Free at last... now what?

Now that I am finally finished with the dissertation, I find myself with considerably more free time. As my wife has recently pointed out, I have a rare opportunity now to pick up a hobby before I allow myself to get bogged down with the next project or any of life's other pressing demands on my time. So, in addition to spending more time with my kids, and possibly doing little light blogging from time to time, what else could I be doing that I would enjoy and still fell like I'm making good use of my time.

One of the things you learn while getting a PhD is just how little you know out of all that is possible to know. I feel that I've learned a great deal during my studies, but there is a great deal more that I want to know... that I need to know. So, I find that it is time for me to leave the sheltered halls of academia and to try and make my way in the real world. I'm ready to put my hard earned education to work, but I am fully prepared to have to learn more in order to do so.

Power and propulsion are two topics that I love to ponder, but I don't think I'll have the resources to start tinkering with actual hardware for some time. If I'm extremely lucky, I might be able to land a job with one of the new space startups, where I'd be able to do that kinda thing as my day job. I'd jump at the chance to work with the likes of SpaceX, Blue Origin, XCOR, Masten Space Systems, Armadillo Aerospace, Ad Astra Rocket, or Scaled Composites.

I've also been wanting to get more seriously into robotics and astronomy for long time now. I have some brief experiences with both of these, but I'd like to be able to advance my skill set to the next level if possible. I often find myself thinking about better ways to interface to tele-operated devices. If Jeff Hawkins is correct about the hierarchical organization of the brain, then it should be possible to build a robotic system which can learn some basic, low-level behavior in response to commonly encountered stimuli, but still be able to pass on unexpected or novel information to a higher cognitive level (possibly a user). Specifically, I'm thinking about robotic telescopes which will be able to scan the sky autonomously, but be able to direct their attention to more novel phenomena based on their own past experiences.

One project that I've been putting off for a long time now (because I couldn't justify spending the time on it with the dissertation hanging over my head) is to look into doing more sophisticated mission prototyping using the spaceflight simulator Orbiter. Although the development of the main program seems to have stalled, there is still an active community of third party developers generating fresh and interesting add-ons for the simulator.

I have been contemplating a building rapid prototyping tool for designing rockets, RLV's, and other spacecraft. The program would be similar to NASA's Rapid Aircraft Modeler (RAM) that I worked on a few years ago. One simply selects from of list of standard components, then resizes and repositions them to rapidly assemble a desired configuration. Then, I would have the program output the necessary files to fly the model in Orbiter. By making use of some of the advanced modeling capabilities provided by the Orbiter API, it should be possible to get a fairly reasonable approximation of the vehicle's performance for a given class of mission.

And one final thing which looks like it will have to be a hobby since I can't seem to get my supervisor interested in letting me do it for work. I've recently managed to get CUDA installed and running on my laptop. I'd like to teach myself how to program the GPU. There is a lot of potential computing power tied up in those little chips, but not all computations scale equally well on the GPU. I think this is probably something that I will not truly be able to appreciate until I learn it through trial and error. Still, there's at least one instance of someone doing discontinuous Galerkin simulations on the GPU with encouraging results. I'd like to see if I can manage to get at least part of my DG solver running on the GPU.

And it's official..

The day has finally come at long last. I am now officially Eric M. Collins, PhD.

It has been such a long and arduous process that I'm finding it difficult to accept that I'm actually done. From the perspective of fulfilling a life-long ambition, it was well worth it. Now we will see if it was worth the delay in getting a real job and postponing all of those other things that grown-ups with a decent income get to do.

While I've still got a lot of work to do and papers to write, I also need to focus on looking for a job. I have until the end of the year to find something. I would very much like to get on with one of the new-space companies (e.g. SpaceX, Blue Origin, etc.), but I will also be looking into NASA and some of the national labs. If there is anyone out there who wants to hire a computational engineer with an intense interest in enabling technologies for exploration and exploitation of the space environment, please feel free to contact me.

