If ESA’s Mercury orbiter of the BepiColombo mission seems to stand at an unusual angle above its test chamber floor, that’s because it does – intentionally so.
The orbiter underwent ‘electromagnetic compatibility, radiated emission and susceptibility’ testing last month inside the Maxwell chamber of ESA’s ESTEC Test Centre in Noordwijk, the Netherlands.
Maxwell’s shielded metal walls and doors form a ‘Faraday cage’ to block unwanted external electromagnetic radiation, while its internal walls are cover with ‘anechoic’ radio-absorbing foam pyramids to mimic boundless space.
“We are performing two types of compatibility testing,” explained Marco Gaido, assembly, integration and test manager for BepiColombo.
“First, we are checking the craft is electrically compatible with the electrical field generated by the Ariane 5 launcher that will deliver it into orbit, with no possibility of interference with BepiColombo’s receivers.
“Secondly, we are testing if there is any risk of incompatibility between the different subsystems of the spacecraft itself when it orbits Mercury. In particular, we want to check that its trio of antennas on top can communicate properly with Earth.
“Accordingly, it was deliberately oriented to simulate a worst-case scenario for test purposes.”
The orbiter was positioned to allow deployment of its medium-gain antenna in terrestrial gravity. The high-gain antenna reflector meanwhile was deployed in a worst-case position, supported by a dedicated fixture.
The spacecraft was tilted by means of a large platform while the high-gain antenna was supported by a tower made of wood, transparent to radio waves. All test cables used were shielded to reduce potential interference.
ESA’s Mercury Planetary Orbiter will be launched to Mercury together with Japan’s Mercury Magnetospheric Orbiter aboard an ESA-built carrier spacecraft, the Mercury Transfer Module. This entire three-module BepiColombo stack will undergo similar testing at ESTEC.
This beautiful landscape feels within arm’s reach in this stunning view across the Imhotep region on Comet 67P/Churyumov–Gerasimenko.
The view was captured by Rosetta’s OSIRIS narrow-angle camera on 17 January 2016, from a distance of 86.8 km. Measuring 3.2 km across, it captures one of the most geologically diverse areas of the comet.
Imhotep is perhaps most easily identified by the broad smooth area that occupies the centre-right portion of this view. This smooth dusty terrain, which covers about 0.8 sq km, is etched with curvilinear features stretching hundreds of metres and which have been found to change in appearance over time.
Many large boulders are also seen scattered within the smooth terrain, including the boulder Cheops in the foreground. Smaller but more numerous boulders are associated with exposed cliff faces and are most likely the product of erosion. In some debris falls, detailed analysis has revealed the presence of water ice.
Particularly eye-catching is the distinctive layered and fractured material to the left of centre in the background. Similar patterns are also seen in the exposed cliff-like faces towards the right of the scene too, where Imhotep transitions into the Khepry region.
Just in front of the prominent left-hand stack of layers a number of small round features can be found. They have a well-defined rim with a smooth interior and appear slightly raised from the surrounding material. One explanation for their appearance is that they are ancient sites of active regions covered by dust and are now being revealed by varying erosion of the overlying layers.
Further in the foreground again and a relatively smooth ‘pathway’ appears to lead towards a more consolidated summit. To the left of this path is the Ash region, while the sheer apex at the top left of the view marks the boundary with Apis.
Use the comet viewer tool to aid navigation around the comet’s regions.
This image was first published on the OSIRIS image of the day website on 21 January 2016.
An unusual view of a spacecraft – looking from below, directly into the thruster nozzles. This is a test version of ESA’s service module for NASA’s Orion spacecraft that will send astronauts further into space than ever before.
The European Service Module provides electricity, water, oxygen and nitrogen, and thermal control as well as propelling the spacecraft.
The large cone is the spacecraft’s main engine, the same model that was used on the Space Shuttle for orbital manoeuvres. The surrounding red cones are auxiliary thrusters. The engines will provide almost 30 kN of thrust, only one-tenth that of a Jumbo Jet engine, but enough to manoeuvre in space. More thrusters are carried on the module’s sides.
This structural test model is used for testing purposes before installing the real thing. It is as close to the flight version as possible while keeping costs and development time manageable. The structure and weight are the same, while mass equivalents stand in for electronics boxes not needed for the series of tests.
The model was installed under a test version of the Crew Module Adapter, and sits on the Spacecraft Adapter that will attach Orion to its launch vehicle. This is the first time the European hardware has been physically connected to NASA’s elements.
The service module will be shaken at NASA’s Plum Brook station in Sandusky, Ohio, USA, to recreate the vibrations of launch, as well as being subjected to acoustic and shock environments.
Copernicus is the most ambitious Earth observation programme to date, and it is providing accurate, timely and easily accessible information to improve the management of the environment, understand and mitigate the effects of climate change, and ensure civil security.
ESA is developing a new family of satellites, called Sentinel, specifically for the operational needs of the Copernicus programme. The six Sentinel missions are providing a unique set of observations, starting with all-weather, day-and-night radar images from Sentinel-1A, launched in April 2014, and multispectral high-resolution images for land monitoring from Sentinel-2A, launched in June 2015. The first Sentinel-3 satellite, an ocean and ice-sensing mission, will be launched next month.
