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Following its loss of contact on 8 April, and a subsequent failure to recover the spacecraft, the European Space Agency (ESA) has formally declared that the Envisat environmental and remote sensing satellite mission is now over. 

Since the failure, engineers and scientists from ESA and Envisat's manufacturer Astrium have struggled to recontact the craft. The attempt at fault finding and recovery even enlisted ground radar and telescopes on Earth and Pleiades imaging satellites in space.  However, in the end all the effort was fruitless. 

Artist's impression of the Envisat spacecraft.  Courtesy: Astrium

Despite the formal ending of the mission, engineers will continue to investigate the failure and carry on with attempts to recontact the craft.  For the time being, an internal power regulator failure or short circuit is suspected of causing the sudden failure of the telemetry and command system or its safe mode solar pointing default procedure; failures that there would normally be no way back from.    

Launched in March 2002, Envisat exceeded its five year minimum design life by over five years.  During its ten year life the spacecraft has yielded valuable Earth monitoring data covering weather, atmospheric and temperature measurements as well as providing optical and infrared imagery.  Concerns remain within the climate change science community that the dataset will now be significantly interrupted until ESA's new Sentinel spacecraft from Europe's Global Monitoring for Environmental Security (GMES) programme, can come online.

 

The European Space Agency is to launch a second pair of Galileo navigation satellites on 28 September before beginning a fast-track launch schedule in 2013 to orbit 18 satellites by the end of 2014 for a functional service, and 26 satellites by the end of 2015 for near-global coverage. The full constellation of 27 spacecraft and three orbiting spares should be deployed by 2019.

All launches will be from ESA's Kourou, French Guiana spaceport. The first Galileo flights are Soyuz rockets, including the veteran Russian launcher's maiden flight from Kourou last October.

From the second half of 2014, a requalified Ariane launcher, known as Ariane 5 ES Galileo, should be equipped with a four-satellite dispenser and be capable of delivering the spacecraft to orbital altitudes of 23,200km. The current ES launcher is used to launch ESA's Automated Transfer Vehicle to the International Space Station at about 380km.

In its "Cosmic Vision" push to explore the Solar system, Europe has set its sights on Jupiter icy moons, with a mission to launch for Europa, Ganymede and Callisto in 2022.

The so-called JUICE mission - Jupiter Icy moons Explorer - will arrive at Jupiter in 2030 and spend at least three years making detailed observations. Europa, Ganymede and Callisto are all thought to host internal oceans, so the mission will study the moons as potential habitats for life, addressing two key themes of Cosmic Vision: what are the conditions for planet formation and the emergence of life, and how does the Solar System work?

JUICE will continuously observe Jupiter's atmosphere and magnetosphere, and the interaction of the Galilean moons with the gas giant planet.

It will visit Callisto, the most heavily cratered object in the Solar System, and will twice fly by Europa. JUICE will make the first measurements of the thickness of Europa's icy crust and will identify candidate sites for future in situ exploration.

The spacecraft will finally enter orbit around Ganymede in 2032, where it will study the icy surface and internal structure of the moon, including its subsurface ocean.

Ganymede is the only moon in the Solar System known to generate its own magnetic field, and JUICE will observe the unique magnetic and plasma interactions with Jupiter's magnetosphere in detail.

"Jupiter is the archetype for the giant planets of the Solar System and for many giant planets being found around other stars," says Alvaro Giménez Cañete, ESA's director of science and robotic exploration. "JUICE will give us better insight into how gas giants and their orbiting worlds form, and their potential for hosting life."

JUICE was chosen over two alternatives: NGO, the New Gravitational wave Observatory, to hunt for gravitational waves, and ATHENA, the Advanced Telescope for High-Energy Astrophysics. Either of these may be reconsidered when ESA again polls the scientific community in another call for large missions, expected in 2013.

ESA's next big Solar System venture is the BepiColombo mission to put two orbiters around Mercury from 2022, following a launch in 2014. That mission will just the third to the planet closest to the Sun, after NASA's Mariner 10, which made fly-bys in 1974-75, and Messenger, which has been in orbit around Mercury since March 2011.

And, in 2016 and 2018 ESA is planning a pair of launches to Mars. The ExoMars missions will test a descent module and then land a rover equipped to test geological samples gathered by deep drilling.

The European Space Agency remains hopeful that it can regain contact with its Envisat Earth observation satellite, which unexpectedly stopped sending data to the ground on 8 April.

Attempts to regain contact have so far been unsuccessful, but the spacecraft - one of the most sophisticated of its type and invaluable in such efforts as quantifying climate change - is in a stable orbit, ESA has determined by optical, radar and laser observation.

But earlier this week France's Pleiades Earth observation satellite passed within about 100km of Envisat and was successfully turned to gather images of Envisat that are being analysed along with ground-based observations to determine whether its solar panels are oriented to the Sun. If they are, ESA says, Envisat may have enough power to have entered a safe mode - and, possibly, enough power for re-establishing communication with Earth.

Information on Envisat's orbit is being provided by the US Joint Space Operations Center. In addition, multiple laser ranging stations on the ground are providing information to verify the stability of the satellite's orbit.

