Space Architecture

Thursday, November 27, 2008

Use Multi-Payload Adapters to reduce launch costs

For more than a year, I have been fixated on one question: why does it cost so much to get into space?

A previous blog entry discussed trends in launch costs. Namely, that “Steven Buckley noted that while the capabilities of the vehicles have grown—the Minotaur 4, derived from the Peacekeeper ICBM, has nearly four times the payload capability of a Pegasus XL—the vehicles have all had 'flyaway' costs of about $20 million a launch” [from “Reducing launch costs: a lower limit?” by Jeff Foust].

Steven Buckley also co-wrote a paper with Tim D. Luddeke and Horst D.E. Knorreck in 2003 titled “Low-Cost, Flexible Spacelift for Research and Development Satellite Using Peacekeeper ICBM Derived Space Launch Vehicle”. In the abstract, they say,

Over 40 years ago, the federal government decided it was prudent to store decommissioned ICBMs for possible future use. National Space Transportation Policy allows for the use of these assets as space launch vehicles on a case-by-case basis and under specified terms. The Air Force's Rocket System Launch Program (RSLP) is chartered to store and manage the reutilization of surplus Intercontinental Ballistic Missions (ICBMs)...

RSLP and the Air Force Research Laboratory, Space Vehicles Directorate are currently developing a Peacekeeper Space Launch Vehicle (PKSLV) Multi Payload Adapter (MPA), designed to allow several payloads to be launched in a variety of configurations to maximize our ability to meet unique customer requirements. More importantly, this multi-payload configuration also allows customers to cost share space access thus reducing their overall program cost.

Using the MPA, the PKSLV can lift eight 300lbm [sic] satellites into a two-year polar orbit for approximately $20M or $2.5M per satellite. This equates to a pound to orbit cost of $8,300/lb.

The principle at work here is the same as in any other transport vehicle: the more people or stuff you fit into the vehicle, the lower the cost of moving those people or stuff per unit of mass, distance, or energy. Economy of scale.

Wednesday, September 24, 2008

The Space Elevator, and Nanotechnology

Slashdot had an article from the Times Online UK about the Japanese Space Elevator Association, and their attempt to make the space elevator a reality. The quoted price for such an elevator is one trillion yen, which is about $9.4 billion. To put that in contemporary perspective, the Bush Administration has proposed a $700 billion plan to bail out various Wall Street firms. The price for the space elevator is premature, and most likely much lower than what the actual cost will be. I won't even touch the Wall Street issue.

The reason, that the price for the space elevator is premature, is because the material necessary for the cable does not yet exist. A great deal of this material will be needed, and is the critical component of the space elevator. Any price tag at this point is meaningless.

The most commonly looked-at material for the cable is carbon nanotubes. I wrote about nanotechnology in general for my Master's Thesis, and trying to summarize the current state requires more than a typical blog post.

Let us take one thing at a time, starting with the Slashdot commentary. Some of the best reader comments are more informative than the articles to which they are responding.

Poster "Rei" says, "The problem is that even the *simplest* form is way beyond what we can produce in the present day, and you're wanting to do a form that's far harder.

"In a space elevator, the tether has to be long. Very, very, very long. So much that even if you could build a cable with the density of graphite and a tensile strength of 100GPa, it'd still have to taper severalfold as it reaches toward the earth. With the taper requirement, pulleys are simply right out (can't have the pulley's cable change shape as it goes, now can you?), as is *anything* that can increase the weight of the fiber. You need elevator "climbers", powered by beamed power transmission.

"The problem remains the cable. 100GPa with the density of graphite is just so far beyond anything that we can achieve today it's really just a sci-fi concept that people like to dream about. The last I checked, the strongest *individual single-walled carbon nanotubes* that people had directly measured the strength of broke at just over 60GPa. This is for single tubes, let alone bundles of tubes, let alone a bulk fiber, let alone an entire tapered cable. Tubes theoretically can be stronger, but I haven't seen any measurements confirming such extreme theoretical strengths. The strongest SWNT bulk fiber I've read about was planar sheets that were about 10GPa.

