Under the DCSP, several increasingly sophisticated satellite series would test and provide long-range communications between "fixed, transportable or shipboard terminals".

[1] This decision came on the heels of the cancellation of Project ADVENT, the first attempt at a military geosynchronous communications satellite system, begun February 1960.

This change did not go unchallenged; the House Committee on Government Operations denounced the move, saying that the "plan for short-range economies depending on a high-risk program may prove costly in the end".

With the selection of the Titan IIIC as the IDCSP booster, the Pentagon dropped contract negotiations with Philco, preferring to develop the satellites in-house.

[2] Developed primarily by TRW, the IDCSP spacecraft were identical communications satellites, spin-stabilized, 26-sided polygons, 86 cm (34 in) in diameter, covered with solar panels, and had a mass of 45 kilograms (99 lb).

[5] They were specifically designed to be simple to avoid the problems faced by the earlier Courier and Advent programs:[6] no in-orbit control mechanisms were included, nor were the satellites equipped with batteries.

[4] Complementing these satellites were ground communications terminals used to transmit and receive via IDCSP satellite voice, imagery, computerized digital data, and teletype channel using Frequency-division multiplexing/Frequency Modulation (FDM/FM), Differential Phase Shift Keying (DPSK), Multiple frequency-shift keying (MFSK), and Spread Spectrum Multiple Access (SSMA) modulation techniques.

[8] The Eimac Division of Varian Associates supplied one of the two traveling wave amplifiers used by the satellite's transmitter, the other being produced by Watkins-Johnson Company.

[4] The second set of IDCSP satellites, totaling eight, was lost 26 August 1966 when a faulty payload fairing caused the launch failure of the fifth Titan IIIC.