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Archives for October 2010

Asteroids: When the time comes to duck

Jonathan Amos | 23:09 UK time, Friday, 29 October 2010

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Somewhere out in space there’s a big rock that has our address on it.

Throughout geological history, our planet has been hit by a succession of major asteroids and the probabilities suggest further impacts will occur in the future.

No-one can say today when these might happen; we haven’t yet identified an asteroid of sufficient size and on a path that gives us immediate cause for concern.

Artist's impression of an asteroid mission

If an object was sent to strike the asteroid, the rock's course could be subtly changed

But the evidence hints strongly that something could find us sooner or later, and we need to be ready.

On average, an object about the size of car will enter the Earth's atmosphere once a year, producing a spectacular fireball in the sky.

About every 2,000 years or so, an object the size of a football field will impact the Earth, causing significant local damage.

And then, every few million years, a rock turns up that has a girth measured in kilometres. An impact from one of these will produce global effects.

We know of some Near-Earth Objects (NEOs) today that are several km wide but fortunately none of them comes close enough to make us sweat.

The important thing is we keep looking. The US space agency’s NEO programme has been running since the late 1990s.

It was tasked with finding 90% of the potentially hazardous objects out there larger than 1km and it’s about 80% through this search. A few years back, the US Congress asked Nasa to extend the survey to include rocks down to about 140m in size.

That requires more and better telescopes and these are coming online. You will hear much more information on NEOs in the coming years because of this finer-scale sweep of the skies.

When a potentially hazardous rock is discovered, one of the best ways to determine its true status is to complete a study using radar, an extremely powerful tool.

Facilities such as the Arecibo Observatory in Puerto Rico or the Goldstone complex in California can pin down a rock’s key properties, determining its velocity to a precision of better than 1mm per second, and enabling scientists to compute its orbit hundreds of years into the future.

One of the more interesting facts that I became aware of recently is just how many of these objects are actually binaries – that’s to say, when the radar observations are done it becomes apparent that the asteroid is really two asteroids, or even a trio.

Toutatis

Contact binary: Toutatis (4.5km long) frequently gets to within a couple of Earth-Moon distances

Some of these are what are termed contact binaries – they touch each other. These are the objects that look like giant peanuts. (My favourite contact binary is the “dog bone” asteroid, 216 Kleopatra, although this is a long way from Earth and no threat to us).

About a quarter of all the objects investigated by radar turn out to be binaries of some kind.

So the inevitable question arises, what do we do if we find that huge rock with our address on it?

The powers that be are on the case. A lot of this work goes under the aegis of the United Nations, and in this context a meeting took place this week hosted by the European Space Agency.

The Mission Planning and Operations Group (MPOG) workshop included astronauts and space scientists.

It was the latest in a series organised to report to the UN's Committee on the Peaceful Uses of Outer Space.

The gathering of experts urged the world’s space agencies to improve their search and tracking capabilities, and to start developing concepts to deflect asteroids.

One of the leading figures in this initiative is the Apollo 9 astronaut Rusty Schweickart. He’s the chairman of the B612 Foundation, which campaigns on the NEO topic [PDF], and was one of the attendees at the MPOG meeting. He characterises the threat thus:

“At the upper end, you’re talking about wiping out the dinosaurs and most of life on Earth 65 million years ago; at the smaller end you’re talking about a million objects that hit the Earth last night – we call them shooting stars. It’s the objects in between that occur every few hundred years that we’re concerned with.”

Schweickart is convinced the solutions are within reach to deal with most hazardous asteroids on a collision path with Earth. In the majority of cases, the preferred concept would look much like Nasa’s Deep Impact mission of 2005 which saw a shepherding spacecraft release an impactor to strike a comet.

This gentle nudge, depending when and how it's done, could change the velocity of the rock ever so slightly to make it arrive “at the intersection” sufficiently early or late to miss Earth.

