Thursday, November 08, 2007

Turning Mountains into Mollhills to Solve Global Warming

I have to admit that I've thought Carbon sequestering has been a dead end idea since the first time I heard of it, but now scientists at Harvard are taking the cake. Their idea? Create Hydrochloric acid out of sea-water, I suppose using atomic energy or at least something that doesn't create more CO2, then dump it onto a very large pile of volcanic rock -- perhaps the island of Hawaii -- dissolving it until it becomes a mere nub of its former self, and the toxic effluent will runoff to the ocean, sequestering carbon therein and feeding coral reefs at the same time. WOW! What a deal!

I don't suppose anyone at Harvard has every considered addressing the root of the CO2 excess problem, such as advocating the use of nuclear power or weening Americans off of their gas guzzling SUVs (I picked SUVs only for example, don't go getting your shorts in a knot). I went to the elementary school to vote the other day and there was a gaggle of Ford Expedition-sized SUVs in the parking lot, undoubtedly owned by soccer moms at the PTA meeting. Given that my town is about 40 miles away from any gainful employment, then each of the those vehicles should go through about 8 to 10 gallons of gas a day just commuting. I'm guessing for that bunch, melting mountains into the sea is a more palatable idea than getting rid of their behemoths.

Wednesday, November 07, 2007

55 Cancri Offers a Habitable Zone Planet

However, be forewarned. This is a planet 45 times the mass of Earth with a probable surface gravity of 3.5 Gs (based on the assumption that it's a rocky planet like ours with similar density). It's not quite "earth-like" just yet, but perhaps one of it's possible moons could be. Of note is that this planet has an orbital period of 260 days and was found by monitoring the wobble of the system's G-class star. This is the same method that a few years ago could only find massive planets orbiting extremely close to red dwarfs.

The method of detecting the star wobble is to detect the doppler shift in the star's observed light. As a planet is orbiting a star, it ever so slightly drags the star towards it. When the orbit of the planet is such that it's moving towards the earth, the star also moves towards the earth, shifting it's spectral output ever so slightly towards the blue side of the spectrum. Later on, as the planet is moving away from the earth, the star is dragged away from earth, shifting it's spectral output towards the red side of the spectrum. The star's movement is tiny, even more so is the spectral shift.

It becomes apparent that two things impact the movement and spectral shift of the central star and thus make detection easier or harder. The smaller the relative mass of the star versus the planet determines how much the star will be dragged about by the planet. The lower that ratio, the more dragging occurs. This is great stuff, but the orbital period also comes into play. For the same given mass ratio, a rapidly orbiting planet will drag the star back and forth faster than a slower orbit, and since doppler shift is actually measuring the speed of the star's movement, the rapid orbit creates a greater spectral shift and is more easily detected. This is why red dwarfs with massive planets with orbits of a few days have stood out in the planetary detection business.

G-class stars such as 55 Cancri and our sun, due to their much greater mass (and therefore assumed greater mass ratios), make planetary detection much more difficult, so too do the necessarily longer orbital periods of planets in their habitable zones (generally speaking, orbital periods of about a year for G-class stars). What this news really tells us is that the science of planetary detection is maturing quite rapidly. Who knows what will be detected next year.

By the way, the planet was detected by a team led by Debra Fischer of San Francisco State University and Geoffrey Marcy of UC Berkeley. A related article can be found here and a video can be found here.

Saturday, November 03, 2007

Solar Array Repairs Complete

Say what you will about NASA, but fixing the solar array this Saturday, especially while strapped to the end of a 90 foot (27 meter) pole took serious guts and coordination on the part of the entire crew. Congratulations for a job well done.

Now, hopefully, they'll end this practice of retracting and extending the solar arrays every time they want to add another bit to the space station. The grit in the array bearing is still a quandry though.

Friday, November 02, 2007

A New Controversial Study

A new, important, controversial study has been revealed on aRocket. Thanks to Carl Tedesco for pointing it out! I don't dare discuss it here, so go follow the link, above.

Open Source Hardware: A Proposal

A mixed bag of successes and failures in the nascent entrepreneurial rocket industry demonstrates that it's having growing pains, and why shouldn't it? Each group is developing its own rocket engines, IMUs, etc. on its own. While this provides development on a broad selection of designs, it makes one wonder if all of this parallel reinvention is all that necessary. After all, the space industry has existed for over 60 years, with a very broad spectrum of designs and data already available in many cases.

