Adelaide joined NASA as the librarian for the Electronic Research Center in 1965. Four years later she joined the Goddard Space Flight Center where she became Head of the Library Branch and Technical Officer of a major library support contract. In 1984, she spearheaded a project which linked NASA libraries together for the first time, allowing them to share resources, greatly improving the efficiency and effectiveness of the NASA library system. In 1987, she was appointed as NASA Librarian at NASA Headquarters to continue the oversight, coordination, and guidance to the future of NASA Libraries. In the 1980s, Adelaide testified before Congress concerning the implications of the Office of Management and Budget's Circular A-76 mandating the contracting out of federal library services, as she led the fight for recognition of the significant role played by federal libraries.

Adelaide contributed her time and talents to many organizations, including the Chevy Chase Library. As a member of the Board, she defended the library budget before the County Council Board of Directors. During her years of service to NASA, she was the recipient of several awards, including the FAFLRT (Federal and Armed Forces Libraries Round Table) Achievement Award (1986-1987), and the SLA (Special Libraries Association) 1990 John Cotton Dana Award. Her tireless efforts continued even through illness until shortly before her death in December 1991.

Adelaide is remembered professionally with the annual Federal Librarians Adelaide Del Frate Conference Sponsorship Award, a $1000 award given in Adelaide's memory to a qualifying library student for attendance at the annual ALA Conference. She is remembered personally for her kindness, enthusiasm, and constant and unwavering love and devotion to family. Decades after her death, she is still sorely missed.