A Soyuz-U rocket carrying the Progress MS-04 spacecraft lifts off Dec. 1. A problem during the rocket's third stage burn caused the loss of the mission.

The report indicated the “defective workmanship” in the assembly of the third-stage engine may have played a role in the failure.

This post is only available to members.

Jeff Foust has more than a decade of experience writing about space policy, entrepreneurial ventures and regulatory affairs. In 2001, he established spacetoday.net to aggregate and summarize the day's space-related news stories. In 2003, he started The...