A team of researchers from various institutions has demonstrated the distribution of quantum entanglement over a distance of 144 km between the Canary Islands of La Palma and Tenerife using a free-space optical link. This experiment confirms the quantum mechanical prediction that entangled particles maintain their correlations over arbitrary distances. The experiment involved generating polarization-entangled photon pairs at a high altitude on La Palma and transmitting one photon via a free-space link to a receiver on Tenerife. The photons were detected by two observers separated by 144 km, and the results violated the Clauser-Horne-Shimony-Holt (CHSH) inequality by more than 13 standard deviations, demonstrating genuine quantum correlations. The experiment also demonstrated the feasibility of quantum communication in space, involving satellites or the International Space Station (ISS). The distance achieved in this experiment is more than an order of magnitude greater than previous free-space experiments and exceeds the limits of ground-based free-space communication. The results show that quantum entanglement can be distributed over long distances, which is a crucial step towards establishing a worldwide quantum communication network. The experiment used a high-precision closed-loop tracking system to stabilize the link despite atmospheric drifts. The quantum cryptographic key was generated using the entangled photons, and the results showed that the quantum key distribution protocol was successful, with a secure key of 178 bits being distilled from the raw key. The experiment also demonstrated the adaptability of the Optical Ground Station (OGS), developed for standard optical communication to and from satellites, for use in quantum communication protocols. The results confirm the feasibility of satellite-based distribution of quantum entanglement, which is the first step towards establishing a worldwide network for quantum communication.A team of researchers from various institutions has demonstrated the distribution of quantum entanglement over a distance of 144 km between the Canary Islands of La Palma and Tenerife using a free-space optical link. This experiment confirms the quantum mechanical prediction that entangled particles maintain their correlations over arbitrary distances. The experiment involved generating polarization-entangled photon pairs at a high altitude on La Palma and transmitting one photon via a free-space link to a receiver on Tenerife. The photons were detected by two observers separated by 144 km, and the results violated the Clauser-Horne-Shimony-Holt (CHSH) inequality by more than 13 standard deviations, demonstrating genuine quantum correlations. The experiment also demonstrated the feasibility of quantum communication in space, involving satellites or the International Space Station (ISS). The distance achieved in this experiment is more than an order of magnitude greater than previous free-space experiments and exceeds the limits of ground-based free-space communication. The results show that quantum entanglement can be distributed over long distances, which is a crucial step towards establishing a worldwide quantum communication network. The experiment used a high-precision closed-loop tracking system to stabilize the link despite atmospheric drifts. The quantum cryptographic key was generated using the entangled photons, and the results showed that the quantum key distribution protocol was successful, with a secure key of 178 bits being distilled from the raw key. The experiment also demonstrated the adaptability of the Optical Ground Station (OGS), developed for standard optical communication to and from satellites, for use in quantum communication protocols. The results confirm the feasibility of satellite-based distribution of quantum entanglement, which is the first step towards establishing a worldwide network for quantum communication.