"Yes, you can build a space elevator with a tensile strength of less than 100GPa. But your taper factor for the elevator rises *very fast* with decreasing tensile strength or increasing density, which means that its mass increases *very fast*, which rapidly puts it outside the realm of possibility. Honestly, something more like 120GPa would be much easier to build, but that's even further from what we can achieve today. I'm not even sure it's physically possible to achieve. SWNTs are pure graphene SP2 structures; how can you get stronger than that? The only thing I can think of that could help us best today's best strengths are complete perfection, every atom of the fiber all the way up, and I'm not sure that would do it". [Rei's website]

That is the problem in a nutshell. The cable must go out past Geostationary Orbit, which is about 35,800 km above the surface of the Earth. GPa is a measure of tensile strength. Tension is the critical issue here, because to keep the cable aloft, the cable needs to be pulled away from the surface of the Earth as much as Earth's gravity pulls it down.

This 2001 paper describes the tensile strength of carbon nanotubes (CNTs) as ranging from 0.14 - 0.177 TPa. If you know metric, T is for Tera, which is 1,000 times greater than G (Giga). However, those numbers are theoretical, as the research team in the paper notes, testing the CNTs is quite difficult, due to their very small size. A more recent 2003 paper shows that strength for both single-wall CNTs and multi-walled CNTs to range from 40 - 50 GPa, far below the requirements for a space elevator.

So, you have two issues: strength and size. I expect strength to vary as the length of the cable grows, and is exposed to conditions different than that of a laboratory. I also expect that when someone grows a CNT to some decent length (say, 1 meter), they will take it outside and test it under ambient-environment conditions. The longest CNT is currently about 2 cm.

What is the hold-up on length and strength? According to "Carbon Nanotubes -- the Route Toward Applications" (2002), "All currently known synthesis methods for SWNTs result in major concentrations of impurities. Carbon-coated metal catalyst contaminates the nanotubes of the HiPco route, and both carbon-coated metal catalyst and, typically, ~60% forms of carbon other than nanotubes are formed in the carbon-arc route (11). These impurities are typically removed by acid treatment, which introduces other impurities, can degrade nanotube length and
perfection, and adds to nanotube cost".

What is HiPco? High-Pressure carbon-monoxide. The HiPco route appears to be one of many methods of creating carbon nanotubes, using gas-phase growth procedures.

Essentially, the length and strength problems are problems of production. The above quote from the 2002 article is but one example of the many problems one runs into when trying to produce nanotubes. The machines seem to suffer an analogous problem to that of the ones used to measure the effects of quantum mechanics. Trying to detect the motions of electrons by throwing objects the same size or bigger than the electron itself.

With nanotube production, you are producing atomic-sized creations not necessarily by throwing atoms together, but by creating chemical environments optimal for producing the chemical reactions that lead to the tubes (or fibers, plates, dots, etc). These same environments produce other compounds that you may not want, so another process is required to purify your batch, with the side effect of weakening your nanotubes.

Despite this, as one reads the literature over the years, there has been a gradual improvement. Perhaps the Japanese Space Elevator Association is banking on continued improvement. As the Times Online article mentions, there will be an international conference in November to create a timeline.

Saturday, May 17, 2008

New Website

Please take a look at a website that I have been putting together: Off-World Architecture. The term is borrowed from an advertisement playing in the background in the movie Blade Runner. I have been working on the HTML and CSS off-and-on, fixing mistakes, trying to maintain a clean, contemporary image.

This is a portfolio of work, after all. The intention the site is to demonstrate what I and others from the Sasakawa International Center for Space Architecture have done. We have the skills necessary to create an architecture for building typologies that do not yet have one.

We have a way of thinking, a systems-of-systems approach. Integrating the necessary engineering requirements into a deliverable product ("the pressurized capsule"), and including in those requirements, human factors and social-psychological concerns. This is not "architects/architecture in space", this is "architecture about/with-respect-to space". This is about making living areas in space less of a laboratory environment, and more like home.

