Space Mission Analysis and Design: Chapter 1

I've had a really large stack of books from my school's library that I've not read, so I'm going to read these books and apply what I learn to space habitation. This post will look at chapters 1 through 5 of Space Mission Analysis and Design[affiliate link], second edition. I'm also going to try out Amazon affiliates program, just to see if you, the readers, riot.  *Puts on riot helmet and holds up shield*

Chapter 1: The Space Mission Analysis and Design Process

This chapter is of use when studying space settlement because it teaches us how to complete mission objectives with the lowest cost possible. This is import to learn because of the demonstrated lack of business sense in space commercialization plans.

On page 2, there is an important quote: "there is strong pressure to proceed to ever greater detail, and never revise a decision once it haw been made...we must also review the mission design regularly for better ways to achieve the mission objectives". From my view of the space community, this maybe a problem. There are a ton of politics around the space program that force it to remain on a path once that path is set. I point to the cancellation of the Ares program. While there should be an active debate on whether or not to follow Obama's plan, the discussion should not consider the money already spent on the system. It is simply better to waste money in the short term for the long term savings gained by a more efficient system...if we can prove the it is more efficient. This will be a big deal in space settlement because of the massive amounts of money that will be involved, scraping the design of a space habit could mean millions in wasted designing time. But, if it means a better, more profitable space settlement, we must be willing to let go.


The author then goes on to say that "[n]early any mission is technically feasible...[however] we must select each space mission, not to achieve something that could not have been done before, but to achieve something that should be done or is worth doing" (Page 5). This is important because space settlement lies on that line. The author gives the example of a forest fire tracking system that could be tackled by aircraft or ground crew, the same is true of space habitation. For the cost of settling space, we could easily mount a massive planetary defence program, start huge recycling programs, being to develop extremely efficiently cities that can support themselves and develop other Earth bound technology to tackle the same problems that space habitation tackles. In order for space settlement to pass this type of engineering analysis, it must bring something to the table that nothing on Earth can do...that will be difficult to do.

This chapter also discusses the need to consider the hidden agendas when planning a mission, I've never considered this before. Space settlement would have a vast number of political and social meanings that must be addressed in order for the project to be successful. This means that we must consider what effects a space settlement will have on world dynamics; an international effort could mean peace, thus less need for armour and weapons, but a imperial space settlement mission could require the need for a heavy military structure. We would need to be able to accept a space habitat's position as the first, and many only, source of aid for stranded and injured space explorers.

Finally, when reading this chapter, I felt chills at the thought that the space habitation movement may only still be in conceptional design. I would need to be a master to make that call, but it is something that worries me.

Right, I'm just beta testing this format, if this blog isn't in flames by morning, I'm going to write posts that detail 5 chapters at a time; these books are really dense. I just wanted to get a feel for the audience. Feel free to leave me a comment below, or at-least use the check boxes at the bottom to give me feedback...I need it, badly.

SPC #20: Moon Construction

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 Engineering, Design and Construction of Lunar Bases. I am using a new format based on the Lifehacker article Back to School: Keep an Academic Reading Journal.

Article Information

Title: Engineering, Design and Construction of Lunar Bases

Author(s): Haym Benaroya, Leonhard Bernold and Koon Meng Chua

Date: April 2002

Journal: Journal of Aerospace Engineering

Volume: 15

Issue: 2

Pages: 33-45

Article Overview

Building on the moon is harder than it looks. Traditional construction methods fail to be useful on the harsh surface. The moon’s soil clings to everything and binds moving parts (not even WD-40 can fix that). The temperature variances weaken structures. This paper is an index and summary of the top papers in lunar construction. 

Key/Interesting Quotes

“On the lunar surface, numerous constraints,different from those for terrestrial structures, must be satisfied by all designs.” Page 1

“A post-Apollo evaluation of the need for a lunar base has been made (Lowman 1985) with the following reasons given for such a base: Advancing lunar science and astronomy; Stimulus to space technology and test bed for technologies required to place humans on Mars and beyond; Utilization of lunar resources; Establishment of U.S. presence; Stimulation of interest of young Americans in science and engineering; and Beginning of long-range program to ensure survival of species.” Page 1

