Go Translife

John Creighton · 2001-09-04 14:32:56

The announcement of the translife project is the first really exciting news I have heard about mars exploration. It shows real vision on the part of the mars society and it makes me proud to be a member. I now what to hear updates on this project so I know what needs to be done to make it a success. How is the fundraising going? Who is designing the mission? What progress have they made so far?

Stu · 2001-09-05 09:31:52

Don't want to sound too angsty here, but whilst I agree that the proposed Translife project is certainly intriguing, and has the potential to provide us with useful and valuable biological data, I can't help thinking that our first Big project should be aimed more at enhancing the public's interest in, and enthusiasm for, Mars exploration by *showing* them what an amazing place it is.

I've thought for a long time that there won't be a public (and therefore political) demand for putting people on Mars until one of three things happen - a) Mars becomes the finishing line of a new "Space Race", perhaps with China, b) a probe discovers life, or evidence of life there, or c) people come to realise that it literally is a whole New World, a place to explore and be amazed by. Now, a) is a distinct possibility, we'll see what happens, b) well, ALH84001, you know... c)? Isn't going to happen unless we give people more than still Pathfinder photos, as amazing as they were.

So, as useful and as educational as flying mice or whatever half-way to Mars would be, I'm thinking - and have thought for a while - that it would get more public (and, importantly, media) interest - if we did something to "bring Mars to Earth", maybe by helping fund the flight of an Imax camera to Mars, which could then send back some amazing footage of flights over the volcanoes, down Marineris, over that blessed "Face" etc... Imagine the impact watching *that* film would have on the public, hundreds of people at a time, in darkened movie theatres, flying over Mars, seeing it as a real place, a real world...

Stu

John Creighton · 2001-09-05 11:07:46

Those also sound like real good ideas too. The reason I like translife is it is the first sign I saw from the Mars Society that said to me that they are prepared to ask what problems might occur and look for the answer. Perhaps, translife won?t have the same publicity effects but it shows that the mars society is willing to address criticism of why a mars mission might not work. For some people hand waving, is not sufficient. Saying that we have all the technology in place to go to mars today, falls far short of serious engineering and scientific efforts to establish a colony on mars. So what if we know more today about going to mars then we did about going to the moon in the 1960's. Let?s find out about what we don?t know and answer those questions. We are not sending people on mars to risk there lives trying to set a new altitude records. We are trying to make mars a place where many people will seriously consider living

saxifrage · 2001-09-07 02:14:36

I'm really excited about this Translife Project. The most annoying thing about NASA is their insistance upon zero-g living. Humans simply get unhealthy when living without gravity. The solution is simple: design and build space vehicles with simulated gravity.

I'm glad that the Mars Society is heading this up, too. We have got to start learning what it will be like to live on mars. This project will show us if mammals can reproduce and grow up successfully in .38 g.

Mice today, grandchildren tomorrow!

sax

Kerstens · 2001-09-08 14:36:09

Hello,

http://www.spacefuture.com/archive....s.shtml

if you are interested in AG specs.

Wim
Webmaster
Mars Society Belgium

kelly · 2001-09-10 12:51:04

One item I haven't seen addressed anywhere are what controls will be placed on Translife? Will we be able to have a second set of mice on the ISS eating the same food, same basic conditions (sans gravity)? How about a third group on earth?
I think this would be critical so a more exact comparison can be made on the effects of low gravity environments.

Alexander Sheppard · 2001-09-28 00:38:33

I would just like to note to everyone reading this thread: my e-mail has been changed from alex1s1emc22@icqmail.com to alex1s1emc23@icqmail.com due to an accidental deletion of my original account: for anyone who cares, update your info.

