23 February 2012
 
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This artist’s impression shows a binary system containing a stellar-mass black hole called IGR J17091-3624, or IGR J17091 for short. The strong gravity of the black hole, on the left, is pulling gas away from a companion star on the right. This gas forms a disk of hot gas around the black hole, and the wind is driven off this disk.

New observations with NASA’s Chandra X-ray Observatory have clocked the fastest wind ever seen blowing off a disk around this stellar-mass black hole. Stellar-mass black holes are born when extremely massive stars collapse and typically weigh between five and 10 times the mass of the Sun.

The record-breaking wind is moving about twenty million miles per hour, or about three percent the speed of light. This is nearly ten times faster than had ever been seen from a stellar-mass black hole, and matches some of the fastest winds generated by supermassive black holes, objects millions or billions of times more massive.

Another unanticipated finding is that the wind, which comes from a disk of gas surrounding the black hole, may be carrying away much more material than the black hole is capturing.

The high speed for the wind was estimated from a spectrum made by Chandra in 2011. A spectrum shows how intense the X-rays are at different energies. Ions emit and absorb distinct features in spectra, which allow scientists to monitor them and their behavior. A Chandra spectrum of iron ions made two months earlier showed no evidence of the high-speed wind, meaning the wind likely turns on and off over time.

Credits: Illustration: NASA/CXC/M.Weiss

22 February 2012
 
This car was not snapped with a camera but scanned by a 3D imaging lidar, the laser equivalent of radar. ESA is developing the sensor as a navigation aid for exploring deep space.
 
Lidar stands for ‘light detection and ranging’, with a pulsed laser beam scanning targets by measuring the time it takes for the light to bounce back.

The wavelength of light is so much shorter than that of radio waves – measured in billionths of a metre rather than centimetres – so lidar gives much more precise measurements.

ABSL prototype lidar

Laser ranging is already used for rendezvous and docking in orbit. When ESA’s ATV cargo ferry docks with the International Space Station it bounces laser beams off reflectors on the orbital outpost to judge the distance to within a couple of centimetres.

For missions deeper into our Solar System, ESA hopes to use 3D imaging lidar to build up a complete picture of targets such as a boulder-strewn surface.

This would be like a stereoscopic imager but it would also work in total darkness or blinding sunlight.

“The 3D imaging lidar we’ve been working on has three main potential applications,” explains Joao Pereira Do Carmo, overseeing the project for ESA.

	ATV uses lasers for docking

“The first is for the guidance, navigation and control of planetary landers, in particular in selecting a safe landing site.

“The second is for steering rovers on planetary surfaces, and the third is for docking in planetary orbit. That would be essential for the proposed Mars Sample Return Mission, for example, when the ascent module carrying material off the martian surface will have to be tracked and captured by its mother craft waiting in orbit.

“Terrestrial imaging lidars already exist, typically used for scanning buildings or industrial sites, but they are much too bulky for use in space.

Lidar test 5km across the Saale Valley

“The challenge is to produce a new class of imaging lidar, much smaller and needing less power.”

Reflecting the technical difficulties involved, separate designs were developed in parallel by two consortia, one led by Jena-Optronik in Jena, Germany and the other by ABSL in Culham, UK.

The shoebox-sized imaging lidars rely on a steerable scan mirror that flicks the laser beam across the target, with a highly sensitive light detector capable of measuring the returning beams from up to several kilometres away.

	Jena-Optronik prototype lidar

The two designs aim at different guidance and navigation applications. The German-led unit demonstrates a future rendezvous sensor, while the British-led design is intended to help a lander touch down safely on a planet, detecting and avoiding hazards.

The Imaging Lidar Technology project was supported through ESA’s Basic Technology Research Programme aimed at prototyping promising new engineering concepts.

ESA Lunar Lander

Building on this progress, a landing lidar is now being designed for ESA’s Lunar Lander, planned to touch down at the lunar south pole in 2019.

The engineers are also looking at ways of making the lidars even smaller perhaps by using new types of detectors and micro-mechanical optical mirrors.

“It is expected that we can reduce the mass and power consumptions of current commercial imaging lidar systems by at least 70%,” Joao concludes.

22 February 2012
 
When liquids and bubbles are in space, odd things start to happen. ESA astronaut André Kuipers is taking schools across Europe on a microgravity waltz to learn what is behind seemingly simple phenomena such as convection and foams.
 
Space oddities on the International Space Station will help thousands of schoolchildren to realise that the consequences of the laws of physics running our Universe can be complex – and on Earth they are not the same as in the Station’s weightlessness.