“Scientific advantages of a polar location for a lunar base (Burke 1985) are that half the sky is continuously visible for astronomy from each pole and that cryogenic instruments can readily be operated there due to the fact that there are shaded regions in perpetual darkness.” Page 2

“Relationships between severe lunar temperature cycles and structural and material fatigue, a problem for exposed structures [need to be studied]” Page 2

“Factors of safety, originally developed to account for uncertainties in the Earth design and construction process, undoubtedly need adjustment for the lunar environment, either up or down, depending on one’s perspective and tolerance for risk [need to be studied]” Page 2

“Buckling, stiffening, and bracing requirements for lunar structures, which will be internally pressurized [need to be studied” Page 2

“…it appears that concurrent engineering will be a byword for lunar structural analysis, design, and erection. Concurrent engineering simultaneously considers system design, manufacturing, and construction, moving major items in the cycle to as early a stage as possible in order to anticipate potential problems. Here, another dimension is added to this definition. Given the extreme nature of the environment contemplated for the structure, concurrency must imply flexibility of design and construction.” Page 2

“…mass rather than weight-based criteria should be the approach of lunar structural engineers.” Page 2

“Newer work and development of nonlinear stress-strain models to describe the mechanics of the lunar regolith can be found in Johnson et al. (1995) and Johnson and Chua (1993)” Page 3

“In the likely situation that a layer of regolith (lunar soil) is placed atop the structure for shielding, the added weight would partially (in the range of 10–20%) balance the forces on the structure caused by internal pressurization” Page 3

“…during the times of low solar activity, the annual dose-equivalent for humans on the exposed lunar surface may be about 30 rem…” Page 3

“…the dose equivalent over an 11 year solar cycle is about 1,000 rem…” Page 3

“…It appears that at least 2.5 m of regolith cover would be required to keep the annual dose of radiation at 5 rem, which is the allowable level for radiation workers…” Page 3

“Construction in a vacuum has several problems. One would be the possibility of outgassing of oil, vapors, and lubricants from pneumatic systems.” Page 3

“The lunar surface has a layer of fine particles that are easily disturbed and placed into suspension. These particles cling to all surfaces” Page 3

“a device that is simple and conventional looking and has no moving parts is preferred [to those which are complex and have many moving parts in space]” Page 4

“Inflatable structural concepts for a lunar base are proposed (Broad 1989) as a means to simplify and speed up the process while lessening the costs.” Page 4-5

“A concept proposed by King et al. (1989) would use the liquid oxygen tank portions of the Space Shuttle external tank assembly for a basic lunar habitat…this idea, if proven economically feasible, may provide the most politically palatable path to the lunar surface, with the added advantage that many of the necessary technologies already exist and only need resurrection” (Page 5)

“Horiguchi et al. (1998) study simulated lunar cement.” Page 5

“In order to avoid the difficulties of mixing concrete on the lunar surface due to lack of water, Gracia and Casanova (1998)have suggested examining use of sulfur concrete because sulfur is readily available on the Moon.” Page 5

“Construction of a lunar base will at least partially rest on the capabilities of the Army Corps of Engineers.” Page 6

“‘In all human societies, the quality of life depends first on the physical infrastructure that provides the basic necessities such as shelter, water, waste disposal, and transportation,’ wrote Grigg (1988) Today, and especially for the lunar base, we have to add communication and power as part of the physical infrastructure.” Page 7

“…the regolith reaches the relative density of 90–100% below 30 cm.” Page 7

“Although the ejection of regolith would not be acceptable on the lunar surface, since the resulting dust would travel far, research showed that explosives buried deep enough would not create craters but loosen the soil very effectively.” Page 7

“Bernold (1994) showed that the compaction of lunar soil necessary for creating a stable road base would create unique problems. Preliminary research data indicated that the normal size distribution of soil particles would make it impossible to achieve needed density and strength using common methods of static or vibratory compaction.” Page 8

‘‘Lunar tramway systems can take advantage of the reduced gravity, which permits building wider spans and/or using smaller cable diameter for lifting and transporting heavy loads.” Page 8

“One of the main problems in robotic control of equipment is the time that signals need to travel through vacuum, atmosphere, or fiber-optic or other communication lines.” Page 9

Personal Response to the Paper

The idea that regolith has a density of 90%-100% below 30cm (about 11.8 inches) stunned me. A lot of the moon base ideas assume that we can build underground, I don’t think we can get through bedrock. On Earth, we blast, but this paper proves that is impractical because the debris produced would orbit the plant, at a low altitude, making the process dangerous. The paper mentions using a wire to loosen the soil, but it is still a difficult process.

