]

I believe that for humans to attain any real "sizeable" success commercially in space (which I believe is the key to getting on the fast track to real progress), mankind will need to figure out a way to simulate gravity. The challenges before we even get to this point are of course difficult, but are already being worked on with seemingly good progress by both commercial and public sectors. Astronauts and the most exceptionally physically gifted among us can tolerate zero or similar gravity via strict regimens and training .. but I find it hard to believe that the average human will ever adjust enough (or spend their hard earned money) to live or play in space for extending periods without making a truly earth-like experience possible. Sure it would be cool to experience an hour up to one day of zero G, but this would get old FAST, especially when the easiest tasks such as going to the bathroom, or swallowing your dinner are concerned.<br /><br />I know there are theoretical cases for accomplishing the simulation of gravity via centrifugal force or the like, but how close to getting to "prime time" are we really in accomplishing this with current or "on the horizon" technology? Is it even feasible? Are there other methods for accomplishing this?<br /><br />Would love to hear others' take on this. <br />

 

[jimfromnsf]

"Astronauts and the most exceptionally physically gifted among us can tolerate zero or similar gravity via strict regimens and training"<br /><br />Astronauts are normal and not exceptionally physically gifted. They are the same as you and me. Exercise is the key to zeroG

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>Astronauts are normal and not exceptionally physically gifted. They are the same as you and me. Exercise is the key to zeroG<p><hr /></p></p></blockquote><br /><br />Aww...and I thought the had two brains! LOL! <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[holmec]

Studies have been done on the centrifuge. With rats, they found that they can adjust and live in 3G environments.<br /><br />Besides the centrifuge, there may be three other ways (that I am aware of) to create gravity.<br /><br />The first one is obvious but not sustainable, at this time, is to accelerate your craft a 1G constantly.<br /><br />The other is sort of a compramise. Using magnetic fields.<br />Like in Sci-Fi you can have magnetic boots that stick to a surface. If you don't stick to the surface directly, you can unstick easier. If you have a magnetic field big enough you can apply a force on any organism, but that uses up a lot of power. Or you could have a less powerful field that only affects inanimate objects, so Astronauts would don suits that are affected by the magnetic field.<br /><br />Another idea is not to use artificial gravity at all but a suit that resists motion thus causing muscles to work and bones to experience force. This idea is along the line of isometric exercise.<br /><br /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[thereiwas]

But only real gravity, whether by acceleration or rotation, helps with your internal organs and postural muscles. The astronauts experience a "full head" feeling due to fluid accumulation. As a result they have little sense of taste and can't enjoy their food. They'll put taco sauce on breakfast cereal to try to make it appetizing. Only real gravity helps with that

 

[fwyesterday]

Very cool stuff guys .. thanks. What about the whole 2001 (movie) premise whereby a spacecraft spins forcing everything against the perimeter ..is this that far fetched to implement with current technology ...?

 

[Boris_Badenov]

<font color="yellow"> What about the whole 2001 (movie) premise whereby a spacecraft spins forcing everything against the perimeter ..is this that far fetched to implement with current technology ...? </font><br /><br />The technology has been available for around 40 years.<br /><br /> Self-Deploying Space Station <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[skyone]

The resistive suit has been tested before, and no one liked it. Extremely uncomfortable.

 

[qso1]

The 2001 station featured something that we could do now but technology is not the reason for not having gravity...cost is.<br /><br />Its too expensive to develop a large enough craft to generate a rotation of 1G at a low enough RPM to prevent vestibular problems for the crew/passengers. If current private sector efforts work out, the space tourism industry will not need gravity in spacecraft because the tourists won't be in orbit for more than a few days tops.<br /><br />One day if we get sufficiently industrialized in low orbit, we will probably see the 2001 type stations be developed for long term space crews. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[jimfromnsf]

"The resistive suit has been tested before, and no one liked it. Extremely uncomfortable."<br /><br />They are used by every ISS crew member. They are called penguin suits

 

[holmec]

Thanks for the info. I didn't know they tried that one out. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[holmec]

