Thursday, June 26, 2008

Astronauts: Space-Age Weed Eaters?

While NASA contemplates what plants might be grown in space for the Astronauts based on the moon or on their way to Mars, may I offer a few of my own plant candidates? These candidates probably haven't been researched much so far because, for most people, they're dismissed as common weeds.

Summer Purslane - Portulaca oleracea

Summer Purslane, or common purslane, is a common bane to most gardeners. This flat-growing, succulent-leafed plant grows just about anywhere soil is devoid of other plants, "it tolerates poor, compacted soils and drought" -- See the Wikipedia link, above. It grows during the warmer times of the year and contains more Omega 3 fatty acids than any other leafed vegetable. It also contains a fair bit of vitamin C.

I like summer purslane for four reasons: (1) it's tasty, (2) it likes poor soils, (3) you can eat almost the whole thing, and (4) it grows as a flat mat, which allows a space-cramped astro-farmer to grow closely stacked shelves of it in a corner of his/her biosphere. Here I envision shelves where the bottom side is covered in LEDs to illuminate the plants on the shelves below it.

Miner's Lettuce - Claytonia perfoliata

Miner's lettuce, sometimes called Winter Purslane, is one of the first plants to appear in the California springtime. When it's still chilly outside, it's tender shoots break through the poor soil into the shady areas in which it usually grows. When the heat of summer kicks in, Claytonia begins to fade from the spotlight, but not before producing a bounty of seeds. The name "Miner's Lettuce" comes from the Gold Rush era, when miners would eat it to prevent scurvy, obviously because of it's vitamin C content. I like miner's lettuce for six reasons: (1) it's tasty - much like lettuce or spinach, (2) it likes cool shade, (3) it contains vitamin C, (4) with its round central leaf it looks like it should be a space vegetable, (5) you can almost eat the entire plant, and (6) it doesn't much care what soil you try growing it in. From our astro-farmer's point of view, miner's lettuce is an ideal vegetable when you're running short of light and heat, such as during the lunar nighttime when power consumption would be at a minimum.

Common Chickweed - Stellaria Media

Another fine winter plant, chickweed is tasty stuff that grows almost anywhere there is space. Like miner's lettuce and summer purslane, above, chickweed is almost entirely edible. As a medicinal plant, it has been traditionally used to treat skin-related ailments. I like this plant for 5 out of the 6 reasons I like miner's lettuce -- chickweed, however, doesn't look much like a space vegetable.

Common Dandelion - Taraxacum officinale

Dandelions can be used as salad greens and the taproot can be dried and roasted as a coffee substitute. Naturally this means that nearly the entire plant can be consumed. Dandelions are easy to grow, perhaps much harder not to grow. No space garden should be without a patch of the cheery yellow flowers.


You'll notice by now that the candidates I've offered have a few common attributes. The first, in all cases the plants can be almost entirely consumed. When you look at many of the NASA-tested vegetables, such as tomatoes, potatoes, and wheat, there remains a fair amount of plant waste after harvest that needs to be broken down and returned to the soil/nutrient solution. This requires room and energy to accomplish and effects the O2/CO2 balance if composting or incineration are used.

All the candidates can grow in relatively poor soil. Weeds are robust members of the plant community. They are opportunists which usually grow quickly wherever they end up, and they generate a fair number of seeds as a matter of course, allowing for a multitude of re-plantings. Two of the candidates are winter vegetables, requiring less energy than typical summer vegetables. One of the candidates grows as a flat mat, allowing it to grow on tightly spaced shelves where space is limited.

These candidates demonstrate that by looking a bit "outside of the box", growing space vegetables may be easier than currently anticipated.

Thursday, June 19, 2008

Various Random Thoughts

It's been a very long while since I've written anything in the blog, so I thought I'ld catch up a bit.


Several month's back (April, I think), I went to the Ames Research Center's Open House and sat through some interesting lectures about LCROSS, standing for Lunar Crater Observation and Sensing Satellite or the Lunar Whack-a-mole Project as I like to think of it. The purpose of the program is to create an small, artificial crater on a permanently shadowed part of the moon and see what volatiles arise out of it. This is somewhat of a follow up to the experiment attempted with the Lunar Prospector at the end of its mission, which was inconclusive.

