Joseph likes Astronomy, History and Archaeology. They have been talking about Gaia, the space observatory of the European Space Agency (ESA) launched on a day like today in 2013.
Gaia is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until c. 2022. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented precision.
The mission aims to construct by far the largest and most precise 3D space catalog ever made, totalling approximately 1 billion astronomical objects, mainly stars, but also planets, comets, asteroids and quasars among others.
The spacecraft will monitor each of its target objects about 70 times over the first five years of the mission to study the precise position and motion of each target, and will keep doing so.
The spacecraft has enough micro-propulsion fuel to operate until about November 2024. As its detectors are not degrading as fast as initially expected, the mission could therefore be extended.
The Gaia targets objects brighter than magnitude 20 in a broad photometric band that covers most of the visual range; such objects represent approximately 1% of the Milky Way population. Additionally, Gaia is expected to detect thousands to tens of thousands of Jupiter-sized exoplanets beyond the Solar System, 500,000 quasars outside our galaxy and tens of thousands of new asteroids and comets within the Solar System.
More information: ESA
The Gaia mission will create a precise three-dimensional map of astronomical objects throughout the Milky Way and map their motions, which encode the origin and subsequent evolution of the Milky Way.
The spectrophotometric measurements will provide the detailed physical properties of all stars observed, characterizing their luminosity, effective temperature, gravity and elemental composition. This massive stellar census will provide the basic observational data to analyze a wide range of important questions related to the origin, structure, and evolutionary history of our galaxy.
The successor to the Hipparcos mission (operational 1989–93), Gaia is part of ESA's Horizon 2000+ long-term scientific program.
Gaia was launched on 19 December 2013 by Arianespace using a Soyuz ST-B/Fregat-MT rocket flying from Kourou in French Guiana.
The spacecraft currently operates in a Lissajous orbit around the Sun–Earth L2 Lagrangian point.
The Gaia space telescope has its roots in ESA's Hipparcos mission (1989–1993). Its mission was proposed in October 1993 by Lennart Lindegren (Lund Observatory, Lund University, Sweden) and Michael Perryman (ESA) in response to a call for proposals for ESA's Horizon Plus long-term scientific programme.
It was adopted by ESA's Science Programme Committee as cornerstone mission number 6 on 13 October 2000, and the B2 phase of the project was authorised on 9 February 2006, with EADS Astrium taking responsibility for the hardware. The name Gaia was originally derived as an acronym for Global Astrometric Interferometer for Astrophysics.
This reflected the optical technique of interferometry that was originally planned for use on the spacecraft. While the working method evolved during studies and the acronym is no longer applicable, the name Gaia remained to provide continuity with the project.
The total cost of the mission is around €740 million (~ $1 billion), including the manufacture, launch and ground operations. Gaia was completed two years behind schedule and 16% above its initial budget, mostly due to the difficulties encountered in polishing Gaia's ten mirrors and assembling and testing the focal plane camera system.
More information: New Atlas
Gaia was launched by Arianespace, using a Soyuz ST-B rocket with a Fregat-MT upper stage, from the Ensemble de Lancement Soyouz at Kourou in French Guiana on 19 December 2013 at 09:12 UTC (06:12 local time). The satellite separated from the rocket's upper stage 43 minutes after launch at 09:54 UTC.
The craft headed towards the Sun–Earth Lagrange point L2 located approximately 1.5 million kilometres from Earth, arriving there 8 January 2014. The L2 point provides the spacecraft with a very stable gravitational and thermal environment.
There it uses a Lissajous orbit that avoids blockage of the Sun by the Earth, which would limit the amount of solar energy the satellite could produce through its solar panels, as well as disturb the spacecraft's thermal equilibrium. After launch, a 10-metre-diameter sunshade was deployed. The sunshade always faces the Sun, thus keeping all telescope components cool and powering Gaia using solar panels on its surface.
In October 2013 ESA had to postpone Gaia's original launch date, due to a precautionary replacement of two of Gaia's transponders. These are used to generate timing signals for the downlink of science data.
A problem with an identical transponder on a satellite already in orbit motivated their replacement and reverification once incorporated into Gaia. The rescheduled launch window was from 17 December 2013 to 5 January 2014, with Gaia slated for launch on 19 December.
Gaia was successfully launched on 19 December 2013 at 09:12 UTC. About three weeks after launch, on 8 January 2014, it reached its designated orbit around the Sun-Earth L2 Lagrange point (SEL2), about 1.5 million kilometers from Earth.
More information: EO Portal Directory
and leads us from this world to another.
Plato
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