According to Schweickart, rear-ending an asteroid may be the easy part, however. Getting the world’s bureaucracy to act on the threat in a timely fashion may be the bigger challenge, he believes. And here’s why.

Consider the 300m-wide asteroid Apophis. For a while, before the calculations were detailed enough, there was some concern this object might hit Earth in 2036. The odds now are thought to be pretty slim.

But just imagine for a moment that it was headed right for us and we needed to do something about it.

Take a look at the map below. We know enough about the plane of Apophis’s orbit to understand where this rock would intersect the Earth, and it would be somewhere along the red line.

Now imagine the UN meeting convened to discuss whether the mission sent up to deflect the asteroid should try to slow or accelerate the rock. The choice is important because it would determine where on the line the rock would hit if the mission is not entirely successful in getting the asteroid to pass by the Earth.

In other words, one strategy chosen over the other would lessen the risks for some while increasing them for others.

So, you can bet Russia, Venezuela and Senegal would have very different views on which mission profile should be chosen.

That’s why Schweickart believes the geopolitical obstacles need to be tackled now and the mechanisms put in place to deal with thorny issues like the one I’ve just described:

“If we can get past that bureaucratic challenge, we can in fact prevent [large] asteroid impacts from hitting again in our future. This is an amazing and rather audacious statement to make, but if we really do our job right, we should never be hit again by an asteroid that can do serious damage to life on Earth.”
Apophis plane of intersection with Earth

 

 

UK space funding: Steady thrust ahead?

Jonathan Amos | 12:30 UK time, Thursday, 21 October 2010

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When George Osborne stood up to give his Spending Review statement on Wednesday I was walking around a factory cleanroom in Germany inspecting three satellites that will make the most precise measurements of the Earth's multi-layered magnetic field.

The Swarm spacecraft will be so sensitive they will be able to trace even the magnetism induced by the movement of ocean currents.

And although German industry is leading this remarkable project, the UK has been responsible for a major part of the satellites' development and construction.

It is just the sort of activity you would expect from two countries needing to build capability and competitiveness in a global market - academia and industry tied together in excellence to produce world-leading research and product.

A Swarm spacecraft under construction at EADS Astrium, Friedrichshafen

The Swarm spacecraft contain German and British engineering excellence

Mr Osborne clearly agrees. It's one of the reasons he is giving UK science a "flat-cash settlement" over the next four years when those involved were expecting something worse - much worse.

There will of course now be something of a mad scramble from the different areas of UK research as they seek to claim a good slice of the flat cash, because it is certain there will be winners and losers in this money just as there were across the Spending Review in general.

The big difference this time, compared with when a chancellor last set a financial trajectory in the research sector, is the presence of a spanking new body - the UK Space Agency (UKSA).

By April next year, it will be fully up and running and all the space monies that were previously controlled by Britain's Research Councils and government departments will have been transferred across into the agency's single budget line.

So how will it fare in the scramble? Well, science minister David Willetts wasn't being drawn into specifics on Wednesday but in the brief response he gave to a question I had put to him from Germany, there is every reason to believe that space will come out better than average. He said:

"I haven't got details of spending [on space] but what I can say is that the Treasury completely buys the argument that science clearly contributes to long-term economic growth, and in space we have a sector which is growing as fast as the Chinese economy; and it is exactly the kind of area where there are things we can do to maintain its excellent performance; and on the public-sector side we shall fight to do so."

The comparison with the Chinese economy is no boast. Figures I've seen and which will be made public shortly will demonstrate the UK space industry flew through the recession and now has an astonishing annual average growth rate of 10%.

It is now turning over something like £7.5bn a year, and it's taking on more and more people - up 15% year on year.

It's figures like these which explain why the coalition has waved through with little question the publicly-funded space projects announced by the previous government. I'm talking here about projects such as TechDemoSat which I wrote about on Monday.

The idea of a market-barrier-breaking spacecraft to trial innovative UK technologies has been mooted for some time. It is now going ahead and there is even talk of it becoming a continuing programme.

