Keith Cowing’s Devon Island Journal – 22 July 2002: The hottest place on Devon Island

Click on Image for larger view. Images Copyright NASA HMP-2002/SpaceRef

Alain Berinstain wiring up the greenhouse sensor network

Greenhouse sensor network connection to overall HMP network

Keegan Boyd programming greenhouse sensor software

External weather sensors atop instrumentation mast

Instrument readout panel showing internal and external conditions

Marc Boucher programming HOBO data loggers

Closeup of HOBO data logger

Now that construction on the greenhouse has reached a lull, the outfitting of the structure with instrumentation so as to understand its performance is now underway. The intent here is to see how it performs as it cycles through a day, through various types of weather, and also through the seasons of the year.

The folks from CSA and the University of Guelph (Alain Berinstain, Keegan Boyd, and Tom Graham) have been busy installing the sensors. They have been eagerly awaiting this chance. Their eagerness has only been increased by the frustrations that went with losing much of their gear though inept shipping and then having to order replacement hardware.

A control box to contain sensor modules, wires to connect them, and other associated gear are now being put in place on the aft wall of the greenhouse. This is now starting to look like a ‘space’ greenhouse – not just a terrestrial greenhouse i.e. there is lots of instrumentation, readout panels, and computers inside.

Stretched along either side of the greenhouse are strands of wire to which a series of ultra-sensitive thermocouples have been attached. Overhead is a humidity sensor.

The door has a sensor attached so that we can tell when people enter and leave the greenhouse and like this to any change in the internal environment.

Light sensors are placed in a variety of locations and sample the strength and frequency of the light that arrives inside the greenhouse. Outside, a weather station measures wind speed and direction, humidity, light, and rainfall.

At this point we were no longer praying for “good weather” so as to assemble the greenhouse. Instead, we now wanted all kinds of weather: cold and overcast, clear and warm, and everything in between. We wanted to see how this structure performed under all conditions.

Taken together, these readings will give us an idea – based on real data (not simulations) of what conditions we’d have for research to be conducted in subsequent seasons. It is one thing to model what might happen. It is another to measure what actually does.

Moreover, we needed this data so as to understand what amount of temperature regulation (or augmentation) would be required; the amount and character of radiant energy plants would receive and whether we need to augment or modify this; and how all of these variables changed over time.

Luckily, once fully instrumented, we got a sampling of just about every type of weather Devon Island can muster. Over the winter, things will get much more severe. High winds, blowing snow, bitter cold temperatures, and long periods of darkness will all serve to test the ability of the greenhouse to withstand harsh conditions here.

Keegan has come up with an interface that we’ll eventually put online that will allow people to get an instantaneous update of conditions inside and outside of the greenhouse. For now it will only be available on our local network.

In addition to the sophisticated CSA monitoring, SpaceRef is also providing some sensors. We are installing two identical “HOBO” data loggers made by Onset computing. These ultra-rugged little devices have batteries that can last for a year or more while they patiently record various bits of data. The data is then downloaded to a computer.

Marc programmed both HOBOs and successfully tested their ability to record and then download data. As such, we have now placed the HOBOs inside the greenhouse. Over the coming year they will monitor light, humidity, internal temperature, and external temperature.

The CSA/University of Guelph team has decided to leave their instruments in place and let them run until their batteries fail. The data will be retrieved when we arrive again next year.

When we arrive on the island next year we should have an idea of how the greenhouse performed over the winter. We are already planning the augmentation of this facility’s capabilities for next year. In addition, we will be doing the selection of science to be done within the greenhouse.