Original Response Date: November 24, 2021 at Noon EDT The Space Development Agency (SDA) seeks responses to help build the Tranche 1 Transport Layer (T1TL). T1TL is a mesh network of over one hundred optically interconnected satellites that provide a resilient, low-latency, high-volume data transport communication system. T1TL will provide global communications access and deliver persistent regional encrypted connectivity in support of Warfighter missions around the globe by serving as the backbone for Joint All Domain Command and Control (JADC2) built on low-latency data transport and sensor-to-shooter connectivity. T1TL will consist of six near-polar orbital planes of SVs in a 1000 km altitude proliferated low Earth orbit constellation, linked together to form a global space mesh network. SDA expects to make multiple awards from this solicitation. Proposals are due by November 24, 2021 at Noon EDT.