A new NASA mission, launching today (Jan. 25), will ride along with a commercial satellite to investigate the boundary between Earth and space — a critical zone that changes based on the sun above and terrestrial weather below.
The launch window stretches from 5:20 p.m. to 6:05 p.m. EST (2220 to 2305 GMT), and you can watch it live here on Space.com, courtesy of NASA. The mission will launch on Arianespace's Ariane 5 rocket from Kourou, French Guiana, attached to the SES-13 communications satellite.
The Global-scale Observations of the Limb and Disk (GOLD) mission will measure the temperature and composition of the highest layers of Earth's atmosphere — the electrically neutral thermosphere, and the intermingled ionosphere, which gains its charge from the particles and radiation streaming from the sun.
The ever-changing "weather" in that region affects GPS and radio communications, but until now researchers have had no way to track its changes over short segments of time, NASA scientists said. The little GOLD instrument — between the size of a microwave and a minifridge — will ride on its satellite in a high orbit that stays steady over one part of Earth, so it can continuously observe almost an entire hemisphere. That will let GOLD track the upper atmosphere's temperature on a half-hourly basis as its instruments scan back and forth.
This launch marks the first time NASA has sent a science mission as a hosted payload on a commercial satellite. While SES-14 offers telecommunications services to Latin America, the Caribbean, North America and the North Atlantic, GOLD will send data back to Earth allowing researchers to build the first comprehensive models of the (inner) edge of space.
The rocket will release SES-14 into a geostationary transfer orbit, where it will use electric propulsion to move to its final geostationary orbit, and will also carry another satellite — the Al Yah 3, built by Orbital ATK, which will offer communications services to Africa and Brazil.