Two specific issues come to mind and are worth watching. There are plenty of others, but these happen to be in my head right now.

The UK Space Agency has a notional combined budget of about £250m, but two areas of major civil space expenditure still sit outside this pot.

One is the grant line for researchers at universities to exploit space data - still controlled by the Science and Technology Facilities Council (STFC). The other is the UK's contribution to the European meteorological space agency, Eumetsat. This remains the responsibility of the Met Office and MoD.

In the case of grants, these are often the easiest items to squeeze and in the case of the STFC with so many other areas of its expenditure fixed and unmoveable, there will be concern in the research community that these grants could be one of the "losers" as the cash is divvied up.

In the case of the Eumetsat side of things, I go back to something I saw in that German cleanroom. This was a pair of colossal satellites called Metop-B and Metop-C.

Their sibling, Metop-A, is currently circling the poles gathering data that informs our daily weather forecasts. The B and C spacecraft are the follow-ons; they will be launched in the coming years to provide continuity of service through this decade.

But Europe will need soon to order a next generation - to design and start building the satellites that come after Metop-C. This is likely to be a 2.5bn-euro programme in which UK scientists and engineers would want to take a prominent role in the R&D phase.

The reason for that is obvious on one level, but on another it is not quite so obvious. In Europe, the way these kinds of projects are organised means those that do the R&D on the satellites get the contracts to build the operational system. It's a very simple multiplier: you put something in at the beginning and you get a lot more back later.

The UK has not played this game well recently, unlike the Germans and the French.

Britain built the basic structure of the Metop series and installed their propulsion systems. To get similar work on the next generation, it will have to commit money to Eumetsat's R&D partner (the European Space Agency) during this coming spending round, probably in 2012.

Where will that money come from? Whose budget line will it come off? This is just one example of a big-ticket item that will bear down on those who get to play with the numbers announced on Wednesday.

Richard Peckham is the chair of UK Space, the industry umbrella body for the British space sector. He is certainly hopeful that public expenditure on space will come out "better than average":

"The argument in favour of space is that it is so cross-cutting - it is important science, it's important to defence and security and it's vital for economic growth. I'm reasonably optimistic that given a flat budget, we'll do alright. I notice also that the government is talking about finding efficiencies and for the money that's saved being re-invested. So some of the public 'spend' on space may actually end up being slightly more than they're saying."
Metop-B and Metop-C being prepared for launch

Metop-B and Metop-C will maintain continuity - but will the UK be involved in their successors?

Recollections from a life on Mars

Jonathan Amos | 12:06 UK time, Monday, 18 October 2010

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It was literally a book launch.

Colin Pillinger's account of the ill-fated Beagle-2 mission was placed atop a 3.5m rocket at the weekend and blasted into the sky, high above Cambridgeshire.

Several minutes later, the hardback - called My Life on Mars (The Beagle-2 Diaries) - floated back to Earth by parachute.

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Cover of My Life on Mars

The front cover features Colin Pillinger pictured in Sandy Quarry, which is often used by space engineers to simulate the Martian landscape

Colin is one of the most recognisable scientists in the UK. Those whiskers and that Bristolian accent have added to his appeal - which remains as strong as ever.

I was with him at a book event in Stevenage two weeks ago. The room was packed with people eager to hear the Open University researcher's story and how he got into the space business.

A little later in the evening, as everyone left, we reflected on the Beagle legacy, and he recalled an incident that pretty much summed it up:

"About nine months ago, I pulled into the OU car park and there was this huge lorry, a guy delivering a load of bricks - a builder, obviously. I looked at this guy and I thought 'he's going to take a while', so I dashed in front of him in my car to get into the parking space. Well, the door opened on the lorry and this huge man got out - you could eat your dinner off his hands - and he started walking towards the car. And I thought, 'Bloody hell, I'm going to get thumped'. Well, he stuffed this huge paw through the window and said, 'You're the man who launched Beagle-2, aren't you? I want to shake your hand, mate'. And that to me says everything. There's nobody in the UK I didn't reach."

