MarsPhotos

A Ruby wrapper for NASAs Mars Rover Photos API.

Installation

Add this line to your application's Gemfile:

gem 'mars_photos'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mars_photos

Usage

For basic usage, instantiate an API object either with or without an API key (if you don't provide one it will be set to the demo key, which allows for 30 requests per IP address per hour, and a maximum of 50 requests per day). Get an API key from NASA here.

@api = MarsPhotos::API.new # Sets API key to 'DEMO_KEY'
@api = MarsPhotos::API.new('YOUR_KEY_HERE')

Retrieve photos by rover and sol like this:

@api.get(rover: 'curiosity', sol: 1000)

This returns an array of the photos, each with an img_src attribute.

You can provide an earth date in the format YYYY-MM-DD instead of a sol:

@api.get(rover: 'curiosity', earth_date: '2015-6-3')

For photos from a specific camera, just specify a cam in the method's parameters:

@api.get(rover: 'curiosity', sol: 1000, cam: 'fhaz')

You can call this method with a block:

@api.get(rover: 'curiosity', sol: 1000) do |photo|
  puts photo['img_src']
end

You can also instantiate the Rover class:

@curiosity = MarsPhotos::Rover.new(name: 'curiosity') # uses demo key
@curiosity = MarsPhotos::Rover.new(name: 'curiosity', key: 'YOUR_KEY_HERE')

@curiosity.get(sol: 1000)
@curiosity.get(earth_date: '2015-6-3')

@curiosity.get_by_sol(1000)
@curiosity.get_by_earth_date('2015-6-3')

Rovers

Images are available from three rovers:

Rover	Landing Date
Spirit	January 4, 2004
Opportunity	January 25, 2004
Curiosity	August 6, 2012

Sols

Sol is a time measurement representing the number of Martian solar days since the rover landed. It starts from 0.

Cameras

Abbreviation	Camera	Curiosity	Spirit	Opportunity
FHAZ	Front Hazard Avoidance Camera	✓	✓	✓
RHAZ	Rear Hazard Avoidance Camera	✓	✓	✓
MAST	Mast Camera	✓
CHEMCAM	Chemistry and Camera Complex	✓
MAHLI	Mars Hand Lens Imager	✓
MARDI	Mars Descent Imager	✓
NAVCAM	Navigation Camera	✓	✓	✓
PANCAM	Panoramic Camera		✓	✓
MINITES	Mini Thermal Emission Spectrometer		✓	✓

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/cltweedie/mars_photos.

License

The gem is available as open source under the terms of the MIT License.