Tuesday, March 13, 2012

7. SPACE - YEAR 2012 


7.1 Paths to Space Settlements
7.2 The Big Blue Marble we call home
7.3 Space voyages shouldn't become politically incorrect
7.4 Putting humans in space
7.5 Delta v


7.6 A simple question 

7.7 The three challenges
7.8 Is humanity quietly abandoning a future in space?
7.9 Company unveils plan to mine asteroids
7.10 Water 

7.11 Asteroid capture
7.12 Space race to Asteroids? ( Asteroid, 1986 DA)
7.13 Water

7.14 Asteroid capture
7.15 Space race to Asteroids? ( Asteroid, 1986 DA)



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7.1 Paths to Space Settlements  (29/1/2012)

Al Globus wrote:

The price tag depends on when you start. If you start trying to build
one today, maybe something like this. If you develop space tourism,
space solar power, and asteroid detection and deflection first, then
start, the price tag is much low. That's the idea behind http://alglobus.net/NASAwork/papers/PathsToSpaceSettlement2011.pdf

............

Interesting and very readable writeup.

Few points:

1. The author is in favour of settlements around Earth. Could we get all the seven billion pesky two legged creatures off the planet :-) ??

2. According to the author 'we could capture near earth asteroids for as little as 10cm/s delta v'. What is the legal position in this regard? Would we be allowed to put asteroids in Earth orbit? How close would be safe? This looks like a priority experimental activity! Does NASA have any plans in this regard.

3. The author points out that we could be hit by a large asteroid any time; we need to perfect technologies to divert such objects. Looks like a priority activity which needs to be taken up by the U.N. !!

4. The idea of space hotels and entertainment centres to give a fillip to space exploration. Probably, short term visitors will prefer a near zero G environment. Much easier to achieve!! A slowly rotating 100 m dia space hotel can be planned.

5. Space power. Should not someone put up a SPS of say 100m dia to see how the system works?

... very interesting!

Regards,
Selvaraj


7.2 The Big Blue Marble we call home  (29/1/2012)

The Big Blue Marble we call home:




7.3 Space voyages shouldn't become politically incorrect  (5/2/2012)

Many historians believe our time left on Earth is measured in generations, not in centuries or billions of years. Our past suggests that the greatest threat to our existence may well be ... us. All the great empires that held dominion over Earth were destroyed or faded away. Those that did survive by achieving luxury and great wealth met their end because of self-satisfaction, idleness, loss of ambition, and because those who know only luxury and pampering tend to lose the skills to survive.  



7.4 Putting humans in space  (12/2/2012) 

The idea presented by Al Globus to begin space colonisation by putting habs in orbit around Earth looks very sound.

One damper to the idea of having thousands (some say millions) of space habs orbiting the sun is the issue of conservation of mass; any thruster activity will lead to permanent loss of usable mass in the solar system. This loss is inevitable also for systems in orbit around the Moon and Mars. Hopefully, for systems orbiting Earth it may be possible to use Earth's gravity to recover the mass!? To make this possible we can also limit ourselves to Hydrogen-Oxygen thrusters and put a limit on the exhaust velocities. 

The big barrier to putting habs in orbit around the Earth is the issue of cost, which in an earlier discussions, we have put at around 3 trillion $ for even a modest space hab.

How do we reduce this cost? A possible way to do this is to get accountants of our backs.

RENEWABLE ENERGY FOR COLONISATION OF SPACE: 

1. Allot 50,000 sq Km of land in the Sahara Desert to a planetary country to be called SPACE COLONY ONE. 
2. Populate this country with 200,000 inhabitants (who are judiciously selected). 
3. Give them seed money of 200 billion $
4. They have to meet all their basic needs from the land under their possession (After an initial set up period of 10 years, they will be forbidden to trade with any country for any thing other than raw materials).
5. Their job, to manufacture space colonies and suitable launch systems.
6. They are forbidden to use any form of energy other than solar energy for their operations. All rocket systems must use only Oxygen and Hydrogen. 


Selvaraj



7.5 Delta v  (15/2/2012) 

Some possibilities for space habs orbiting Earth.

1. In low orbit they would need to be regularly boosted up. Tried to find out the delta v requirement for ISS (orbiting at 330 - 410 Km); could not get the information from the net. Apparently hydrazine thrusters (attached to visiting space crafts) are used for the purpose. 
2. For earth observation satellites orbiting at around 800 Km, the delta v requirement is around 1-2 m/s/year
3. For geosynchronous satellites 45 m/s/year

I was wondering whether it would be possible to assemble a space hab at 400 km altitude and then slowly boost it to an orbit of 800 km. The resources of ISS could then be used. 

