NASA is again asking for people to join its "mass collaboration"  effort to produce open-source solutions that address global needs applicable to both life on Earth and life in space. Registration is now open for a 2-day codeathon on April 19-21.

Last year's International Space Apps Challenge took place in 25 cities where events were organized to harnessed the skills, imagination and talents of anybody who was prepared to get involved and work in a team over a 48-hour period.  Over 2,000 people participated and the result was 101 open source solutions to problems set by NASA and its partner organizations.

The locations for the 2013 event have now been announced and the list has grown to 75 cities in 41 countries. There is also the option of Virtual Participation in which you connect online to find a team that needs your specific skills.

Challenges for the event fall into four categories: Software, Hardware, Citizen Science and Data Visualization. There's a wide range of problems in the software category from Create an application that mirrors changes to NASA's github presence, through Expand the online presence for the NASA GIRLS program to mobile and/or tablet platforms and Create a poultry management system for backyard farmers to Create an improved means for accessing SkyMorph images and catalogs or Developing a game to virtually build a lunar industry through a series of "bootstrapping" stages until it becomes self-sustaining.

Some of this year's challenges are extensions of solutions from last year's. For example, the Exploring Asteroids challenge is to adapt the Planet Hopper project and adapt it for use with small body space objects. 

To join in you first need to create an account and register for the event of your choice.