The media, in particular, have always liked Colin's straight-talking - he's "good for a quote", as we say. And there're plenty of those in the new book (the front cover carries that fantastic image by Max Alexander shot in Sandy Quarry).

Testing lunar samples

A young Colin Pillinger analysing Apollo lunar samples (top, near), and with Apollo 11 astronaut  Neil Armstrong (bottom)

Colin is one of those people who keeps a diary - a very detailed diary.

He went to meetings and he wrote down exactly what was said by whom, to whom.

What you get in this book is "his history", his version of how Beagle was made and the battles that had to be fought to get the probe to the launch pad.

As we all know now, Beagle walked a tightrope from the moment it was agreed it should hitch a ride to the Red Planet on the European Space Agency's Mars Express Orbiter.

Funding for the project was hand-to-mouth, and the technical hurdles it had to overcome have been well documented.

No-one really knows what happened to Beagle after it was spun off Mex and sent in the direction of Mars. The best explanation remains that it was caught out by the thinner than expected atmosphere at the Red Planet, and it hit the ground sooner and faster than anyone had anticipated.

There were inquiries - and recriminations - that followed the loss.

And it's fair to say there will be a number of people, especially at the European Space Agency, who won't like what Colin has to say about how they handled events.

For those of us who weren't in the rooms when those conversations took place, it is impossible for us to judge where the truth really lies.

But a couple of things did occur to me after I'd finished the book and put it down.

The first is that the Beagle-2 story is helpful to those who make the case for the UK having a properly funded space agency.

If it is to deal effectively with international partners and manage its own affairs efficiently, the argument goes, Britain has to have an executive body in charge of space policy.

The inability of government back then to put money where it was needed, when it was needed [PDF 800KB], undoubtedly made life harder for the Beagle project.

Book landing

The book returns to Earth

The other point concerns the extraordinary achievement of Beagle as a science package.

Beagle weighed just shy of 70kg when it came off Mex, and that included all the equipment it needed to get into the Martian atmosphere, slow its descent and put down softly on the surface.

Its landing mass of 33kg included the instruments to search for signs of life, and was expected to work for at least 180 Martian days.

Contrast this with Europe's next effort to touch Mars - its 2016 landing module.

When it comes off its orbiter, the entire deployment will weigh 600kg. When it gets to the surface, there will be about 300kg (about 10kg available for science) which will operate for just a few days.

Now, I know I'm "comparing apples with oranges" to some extent here - 2016 is all about developing entry, descent and landing technology for future planetary exploration. But I must confess am left with a degree of disappointment.

Opportunities to touch other worlds do not come around so often that we can afford to pass up the chance to maximise every science possibility.

Nonetheless, I'll write more about 2016 in the coming days; it is still very much a fascinating project.

OMG. Look at that picture over there!

Jonathan Amos | 16:30 UK time, Wednesday, 13 October 2010

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Being in space can change the way you view the Earth.

Earthrise (Nasa)

It was on the Apollo 8 mission that the famous "Earthrise" image was acquired

That was certainly the case for the Apollo 8 crew who produced the iconic image of our planet emerging from behind the limb of the Moon.

It's a picture everyone knows and I put it on a story I wrote on Monday about a possible modern mission that might try to recreate some of the elements of Apollo 8's flight.

At the heart of the story was a discussion about future uses of the completed space station, and the idea that you might launch deep-space missions from the orbiting platform.

As you know, I always put my e-mail address at the bottom of news pages and the topics will usually generate quite a bit of correspondence. But what caught me slightly by surprise this time was the reaction I got to the way I had presented the famous "Earthrise" picture.

I've done it again here on this posting. Is this how you recognise Earthrise, with the Moon's horizon off to the right and the Earth emerging to the left?