The first talk was given by Anthony Colaprete, the principle scientist for the program. He talked about how the LCROSS program was to work and how relatively inexpensive it was to be. The LCROSS mission is piggy-backing onto the same Atlas 5 rocket that is to send the Lunar Reconnaissance Orbiter (LRO) to the moon. The LCROSS sensing satellite is actually built into a secondary payload adapter that sits between the LRO satellite and the Atlas 5 upper stage. After the LRO is released from the upper stage, the LCROSS sensing satellite and upper stage go on a different, much longer trajectory to the moon. During that time, the satellite and the upper stage separate a bit so that when they arrive at the moon, the upper stage hits first, allowing the satellite to monitor the upper stage impact and the volatile, like water vapor, it should stir up. Also during that extended period, the upper stage will bake in the sun, releasing what extra hydrazine and unspent fuel is within it. This is important as those chemicals would muddle the results the satellite is attempting to collect.

In other ways, the team of scientists did their best to reduce the cost of the instruments on-board. For instance, some of the instruments on LCROSS are modified commercially available Intra-Red cameras and such. If memory serves, the LCROSS system should be able to detect water down to 1% of the lunar soil content. The upper stage will make the measurement a bit ambiguous (by about half a percent) due to remaining hydrogen within it. The hope of the mission is to detect around 2% water content in the soil.

The second talk was given by an engineer from Northrop-Grumman. His talk centered around the actual construction of the craft and what design considerations went into creating it. The LCROSS craft was built into a space-rated piece of hardware called the ESPA (EELV Secondary Payload Adapter) ring. The ring looks like a short section of large diameter pipe with holes bored into the side of it. Normally, these holes would be where secondary payloads are attached, while the primary payload attaches to the top of it and the launch vehicle attaches below it. Using the ESPA was the quickest way the engineers could guarantee the LCROSS wouldn't collapse with the LRO on top of it during launch, and since it was already space-rated, there was no engineering work required to make sure it would work. The center of the ring contains the LCROSS fuel tank, while panels on the outside contain instrumentation and a solar panel. Overall, it was an inexpensive craft to build in a hurry.

IT CAME FROM OUTER SPACE! -- Karen Nyberg's Hair

While watching NASA highlights on TV, I couldn't help but notice one astronaut being closely followed by a creature resembling an Afghan crossed with a tribble. The astronaut was Karen Nyberg, a mission specialist in charge of operating three different mechanical arms (one on ISS, one on the Japanese Kibo lab, and one on the Shuttle) and installing and bringing up the rest of the lab alongside Aki Hoshide. Some have inferred that Karen was included in the mission for her space-babe status, which I find absurdly cynical (Read her bio if you don't agree). But the most distracting part of her presence on ISS was her hair, which seemed to have a life of its own. A list of various links to pictures from Reuters and other sources follows:

From All American Patriots
Reuters: "Feed Me, Seymour!"
Reuters: The Astronaut with Two Heads
Reuters: When Tribbles Attack!

One hopes that there were no exposed fans to entangle loose locks. Whenever space travel becomes everyday, braiding services may be provided free of charge, if not required by law.


Four, nearly five dollar gas has got me to thinking. Every time I hear a discussion on the news or on the radio about drilling for more oil or for making biodiesel or ethanol out of switch grass it gets me to wondering if anyone has really done the cold equations. I haven't gone through the math in any detail here, so I won't bother with more than a few trivial details. According to the linked sources, the US uses roughly 146 billion gallons of gasoline per year and biofuel yields for oil and alcohol hover in the 300 to 1000 gallons of fuel per acre per year. As such, the US would need to set aside an area between 146 million and 486 million acres (or between 228,100 and 760,500 square miles [or between something a bit smaller than Texas and a bit larger than Alaska]) of arable land for growing fuel. This simple analysis doesn't cover inefficiencies in the system, but one gets the idea the needed area is huge, and in my opinion, unlikely to be successful. One more note: the use has about 400 million acres of arable land as it now stands.

While I don't have the figure here, I imagine that a large majority of that gasoline consumption is being used in commuting. If we could avoid commuting all together, this crisis could be avoided, but of course bosses need to see your shining face at work every day (or do they?). Imagine what could be done if telecommuting could enable white collar jobs to be done at home instead of in the office. In fact, we are already there for many jobs. The problem is the culture of business hasn't caught up to the technical possibilities yet. Change the business paradigm, and in my humble opinion, saving the world from ourselves will follow (or at least be a bit easier).