It was strange though, I felt encouraged by readying this article despite its presentation of countless problems. It seems that every problem was addressed and those which still need work are neatly listed in an appendix at the back of the paper. This paper provides humanity with a checklist of topics that need to be covered before we can begin lunar settlement. Maybe I feel good about reading this article because it seems a massive task is broken down now. 

Questions Raised by the Paper

What was the process that made the moon’s soil so dense?

The wire on a tramway placed on the moon could produce electricity because of the radiation, could this be a danger to occupants?

The article mentioned most excavation tools wouldn’t work in reduced gravity, I understand most of them, but why wouldn’t a backhoe work?

Assuming we could mix concrete on the moon, what happens to concrete that is outgassed?

What does the Army Corps of Engineers have to do with the moon base and can we use their budget in building it since the article states they will lead the effort?

Engineers as Public Relations Officers

Engineers as inherently focused on details. In my last post I used Seth Godin’s work support the argument that the public is looking for detail in the plans it supports. If this is true, then engineers must take the role as the public relations officers of the 21st century. The public wants every step of a plan, they no longer want only visions of the future. You can not ask the public “do you want to go back to the moon” and expect support. You can expect increased support when you ask for support when you can show all the math, all the technology and all the money which you are basically your plan off of.

Reactions

-Does the public’s response and support of the 2012 doomsday theory could weaken this argument?

Resources

Godin, Seth. "Achievable Avalanche Opportunities”
     Seth Godin’s Blog. 8 September 2009.  Web. 8 September 2009.

     <http://sethgodin.typepad.com/seths_blog/2009/09/achievable
-avalanche-opportunities.html>.

In Case You Skimmed

-In short, the public wants well planned goals, not visions dripping with Kool Aid.

Type 1 and Type 2 Engineering

I stumbled across the late Randy Pausch's lecture on time management. In this lecture, he presented a revision to the tradition to-do list. In his modified to-do list, one would have 4 categories for the following types of tasks: important and urgent tasks; important, but not urgent tasks; not important nor urgent tasks and urgent, but not important tasks. I think this concept can be applied to society's to-do list.

Type one engineering would be the type of engineering that addresses urgent and important problems/needs. Type two engineering is the type of engineering that addresses important, but not urgent problems and needs. Right now, space habitation and all space activities are solely within the field of type two engineering. It is need urgent. But, in order for human society to move forward, we must address space before it become a type one need; an urgent and important need. We can be ok without the resources and room of space for another, I'm guessing here, 50 years. But, what we can not do is neglect the development of space habitation until it become and important need and urgent need.

We already see what happens when we ignore type two needs and wait until they become type one problems. We see this in global warming and the dwindling energy resources. It is coming to the point where human society can not even function without those two problem solved. We saw those two problems coming and we waited, now it is becoming urgent to address those two things. As if it was bad enough, type two engineering is easier then type one because type two engineers have the resource of time available to them.

Basically, the type one engineer is the person running around putting out society's fires. The type two engineer is the society's fire inspector, preventing those fires from even occurring. Let's look at NASA which is the prime example of a type 2 engineering organization. Space is important, don't get me wrong, but we will live till tomorrow without it. But, there will be a day where human society can not function without space. There might even be a day where human society can no longer grow and expand on this planet. If NASA needs becomes a type one engineering organization because society urgently needs space then space will be much harder then if space was accessed when NASA was a type 2 engineering organization. Society might even collapse if the need for public space access become urgent because that need wasn't fulfilled fast enough.

Basically, type one engineering is needed because of short term planning. Type two engineering is needed because of long term planning. The more long term plans we have, the more type two engineering occurs and our problem become less urgent as they are solved earlier.

Reactions

-Do you think space is already a type one need?

Resources

Pausch, Randy. "Randy Pausch Lecture: Time Management"" February 06, 2008. Online video clip. YouTube. Accessed on August 27, 2009. < http://www.youtube.com/watch?v=oTugjssqOT0 >

In Case You Skimmed

• Space habitation is not an urgent need, if it become an urgent need, it will be much more difficult to meet the need.