Skynet is a family of military satellite

Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

s, now operated by Paradigm Secure Communications on behalf of the UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 Ministry of Defence

Ministry of Defence (United Kingdom)

The Ministry of Defence is the United Kingdom government department responsible for implementation of government defence policy and is the headquarters of the British Armed Forces....

, which provide strategic communication services to the three branches of the British Armed Forces

British Armed Forces

The British Armed Forces are the armed forces of the United Kingdom of Great Britain and Northern Ireland.Also known as Her Majesty's Armed Forces and sometimes legally the Armed Forces of the Crown, the British Armed Forces encompasses three professional uniformed services, the Royal Navy, the...

 and to NATO forces engaged on coalition tasks.
There were two Skynet 1 satellites; the first, launched in November 1969, failed after less than a year of operation.