The Spallation Neutron Source (SNS) has built Superconducting Radio Frequency (SRF) processing and testing facilities to support improvement programs and future upgrades. The Cryogenic Test Facility (CTF) system is capable of delivering liquid helium at 4.5K to different test apparatus in support of SRF testing. This paper describes the final stages of fabrication, commissioning and the initial operation of the Horizontal Test Apparatus (HTA). The HTA allows for cold testing of single jacketed medium-beta or high-beta SRF cavities. Heat loads, capacities, and other performance data collected during operation will be presented. Cavity testing lifecycle for plasma processing research and development will be discussed. System changes to allow for 2K helium operation in the HTA will also be addressed.