Ariane 5 Flight VA240 launches four Galileo satellites
At 3:36 p.m. local time (1:36 p.m. EST / 18:36 GMT) on December 12, 2017, an Ariane 5 rocket lifted off from the European Space Agency (ESA)’s Spaceport in Kourou, French Guiana, carrying four Galileo satellites, bringing the total number of spacecraft in the Galileo constellation to 22.
When the rocket reached an altitude of ten kilometers (6.2 miles), Arianespace’s launch commentator said: “And there they go, blazing a trail across the sky here over the spaceport.”
The first pair of satellites was deployed three hours after 26 minutes after liftoff. The second pair was released twenty minutes later at an altitude of 22,922 kilometers (14,243 miles).
The upper stage of the Ariane rocket contained a dispenser that ejected the satellites. From there, they will be steered to their final orbits by ground control. Then they will begin six months of tests by the European Global Navigation Satellite System (GSA). Following completion of the tests, they will go into operation as part of the Galileo constellation.
Galileo, which has no connection to NASA’s Galileo Jupiter probe, is the ESA’s satellite navigational system. There are still two satellites awaiting launch; when complete, the Galileo Constellation will consist of 24 satellites which will provide very precise global positioning for cars, ships, and people, as well as provide precise times.
Jan Wörner, Director General of the ESA, said: “Today’s launch is another great achievement, taking us within one step of completing the constellation. It is a great achievement of our industrial partners OHB (DE) and SSTL (GB) for the satellites, as well as Thales-Alenia-Space (FR, IT) and Airbus Defence and Space (GB, FR) for the ground segment and all their subcontractors throughout Europe, that Europe now has a formidable global satellite navigation system with remarkable performance.”
Paul Verhoef, ESA’s Director of Navigation, said: “ESA is the design agent, system engineer[,] and procurement agent of Galileo on behalf of the European Commission. Galileo is now an operating reality, so, in July, operational oversight of the system was passed to the GSA.
“Accordingly, GSA took control of these satellites as soon as they separated from their launcher, with ESA maintaining an advisory role. This productive partnership will continue with the next Galileo launch, by Ariane 5 in mid-2018.
“Meanwhile, ESA is also working with the European Commission and GSA on dedicated research and development efforts and system design to begin the procurement of the Galileo Second Generation, along with other future navigation technologies.”
ESA officials said: “Galileo navigation signals will provide good coverage even at latitudes up to 75 degrees north, which corresponds to Norway’s North Cape—the most northerly tip of Europe—and beyond.”
ESA has not only developed satellites for navigation, Earth science, telecommunications, and astronomy, but also the agency has developed deep-space probes such as the Rosetta probe which landed on Comet Churyumov–Gerasimenko.
The Ariane 5 rocket is an expendable, heavy-lift launch vehicle operated by Arianespace. The main stage uses liquid hydrogen for fuel and liquid oxygen as the oxidizer. The strap-on solid rocket boosters utilize a propellant mixture of 68 percent ammonium perchlorate (oxidizer), 18 percent aluminum powder, and 14 percent hydroxyl-terminated polybutadiene (HTPB). The second stage uses monomethylhydrazine (MMH) for fuel and nitrogen tetroxide as the oxidizer.
Video courtesy of Arianespace
Collin R. Skocik has been captivated by space flight since the maiden flight of space shuttle Columbia in April of 1981. He frequently attends events hosted by the Astronaut Scholarship Foundation, and has met many astronauts in his experiences at Kennedy Space Center. He is a prolific author of science fiction as well as science and space-related articles. In addition to the Voyage Into the Unknown series, he has also written the short story collection The Future Lives!, the science fiction novel Dreams of the Stars, and the disaster novel The Sunburst Fire. His first print sale was Asteroid Eternia in Encounters magazine. When he is not writing, he provides closed-captioning for the hearing impaired. He lives in Atlantic Beach, Florida.