Shaun Barrett · 2002-01-17 00:22:28

This Translife experiment is a great idea because I don't think we can subject people to zero-g for 6 months and then expect them to perform well in a new and hostile environment. It seems to me that rotating the spacecraft on the way to Mars will be essential and, therefore, we need to find out as much as we can about the effects of "artificial gravity".
What is NASA's position on this problem at the moment? Are they investigating the prospects for separating the Mars craft into two sections connected by cable(s) and "spinning it up"?
If so, how difficult would it be? Presumably a spool of kevlar maybe one or two kilometres long wouldn't weigh much, but what about thruster fuel for spinning up and then spinning down for course-corrections? Are these problems likely to be "show-stoppers" or just minor technical difficulties we can solve with a bit of practice in LEO.
Incidentally, for what it's worth, I think we should try for the longest practicable tether length in order to maximise the g-force with a relatively low rotation speed. This will minimise the coriolis effects. What I think we should aim for is a full 1g of artificial gravity on the outward trip and only 1 revolution per minute. To my mind, this will deliver astronauts in the best possible shape mentally, and especially physically, at Mars. It may be just as critical for the homeward leg of the trip too because, after 500 days on Mars in 0.38g and 180 days in zero-g, it might prove impossible to adjust back to full Earth gravity.
Any information or criticisms?

Bill White · 2002-01-17 14:45:06

I suggest reading the proposed mission designed by the Caltech branch of the Mars Society - The one called "SCHEME"

I recall that they linked two parts of the Mars craft with a solid/rigid strut made from aluminum or perhaps a more exotic alloy. I also recall that the total radius needed to establish .38 g was way less than I had thought. Their paper explicitly discusses the advantages of a rigid strut in favor of a flexible tether.

At another forum, I proposed that we could today tether a used Progress resupply rocket to a Soyuz after it completed its ISS escape vehicle service and practice tethered flight with two vehicles otherwise scheduled for re-entry. (The Progress are intended to burn up upon re-entry and a Soyuz capsule cannot be re used after landing on Earth).

So, the next time you read about a new Soyuz being sent up (with a tourist?) to serve as the new emergency crew return capsule for the ISS, keep in mind that the old Soyuz and a trash filled Progess module should be available, essentially for free, for tether experiments.

Bill White

Shaun Barrett · 2002-01-23 01:28:54

Well, I had a look at "SCHEME" and I didn't like it much. The rigid truss idea is O.K. as far as it goes but I think it just doesn't go far enough.
The radius of spin (you know what I mean) is only 20 metres, which means you have to have the craft spinning at 4 revs per minute to generate a mere 0.38g. The first problem I have with this is that 4 revs per minute has been shown to be more or less the limit as far as adaptation to the disorientating coriolis effects is concerned. So the astronauts gradually get used to the cockamamie way things fall and the swirling feeling in their heads every time they bend over, and then at Mars you "spin-down" the craft and they have to adjust back. And this at a time when they need to be razor sharp! The second problem, and this seems to be common to all the proposed mission-structures, is that nobody seems to want to provide artificial gravity on the way home! It's the "Don't worry, they're coming home to medical help" mentality. As I've said, after 500 days on Mars at 0.38g and 180 days in space at zero-g, I simply can't imagine them ever adjusting back to Earth gravity; with medical help or not! Ignoring this problem is futile; it ain't gonna go away!!
Assuming that trusses are always going to be too heavy/bulky to be used in any significant lengths ... and I mean hundreds of metres ... there seems to be no alternative to cables on spools. And I'm not sure what might be used for a counterweight on the way home (is there a practicable modification that could be made to the Mars Direct mission structure to provide for this?)
I note the concern about a pressurised access tunnel between the two spinning craft. Am I to understand that it is feasible or desirable to attempt to transfer from one craft to the other while they're spinning? Surely the weight transfer would cause some kind of instability in the system, wouldn't it?
With cables, if you need to get at something in the "ballast" craft, you would simply spin-down, wind in the cable, dock the two craft, and open the hatch. Simple!
And now I've had time to think about all this spinning-up and spinning-down for course corrections and other purposes, I've decided the perfect thrusters for the job would be those low-thrust ion motors. They're very efficient and don't need too much weighty propellant ... and who cares if it takes a couple of days to do the job when the journey time is measured in months!
And one more thing: I still think we should be aiming at more than 0.38g, whether outbound or homebound. Doesn't anybody out there agree with me? Imagine your weight suddenly increasing from, say, 180 pounds to 470 pounds! That's what it's going to feel like to those poor astronauts, even if we DO give them 0.38g on the way home!!
Well?! ....

