Sparky was Jaina Solo's red and white R5-series astromech droid during her early tenure with Rogue Squadron in the war with the Yuuzhan Vong. Sparky was destroyed a year into the conflict when Jaina strayed too close to an exploding New Republic ship in her XJ X-Wing at the Battle of Kalarba. Jaina was distraught at the loss of her droid, and eventually replaced the astromech with Cappie, a droid named after Jaina's fallen wingman, Anni Capstan.
Behind the scenes
In Dark Tide II: Ruin, he is described as an R2 astromech droid. It is obviously canon that he is in fact, an R5 unit.