ESA Rosetta mission: Philae lander - the sound of a Comet Touchdown

Image credit: ESA/ATG medialab – Audio file credit: ESA /Rosetta /Philae /SESAME /DLR

Sensors in the feet of Rosetta’s lander Philae have recorded the sound of touchdown as it first came into contact with Comet 67P/Churyumov-Gerasimenko. 

The instrument, SESAME-CASSE, was turned on during the descent and clearly registered the first touchdown as Philae came into contact with the comet, in the form of vibrations detected in the soles of the lander’s feet.

Focus on SESAME. Sensors are located in the three feet as well as in the units of the APXS (centre) and MUPUS-Pen (to the upper right of centre) instruments. Credits: ESA/ATG medialab

SESAME is the lander’s Surface Electrical Sounding and Acoustic Monitoring Experiment, and comprises three suites of instruments:

• CASSE – the Comet Acoustic Surface Sounding Experiment, which allows mechanical parameters of the surface to be deduced, along with details of the structure of the subsurface;
• DIM – the Dust Impact Monitor, which measures properties of impacting comet grains;
• PP – the Permittivity Probe, which determines one of the key electrical properties of the material beneath Philae, which is linked to the water ice content of the surface.

Klaus Seidensticker from the DLR Institute of Planetary Research says: “Our data record the first touchdown and show that Philae’s feet first penetrated a soft surface layer – possibly a dust layer – several centimetres thick until they hit a hard surface – probably a sintered ice-dust layer – a few milliseconds later.”

NASA's Orion spacecraft proves sound under pressure

After a month of being poked, prodded and pressurized in ways that mimicked the stresses of spaceflight, NASA's Orion crew module successfully passed its static loads tests on Wednesday.

When Orion launches on Exploration Flight Test-1 (EFT-1), which is targeted for September 2014, it will travel farther from Earth than any spacecraft built for humans in more than 40 years.

The spacecraft will fly about 3,600 miles above Earth's surface and return at speeds of approximately 25,000 mph.

During the test, Orion will experience an array of stresses, or loads, including launch and reentry, the vacuum of space, and several dynamic events that will jettison hardware away from the spacecraft and deploy parachutes.



To ensure Orion will be ready for its flight test next year, engineers at NASA's Kennedy Space Center in Florida built a 20-foot-tall static loads test fixture for the crew module with hydraulic cylinders that slowly push or pull on the vehicle, depending on the type of load being simulated.

The fixture produced 110 percent of the load caused by eight different types of stress Orion will experience during EFT-1.

More than 1,600 strain gauges recorded how the vehicle responded. The loads ranged from as little as 14,000 pounds to as much as 240,000 pounds.

"The static loads campaign is our best method of testing to verify what works on paper will work in space," said Charlie Lundquist, NASA's Orion crew and service module manager at the agency's Johnson Space Center in Houston. "This is how we validate our design."

In addition to the various loads it sustained, the Orion crew module also was pressurized to simulate the effect of the vacuum in space.

This simulation allowed engineers to confirm it would hold its pressurization in a vacuum and verify repairs made to superficial cracks in the vehicle's rear bulkhead caused by previous pressure testing in November.

The November test revealed insufficient margin in an area of the bulkhead that was unable to withstand the stress of pressurization.

Armed with data from that test, engineers were able to reinforce the design to ensure structural integrity and validate the fix during this week's test.

To repair the cracks, engineers designed brackets that spread the stress of being pressurized to other areas of the module that are structurally stronger.

During these tests Orion was successfully pressurized to 110 percent of what it would experience in space, demonstrating it is capable of performing as necessary during EFT-1.

NASA Sound Rockets leave Tracer Clouds

This photo provided by NASA shows chemical tracers that were released from five rockets launched from NASA's Wallops Island test flight facility in Atlantic, Virginia, US.

The tracers form white clouds that allow scientists and the public to visualise upper level jet stream winds.

Picture: NASA/AP

ESA Education: Student teams Prepare upcoming REXUS Launch

Ten student teams from ESA's Member and Cooperating States have been selected by a panel of experts from ESA, the Swedish National Space Board (SNSB), SSC and the German Aerospace Center (DLR) to fly their experiments on future sounding rocket and balloon campaigns.

