Also known as the Deep Sea Drilling Project or DSDP.
An international programme, initiated in 1968 and planned by the Joint Oceanographic Institutes for Deep Earth Sampling (JOIDES) to drill the Earth in deep water. To accomplish this, the University of California-owned drilling ship D/V Glomar Challenger was used.

The programme resulted in more than 500 boreholes being drilled in the sea bed of the Atlantic, Pacific and Indian Oceans as well as the Mediterranean Sea.

Originally funded solely by the National Science Foundation of America, the DSDP also recieved support and equipment from the United Kingdom, France, West Germany, Japan and the USSR, becoming a truly international effort.

The DSDP yielded a large amount of scientific data: some notable achievements included the discovery of salt domes in depths of more than 1,000 metres which indicated the presence of oil, as well as definitive proof for the theories of continental drift and seafloor renewal at rift zones.

The D/V Glomar Challenger also became the site of a few technological accomplishments in the field of drilling: with drilling pipes reaching up to 6,200 metres to the ocean floor, and borehole depths of up to 1,300 metres, broken drill bits became a large hassle. The engineering crew pioneered the use of sonar equipment to replace drill bits.

The DSDP ended in a sense in 1983: at this point, it became the ongoing Ocean Drilling Programme (ODP) using the ship JOIDES Resolution.