Turbo pump ASCII art

In a comment to a post by John Hare (Told You So - Seleneian Boondocks), I tried to post an ASCII art depiction of a turbo-pump configuration which I thought would better illuminate the point I was trying to make. Unfortunately, the reply window only allows a subset of the HTML markup and decided to severely mangle my ASCII art instead. It really was a good rendering, so I'll post it here, just in case anyone else is curious.

||^                         ^||
||  __       _____       __  ||
||^|__|  V  |_____|  V  |__|^||
|| <  :=======| |=======:  > ||
||____|  V   _|^|_   V  |____||
|_____|     |_| |_|     |_____|
         V    |^|    V         

What you are looking at is the bottom of a proposed thrust chamber analog. High pressure gas is being fed into the chamber and forced down and out ("V" in the diagram) through a turbine blade. The blades are hollow, which allow them to act as a pump (through centrifugal acceleration). Water is then pumped into the chamber through a diffuser along the paths marked by ("<", ">", and "^").

As I mentioned in the comments to the other post, the key to making this design work is minimizing the amount of drive gas which gets leaked into the pump chamber around the ends of the turbine blades. Just as the water within the blades is going to want to be thrown outward, so will the gasses escaping through the blades themselves.

Anyway, before I reveal just how much I don't know about turbopump design, I better just quit now. Feel free to comment on this here or at the original post.

We industrialize!

Now this is the kind of space advocacy that might actually have a chance of appealing to ordinary folks.



There are none of the supposed "justifications" for the space program that NASA contrived a couple of years ago. There's simply a catchy tune, some simple graphics, and a message. That message is that space offers a tremendous opportunity for us to put our ingenuity and productivity to work towards creating a new and innovative economic niche. This niche is one that has yet to be exploited, has tremendous potential for future growth, and one that we appear to be in a rather unique position to take of advantage of at this very moment.

What will we do with this opportunity? Will we continue to throw good money after bad at sectors of the economy which have failed to generate enough wealth to sustain their own activities? Or do we take bold new steps to generate new industries and new services that will form the basis for the next century of economic growth?

The ISS as fuel depot testbed

I've been wondering for some time if the ISS could be used to advance the technology required to perfect propellant depot technology. It seems that nearly all of the required hardware is already on board the station. The current ECLSS on the ISS electrolyze waste water and condensate to generate breathable oxygen, with the excess hydrogen being vented to space. If the hydrogen stream could be diverted into a Sabatier reactor, then CO₂ could be scrubbed from the atmosphere and turned into methane fuel.

I've also been wondering for if a propellant depot infrastructure should be resupplied with pure water rather than the cryogenic fluids. The favorable density and handling properties of water as opposed to LO2/LH2 would appear to make it the better choice for transporting aboard a very simple tanker over potentially long time periods. When shipped as water, the "fuel" can be transported in a non-cryogenic, inert state, and then once delivered to the depot, it can be cracked into O2/H2, liquefied, and stored until it is needed.

Of course, this assumes that your depot has sufficient power and/or time to split water and keep the fuel properly chilled. I found this page which describes the Russian Elektron unit. This article cites a passage from a NASA training manual:

NASA TRAINING MANUAL ON ‘ELEKTRON’

From the “NASA Familiarization Manual on Russian Segment Crew Systems”, Published in 1997.

3.1. Oxygen Supply System
...
The decomposition of 1 kg (2.2 lbs) of water yields 25 L (0.88 ft3) of oxygen per hour at a pressure of 760 mmHg, which is enough to support one crew member for one day. To provide the daily amount of oxygen for 3 - 4 crew members, 3 - 4 kg (6.6 - 8.8 lbs) of water must be decomposed. Power consumption of the process is ~ 1 kW.

A kilogram per hour at one kW, seems like a very reasonable rate, at that's just for one Elektron unit (if I'm reading this correctly). If necessary, this can scaled up with additional units if sufficient power is available. It may be possible to build even more power efficient electrolysis system if the work of Dr. Nocera at MIT can be turned into a practical device that will operate in zero-G conditions.

If the depot is also crewed, then a steady supply of water would be required any way. The crewed depot could also generate methane as an additional propellant option if the ECLSS included a Sabatier reactor as well as an electrolysis unit. With the exception of the Sabatier reactor and some cryogenic storage tanks, the ISS already possesses all of the hardware. The existing U.S. electrolysis units even have hardware available for connecting to a Sabatier reactor.