More than 4000 projects in over 70 countries have been supported with Envisat data, and even if contact is regained, many will have been affected by the loss of continuity of data. Should Envisat remain out of contact, a contingency agreement with the Canadian Space Agency will see some of the users assisted by data from its Radarsat.

But in any case Envisat, launched in 2002 with a planned life of five years has already exceeded its expectations. However, its current difficulties make the launch next year of the first in a series of replacements that much more urgent.

These Sentinel satellites are seies being developed for Europe's Global Monitoring for Environment and Security (GMES) programme and will provide the data needed for information services to improve the management of the environment, understand and mitigate the effects of climate change and ensure civil security. ESA describes the Sentinal series missions thus:

Sentinel-1 is a polar-orbiting, all-weather, day-and-night radar imaging mission for land and ocean services. The first Sentinel-1 satellite is planned for launch in 2013.

Sentinel-2 is a polar-orbiting, multispectral high-resolution imaging mission for land monitoring providing, for example, imagery of vegetation, soil and water cover, inland waterways and coastal areas. Sentinel-2 will also deliver information for emergency services. The first Sentinel-2 satellite is planned for launch in 2013.

Sentinel-3 is polar-orbiting, multi-instrument mission to measure variables such as sea-surface topography, sea- and land-surface temperature, ocean colour and land colour with high-end accuracy and reliability. The first Sentinel-3 satellite is planned for launch in 2013.

Sentinel-4 is a payload that will be embarked upon a Meteosat Third Generation-Sounder (MTG-S) satellite in geostationary orbit scheduled to be launched in 2019. Sentinel-4 is dedicated to atmospheric monitoring.

Sentinel-5 is a payload that will be embarked on a MetOp Second Generation, satellite, also known as Post-EPS, to be launched in 2020. Sentinel-5 is dedicated to atmospheric monitoring.

Sentinel-5 Precursor satellite mission is planned to launch in 2015, thereby avoiding data gaps between Envisat (Sciamachy data in particular) and Sentinel-5. This mission will be dedicated to atmospheric monitoring.

Europe's Galileo satellite navigation constellation has taken another step towards realisation with the shipment of the first of 14 Full Operational Capability navigation payloads from Surrey Satellite Technology in the UK to prime contractor OHB System in Bremen, Germany.

The first two Galileo satellites were orbited in October, and two more are due for launch at the end of this summer. These four, with payloads built by Astrium UK in Portsmouth and integrated into satellite platforms by Thales Alenia Space in Italy, will be followed by the SSTL-OHB spacecraft for launch from 2014.

Once all 14 are in orbit, the 18-strong constellation will provide near-global coverage. Full coverage is planned for 2018, with 30 satellites.

The European Space Ageny has reported that on 8 April, there was a sudden interruption of the communication links with the Envisat satellite, preventing reception of telemetry data. First recovery actions have been started. An anomaly review board is in place to understand the origin of the anomaly and for implementing further recovery actions.

Space Station astronauts are probably more disappointed than we imagined by the delay - from 9 to 23 March - of the European Space Agency's launch of its third Automated Transfer Vehicle robotic supply ship. Named Edoardo Amaldi after the late Italian physicist considered a pioneer of European spaceflight, ATV-3 is loaded with some 2.5t of dry cargo, water and oxygen, in addition to 5.4t of fuel to power itself and "re-boost" the Station to its full altitude. Another 860kg (1,900lb) of fuel will be carried for transfer to the Russian part of the Station.

But now we learn a bit more about that cargo. According to the ATV's builder, Astrium, one of the items the ATV-3 will be carrying is a new ventilator for the European Columbus laboratory, a component that needs regular replacement.

But of much more pressing concern to the astronauts are toothbrushes of different bristle hardness and toothpaste of various flavours - sort of a care package designed to make them feel at home 400km above the ground.

And, they'll also find some Lego Technic sets, part of a range of experiments that NASA is conducting for a special series of lessons for school pupils back on Earth.

Let's just hope the 153 bags containing 1,062 individual items are well labelled, and that the toothpaste and Lego aren't buried too deep in the ATV's hold.

Following its rescheduling from 9 March to Friday 23 March of the Ariane 5 launch to deliver the third Automated Transfer Vehicle robotic supply ship to the International Space Station, the European Space Agency has set the night of 28-29 March for the ship's docking with the Station's Russian Zvezda module.
The precise time will be known after launch, which is set for 04:31 GMT (05:31 CET) from ESA's Kourou, French Guiana spaceport.
The cause of the launch delay, announced on 2 March, has not been detailed but has to do with further checks required on the ATV rather than the Ariane 5 rocket.According to launch operator Arianespace, "a routine inspection concluded that additional measures were required to maximize ATV Edoardo Amaldi's launch readiness".

The two previous ATV launches in February 2011 and March 2008, also from French Guiana, were successful.

It turns out it's the payload - the third of the European Space Agency's Automated Transfer Vehicle robotic Space Station re-supply ships - not the Ariane 5 rocket that's behind the delay to the 9 March launch.