Saturday, March 15, 2008

Compromises on the Shuttle and ISS

ABC News has an amusing article on the compromises that astronauts have to make while in space. Here's an excerpt:

"The astronauts don't just toss the garbage overboard. The mandate is clean your plate and drink all the coffee in your drink bag because all the trash created on orbit has to fit in a container the size of a large kitchen garbage can. That is seven astronauts' times three meals times 12 or so days. The trick is to wrap it up as small as you can when you are done eating and then compress it even more and tape it shut."

People seem to be natural accumulators -- collecting things is easier for most than sorting or disposing. Another challenge with long-duration missions, when the (next) return trip is not scheduled to occur for next few months or years, is collecting all the garbage. Chucking it out the airlock is one option, but one might suppose that recycling all the material would be cheaper and more efficient in the long term.

Those considerations would need to be balanced out with the time and resources built into creating, launching, using, and maintaining the recycling systems. Even water is not completely recycled on board ISS. Developing technologies that create self-sustaining habitats are essential to long-term space development. Which is why projects like Biosphere 2 need to keep going, and be replicated by other organizations.

Thursday, March 06, 2008

Going to Mars Alone, Or, A Better Approach

Yesterday, on Slashdot, there was an article by Nancy Yatkinson. She describes a proposal by Jim McLane to send someone to Mars solo, arguing that:

"'When we eliminate the need to launch off Mars, we remove the mission’s most daunting obstacle,' said McLane. And because of a small crew size, the spacecraft could be smaller and the need for consumables and supplies would be decreased, making the mission cheaper and less complicated".

He goes on to say that more supplies, people, and equipment would follow, though returning to Earth would not be possible. As some people responded, this idea only really makes sense if one is planning on colonizing Mars. Otherwise, this is a dramatic suicide mission, or at least a lifetime prison sentence with scientific endeavours attached.

This idea would provoke a media firestorm, a Congressional protest, and many questions from the House Committee on Science and Technology. Barring very unusual circumstances, NASA is not likely to do this. I would doubt that private space firms would do this, out of liability and shareholder concerns.

If this idea were to actually go through, I would like to know the following things:

1) What studies were performed to show that extended isolation, lasting for years, would not lead to a decline in morale on the part of the explorer?

2) Is NASA, or the organization responsible, prepared for the media response in the event that the explorer dies en route or on Mars, for whatever cause? Can the organization prepare for the nightmare scenario and still carry on with the mission?

3) Define whether or not colonization is the major driver for not bringing astronauts back to Earth.

4) If colonization is the driver, why send just one? What are the costs (where are the spreadsheets) comparing sending six astronauts to Mars, and bringing them back, versus sending the minimum number to prevent inbreeding?

5) If colonization is not, why the one-way trip? How do costs compare for bringing the explorer back, versus continually sending him new supplies and replacement equipment?

6) If this is just to prove that going to Mars is possible, then hasn't this been done before, only with the Moon? Stop treating space like it's Mt. Everest, and more like undeveloped prairie.

The last thing NASA needs is another public failure. An ongoing controversy about a single human spending his time doing only what one person can do is hardly better.

I propose removing the legal barriers that intimidate private space development. If colonization is the long-term goal of NASA, and humanity's necessary "life insurance policy", then encouraging the migration of people off-world is necessary. A single shot publicity stunt is not good public policy, a bad investment, and irrational if one wants to see long-lasting, self-supporting population growth off-world.

Sunday, March 02, 2008

Generation Y (Millennials) at NASA

NASA's Gen Y Speaks Out, Wired

"At the recent NASA Next Generation Exploration Conference at NASA Ames, two young NASA employees, Nick Skytland and Garret Fitzpatrick, gave a powerful presentation called "The Gen Y Perspective"-- a set of charts they had delivered to their center management the week before that made it all the way up to the Administrator's desk. Now they were presenting it at a conference of their peers, with special guest moon walker Buzz Aldrin listening."

