Welcome to the Sunday Paper Club. Every Sunday, this blog will offer an analysis of a paper on space habitation and other related topics. These are my opinions on a weekly scientific paper; basically, I read the paper and write down my thoughts while I read it. They are subject to my perspectives and believes. I am open to debate, so if any reader believes I have misinterpreted something in a paper, please point it out. I'm only a student and I'm still learning how to read these papers and interpret them. All quotes and ideas are from the paper, unless otherwise noted.
This week we are reviewing the paper Kalpana One: A New Orbital Space Colony Design. I am using a new format based on the Lifehacker article Back to School: Keep an Academic Reading Journal.
Article Information
Title: Kalpana One: A New Orbital Space Colony Design
Author(s): Al Globus, Ankur Bajoria and Nitin Arora
Date: May 2006
Conference: International Space Development Conference 2006
Article Overview
This paper is an update to the O'Neill Cylinders and other cylinder space habit designs.
Key/Interesting Quotes
“Cylinders minimize shielding mass per unit of 1g living area compared with other feasible shapes.” Page 1
“Princeton physicist Gerard ONeill led two Stanford/NASA Ames Research Center summer studies that supported the feasibility of kilometer-scale orbital cities. These studies assumed that the NASA space shuttle would operate as expected, a flight every week or two, $500/lb. to orbit, and one failure per 100,000 flights. The studies also assumed that a more efficient follow-on heavy lift launcher would be
available”. Page 1
“Taken together, the earlier designs have a number of serious problems: 1. Excessive shielding mass (Bernal Sphere, Stanford Torus) , 2. Extremely large mirrors to bring in natural sunlight (ONeill Cylinders) , 3. Lack of natural sunlight (Lewis One) , 4. Rotational instability (Bernal Sphere, ONeill Cylinders) , 5. Lack of wobble control (Bernal Sphere, Lewis One, O'Neill Cylinders, Stanford Torus) , 6. Catastrophic failure modes due to rotating hulls with minimal clearance to non-rotating shield mass (Lewis One, Stanford Torus)” Page 2
“Earth orbiting colonies will come first [because]: 1g (pseudo-)gravity levels are possible on orbital colonies...,Rapid resuppply from Earth ...Better communication with Earth ...Weightless and low-g recreation near the axis of rotation ...Relatively easy 0g construction of large living structures ...Near-Earth orbital colonies can service our planet’s tourist, exotic materials and energy markets more easily than the Moon, and Mars is too far away to easily trade with Earth ” Page 2
“Without children, you don’t have a colony, so 1g is a hard requirement for early colonies.” Page 5
“the maximum length of a rotationally stable cylinder is approximately 2.5r” Page 5
“Thus, Kalpana One’s 1g LivingArea is approximately 1500m by 550m, for a total of 863, 500m2 , providing 172m^2 living area for each of 5,000 residents”. Page 6
“It appears that approximately 15cm of steel meets this [hull strength] requirement” Page 6
“Astronauts working on the hull exterior would experience > 1g centrifugal acceleration away from the hull. This is an unacceptable risk, so all external maintenance must be accomplished by teleoperated or automated robots.”. Page 6
“High intensity, controlled environment agriculture requires 50m^2 to feed one person.9 For a population of 5,000, the total agriculture area required is 250, 000m^2” Page 7
“...thermal rejection system consists of thermal radiators attached around the rotation axis of the colony”. Page 8
Personal Response
This colony purposed to use thermal radiators to get rid of heat, however, it is not as easy as the single sentence suggest. Heat transfer would only occur with the radiation of heat through the vacuum of space. This is a painfully slow process, however, this problem is overcome in the design by the size of the panels. But, thermal radiators can be a problem because they must the keep away from the sun's rays. ISS achieved this, so it is possible here.
I think that the station's spinning will have to be stopped with or without robotics to preform external maintenance. It will be very hard to keep the robot on it's target with a 1g outwards force, such a robot would need huge thrusters or some method to stick to the wall . However, Stanford did develop a robot that can stick to the wall like a gecko, maybe it could be of use here.
Questions Raised by Paper
Could we counteract the lack of gravity on other planets by wearing weights?
Can we make steel with resources in space? (There is iron on the moon, but steel is a mix of many elements)