Armed with two ESA educational experiments during his PromISSe mission, André is inviting students aged 10–14 to share his scientific adventure.

Children across Europe have the chance to follow these ‘Take Your Classroom into Space’ experiments with André as part of the ‘Spaceship Earth’ educational programme.

	André with foam experiment

Playing with microgravity
 
Young scientists on Earth can run their own identical experiments on the ground and make their observations while André does his on the Station.

‘Convection’ illustrates how thermal gradients drive convective currents. On the scale of a planet, this is how temperature gradients influence density-driven convection and create currents in the atmosphere and oceans.

A simple device shows how heat affects the density of liquids and the role that gravity plays in distributing the heat.

By grasping the convection loop on one side, heat from the hand is enough to drive a convective current within the loop in Earth’s gravity.

On the Space Station, though, things might be different.

‘Foam Stability’ highlights the properties of wet foams and how gravity influences their stability.

On the Station, foams are free of gravity’s effects. Up there, it is possible to form very stable foams from pure water – rarely seen on Earth.

André will show students how foam is created from pure water in microgravity. He will also play with a beer-like sample and oils.

Understanding how foams form and collapse helps us to improve products on Earth, such as making tastier foods and drinks, or creating stronger and lighter metal foams.

André with foam experiment

Get your space kit
 
Teachers are invited to join the space waltz with André’s oddities. The results of André’s experiment will be accessible on the PromISSe website in May. The school kits with the Take Your Classroom into Space experiments can be ordered here now and delivered free of charge. Dutch schools should get them from www.ruimteschipaarde.nl

The kits are shipped free of charge to ESA* member state schools on a first-come first-served basis. Lessons attached to these two experiments will also be available online.

*ESA Member States: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Romania. Spain, Sweden, Switzerland, United Kingdom.

The three satellites that make up ESA’s Swarm magnetic field mission were presented to the media today. Following a demanding testing programme, the satellites were displayed in the cleanroom before they are shipped to Russia for their July launch.
 
Swarm is ESA’s first constellation of Earth observation satellites designed to measure the magnetic signals from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere, providing data that will allow scientists to study the complexities of our protective magnetic field.

The magnetic shield protects the planet from charged particles that stream in as the solar wind. Without this shield, life on Earth would be impossible.

This shield is generated mainly deep inside Earth by an ocean of swirling iron in the liquid outer core. How the magnetic field is created and how it changes over time is complex and not fully understood.

	Swarm to study Earth’s magnetic field

This force is constantly changing – at the moment, it shows signs of significant weakening.

But with a new generation of sensors, the Swarm constellation will provide greater insight into these natural processes and the ‘weather’ in space.

Swarm will be ESA’s fourth Earth Explorer mission in orbit, following GOCE, SMOS and CryoSat.

In five months, the trio of satellites will be launched together on a Rockot launcher from the Plesetsk Cosmodrome in northern Russia.

Two will orbit very close together at the same altitude – initially at about 460 km – while the third satellite will be in a higher orbit of 530 km.

Swarm

The different near-polar orbits, along with the various Swarm instruments, improve the sampling in space and time. This helps to distinguish between the effects of different sources of magnetism.

At the press event at the IABG centre in Ottobrunn, Germany, where all three satellites have just completed an intensive testing programme, representatives from ESA, the industrial team, the scientific investigator team and other experts from the scientific community gave presentations on the satellites and the mission’s scientific objectives.

It was the last chance to see the satellites before they are packed up and shipped to Russia in May.

ESA’s Director of Earth Observation Programmes, Volker Liebig, said, “Swarm is the next mission in our Earth Observation Envelope Programme.

	Swarm constellation

“We expect the innovative Swarm constellation of three satellites orbiting in formation to deliver the best-ever survey of Earth’s magnetic field.”

Since 2010, engineers from EADS-Astrium, who lead the consortium building the satellites, have testing them against the harsh environment of space by exposing each satellite to different temperatures, vibration and shocks.

 
 
The satellites and instruments have their own magnetic properties and therefore influence the measurements they make. The origins of all the magnetic signals stemming from different parts of the satellites were accounted for so that the measurements taken in orbit are not misinterpreted.

The tests were carried out in a ‘magnetically clean’ environment at IABG, and the instruments on all three satellites performed well.

“This period of the project is really exciting,” said Yvon Menard, ESA’s Swarm Project Manager.

“We collected excellent test results and the team is eager to verify the performances of the constellation in orbit in order to confirm the promises from the ground test campaigns.”