Shaun Barrett · 2002-01-23 01:29:34

Well, I had a look at "SCHEME" and I didn't like it much. The rigid truss idea is O.K. as far as it goes but I think it just doesn't go far enough.
The radius of spin (you know what I mean) is only 20 metres, which means you have to have the craft spinning at 4 revs per minute to generate a mere 0.38g. The first problem I have with this is that 4 revs per minute has been shown to be more or less the limit as far as adaptation to the disorientating coriolis effects is concerned. So the astronauts gradually get used to the cockamamie way things fall and the swirling feeling in their heads every time they bend over, and then at Mars you "spin-down" the craft and they have to adjust back. And this at a time when they need to be razor sharp! The second problem, and this seems to be common to all the proposed mission-structures, is that nobody seems to want to provide artificial gravity on the way home! It's the "Don't worry, they're coming home to medical help" mentality. As I've said, after 500 days on Mars at 0.38g and 180 days in space at zero-g, I simply can't imagine them ever adjusting back to Earth gravity; with medical help or not! Ignoring this problem is futile; it ain't gonna go away!!
Assuming that trusses are always going to be too heavy/bulky to be used in any significant lengths ... and I mean hundreds of metres ... there seems to be no alternative to cables on spools. And I'm not sure what might be used for a counterweight on the way home (is there a practicable modification that could be made to the Mars Direct mission structure to provide for this?)
I note the concern about a pressurised access tunnel between the two spinning craft. Am I to understand that it is feasible or desirable to attempt to transfer from one craft to the other while they're spinning? Surely the weight transfer would cause some kind of instability in the system, wouldn't it?
With cables, if you need to get at something in the "ballast" craft, you would simply spin-down, wind in the cable, dock the two craft, and open the hatch. Simple!
And now I've had time to think about all this spinning-up and spinning-down for course corrections and other purposes, I've decided the perfect thrusters for the job would be those low-thrust ion motors. They're very efficient and don't need too much weighty propellant ... and who cares if it takes a couple of days to do the job when the journey time is measured in months!
And one more thing: I still think we should be aiming at more than 0.38g, whether outbound or homebound. Doesn't anybody out there agree with me? Imagine your weight suddenly increasing from, say, 180 pounds to 470 pounds! That's what it's going to feel like to those poor astronauts, even if we DO give them 0.38g on the way home!!
Well?! ....

Shaun Barrett · 2002-01-23 01:35:14

Oops! Sorry about the duplication. My server was doing strange things.

RobS · 2002-01-23 15:20:42

These are very interesting questions. Zubrin's book gives a formula for calculating the radius and revolutions per minute for any particular amount of gravity. I seem to recall seeing in a book about space colonies that one can get 1 Earth gee at 1 rpm when the radius is about 900 meters. I'll try to find the details and post them in a few days.

I've never seen what the plan is for the Mars Direct Project's return. Astronauts have spent six months in zero gee before and they adjust fine over a week or two (well, some have longer term problems, but minor ones). I was wondering whether the burnt out upper stage of the ERV could be used as a counterweight vis a vis the crew cabin. One could gradually spin up the rotation rate from Mars gee to Earth gee, so that the astronauts gradually adjust to the higher gravity.

-- RobS

Bill White · 2002-01-23 17:09:52

Shaun raises valid points. Personally, I am not qualified to evaluate a rigid truss versus rope like tethers, however, I suspect the Caltech guys have proposed a truss because humans have NO experience with tethered flight - ZERO, NONE, NADA. I look forward to RobS getting some hard numbers on this.

This is why I believe we should start practicing with a Soyuz/Progress duo as soon as possible. I suspect any university or national space agency (the ESA?) could raise the relatively modest money needed to "borrow" a Progress and a Soyuz after their ISS duties are complete and attempt tethered flight manuevers, especially as such an experiment would have zero impact on any ongoing ISS operations.

