This is Amendment #6 to the Request For Proposal (RFP) entitled Support for Atmospheric Sciences, Modeling, and Data Assimilation II (SAMDA II), Solicitation 80GSFCR0021. The purpose of this Amendment is to correct section 11 on SF30 where the is extended box was checked in error. The RFP submission date is not extended therefore, proposals continue to be due on October 28, 2021 at 3pm EST as stated on SAM.gov.