But the easy way is to have a counter weight, and have cables/ropes strung between a capsule and the counter weight (SM?). You don't need a wheel per say. <br /><br />Also I question the "vestibular problems" related to centrifugally force. I don't see NASA worrying about it. On top of that humans don't necesarily need 1G. We need to find the optimum, and my guess that its a fraction of a G.<br /><br />link<br /><blockquote><font class="small">In reply to:</font><hr /><p>There is ample motivation for the development of and testing an artificial gravity rotating device to prevent the major physiological deconditioning associated with long duration space flight. The space station, which is to be largely devoted to investigation of the problems of human long duration flight, will eventually afford the opportunity to test a variety of countermeasures which could be used for a Mars exploration mission. Before embarking on the expensive research program associated with human artificial gravity in space it is important to assess the neuro-vestibular implications of this "ultimate countermeasure". <p><hr /></p></p></blockquote><br /><br />This apparently is from 1996. Then, according to this, they did not know what effects it had on the neuro-vestibular system. Also they say what I said, that there should be a study on the optimal rotation rate and Gs and distance.<br /><br />Has such a study been conducted? (I hope so by now)<br /><br />And it has to be done in space because we can only run our centrifuges at + 1G (hyper gravity) on the ground. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[j05h]

The problem is not muscular degeneration, it is calcium loss in bones, especially in the hip joints. Hips need stressing daily, the bone gets weaker and spongier quicker than other bones, and needs constant toughening. Osteomedicine can only go so far. <br /><br />Rotational spin-G is far simpler than "2001". On a Mars trip, the crew module docks with it's departure stage, then uses a winch system to let out a long tether. Both modules thrust to spin up, the line can be a klick long if you want but swing-arm length can be on the order of several hundred meters. <br /><br />For people living in freefall, they may build higher-G centrifuges. Instead of trying to spend 4-6hrs a day at 1G, they might spend 1 hour exercising at 2G. On Mars, a person might do squats wearing a heavy vest.<br /><br />Artificial G isn't the real deal breaker for human commercial spaceflight. Mars is only 6 months away, the Moon 3 days. Tourists in LEO will want to experience freefall, and when the industry is such that large O'Neill-type habitats can be built, there will be a G-level for everyone, and custom "worldlets". Proper diet and exercise do amazing things for bone retention even now.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[vulture2]

Generating 1-G with a small centrifuge requires a very high rate of rotation. Rotating at anything over 1-2 rpm causes symptoms in some people, though 3-5 RPM is probably tolerable for most. Turning your head while on a rotating structure causes a striking sense of tumbling and can induce nausea.<br /><br />Physiologically, there are several solutions, <br /><br />1) Generate 1-G by a long tether and counterweight structure<br />2) Generate partial gravity by a shorter tether or linear rigid structure with counterweight, include some exercise.<br />3) 0-G with daily exercise, as is done today by most flight crew. <br />4) 0-G without exercise and accept several weeks of postflight recovery, as several Russians have done (complete radiographic recovery of bone takes longer, possibly 18 moths, but the risk of fracture is has not been shown to be increased.)<br /><br />Weightlessness has been tolerated for as long as 14 months without evidence of injury on return to 1-G. Because one of the common reasons for going into space is to experience 0-G, and because the ability to move large objects around the vehicle by hand has proven so useful, it seems unlikely to me that artificial gravity will be considered a priority. <br />

 

[fwyesterday]

I humbly beg to differ .. although weightlessness I believe will be a novelty for most .. I find it hard to believe that anyone would prefer this state of being over normal gravity for more than a day or 2. Most paying customers will pay for comfort .. not to be challenged to perform the simplest of tasks (going to the bathroom, eating, keeping your lunch down). <br /><br />The pioneers of course will welcome the challenges of adapting to an alien environment .. but comfort is key to making money from the average person. Major economies of scale (and resulting progress) wont ever be realized until these challenges are met. <br />

 

[webtaz99]

Sorry for no link, but I read an article on NASA research which suggested that short exposures (30-60 minutes per day) at 1g might be enough to mitigate bone loss. <div class="Discussion_UserSignature"> </div>

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>Generating 1-G with a small centrifuge requires a very high rate of rotation.<p><hr /></p></p></blockquote><br /><br />But you cannot do it in on earth. Any centrifuge on earth will result in a larger than 1 G effect (mathematically impossible to get 1G or less in a working centrifuge on earth). And what radius are you assuming here?<br /><br />Actually with a radius of 1000 meters, you just need 0.6684507609859605 revolutions per minute to create 0.5 G.<br /><br />With a radius of 1000 meters, you just need 0.9472902212829611 revolutions per minute to create 1 G.<br /><br />(These are approximate calculations)<br /><br />Also how do you know these effects of "symptoms in some people" happen in a 1G or less environment? Has an experiment been done? Remember any experiment on Earth using a centrifuge is above 1G. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>