'MARS EXPRESS', THE EUROPEAN VOYAGE TO MARS

Today, The Grandma has received the visit of one of her closest friends, Joseph de Ca'th Lon.

 

Joseph loves Astronomy and Science, and they have been talking about one of the most important European missions in space, Mars Express, the first planetary mission attempted by the ESA that was launched on a day like today in 2003.

Mars Express is a space exploration mission being conducted by the European Space Agency (ESA).

The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency.

Express originally referred to the speed and efficiency with which the spacecraft was designed and built. However, Express also describes the spacecraft's relatively short interplanetary voyage, a result of being launched when the orbits of Earth and Mars brought them closer than they had been in about 60,000 years.

Mars Express consists of two parts, the Mars Express Orbiter and Beagle 2, a lander designed to perform exobiology and geochemistry research. Although the lander failed to fully deploy after it landed on the Martian surface, the orbiter has been successfully performing scientific measurements since early 2004, namely, high-resolution imaging and mineralogical mapping of the surface, radar sounding of the subsurface structure down to the permafrost, precise determination of the atmospheric circulation and composition, and study of the interaction of the atmosphere with the interplanetary medium.

Due to the valuable science return and the highly flexible mission profile, Mars Express has been granted several mission extensions. The latest was approved on 1 October 2020 and runs until 31 December 2022.

Some instruments on the orbiter, including the camera systems and some spectrometers, reuse designs from the failed launch of the Russian Mars 96 mission in 1996 European countries had provided much of the instrumentation and financing for that unsuccessful mission.

More information: ESA

The design of Mars Express is based on ESA's Rosetta mission, on which a considerable sum was spent on development. The same design was also used for ESA's Venus Express mission in order to increase reliability and reduce development cost and time. Because of these redesigns and repurposing, the total cost of the project was about $345 million- less than half of comparable U.S. missions.

Arriving at Mars in 2003, 17 years, 5 months and 11 days ago and counting, it is the second longest surviving, continually active spacecraft in orbit around a planet other than Earth, behind only NASA's still active 2001 Mars Odyssey.

Mars Express mission is dedicated to the orbital and originally in-situ study of the interior, subsurface, surface and atmosphere, and environment of the planet Mars.

The scientific objectives of the Mars Express mission represent an attempt to fulfil in part the lost scientific goals of the Russian Mars 96 mission, complemented by exobiology research with Beagle-2. Mars exploration is crucial for a better understanding of the Earth from the perspective of comparative planetology.

The spacecraft originally carried seven scientific instruments, a small lander, a lander relay and a Visual Monitoring Camera, all designed to contribute to solving the mystery of Mars' missing water. All the instruments take measurements of the surface, atmosphere and interplanetary media, from the main spacecraft in polar orbit, which will allow it to gradually cover the whole planet.

The total initial Mars Express budget excluding the lander was €150 million. The prime contractor for the construction of Mars Express orbiter was EADS Astrium Satellites.

The spacecraft was launched on June 2, 2003 at 23:45 local time (17:45 UT, 1:45 p.m. EDT) from Baikonur Cosmodrome in Kazakhstan, using a Soyuz-FG/Fregat rocket.

The Mars Express and Fregat booster were initially put into a 200 km Earth parking orbit, then the Fregat was fired again at 19:14 UT to put the spacecraft into a Mars transfer orbit. The Fregat and Mars Express separated at approximately 19:17 UT. The solar panels were then deployed, and a trajectory correction manoeuvre was performed on June 4 to aim Mars Express towards Mars and allow the Fregat booster to coast into interplanetary space. The Mars Express was the first Russian-launched probe to successfully make it out of low Earth orbit since the Soviet Union fell.

Since orbit insertion, Mars Express has been progressively fulfilling its original scientific goals. Nominally the spacecraft points to Mars while acquiring science and then slews to Earth-pointing to downlink the data, although some instruments like Marsis or Radio Science might be operated while the spacecraft is Earth-pointing.

More information: ESA

 I would like to die on Mars.
Just not on impact.

Elon Musk

GAIA, THE ESA SPACE OBSERVATORY FOR ASTROMETRY

Today, The Grandma has received the wonderful visit of one of her closest friends, Joseph de Ca'th Lon.

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

 Astronomy compels the soul to look upwards
and leads us from this world to another.

Plato

THE CASSINI-HUYGENS LAST MISSION IN SPACE

The Cassini–Huygens

The Cassini–Huygens mission was a collaboration between NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a probe to study the planet Saturn and its system, including its rings and natural satellites. The Flagship-class unmanned robotic spacecraft comprised both NASA's Cassini probe, and ESA's Huygens lander which would be landed on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit. The craft were named after astronomers Giovanni Cassini and Christiaan Huygens.

Launched aboard a Titan IVB/Centaur on October 15, 1997, Cassini was active in space for more than 18 years, with 13 years spent orbiting Saturn, studying the planet and its system after entering orbit on July 1, 2004. The voyage to Saturn included flybys of Venus, Earth , the asteroid 2685 Masursky, and Jupiter. 

Its mission ended on September 15, 2017, when Cassini was commanded to fly into Saturn's upper atmosphere and burn up, in order to prevent any risk of contaminating Saturn's moons, some of whose environments could potentially bear life, with stowaway terrestrial microbes. 

The Cassini–Huygens

The mission is widely perceived to have been successful beyond expectation. Cassini-Huygens has been described by NASA's Planetary Science Division Director as a mission of firsts, that has revolutionized human understanding of the Saturn system, including its moons and rings, and our understanding of where life might be found in the Solar System.

Cassini's original mission was planned to last for four years, from June 2004 to May 2008. The mission was extended for another two years until September 2010, branded the Cassini Equinox Mission. The mission was extended a second and final time with the Cassini Solstice Mission, lasting another seven years until September 15, 2017, on which date Cassini was de-orbited by being allowed to burn up in Saturn's upper atmosphere.

More information: NASA

The Huygens module traveled with Cassini until its separation from the probe on December 25, 2004; it was successfully landed by parachute on Titan on January 14, 2005. It successfully returned data to Earth for around 90 minutes, using the orbiter as a relay. This was the first landing ever accomplished in the outer Solar System and the first landing on a moon other than our own. Cassini continued to study the Saturn system in the following years.

Landed on Saturn's largest moon Titan

At the end of its mission, the Cassini spacecraft executed the Grand Finale of its mission: a number of risky passes through the gaps between Saturn and Saturn's inner rings. 

The purpose of this phase was to maximize Cassini's scientific outcome before the spacecraft was destroyed. The atmospheric entry of Cassini effectively ended the mission, although data analysis and production will continue afterwards.

Until September 2017 the Cassini probe continued orbiting Saturn at a distance of between 8.2 and 10.2 astronomical units from the Earth. It took 68 to 84 minutes for radio signals to travel from Earth to the spacecraft, and vice versa. Thus ground controllers could not give real-time instructions for daily operations or for unexpected events. Even if response were immediate, more than two hours would have passed between the occurrence of a problem and the reception of the engineers' response by the satellite.

More information: Cassini-The Grand Finale

We must believe then, that as from hence we see Saturn and Jupiter; 

if we were in either of the Two, 

we should discover a great many Worlds which we perceive not; 

and that the Universe extends so in infinitum.
 

Cyrano de Bergerac