NASA is conducting an internal review of the Space Launch System rocket’s affordability, two sources have told Ars Technica.

Concerned by the program’s outsized costs, the NASA transition team appointed by President Joe Biden initiated the study. The analysis is being led by Paul McConnaughey, a former deputy center director of NASA’s Marshall Space Flight Center in Huntsville, as well as its chief engineer.

The SLS rocket program has been managed by Marshall for more than a decade. Critics have derided it as a “jobs program” intended to retain employees at key centers, such as Alabama-based Marshall, as well as those at primary contractors such as Boeing, Northrop Grumman, and Aerojet Rocketdyne. Such criticism has been bolstered by frequent schedule delays—the SLS was originally due to launch in 2016, and the rocket will now launch no sooner than 2022—as well as cost overruns.