Question on Rocket Artillery units

[Oli4]

Hi everyone,

the recipient of the order i am currently reasearching is listed on his service card as having served in a rocket artillery battery in the 29. Separate Rifle Brigade from 22/12/1941 (shortly before it was converted to the 1. Guards Rifle Brigade). My question is if this is indeed indicating this brigade had its own rocket unit or is inaccurate and he was more likely in one of the "ОГМД"s (Independent Guards Mortar Battalions) supporting this unit in early 1942?

Kind regards,

Oli