Regards,
Selvaraj


7.6 A simple question  (8/3/2012)

How much would it cost to put a rotating space hab in orbit around earth, capable of accommodating 20 persons. The space hab must produce one G and should be capable of producing all the food required and recycling all waste. The space hab must be designed with a margin of safety of three, to keep these 20 people alive for 10 years, without any outside support.

If we can achieve this we are ready to start colonizing space.

Selvaraj


7.7 The three challenges  (21/3/2012)

For setting up space habitats we can visualize three challenges:

1. The problems associated with carrying huge mass of materials from Earth or Moon to the designated places in space.
2. The structural design of these habitats
3. The functioning of these habitats as enclosed biospheres which support human life and provide a congenial and happy environment for human beings. 

In an earlier post where I had proposed the following plan:

----------------

RENEWABLE ENERGY FOR COLONISATION OF SPACE: 

1. Allot 50,000 sq Km of land in the Sahara Desert to a planetary country to be called SPACE COLONY ONE. 
2. Populate this country with 200,000 inhabitants (who are judiciously selected). 
3. Give them seed money of 200 billion $
4. They have to meet all their basic needs from the land under their possession (After an initial set up period of 10 years, they will be forbidden to trade with any country for any thing other than raw materials).
5. Their job, to manufacture space colonies and suitable launch systems.
6. They are forbidden to use any form of energy other than solar energy for their operations. All rocket systems must use only Oxygen and Hydrogen. 

------------------

I had the third problem firmly in mind. It is good to remind ourselves that the only successful biosphere in the known universe, is a natural biosphere on planet Earth, which existed long before humans arrived on the scene. Scientists have mainly exploited this biosphere so far, they have very little skill in creating autonomous biospheres. The third challenge is a very real one and we should not wait to finish tackling the first two problems before we start tackling the third one. 

If space enthusiasts start tackling the third problem first, they are also likely to receive public support, as many of the problems they will have to tackle will also solve the current problems on planet Earth: 

1. The problem of product design so that waste can be easily recycled.
2. Design of products suited for a population living with limited resources.
3. Proper recycling of waste to support agriculture.
4. Development of social systems suited for people living in an enclosed  and limited space. 
5. Creative use of limited space, so that people do not feel hemmed in. 
6. Creative sharing of responsibilities, and development of skills.
7. The use of solar power.  

... etc. 

Regards,
Selvaraj



7.8 Is humanity quietly abandoning a future in space?  (18/4/2012)

 Is humanity quietly abandoning a future in space?

One possibility is to pool resources under the ambit of the United Nations. A lot of countries do not have their own space programs, but could contribute money.

Selvaraj


7.9 Company unveils plan to mine asteroid  (26/4/2012)

SEATTLE — Space-faring robots could be extracting gold and platinum from asteroids within 10 years if a new venture backed by two Silicon Valley titans and filmmaker James Cameron goes as planned.
Outside experts are skeptical about the project, announced Tuesday at a news conference in Seattle, because it would likely require untold millions or perhaps billions of dollars and huge advances in technology. But the same entrepreneurs pioneered the selling of space rides to tourists — a notion that seemed fanciful not long ago, too.
"Since my early teenage years, I've wanted to be an asteroid miner. I always viewed it as a glamorous vision of where we could go," Peter Diamandis, one of the founders of Planetary Resources, told reporters at the Museum of Flight in Seattle. The company's vision "is to make the resources of space available to humanity."
http://www.knoxnews.com/news/2012/apr/26/company-unveils-plan-to-mine-asteroids-for/



7.10 Water (14/7/2012)

The isotopic composition of the bulk Earth appears to be more consistent with chondrites than with comets, researchers said. There are many different types of chondrites, and no single group is a perfect match. So our planet probably accreted its water and other volatiles from a variety of chondrite parent asteroids, they added.
http://news.yahoo.com/asteroid-crashes-likely-gave-earth-water-180909700.html

7.11 Asteroid capture (22/7/2012)

The asteroid is estimated to be 2,000 to 4,500 feet wide, and qualifies as a ‘near Earth object’. NEA (near-Earth asteroid) 2002 AM31 is described as ‘the size of a city block’, the ‘Daily Mail’ reported.
It will pass through space 14 times further from Earth than the Moon.The space rock will be tracked live by cameras on Earth and in space.
..........
What would it take to capture this asteroid and position it at 'three moon distance' from Earth? How long would it take?
Regards,
Selvaraj

--------------------------

See http://kiss.caltech.edu/study/asteroid/asteroid_final_report.pdf
for a discussion of returning a somewhat smaller object to Earth orbit.

