Velta, who started for the Lommedalen IL ski club , began his international career in 2007 in the FIS Cup . After good results, he started in the Ski Jumping Continental Cup for the first time in September 2008 . Since he was able to jump to the top positions for the first time in Oslo in March 2010 , he was nominated for the ski jumping World Cup . He took part in a World Cup competition for the first time on March 14, 2010, but did not score any points. In the summer it was used for the first time in the Grand Prix . After failing to qualify in Hinterzarten and Courchevel , he qualified in Liberec and then narrowly missed the second round in 32nd place. A few days later he was able to qualify again in Klingenthal and surprisingly took 7th place the next day. At the beginning of winter he was called up in the national group in the Norwegian team in Lillehammer, Norway. In both competitions he surprisingly took 17th and 10th place. After he was disqualified at the Four Hills Tournament 2010/11 in Oberstdorf and missed qualification in the other three competitions, he was transferred back to the Continental Cup squad. At ski flying in Vikersund he was back in the World Cup squad and reached 16th place in both competitions. He finished the season in the Continental Cup in 66th place overall. At the Norwegian Championships in March 2011, he finished second behind Anders Bardal in the individual and won the team competition with the Akershus team, as in the previous year.
At the opening competition of the 60th Four Hills Tournament in Oberstdorf on December 30th, 2011, he was the third best Norwegian and reached 18th place. He was able to improve this position in the second competition in Garmisch-Partenkirchen by finishing 11th as the second best Norwegian. He also took this place in the overall ranking. On January 15, 2012, he achieved eighth place in ski flying in Bad Mitterndorf, his best ever World Cup result. On February 11, 2012, he won the opening competition of the FIS Team Tour with the Norwegian team on the Mühlenkopfschanze in Willingen and was able to achieve his first World Cup victory.
On February 25, 2012, he achieved his greatest success to date when he became vice world champion in ski flying in Vikersund.
In the 2012/13 season he achieved his first podium in an individual World Cup competition on January 9, 2013 in Wisła with a third place. Velta's best individual result in the World Cup dates from the same year: at the end of the season, he finished second in ski flying in Planica . On February 1, 2015, he was able to take second place in an individual competition when jumping from the Mühlenkopfschanze in Willingen, Hesse .