The teams selected for the REXUS 13/14 (Rocket Experiments for University Students) are:

• CAESAR (Switzerland): Capillarity-based Experiment for Spatial Advanced Research - Investigation into the behaviour of liquids under high Bond numbers, using propellant management devices.
• Gekko (Hungary): Measurement of the variation in electric conductivity with altitude.
• MUSCAT (Sweden): Multiple Spheres for Characterisation of Atmospheric Temperature - Measurement of atmospheric temperatures and horizontal winds in the mesosphere.
• PoleCATS (United Kingdom): Polar test of the Conceptual And Tiny Spectrometer - Demonstration of conceptual space plasma instrumentation to sample plasma energy distributions in upper atmosphere.
• SOLAR (Sweden): Soldering Alloys in Reduced gravity - Studying the effects of reduced gravity on soldering in a low pressure environment.
• StrathSat-R (United Kingdom): Investigation into the use of two Cubesat-based deployable inflatable structures including a solar sail and a dynamic structure that adapts to varying conditions.

Martin Klimas Painting With Sound - Slide Show

Like a 3-D take on Jackson Pollock, the latest work by the artist Martin Klimas begins with splatters of paint in fuchsia, teal and lime green, positioned on a scrim over the diaphragm of a speaker.

Then the volume is turned up. For each image, Klimas selects music — typically something dynamic and percussive, like Karlheinz Stockhausen, Miles Davis or Kraftwerk — and the vibration of the speaker sends the paint aloft in patterns that reveal themselves through the lens of his Hasselblad.

Klimas rose to prominence in the art world four years ago for a series of photos that captured porcelain figurines just as they shattered.

For this series, Klimas spent six months and about 1,000 shots to produce the final images from his studio in Düsseldorf, Germany.

In addition to the obvious debt owed to abstract expressionism, Klimas says his major influence was Hans Jenny, the father of cymatics, the study of wave phenomena.

The resulting images are Klimas’s attempt to answer the question “What does music look like?”

New York Times slideshow

High Speed Image of Coloured salt - Fabian Oefner

Photographer Fabian Oefner has used coloured grains of salt and sent them into the air using different songs. 

He placed the salt on thin plastic foil stretched over a loudspeaker.

When the speakers are turned on it sends the salt into the air and he is able to capture the moment using a high speed flash.

He says: "Depending on the frequency of the sonic wave, different sculptures are created, from gentle and spaced sculptures to high pitch volcano-eruption-like figures."

Picture: FABIAN OEFNER / CATERS NEWS

Detecting land mines with sound

Detecting land mines with sound

The researchers built a prototype detector and tested it at the Cold Regions Research and Engineering Laboratory Army Corps of Engineers land-mine facility in New Hampshire. They were able to detect both metal and plastic mines but said that the system will have to get a major boost in acoustic power before minefield searchers can use it safely.

Robert W. Haupt, a technical staff member at Lincoln Lab, explores innovative ways to find and reduce the large number of land mines abandoned in war-torn countries. An estimated 26,000 people are killed or maimed every year by 60 to 70 million undetected land mines in 70 countries. Those casualties include military troops but most are civilians--half of them children under age 16--who step on uncleared minefields after a war.

Many existing prototype mine detection systems can detect only metal, have limited range or are impractical in the field. "Reliable methods that quickly and accurately locate land mines made of metal and plastic, unexploded ordnance and other mine-like targets are desperately needed," Haupt said.

Haupt and fellow Lincoln Lab staff member Ken Rolt developed a high-powered sound transmitter that looks like a stop sign studded with 35mm film canisters or prescription pill containers. This is called a parametric acoustic array, and Haupt and Rolt have built one of the most powerful ones around.

The array is made up of ceramic transducers--devices that emit a powerful narrow acoustic beam at ultrasonic frequencies. One meter away, the ultrasonic pressure level measures 155 decibels--more acoustic power than a jet engine. Immediately outside the beam, the acoustic intensity dies away to almost nothing.

By a process know as self-demodulation, the air in front of the acoustic beam converts the ultrasound to much lower frequency audible tones that sound like extremely loud tuning forks. Unlike ultrasound, the low-frequency sound can penetrate the ground, causing detectable vibrations in the mine's plungers and membranes.

"The use of ultrasound allows us to make a very narrow and highly directional beam, like a sound flashlight," Haupt said. It would take a huge number of conventional loudspeakers to do the same trick, and they would weigh too much, take up too much space and use too much power to be practical, he said. Plus, they would deafen anyone within earshot. "Using a narrow sound beam, we can put sound just where we want it, and we can minimize sound levels outside the beam to avoid harming the operators or people nearby," he said.