See http://space.alglobus.net/presentations/DraftAsteroidMiningTalk2012.pdf
for a presentation related to this. There will be a paper on this
in the very near future (to be presented at AIAA Space 2012)

---------------------------------

Glanced through the first reference. Very interesting! It looks as if our present ambition is limited to asteroids of 7m diameter in size. Apparently we are still to build up our capabilities to locate small asteroids. (Let's hope our ability to locate large asteroids is better, so that we don't get zapped).

Is it possible that there could be a good number of asteroids travelling relatively synchronous with Earth? If we could identify these asteroids very little delta V would be required to capture them.

Should we first install a powerful radar on the Moon to locate asteroids? (It can be designed to fire pulses only when the radar is facing away from Earth).

Regards,
Selvaraj

-------------------------------

We could also think of putting a radar satellite ( + optical?) into orbit around the sun, in an orbit similar to that of the Earth, to find out the asteroids which could be easy picking. (Is the Hubble Space Telescope any good at picking out asteroids?)

It looks as if it may be worth it to have a permanent observatory (Robot operated?) on the Moon.

Regards,
Selvaraj

-------------------------------------

Asteroid hunters have announced plans to launch the first privately funded deep space mission in history to look for asteroids that could threaten Earth.
http://www.dnaindia.com/scitech/report_1st-private-deep-space-mission-to-track-dangerous-near-earth-asteroid_1708434


7.12 Space race to Asteroids? (Asteroid,1986 DA) (28/7/2012)

(6178) 1986 DA is a 2.3-kilometre-diameter M-type Mars-crosser and near-Earth asteroid, notable for being significantly more radar-reflective than other asteroids. It is an Amor asteroid, which means it approaches the orbit of Earth from the outside but does not cross it.
.. Asteroid 1986 DA achieved its most notable recognition when scientists revealed that it contained over "10,000 tons of gold and 100,000 tons of platinum", or an approximate value at the time of its discovery of "$90 billion for the gold and a cool trillion dollars for the platinum, plus loose change for the asteroid's 10 billion tons of iron and a billion tons of nickel."[3]
At today's (2012) prices 100,000 tons of platinum is worth five trillion dollars.
..............
Quite clearly we need to sharpen space related treaties. 
Selvaraj


7.13 Water (14/7/2012)


The isotopic composition of the bulk Earth appears to be more consistent with chondrites than with comets, researchers said. There are many different types of chondrites, and no single group is a perfect match. So our planet probably accreted its water and other volatiles from a variety of chondrite parent asteroids, they added.
http://news.yahoo.com/asteroid-crashes-likely-gave-earth-water-180909700.html



7.14 Asteroid capture (22/7/2012)


The asteroid is estimated to be 2,000 to 4,500 feet wide, and qualifies as a ‘near Earth object’. NEA (near-Earth asteroid) 2002 AM31 is described as ‘the size of a city block’, the ‘Daily Mail’ reported.
It will pass through space 14 times further from Earth than the Moon.The space rock will be tracked live by cameras on Earth and in space.
..........
What would it take to capture this asteroid and position it at 'three moon distance' from Earth? How long would it take?
Regards,
Selvaraj




7.15 Space race to Asteroids? (Asteroid, 1986 DA) (28/7/2012)

(6178) 1986 DA is a 2.3-kilometre-diameter M-type Mars-crosser and near-Earth asteroid, notable for being significantly more radar-reflective than other asteroids. It is an Amor asteroid, which means it approaches the orbit of Earth from the outside but does not cross it.
.. Asteroid 1986 DA achieved its most notable recognition when scientists revealed that it contained over "10,000 tons of gold and 100,000 tons of platinum", or an approximate value at the time of its discovery of "$90 billion for the gold and a cool trillion dollars for the platinum, plus loose change for the asteroid's 10 billion tons of iron and a billion tons of nickel."[3]
At today's (2012) prices 100,000 tons of platinum is worth five trillion dollars.
..............
Quite clearly we need to sharpen space related treaties. 
Selvaraj




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