Missile practice for Moon mission

Tests on a UK-led technology at the heart of a planned Moon mission have been a spectacular success according to the scientists involved in the project.
Three penetrator missiles were fired into a sand bunker in Wales, designed to mimic the lunar surface.
Professor Alan Smith, of Mullard Space Science Laboratory, told BBC News the results had exceeded expectations.
He is a leading figure in the Moonlite mission, which hopes to fire instruments into the Moon in 2013.
A BBC team witnessed the final day of the tests at the Ministry of Defence test site at Pendine, near Tenby.
The site has been open since 1940 but is now operated by Qinetiq, the privatised MoD spin-off company which developed the penetrator technology. Three projectiles were tested on three consecutive days at the end of May.
They look like missiles but rather than exploding on impact, they are designed to stay intact to protect the scientific instruments inside.
The Moonlite mission plans to fire four penetrators into the lunar surface from an orbiting spacecraft. They will come to rest three metres (10ft) underground.
The onboard instruments will send back a mass of information, everything from seismic activity and mineral composition to the underground temperature.
Sand blasted
Security at Pendine was tight - we had to show passports to gain entry. The high-speed test track is set in a large area of sand dunes paradoxically full of birds and flowers. It’s a hard hat site; during the firing itself, all staff must take cover. We were actually confined to the control centre.
Earlier, we saw scientists loading instruments into the third and final penetrator to be tested.
The purpose of the test firings was to check how well the penetrators would withstand being slammed into several tonnes of sand at 1,100km/h (700mph) and whether the instruments inside would survive.
The difference between the penetrators that had already been fired and the one that had yet to be tested was striking.
The blue paint on the fired ones was scraped off and the steel nose cones were distorted.
But despite their battered appearance, Peter Truss of Qinetiq confirmed that they had done their job and protected the instruments inside: "our confidence is growing with every test".
Qinetiq not only contributed to the missile derived design of the penetrators themselves, but to the batteries and communication systems they will carry.
Ultimately, the plan will be to apply this technology to other rocky planets and moons in the solar system, particularly to Jupiter’s icy moon Europa, which may have oceans below its frozen surface.
Other candidates include Saturn’s moons Titan and Enceladus.
Deep space
Until now, previous missions have only been able to scrape the surface of other planets.
"We're developing the technologies now to enable a much more in depth analysis of these planetary bodies and with the increase in technology that we can apply to these problems, all sorts of possibilities open up," explained Peter Truss.

The other advantage of penetrators is that it’s easier to fire into a rocky planet than to land gently on the surface.
Loading and safety checks complete, the penetrator was driven out to the test track. This stretches 1,500m through the sand dunes but the penetrator and its rockets were strapped to a firing sled 300m from the target.
We retired to the control room and looked on as scientists waited anxiously for the final countdown. When it came, the firing shattered the quiet with a reverberating bang. There were cheers from the scientists at the completion of the last test.
Then it was time to break cover and head down to the sand bunker with a metal detector and some shovels to locate the penetrator and dig it out. Researchers measured how far it had pushed into the sand and collected samples.
In each test, the penetrators described a curved trajectory upwards through the sand, ending up only slightly below the surface.
Intruigingly, they also turned the sand they touched black, possibly as a result of its high coal content reacting to the heat.
Speaking later, back at the Mullard Space Science Laboratory, Professor Smith said Nasa and the European Space Agency were showing interest.
"The results have been spectacular and the space agencies are sitting up and taking notice," he said.
"Before now it had all been on paper. Now we have real hardware to show them."

Plan for quake 'warning system'

Nasa scientists have said they could be on the verge of a breakthrough in their efforts to forecast earthquakes.

Researchers say they have found a close link between electrical disturbances on the edge of our atmosphere and impending quakes on the ground below.
Just such a signal was spotted in the days leading up to the recent devastating event in China.
They have teamed up with experts in the UK to investigate a possible space-based early warning system.
Many in the scientific community remain deeply sceptical about whether such signals are indeed indicators of an approaching earthquake.
But Minoru Freund, a physicist and director for advanced aerospace materials and devices at Nasa's Ames Research Center in California, told BBC News: "I do believe that we will be able to establish a clear correlation between certain earthquakes and certain pre-earthquake signals, in an unbiased way."

He added: "I am cautiously optimistic that we have good scientific data, and we are designing a series of experiments to verify our data."
Despite years of searching for earthquake precursors, there is currently no method to reliably predict the time of a future earthquake. Yet, most scientists agree that some form of early warning system could save tens of thousands of lives.

The ionosphere is distinguished from other layers of Earth's atmosphere because it is electrically charged through exposure to solar radiation.
On a significant number of occasions, satellites have picked up disturbances in this part of the atmosphere 100-600km above areas that have later been hit by earthquakes.
One of the most important of these is a fluctuation in the density of electrons and other electrically-charged particles in the ionosphere.

Early warning

One study looked at over 100 earthquakes with magnitudes of 5.0 or larger in Taiwan over several decades. The researchers found that almost all of the earthquakes down to a depth of about 35km were preceded by distinct electrical disturbances in the ionosphere.
The analysis was carried out by Jann-Yeng Liu, from the Center for Space and Remote Sensing Research in Chung-Li, Taiwan.

Though full details have yet to be released, the BBC understands that scientists also observed a "huge" signal in the ionosphere before the Magnitude 7.8 earthquake in China on 12 May.The team at Nasa has also been working with Surrey Satellite Technology Limited (SSTL) in the UK, to investigate the feasibility of a satellite-based early warning system.

Stuart Eves, head of business development at the company, told BBC News: "The evidence suggests we're now crossing the boundary in terms of technology readiness."
He added: "What we don't know is how big the effect is and how long-lasting it is before the earthquake."
Minoru Freund believes other earthquake "precursors" could feed into this system. These include enhanced emission of infrared (IR) radiation from the earthquake epicentre, as well as anomalies in low-frequency electric and magnetic field data.

Rock 'batteries'

Minoru and his father Friedemann Freund, also from Nasa Ames Research Center, developed the scientific theory behind these earthquake precursors. It boils down to the idea that when rocks are compressed - as when tectonic plates shift - they act like batteries, producing electric currents.
"We now pretty much understand the solid-state physics of these rocks," Minoru added.
According to their theory, the charge carriers consist of a specific type of electron, called a phole, which can travel large distances in laboratory experiments.
When they travel to the surface of the Earth, the surface becomes positively charged. And this charge can be strong enough to affect the ionosphere, causing the disturbances documented by satellites.

When these pholes "recombine" at the surface of the Earth, they enter an excited state. They subsequently "de-excite" and emit mid-infrared light particles, or photons. This may explain the IR observations.
Dr Mike Blanpied, a geophysicist at the US Geological Survey (USGS), who is unconnected with the work told BBC News: "At this point, the connection between the laboratory phenomena and processes at work in the Earth has not been demonstrated and is the subject of research."
He has two principal criticisms of the work. Firstly, he said the experiments had been done on dry - or briefly soaked - rocks at room temperature and pressure. But deep in the crust, rocks have all their voids filled with mineral solutions and are subjected to high temperatures and pressures.
Secondly, he said, the researchers' hypothesis held that rapid changes in stress and strain in the crust began a few days before earthquakes.
Dr Blanpied, who is based in Reston, Virginia, said there had never been an observation of rapid strain changes before an earthquake, which meant precursor strains before earthquakes might be too small to have been detected.
Minoru Freund agrees that more work is needed to improve on the theory and some of the data. But he said he was planning to work up a proposal for a low-cost, space-borne early warning system based on at least three satellites.