Nick Coleman: nasa

History of Space Flight

Nick — Fri, 15 Jul 2011 18:53:00 -0700

Sigh, indeed.

Amazing to think that we landed on the Moon just 42 years after the first major intercontinental flight, and that we are now 42 years after that.

(Cartoon from a local newsletter, I don't know the source.)

Stunning Image of ISS

Nick — Wed, 08 Jun 2011 08:50:00 -0700

NASA's Image of the Day shows some stunning photos occasionally, and this is one of them.

Endeavour docked to the ISS, taken from Soyuz (click for bigger)

The pictures are the first taken of a shuttle docked to the station from the perspective of a Russian Soyuz spacecraft. On May 23, the Soyuz was carrying Russian cosmonaut Dmitry Kondratyev, NASA astronaut Cady Coleman and European Space Agency astronaut Paolo Nespoli back to Earth. Once their vehicle was about 600 feet from the station, Mission Control Moscow, outside the Russian capital, commanded the orbiting laboratory to rotate 130 degrees. This move allowed Nespoli to capture digital photographs and high definition video of shuttle Endeavour docked to the station. Credit: NASA

NASA: Aeronautics, Space?

Nick — Tue, 19 Apr 2011 10:00:00 -0700

I was struck by the caption of today's NASA Image of the Day. Here is a small copy of the image, and I've copied the caption below as it is hard to read on this small image:

The terrain for the scientific work conducted by ICESCAPE scientists on July 4, 2010, was Arctic sea ice and melt ponds in the Chukchi Sea. The five-week field mission was dedicated to sampling the physical, chemical and biological characteristics of the ocean and sea ice. Impacts of Climate change on the Eco-Systems and Chemistry of the Arctic Pacific Environment, or ICESCPE Mission, is a multi-year NASA shipborne project. The bulk of the research will take place in the Beaufort and Chukchi Seas in summer of 2010 and fall of 2011.

NASA, shipborne? Why is NASA doing earth science research on a ship? Where does shipborne fit into "aeronautics" and "space"?

NASA does do much earth science, but it's within its purvue of space: satellites and so on.

It looks like NASA is doing whatever it can to keep its budget even when it is nothing to do with its mission statement.

I know that NASA is a highly political organisation, but it must be frustrating having to resort to distractions like this.

No doubt the research is worthy and needs doing, but it should be done by one of the many earth-bound science organisations. I can't fathom any reason for NASA (and, more importantly, its tight budget) to be involved.

NASA's Mars Spirit Stops

Nick — Tue, 05 Jan 2010 17:37:00 -0700

You may know that NASA's Mars Exploration rover Spirit has been bogged in one place since about April 2009. It broke through the crust into soft sand, got bogged and then one wheel stopped working.

From what I read, they're not hopeful of freeing it. The issue now is that dust is accumulating on the solar panels and, with winter approaching, they are not confident that the batteries will recharge. Which means the end of it.

It's too early to call for closing-drinks, but it's getting near.

Interesting to see a plastic shopping bag, and a well-used track heading off to the local shops and a pub, no doubt. That's where we'll have the last drinks.

It's done a great job. It's design brief was for an extendable 90 days, and it has lasted for six years. The engineers should be and no doubt are proud of what they've made.

Let's remember that this was one of NASA's cheapest missions and one of its most productive. Surely robot missions are the future for exploratory work.

This image is NASA's Image of the Day for 4 Jan 10 and is quite poignant.

Image Caption

Click on the image for a larger version. You can see the caption text that I wrote about in a previous post.

Adding a caption to NASA's Image of the Day

Nick — Mon, 21 Dec 2009 08:30:00 -0700

I recently wrote about converting text to an image, and gave a brief example using image magick. To recap, here's the command-line:

convert -fill white -background '#007a7a' -gravity "West" -size 300x50 caption:"address@domain.toplevel" email.jpg

One very useful way of using this text-to-image feature is to add a caption to an image. We will go through this and use NASA's Image of the Day as an example. (In actuality, image of the working week give or take a day. No image on the weekend, I'm afraid.)

If you're not familiar with it, NASA's Image of the Day is a high-scale photo released by NASA's PR department, usually chosen for its stunning imagery or its relevence to a science mission. It's been going for years and is a bit of an institution among the astronomy and science set.

The image used to be available on it's own page, along with some explanatory text and photo credits below. Having its own page meant that you could store a simple bookmark, which would never change, to view it every day.

Before long, people were automatically downloading the image using wget or an ftp script and putting it on their desktop. A nice new photo every day.

Nowadays, in the curse of multimedia everywhere, there is no consistent link. You have to visit NASA's multimedia gallery and scroll through the list of images to see the latest. Each image has its own URI, and there is no link to that entity previously known as "the image of the day".

However, NASA does provide an RSS feed that contains a link to the latest image and a caption. That's great, we can use the contents of the feed both to pull down the image and to overlay the caption.

One of image magick's very useful features is its ability to work on several layers at once. We will use that feature to create a caption on one layer using the same technique as in my previous post, and we add the image itself to another layer. Then flatten the layers, resize the image to suit our desktop, and save it. Presto, we have a nice new desktop image every day.

Here is a sample of bash code (easily alterable to any command-line, including DOS):

# Get the rss file that contains the direct link to the image. # It is always #lg_image_of_the_day.rss #. lg_ means large, there are # other sizes too: see the NASA website section on feeds. wget -N http://www.nasa.gov/rss/lg_image_of_the_day.rss

# Parse it to get the actual image URI, and use tail to get the # last line. # Search for the text "url" and grab what follows. image_url=$(sed '{s/^.*image\/jpeg \" url=\"$.*$\"\/> <\/item><\/channel> .*/\1/;}' lg_image_of_the_day.rss | tail -n 1)

# Get the image itself. wget -N $image_url
... various techniques to calculate resizing, both for the desktop and for the aspect ratio. I'll post them if people are interested...
# Parse the rss to extract the caption (in XML tag ) and # save it. This is searching for the tag and getting everything after, up # to some arbitrary text limit, here the photo credit. I had to set a # limit as sometimes the text runs for several hundred characters. # An alternative method would be just to grab a certain number # of characters. sed 's%.*$.*$$Photo\|Image$ Credit.*%\1%' \ lg_image_of_the_day.rss | tail -n 1 > NasaIod.txt

# And finally convert the text to an image, overlay it on the photo image # and save it. Saving it to a non-layer format flattens the # layers automatically. convert \ $ -fill white -background '#0008' -gravity NorthWest -size \ $width caption:"@NasaIod.txt" $ \ $ $image $resize $ \ +swap -gravity South -composite image.jpg

The first set of parantheses creates one layer and the second set a second layer.

The interesting part in the last statement is the caption:"@NasaIod.txt". This reads a file containing text, which we created previously when we parsed the rss.

I'll quickly go through the image magick options(the 'convert' command which forms part of the image magick suite of programs).

We put the text into the first layer rather than the second, then '+swap' them so the text is on the top layer. There is a reason for this, but I can't remember it (so shoot me). I seem to recall that, if the text layer is placed on top of the photo layer, it resizes to fit, making it too large.

'-gravity' places the smaller text layer at the bottom (South) of the larger photo layer.

'-composite' merges the two layers.

I haven't gone into too much detail on the rest of the script, assuming you understand sed and some bash. I'll explain it further if anyone requests it.

I have put this entire process into a script that completely automates it. It can handle tall narrow images, adjusting the caption width to take aspect-ratio into account. I run it with cron every morning and have a nice new desktop image most days.

And, the NASA images are simply stunning!