So, what would be the point of having the ISS generate and store propellant? Well, first of all, it is currently our only manned research outpost in zero-G. It would therefore be expedient to take advantage of these facilities to work out the basics of cryogenic fluid transfer in micro-gravity. The data obtained from ISS experiments could go along way towards reducing the techological risks associated with propellant depot development.

The ISS also needs fuel for station-keeping. Having the ability to generate it's own propellant would be a nice capability to have. This would also simplify the ISS resupply requirements. Rather than having to deliver water and propellant, each in the individual compartments, only water would be required. The water tanks could be made larger, and therefore more mass efficient. Since propellants would no longer need to be transported (I think hypergolics are currently used), the handling of the payload for resupply missions would be much less hazardous.

Finally, with the ability to produce fuel, the ISS could support a small array of space tugs and transfer vehicles which would service the station and other objects in nearby orbits. For example, imagine that SpaceX puts up a couple of Dragon lab modules in orbits which are coplanar with the ISS. Now imagine that the ISS has a slightly modified ATV docked to it. It might then be possible for an ISS astronaut to use the ATV to rendezvous with the Dragon module and perform any necessary maintenance or repairs.

I have some additional thoughts on how to convert the ATV into a crewed orbital transfer vehicle, but I think I'll save those for another post.

A Biological Imperative

Every few months, the debate over humans in space seems to flare up again. The motivations for human spaceflight are usually touched on briefly while reflecting on the loss of the astronauts of the Apollo I, Challenger, and Columbia spacecraft. Sometimes the discussion is sparked by the humans vs. robots debate. Other times it shows up while attempting to justify the human spaceflight budget. Depending on the context and the participants, the discussion can be anywhere from cordial to an outright flame war.

Jeff Foust recently posted a fairly innocuous summary of reactions to the new administration's budget request (Reacting to the budget proposal - Space Politics) which has somehow managed to stir up a fair amount of discussion in its comments. Unfortunately, by the time I got around to reading through it, some of the comments had already began devolving into pointless bickering.

Of course, I felt compelled to post some of my own thoughts. I am reposting them here for my own benefit, and in case anyone would like to discuss them away from the flames of the other post.

Human space exploration is not about science, or even exploration for that matter. These things are a consequence - a side effect - of having humans in space. In fact, science and exploration are a consequence of humans being just about anywhere, including the bottom of the ocean or in caves dozens of kilometers below the surface. Humans will make observations (either directly or through remote probes), form hypotheses, test them, and then find a way to exploit the results somehow. That's what humans do.

The question on everyone's mind is "Why?" Why do we go to all of these extreme places (in person and with probes)? The answer is quite simple: niche exploitation and expansion. It's a biological imperative. We do what biological organisms have always done: expand to fill an available niche, exploit resources where possible, and then search for new niches to fill. In every biological population, there are individuals or groups which make it their purpose to accomplish each of these tasks. Humans are particularly adept at this and are doing so at an unprecedented rate.

What makes humans so special is that they are the first species capable of expanding the biosphere beyond the surface of the Earth. Humans alone are capable of taking this simple biological imperative out into the universe; exploiting the resources found there, remaking the environment to sustain themselves, and always pressing forward. It is for this purpose that the robotic probes are made and sent out in advance; and that robotic machines are being created to assist humans in hostile environments. It is also for this reason that we cannot send robotic probes alone.

In a way these thoughts are complementary to those I have posted previously (Why Space? and Not Just Science). I find that my thoughts have evolved somewhat since then. I have been trying to come to a better understanding of what it is that space advocates are trying to articulate when they give the 'basic human need to explore' argument. Although most space advocates feel this in their bones, they usually fail to give an adequate explanation of this feeling to those who do not necessarily share their passion for space. I'm not saying that my comments above will go much further at bringing this point home to the average Joe. However, I do feel that if we can get past our own personal motivations and cast human spaceflight in a broader context, we may eventually be able to convince others that it is well worth the expense.

Dragon as the new CRV?

In my previous post (A more gentle transition) I tossed out an idea that perhaps a Dragon capsule, launched to the station in support of ISS logistics, could be modified to serve as a crew lifeboat while it is docked to the station. I was quite surprised, then, to stumble across this post (The new X-38/CRV: SpaceX's Dragon?) by Rob Coppinger yesterday, which references this article (Race to the International Space Station begins in earnest) by John Croft over at Flight Global.