The PDF is of a slideshow.

Years ago, I posted to a website called The website was based on the book The Fourth Turning, by Neil Howe and William Strauss. The site has a discussion forum, and I was active on it from 1999 through around 2003. The conversation there is one of the best on the internet for historical and current event analysis. The members are really into the thick of the theory, so first-time visitors can be overwhelmed with all the jargon.

Without going into a lot of detail, here's the gist of Gen Y / Millennials, according to the work of Howe and Strauss:

- History influences generations (millions of people)

- Generations influence history (via large social trends)

- One can find similarities in various generations throughout US history

- These similarities repeat over time, usually in the same order.

- Generation Y / Millennials is more like the generation who came of age during the Great Depression and World War II, than the previous generation who came of age largely during the 1910s (World War I) and 1920s (Prohibition).

- This is very macro, attempting to describe tens of millions of people, and their associative behavioral trends. Individual and group exceptions apply, etc.

What the presenters get at is that selling space development and NASA the way it was [not] sold to the Boomers and Gen X is not going to work, and that this bodes ill for NASA and space development in the future. There is heavy focus on NASA specifically, and one can make arguments for the enthused private business attempts at making space development a reality. These businesses are ran largely by Boomers and Xers (due to experiential and financial constraints), so enthusiasm is not restricted to the Millennials.

That may the concern that the presenters are getting at. The Boomers have the Moon Landing as a pivotal, shared historical experience. Gen X saw the space shuttle, and the infamous 1986 explosion on live TV. For the shuttles have always blown up, the space station was either Russian, or a continuously delayed international one.

From personal experience, I was born in 1982. I don't remember the shuttle explosion. The first major disaster was the Exxon Valdez spill. I remember the space station being a big deal right up until 1993, and then Mir fell into the ocean, after suffering through many problems. NASA seems to get less done, at a slower speed, than the City of San Antonio. Were it not for SICSA, I may have not have gotten into Space Architecture in the first place, going instead into hi-tech building design or urban planning.

As Dwayne A. Day writes,

Unfortunately, the human projects are in worse shape. The shuttle is still grounded, the International Space Station is still years away from completion, and the bold new space exploration “Vision” is mired in the drudgery of budget politics. But wondrous things are happening way out there in the deep cold black of outer space and we do not have anybody to turn the science into poetry."

From personal experience, I was born in 1982. I don't remember the shuttle explosion. The first major disaster was the Exxon Valdez spill. I remember the space station being a big deal right up until 1993, and then Mir fell into the ocean, after suffering through many problems. NASA seems to get less done, at a slower speed, than the City of San Antonio. Were it not for SICSA, I may have not have gotten into Space Architecture in the first place, going instead into hi-tech building design or urban planning.

The Gen Y presenters call for making NASA (and/or its image) more interactive. Engage people with all the tools of social networking. My criticism is that internet-based technologies move fast, and trends faster. By the time someone at NASA has made a move, the crowds have moved on. Maybe letting private astronauts and scientists take their own initiative, if they so desire. But, a TV presence is still necessary, until astronauts can liveblog the launch experience from within the shuttle, and upload the video to YouTube.

Now, wouldn't that be cool?

Wednesday, June 13, 2007

PowerPoint Upload 3

Here it is.

Here is an excerpt:

No metal is more malleable or ductile than gold. It can also retain its shape and maintain its appearance longer than many other metals, which helps to explain in historical value.

Gold has one outer shell electron. It will only bond to one other atom under most conditions. Gold is like hydrogen in this respect. However, gold is not as reactive as hydrogen.

Gold exists naturally in an unadulterated state, and can be sorted from sands and gravel through a process known as panning. Its pure state is so soft that to add strength, gold is alloyed with other elements.

Gold can be plated onto particles, and can covert light into heat. This has proven useful as a cancer treatment in tests conducted at Rice University. Gold's biological inertness contributed to its usefulness.