Blackjack LEO Constellation
Blackjack is a DARPA program which will replace the old National Security Space (NSS) satellite infrastructure in GEO with a LEO mesh grid made entirely out of commercial, easily interchangeable, over-the-counter products. DARPA intends to use this program to provide the United States Department of Defense with a consistent military network for sensing, communication, and data transport.  Blackjack aims to have all satellite buses selected by the end of 2020 and have all satellites in LEO by 2021.  Since modern satellites cost almost $1 billion to design, build, operate and maintain, DARPA limited the budget per satellite to $6 million. DARPA aims to operate on that limited budget by outsourcing the project to the private sector.
In June 2020, DARPA announced that it had awarded a $14.1 million contract to Blue Canyon Technologies to develop satellite buses for the constellation. It also announced that it had awarded a $16.3 million contract to SA Photonics to support Blackjack payloads. 
In May 2020, DARPA announced that three Blackjack satellites will be launched in late 2020: Mandrake 1, Mandrake 2, and Wildcard. DARPA says that the Mandrake satellites could form the basis of a future LEO optical mesh network. Wildcard is a software-defined radio satellite which will perform experiments with radio links in LEO. 
In 2018, DARPA awarded Telesat a $550,000 contract to study implementation of satellite buses in the Blackjack program. European satellite manufacturer Airbus Defense and Space received a $2.9 million contract. Blue Canyon Technologies of Boulder, Colorado, received a contract for $1.5 million.  Trident Systems Inc. was given a $1.5 million contract for satellite payloads.