I had no idea if such a thing was possible; only that it would make sense to try and use the Dragon for ISS crew-return if dealing with the Russians proved to be problematic in the future. Using the Dragon this way would also remove one of the frequently cited reasons why the Shuttle should not be used to service the ISS beyond 2010; namely that it could not remain docked to the ISS for extended periods of time, and thus could not be used as an ISS lifeboat. But if this story is correct, then there are already studies underway to validate this concept.

The primary difference between this report and my hypothetical scenario is that they appear to be studying the prospect of delivering the Dragon capsule in the payload bay of the Space Shuttle. I guess I assumed that the Falcon 9 would have successfully flown by the time this would be needed. I cannot think of any other reason why they would rather use the Shuttle. If Falcon 9 has been successfully flown by 2010, then it would certainly be cheaper to launch the capsule to the station using a Falcon 9; not to mention the fact that the Dragon is designed to be launched by a Falcon 9.

My other assumption regarding how it might be easy to temporarily convert a cargo Dragon into a CRV while it is docked to the station, may have also been a little too optimistic. There are probably alot of sub-systems that would be present in a crewed Dragon (even a minimal reentry version), that would probably not be found on an unmanned cargo Dragon. If absolutely necessary, a crew could probably ride down like cargo; however, they would most likely want a more robust life-support capacity and manual flight controls available in an actual CRV Dragon.

I have just one more idea, that I'd like to throw out there. I've been thinking for some time now that NASA should get a Sundancer class module from Bigelow and launch it into an orbit near the Hubble space telescope. That way, if anything goes wrong with the STS-125 mission, they would at least have the opportunity to use the module as a safe haven until a rescue mission can be mounted.

Now, there may be another way to add crew rescue capability to STS-125. If they are actually studying the feasibility of launching the Dragon on the Shuttle, then perhaps it would be possible to tuck one away in the back of the payload bay for the Hubble repair mission. Would there be room? Would the Dragon be ready in time? My guess is: probably not, but it's an interesting idea none-the-less.

A more gentle transition

There has been much gnashing of teeth concerning the imminent, and all but inevitable, gap in American manned spaceflight capability after the Shuttles are mothballed in 2010. I've been thinking about this problem, off and on, for some time now. Given the current state of NASA and the commercial space transportation industry, there are really only a couple of realistic options for dealing with "the Gap".

The first option is for NASA to continue flying the shuttle a couple of times a year beyond 2010 until a suitable replacement is available. I have never really had a problem with flying the Shuttle past 2010. It will be just as dangerous to fly it then as it is now (and yes, I would jump at the chance to fly in it if it were offered to me). Many have dismissed the possibility of extending the Shuttle service on the grounds that: a) it's too expensive and would consume resources that NASA would rather be devoting to Ares I/Orion, and b) it wouldn't solve the underlying problem of how to get our own astronauts to and from the space station without having to rely on the Soyuz capsules as lifeboats.

In my own opinion, I think that using the Shuttle strictly for crew-rotation and logistics deliveries is a terrible waste of the Shuttle's unique capabilities. Instead, I'd like to see NASA take advantage of these extra flight opportunities to continue expanding the ISS beyond the minimal 'US core complete' configuration. Many additional modules have been, or are nearly, completed. The Shuttle was conceived, designed and built to support the construction of a Space Station. So long as the Shuttle is still active, it should be doing what it does best.

Another possibility for reducing 'the Gap' is for NASA to provide additional resources to companies like SpaceX to assist with the rapid development of launch vehicles suitable for manned spaceflight. For a very small fraction of the resources currently being poured into the Ares/Orion development, SpaceX could potentially have the Falcon 9 rocket and the Dragon capsule ready two to three years before the first Orion capsules would be available.

There may other options which have some chance of mitigating the consequences of retiring the Shuttle before its successor comes online, but for now, I'd like to explore a third option that lies somewhere in between the two options mentioned above.

