Monthly Archives: September 2015

Plants in Space

Several weeks ago there was a big splash in the media about astronauts aboard the International Space Station (ISS) eating lettuce they had grown in Earth orbit. Having once spent ten weeks on a faculty fellowship at Kennedy Space Center working on potential problems associated with growing plants in space, I was curious about the progress that had been made since I had that experience.

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Cosmonaut Maxim Suraev holds lettuce plants grown onboard the International Space Station.
Credits: NASA

Okay, I was more than a bit curious. I’m also writing a science fiction novel where plants grown in a greenhouse provide oxygen and food for the crew on a long-duration space mission. The reports from the ISS hardly dented the array of issues I’ve had to consider in creating a system that uses plants to provide crucial life-support for astronauts. By contrast, this recent story seemed almost trivial, a novelty. Astronauts had something better to eat for a change than vacuum-wrapped dry food or paste packaged months earlier back on Earth. I know NASA has grown plants in space for years. Is this the first time astronauts have officially eaten something they’ve grown in orbit? Really?

In fact, I have come up with a list of questions I hope to pose to NASA public relations contacts about plants in space. My questions follow below, and if anyone reading this list either has an answer, knows where I can find an answer, or knows who I might ask for an answer, please reply with a comment to this post.

1. Was the recent event on the ISS the first time space-grown plants have been eaten by astronauts in orbit?

I’ve found a tantalizing hint or two of other astronauts or cosmonauts eating space-grown food unofficially. But it seems that most space-grown plants were harvested and frozen or otherwise stored for shipment back to earth. Which leads to my next question.

2. Have space-grown plants ever been eaten by Earth-bound scientists before?

So if the space-grown veggies were promptly shipped back to Earth, did they get taste-tested there? I’ve gathered hints here and there about concerns that space-grown plants might not be safe for human consumption. I have to admit this sounds a bit like the worries about the safety of genetically-modified crops (GMCs). If it grows like a leaf of lettuce, is the same color – green, and looks like a lettuce leaf… Which leads to the next question.

3. Have toxic compounds ever been discovered in space-grown plants as a result of their growth in microgravity?

If it’s a serious concern, and not the wide-eyed speculations of someone who would rather bring food up to orbit from traditional farms back on good old planet Earth, then presumably space-grown plants have been tested for their safety. Has anything been found to justify further testing, or can our astronauts relax and enjoy any veggies they find the time and space to grow up there in the Space Station?

My last question, for now, goes back a bit further than the International Space Station and even the Space Shuttle. I think I know the official answer to this one, but it was a long boring ride (when nothing went wrong anyhow) from Earth orbit to the Moon.

4. Were plants ever grown by Apollo astronauts on a lunar landing mission either on the Moon or on the way there?

Once again, if you know part of an answer to any of these questions, please share. Even if you’re not sure, share your speculations. Or if you know where I might find an answer, or who I might ask, speak up. And thanks in advance.

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HURRICANE GENESIS: A science review by Mark Betancourt in Air & Space Smithsonian

I’ve enjoyed Air & Space magazine for years, but an in-depth article by Mark Betancourt in the August 2015 issue goes above and beyond. I expect informative technology reviews and personal interest articles sating my inborn curiosity in aviation and space developments, but this story is one of the best science reviews I’ve read in a popular magazine.

Mr. Betancourt elucidates the state and the art of hurricane science, describing the methods and tools used to ask and answer the important questions. Of course, that’s how scientists operate, figuring out how to devise and conduct the tests required to solve the unknowns. Here we have the story of hurricane genesis focused on those tools and techniques climate scientists have used in the past as well as the new methods used today. But this story goes even further, into the future, laying out the questions we need to answer about how hurricanes begin.

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Eye wall of Hurricane Katrina from NOAA aircraft

Betancourt does all this without forgetting how Air & Space magazine adroitly grabs reader’s attention with personal stories about real people. So we read about the first pilot to penetrate a hurricane in an airplane. Joseph Duckworth, an Army Air Corps flight instructor and unusually skilled instrument pilot, was eager to show his British student pilots the capabilities of the AT-6 Texan aircraft they liked to ridicule. In July, 1943, he flew an AT-6 into a hurricane off Texas’ Gulf Coast, and returned unscathed. A fascinated colleague asked Duckworth to take him into the hurricane on a repeat of his daring flight. He did so, again returning safely.
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Restored AT-6 Texans flying at Oshkosh, July, 2015

Thus began the era of aircraft flying into a hurricane to take measurements of its strength and movement. P-3 Orions and C-130s have done it now for years, but here we taste the future with details of large and small drones used to study hurricanes up close.

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NOAA WP-3D Orion Hurricane Hunter

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Global Hawk outfitted for hurricane duty with NOAA

The large drone is the Global Hawk, 44’ long with a wingspan of 130’, weighing as much as 32,000 pounds and able to stay aloft in and above a hurricane for 18 hours. The Global Hawk is big enough to release dropsondes that fall through the storm sending back measurements.

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Coyote drone dropped into hurricanes by NOAA

At the other end is the Coyote, a three-foot long handheld drone with a six-foot wingspan weighing just seven pounds and capable of short two-hour flights through a hurricane. The Coyote is itself deployed from a manned P-3 Orion Hurricane Hunter.

The Genesis Part

Along with the personal interest stories and latest technology updates, Mr. Betancourt delivers sound science surrounding the still mysterious forces that coalesce to create a hurricane. He starts with three things we understand, evaporation, convection, and condensation. Water evaporates from the warm ocean surface making the air at the ocean’s surface less dense, causing it to rise – convection. As it rises, the air cools and the evaporated water molecules begin to condense into small droplets. When the droplets grow larger gravity forces them to fall back into warmer air below. When this happens, the droplets partially evaporate, cooling the air around them. This newly cooled air continues to fall, being heavier than the warmer air below. This is a classic downburst of rain and cool air, and it replaces the warm surface air mass that fed convection in the first place. Further evaporation and convection is stopped, and the storm is over.

I knew about evaporation, convection, condensation, even downbursts. But I didn’t know downbursts kill the storm.

What does this have to do with the mystery surrounding the genesis of a hurricane? As a cluster of convective storms come together, the middle layer of air through which rain falls becomes too warm and humid for the raindrops to evaporate, so there is no cooling. The downburst stops, or never really gets going, and rather then being cut off, the storms continue to grow bigger. More evaporation leads to more convection across a broad swath of the ocean surface as the storms coalesce and strengthen. A low pressure center builds as the warm air rises en masse. Cool, dry, and dense air from outside the low pressure center rushes inward from all directions, pushing the warm moist air up faster, allowing more evaporation to occur at the warm ocean’s surface, pushing more convection and ever lower pressure. The inward rushing air speeds up, further increasing surface evaporation and convection, and a positive feedback loop leads to a stronger and stronger storm. Bingo, a hurricane is born.

Unanswered questions include what causes a cluster of storms to coalesce rather than stay isolated and dissipate as they normally do, and what is the role of warm ocean surface waters? But thanks to this well-designed story that focuses on the tools, techniques, and unknowns surrounding the birth of hurricanes, those questions come forth with clarity. That’s how science operates. What’s rare is to see this in-the-field process of scientific investigation form the basic structure of a compelling story.