One of the big advantages the big aerospace companies have is access to their own voluminous databases of designs and test data, especially information that is not publicly accessible. Meanwhile, entrepreneurial space is just getting started, designing various liquid-fueled engines in each of their shops, and going through the trials and tribulations of rocket design, such as hard starts, combustion instability, etc. and slowly building up their own knowledge bases and sharing what they will between each other. (I have to admit that aRocket is a very good forum in this capacity.) But in this industry, it occurs to me that intellectual property, especially the hording and selling thereof, has a cost associated with it that's prohibitively high. A collaboration model might work better. For instance, if company A and company B build their own versions of a LOX-alcohol engine of a partuclar thrust it may take X amount of time to come up with two solutions to their common problem. If they were to collaborate on a common design, each trying their own variations on it, but keeping the elements that work and cycling them back into the common design, then it may take X/2 amount of time to come up a common engine solution. Not only that, since the solution is common, the two companies could share parts as needed.

It's still possible for two companies to make money independently this way. Although the engine design may be common, there are still issues of manufacturing capability and customer management to allow both companies to flourish. For instance, company A may be better at manufacturing the engines, so company B may buy their engines from them or company C may do the same for that matter, because in an Open-Source method, everyone knows the engine's specifications, requirements and performance, or they may opt to build their own if company A is charging a really prohibitive price for the manufactured product. Everyone can also determine how well the engine works and uncover bugs much more quickly than one company could do alone. So potentially this could result in lower-cost, safer, hardware.

I once worked for a company that was oriented along product groups. Although at first this seemed like an inefficient way of running a company, the benefit was that each group could come up with unique solutions to their problems, and although this sounds like how the current entrepreneurial rocket industry is working, the critical difference was that if team A's product or tester or software was working better than your own, there were no barriers for you in team B to leverage their design for your own purposes, and visa versa. Everyone had the common goal of making money for the overall company, and it was a remarkably healthy environment to work in.

The people behind the entrepreneurial rocket industry may want to decide if they're in the business of building rockets or the business of flying customers. If they choose the former, then I fear the growth of the industry will be slow and expensive, if they choose the later, I expect something much faster.

Thursday, November 01, 2007

Band-Aids, Bailing Wire, and Tunnel Vision

The STS-120 crew will attempt a repair of the crippled solar array of the International Space Station. By using the shuttles self-inspection boom and the station's Canadarm II, mission specialist Scott Parazynski will be able to access the damaged part of the array. He will be attached to a precarious perch while working on a torn electrical circuit with 110 volts running through it at who knows how high of a potential current. The issue here is that the solar array starts working once exposed to sunlight, although disconnecting both ends of the array's electric circuit and turning it parallel to the sun's rays would go a long way to providing a modicum of safety. The purpose of the repair is to mechanically reinforce the array, presumably so it can be fully deployed. I can't imagine they're going to try and electrically fix any broken wiring, but I could be wrong.

So here's my only beef. I would hope that by now somebody at NASA has figured out that the solar arrays should've only been extended ONCE. The previous news conference I listened in on had the NASA representative speaking to reporters about the FA analysis of what might have caused the rip this time versus the jammed grommet last time, and whether or not atomic oxygen was playing any part in the failure (which he said it wasn't). Not one reporter or any NASA representative ever questioned the retracting/extending practice, which seemed to be the root cause as far as I could tell, and that made me think that there must be a lot of people at NASA who have serious tunnel vision.

I say the same tunnel vision is behind the development of the CLV. The rationalization must have sounded like this, "Hey, we have to do this on the cheap, so let's reuse Shuttle parts since all of our manned spaceflight infrastructure is built around the shuttle. We'll use an Apollo-like capsule, because we know how to build that and we know it works. We'll use an SSME to get us into the final orbit, because we'll have quite a few of them to spare and they're man-rated. Oh wait, scratch that, SSME can't be air-started, so we'll use a modified J2, since we built that for Apollo -- well not really, but we sort of did. Finally we'll use an SRB for the first stage since it's man-rated.. wait.. we need a little more boost.. OK, we'll use a 5 segment SRB as a first stage, because it's sort of man-rated and besides which we know the SRBs have never given us any trouble, except for that one time..."

..and volois, you have an almost completely new rocket, and it's still using a firecracker for a first stage (In case you haven't guessed by now, I'm not a fan of man-rating solid rocket boosters, which remind me too much of either a bottle rocket or a red rat if turned sideways). On the other hand if you start with the idea that you are building a brand new rocket, then your design process can be more flexible.

Somebody might've well said, "Hey, if we're really just going back to an Apollo, less the LEM, why don't we just use an F-1 and a bit of tankage for a first stage, a J2/cluster for a second stage, and this new bigger capsule/command module and call it a day. We still have a few F-1s laying around and besides, it's not like they caused us any trouble, EVER. And it's not as though we can't figure out how to make more of them because their dead simple to start with.

NOTE to the regular readers. See how the posts are beginning to knit together? Cool , huh?

Or you could say, Lockmart and Boeing are building EELVs, let's use them. And call it a day that way.