Let's assume that SpaceX will be able to demonstrate reliable cargo delivery to the station and safe return to the Earth with the Dragon capsule by the end of 2010 or early 2011. At that point, the main thing preventing crew rotation using the Dragon is the development and demonstration of safe and reliable crew launch on the Falcon 9. Elon Musk has stated that SpaceX could have crewed Dragon ready within three years if they were to be funded under the COTS-D program (perhaps a couple more years if no COTS-D funding were provided). That's most likely an optimistic estimate, but even still, that means no crew launch capability until at least the 2012-2013 time frame.

Let's imagine then that NASA is persuaded by Congress to continue flying the space shuttle to the station twice a year until a suitable replacement vehicle is ready. By that time the Dragon will likely have demonstrated the ability to stay on orbit at the station for months at a time and then execute a safe and controlled reentry. With probably very few modifications, it should be possible to convert the Dragon capsule into a crew life boat once it has delivered its cargo to the station. That's a lifeboat that can seat seven (i.e. the entire ISS crew complement with room to spare).

So long as no problems arise, the crews can be rotated in and out on the shuttle. The Dragon could continue to be used to de-orbit important cargo, but in the event of a emergency situation, it could also be used to return all or just part of the crew. Assuming the Russians still have at least one Soyuz docked to the station, the redundant life-boat capability would mean that the station would not necessarily have to be abandoned if only one or two of the crew needed to be immediately returned to Earth.

So, rather than saying either Dragon or the Shuttle, why not say both. We can make the most out of the Shuttles' extension to really finish building out the ISS. At the same time, the Dragon can be fulfilling a useful role as a lifeboat for the expanded crew without having to rely on the availability of additional Soyuz capsules. When the Falcon 9 / Dragon capsule has been qualified for manned launches, then crew rotations can be transitioned from the Shuttle to the Dragon, and the Shuttles can finally be retired for good.

Dragon, you are up.

Most of you reading this probably already have heard about the remarks made by Senator Bill Nelson to the Orlando Sentinel (link) concerning the recent actions taken by Russia in South Ossetia and how it will negatively impact the current negotiations for purchasing Soyuz flights beyond 2011. From what I've read in the mainstream media, they have pretty much taken the Senator's statement to mean that we will be effectively cut off from the ISS after the shuttle is retired until Ares/Orion is ready to fly. However, there is an alternative that they seem to be overlooking.

For over a year now, NASA (and Congress) have been avoiding making a decision on whether or not to provide funding for the COTS-D option. With these latest developments, it seems as though Plan A (continue purchasing Soyuz flights ad nauseum) may no longer be politically feasible. That means that Plan B (development of the crewed SpaceX Dragon capsule) may now start getting some serious support, and resources, thrown its way.

There have been some in the mainstream media who have not looked favorably upon SpaceX after its recent third failure to launch the Falcon I rocket. Some doubt that SpaceX will be able to meet its existing COTS commitments, let alone be able to provide crewed launch capability. As one person commented, "If they can't launch the little one, how do they expect to launch the big one?"

The primary purpose of the "little one" is for rigorously testing, debugging, and characterizing the performance of the very same systems that will eventually fly on the "big one". This is a very sound strategy, and once the Falcon I has successfully shaken out all of the bugs in its systems, I would be very surprised if any of the first flights of the Falcon IX vehicle fail to make it into orbit. The design of the Falcon IX vehicle is more robust than that of the Falcon I, and as such it is much more likely to be able to compensate for any remaining small glitches which may crop up and still succeed in its mission.

Elon Musk has stated on several occasions that SpaceX can close the gap in US access to the ISS. Well, now may be the perfect opportunity for him to get the support he needs to complete work on the crewed Dragon and have it on the pad by 2011. Although I suspect that work on the Dragon capsule has been progressing towards crewed capability regardless of whether or not NASA comes through with the COTS-D funds, additional political and financial support would certainly help things along.

The Ares I/Orion was never going to be able to close the gap in US access to the ISS. NASA has been willing to rely on the "devil they know" with access via Russia's Soyuz capsules, but that may no longer be possible. It now seems like the Dragon capsule may be our best hope (our only hope) for uninterrupted access to the ISS.

Dragon, you're up. Let's see what you can do.

2007 Blackburn Academic Symposium (Part 1)

So, here I was thinking that I'd be the only space blogger within a hundred miles of Tuscaloosa, AL that could get to Burt Rutan's talk at the Inaugural Gloria and John L. Blackburn Academic Symposium at the University of Alabama. Upon arriving however, I find none other than Jeff Foust sitting two rows in front of me. Oh well, so much for the scoop.