Each mission is based on a constellation of two satellites to provide robust coverage for Copernicus services.
As part of an extended ‘ground segment’ responsible for flight control and for distributing the Sentinels’ crucial data, mission control teams work at ESA’s ESOC operations centre in Darmstadt, Germany, on daily operations.
This week, the Sentinel-1 team began intensive simulation training for the launch of Sentinel-1B, planned for April.
Working under Sentinel-1 Spacecraft Operations Manager Ian Shurmer, engineers are being exercised through all aspects of the critical launch and early operations phase. This will ensure, come launch day, that experts from flight control, flight dynamics, ground stations and software systems are ready to work together in a tightly integrated ‘team of teams’.
In the image at left: Duncan Warren; at right, Adrian Segura Cabrera.
Part of Sierra Leone in West Africa is pictured in this image the Sentinel-2A satellite captured on 11 December 2015.
The country’s capital, Freetown, sits on a peninsula at the bottom of the image. Its economy revolves around its natural deep water harbour – one of the world’s largest. North of Freetown and across the river, we can see the runways of the Lungi International Airport.
The area in the central-right portion of the image is the Sierra Leone River Estuary. The estuary is dominated by mangroves and lowland coastal plains and is an important breeding habitat for multiple waterbird species.
Diverse socio-economic activities are supported by the estuary, such as fishing, tourism and sea transport, which help to alleviate poverty at the community level.
But the estuary is being threatened by a growing population. For example, unauthorised housing development has caused the removal of about 20 hectares of mangrove vegetation over the past five years alone. Poor waste disposal, unsustainable fishing and many other factors are also taking their toll on the ecosystem.
Some 295 000 hectares of this estuary is protected under the Ramsar Convention – an intergovernmental treaty for the sustainable use of wetlands. There are over 2000 sites worldwide considered to be wetlands of international importance by the Convention.
ESA assists the Ramsar Convention through the GlobWetland Africa project and the TIGER initiative ‘Looking After Water in Africa’, which provide satellite data to be used to monitor and sustainably manage these precious resources.
World Wetlands Day is observed on 2 February, the anniversary of the signing of the Convention. The theme of this year’s World Wetlands Day is ‘Wetlands for our Future: Sustainable Livelihoods’.
This image is also featured on the Earth from Space video programme.
This perspective view in Noctis Labyrinthus was generated from the main camera’s stereo channels on ESA’s Mars Express.
It shows the beautiful details of landslides in the steep-sided walls of the flat-topped graben in the foreground, and in the valley walls in the background.
The scene is part of region imaged by the High Resolution Stereo Camera on Mars Express on 15 July 2015 during orbit 14632. The image is centred on 6°S / 265°E; the ground resolution is about 16 m per pixel.
OSIRIS narrow-angle camera image taken on 27 January 2016, when Rosetta was 71.4 km from Comet 67P/Churyumov–Gerasimenko. The scale is 1.29 m/pixel.
More details via the OSIRIS Image of the Day website.
SmallGEO AG1: solar panel deployed for testing at IABG, in Germany, on 22 January, 2016.
Hispasat Advanced Generation 1 (AG1) is the first telecommunications satellite to use Europe’s new SmallGEO platform.
SmallGEO is developed by OHB under ESA’s Advanced Research in Telecommunication Systems (ARTES) programme in a public–private partnership. It will strengthen the position of European industry in the commercial telecommunications market, expanding the current range of available products.
Despite its unassuming appearance, the edge-on spiral galaxy captured in the left half of this NASA/ESA Hubble Space Telescope image is actually quite remarkable.
Located about one billion light-years away in the constellation of Eridanus, this striking galaxy — known as LO95 0313-192 — has a spiral shape similar to that of the Milky Way. It has a large central bulge, and arms speckled with brightly glowing gas mottled by thick lanes of dark dust. Its companion, sitting pretty in the right of the frame, is known rather unpoetically as [LOY2001] J031549.8-190623.
Jets, outbursts of superheated gas moving at close to the speed of light, have long been associated with the cores of giant elliptical galaxies, and galaxies in the process of merging. However, in an unexpected discovery, astronomers found LO95 0313-192 to have intense radio jets spewing out from its centre! The galaxy appears to have two more regions that are also strongly emitting in the radio part of the spectrum, making it even rarer still.
The discovery of these giant jets in 2003 — not visible in this image, but indicated in this earlier Hubble composite — has been followed by the unearthing of a further three spiral galaxies containing radio-emitting jets in recent years. This growing class of unusual spirals continues to raise significant questions about how jets are produced within galaxies, and how they are thrown out into the cosmos.
ESA astronaut Tim Peake posted this photo on his social media channels, commenting "Beautiful night pass over Italy, Alps and Mediterranean".
Tim's six-month mission to the International Space Station is named Principia, after Isaac Newton’s ground-breaking Naturalis Principia Mathematica, which describes the principal laws of motion and gravity.
He is performing more than 30 scientific experiments for ESA and taking part in numerous others from ESA’s international partners.
ESA and the UK Space Agency have partnered to develop many exciting educational activities around the Principia mission, aimed at sparking the interest of young children in science and space.
More about the Principia mission: http://www.esa.int/principia
More photos from Tim on his flickr photostream: https://www.flickr.com/photos/timpeake
Week In Images
25-29 January 2016