Friendship 1 (UESPA-1) was a deep space probe launched by the United Earth Space Probe Agency in 2067 with the purpose of finding other species. The probe contained a great deal of technological, scientific, and cultural information, such as translation matrices, data on computer chips, transceivers, and warp drive, and Vivaldi's The Four Seasons.
The opening greeting of the probe was: "We the people of Earth greet you in a spirit of peace and humility. As we venture out of our solar system, we hope to earn the trust and friendship of other worlds." Both Harry Kim and Tom Paris had to memorize the greeting in third grade.
Starfleet lost contact with the probe in 2248. Friendship 1 eventually landed on the planet Uxal in the Delta Quadrant. The Uxali learned about antimatter from the probe and applied it in a planetary power grid. However, they lacked the technological expertise to utilize it safely and antimatter was accidentally released, causing a nuclear winter and contaminating the surface with antimatter radiation.
In 2378, Starfleet charged the USS Voyager with finding the probe, its first official mission in seven years. They came into conflict with the survivors on the planet where Friendship 1 landed, who blamed Humans for giving them the information that caused their self-destruction. Eventually, Voyager was able to eliminate the radiation by triggering an atmospheric isolytic reaction with its photon torpedoes. (VOY: "Friendship One")