Ostensibly, the Blackburn Academic symposium was created as a forum to bring together academic, industrial, and political leaders to discuss issues facing the state of Alabama and the nation. The focus of this inaugural symposium was "Responsibility for the Future Exploration and Development of Space", and the list of invited guests reflected this theme. During the morning, there were two keynote speakers: Burt Rutan, and Dr. David King, director of NASA Marshall Space Flight Center. The afternoon was taken up by two panels. The first discussed the roles of industry, government, and academia in the future of space exploration. The second featured three astronauts: Col. Jim "Vegas" Kelly, Dr. Jan Davis, and Col. Jim Voss; all of whom are alumni of Alabama universities. The event was free and open to the public.

Certainly, the highlight of the day, for me at least, was the talk by Burt Rutan. The topics brought up in his keynote address seemed to reverberate throughout the rest of the day. Mr. Rutan spoke of the interplay between inspiration and innovation in the field of aerospace, though his comments could certainly have broader application to just about any field of human achievement. The key thesis of his presentation was that nearly everyone who strives to do something difficult and meaningful in their adult lives were inspired by some seminal event or events at a crucial time in their childhood between the ages of 3 and 14. This observation was borne out again and again throughout the day as almost every other speaker at the symposium related their own personal story of childhood inspiration which lead to their desire to work in the area of spaceflight.

Mr. Rutan's own experience was playing with a model airplane in his back yard when a formation of B-52 bombers flew directly overhead. From that point on, he knew that he would work in the world of aviation. Even when he went to college in the mid-60's, during the height of the space race, he steered away from space-related engineering disciplines and focused on general aviation. From there his professional experience lead him down a path which would allow him to be both creative in aircraft design as well as attempt a number of significant aeronautical and aerospace milestones. Among these accomplishments were the Voyager aircraft which circled the globe non-stop back in the 80's, and of course, Space Ship One. He said, "It is important for an entrepreneur to attempt these milestone challenges if it is at all possible."

There was one other significant point brought up by Mr. Rutan, that would reemerge briefly later in the day. One of the main reasons why innovation in aerospace has been stagnating recently is not so much due to a deficiency in our educational system, but because no one has asked for any thing truly remarkable in recent memory. No one has dared to ask for the impossible since President Kennedy challenged America to send a man to the moon. The very best among us are compelled to seek out the most difficult challenges, and they will almost always rise to the occasion when presented with a daunting task. For the past 20 years, most of the innovators have been drawn to the challenges in computing, the internet, and more recently, in biotechnology. There simply have been no compelling challenges put forth in aerospace since the days of the development of the Concorde and the Space Shuttle. I was left to wonder if this deficiency came from a lack of vision or a sudden rise in risk aversion on the part of our nation's leaders.

Dr. David King gave his keynote address immediately following Burt Rutan, but the difference in presentation of the two speakers was striking. While Dr. King spoke of the Vision for Space Exploration and of the need to inspire the next generation of scientists and engineers, there was really nothing in his talk which reached in and grabbed me. I felt no emotional attachment to the kind of inspiration he was describing. In contrast, Burt Rutan made the connection almost personal. Rutan spoke to some basic truths in the human spirit and in the imagination which made one feel compelled to do something to fulfill those childhood dreams. Dr. King's talk felt more like taking a pill. Something external to me, which I may or may not be directly responsible for bringing about, is going to somehow make everything better.

The difference in these presentation underscores, at least for me, the perceived difference in approaches to space exploration being undertaken by NASA and the new space industry. NASA seems to be indicating that they will lead by example, and merely by the act of doing these wonderful things, they will inspire young people to become future leaders in science and technology. While this may be true in some sense, I think that the new space approach feels much more personal. The main distinction is of course in the underlying sense that NASA is going to be doing these great things, and oh, the rest of us might get to watch, while many in the new space community seem to be interested in opening up the space frontier for everyone to participate.

Those are my initial impressions of the morning session. I think I have at least one more post in me wherein I will describe the afternoon session and then try to go into more detail about what I perceived to be the recurring themes of the day.