As far as the Earth to Mars transit, Kim Stanley Robinson had the best idea of all, in my opinion. Start out at .95 gee and steadily decrease the spin rate to end up at .4 gee about 10 days before Mars arrival. (Ending up somewhat higher than .38 may give the astronauts an early stamina advantage upon Mars arrival. Also, wouldn't aerobraking require termination of tethered flight with at least several days (?) of zero gee before landing).

I also agree that a counterweight for the return trip would be highly desirable. You could also "spin up" slowly and steadily starting at .4 gee and hitting 1.0 gee a few weeks before Earth aerocapture.

If the Mars - Earth counterweight could be "parked" in LEO, it could be re-used on the next Earth - Mars mission to save the cost of lifting the mass from Earth to LEO. A more radical idea would be to rendevouz the ERV with the Shuttle and refit the ERV for a subsequent mission.

Mars SCHEME envisions re use of ERVs parked in LEO as future Earth - Mars crew vehicles.

Thoughts?

Shaun Barrett · 2002-01-24 01:06:45

Thank you RobS and Bill. It's always gratifying to find that others can see what one perceives to be a problem, and that they concur.
For so many years now, people have spoken routinely of the lead the Russians have in the study of the long-term effects of microgravity; usually with reference to Mars missions. I have never been able to generate any enthusiasm for these studies because the effects are all bad, the prospects for fixing them are all bad, and the ramifications for a trip to Mars under these conditions are all bad!
Maybe startling advances in space medicine over the next half-century will produce a pill you take twice a day in space, which will keep you in perfect shape no matter how long you spend in zero-g. But for now we need centripetal force.
It seems to me that whatever engineering problems may be involved in rotating a manned interplanetary spacecraft, they pale into insignificance next to the plethora of medical problems you face if you don't rotate it!
I'm looking forward to any further comments or ideas you may have, RobS, Bill, and anyone else interested in this topic. I thoroughly enjoy this Forum and feel encouraged at the obvious depth of talent and knowledge among Mars Society members. It's a privilege to "meet" you for a chat! Thanks again to all of you.

RobS · 2002-01-25 00:33:50

Here's the formula for calculating gravity: F = (0.0011)W2R where F is in gravities, W is the spin rate in rpm, and R is the radius (spin arm) in meters. This is found in Zubrin, *The Case for Mars,* page 123. He also notes the following on that page:
for making Martian gravity, 1 rpm requires an r of 345 meters; 2 rpm requires an r of 86 meters, 4 rpm requires an r of 22 meters, 6 rpm requires an r of 10 meters.

I also favor centrifugal gravity. Weightlessness produces effects similar to prolonged bedrest and aging: oseoporosis, cardiovascual weakening, muscular weakness, etc. Millions of dollars is being poured into ameliorating those conditions.

Zubrin also notes that many spinning spacecraft have performed midcourse corrections without despinning first; the correction is chopped into a series of computer-controled short bursts and are timed for the moment the engine is pointed the right way. He favors putting useless weight at the other end of the tether, not a vital part of the mission.

-- Rob S

alokmohan · 2003-09-24 03:20:46

Longlive translife experiment.

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#1 2001-09-04 14:32:56

Re: Go Translife

#2 2001-09-05 09:31:52

Re: Go Translife

#3 2001-09-05 11:07:46

Re: Go Translife

#4 2001-09-07 02:14:36

Re: Go Translife

#5 2001-09-08 14:36:09

Re: Go Translife

#6 2001-09-10 12:51:04

Re: Go Translife

#7 2001-09-28 00:38:33

Re: Go Translife

#8 2002-01-17 00:22:28

Re: Go Translife

#9 2002-01-17 14:45:06

Re: Go Translife

#10 2002-01-23 01:28:54

Re: Go Translife

#11 2002-01-23 01:29:34

Re: Go Translife

#12 2002-01-23 01:35:14

Re: Go Translife

#13 2002-01-23 15:20:42

Re: Go Translife

#14 2002-01-23 17:09:52

Re: Go Translife

#15 2002-01-24 01:06:45

Re: Go Translife

#16 2002-01-25 00:33:50

Re: Go Translife

#17 2003-09-24 03:20:46

Re: Go Translife

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