Perhaps not, but this is precisely how astronaut William Anders (who took the picture) saw it. Examine a high-res version and you'll see Africa is "on its side".

If we are to orientate Earthrise to fit with "North" as we understand it here on Earth, then the "correct" way to render the picture ought to be as I've done it.

Bob Zimmerman got in touch to comment on the topic. It's been something of a personal battle of his to get newspaper and magazine editors to print Earthrise in this fashion.

Bob wrote Genesis: The Story of Apollo 8, a definitive account of the 1968 mission. He says he first realised the significance of the orientation when he went to visit Anders in his home and saw the way the astronaut himself had presented the picture.

As Bob recalls in the book:

"That's how I took it. To Anders, floating in zero gravity, the Earth wasn't rising from behind a horizon line (which is how a human living on a planet's surface would perceive it). Instead, floating in a space capsule seventy miles above the Moon, Anders saw himself circling the Moon's equator. The lunar horizon therefore appeared vertical to him, and the Earth moved right to left as it came out from behind the Moon."

I can't recall when I first had this realisation, but I do remember doing my university astronomy and the vision I had in my mind of the Solar System with the planets circling about the ecliptic plane. What was of interest to me was the degree to which various objects were inclined to that plane.

So thinking about Earthrise as Anders saw it seems very intuitive. But then again, if you were an astronaut at a lunar base sited at the Moon's equator - the traditional view of Earthrise is how you would see Earth in the sky.

As Bob told me:

"As for how the mistake got started, it was a natural thing. When you look at the 35mm film strips that hold the image, there is no obvious way to know the image's top or bottom or side. The Nasa officials who first released the image naturally chose to put the horizon on the bottom, because that's how we here on Earth see it.
  
"I've written and lectured on this subject many times. Frank Borman took a black & white Earthrise image mere minutes before Anders. He has his B&W image framed at his house with the horizon on the bottom."

Bob has his own site, Behind the Black, if you want to follow what he's doing.

There's no doubting the impact of Earthrise, whichever way you choose to present it.

Another historian and former colleague of mine, Chris Riley, sourced for me the audio recording of the moment the Apollo 8 crew first realised they had a magic moment on their hands.

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Chris wrote his own take on Earthrise for the BBC on the 40th anniversary of the picture's acquisition.  

And if you still haven't seen them, view the videos captured by the Japanese Selene spacecraft in 2007. As a polar orbiting mission, it really does make sense to render its images with the horizon along the horizontal.

 

Selene's version of Earthrise

The Japanese Selene (Kaguya) spacecraft produced its own version of Earthrise

 

When the 'expert testimony' comes from space

Jonathan Amos | 18:27 UK time, Wednesday, 6 October 2010

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It may have been the 53rd anniversary of Sputnik this week but satellites are still a relatively new phenomenon.

They're not quite all pervasive - although it's fast heading in that direction. As I posted recently, the average number of spacecraft launched per year this decade is expected to exceed 120, up significantly on the 77 per year during the 2000s.

More and more, what these "birds" do and see is going to impact our daily lives.

This was very evident from the fascinating workshop [100KB PDF] I attended this week organised by the London Institute of Space Policy and Law.

Increasingly, Earth observation (EO) data acquired by satellites is being introduced as evidence in courts and tribunals.

What sort of information is admissible? What weight should such evidence carry? Should it be treated any differently from the electronic evidence of a scientific nature presented by other expert witnesses? And do lawyers understand enough about what satellites are capable of doing to begin to examine the evidence properly?

Clearly, some American defence lawyers have cottoned on, and, wary of its power, have challenged this "newfangled" information on the basis of the Fourth Amendment to the US Constitution, which prohibits search without warrant.

It's something we're all going to have to get used to, however.

Radar image of oil spill

The elongated dark feature in this radar image is typical of an oil discharge from a ship

In Europe, we should see the first of a new fleet of remote-sensing satellites called the Sentinels launch in 2012/2013. Initiated by the EU and Esa, these spacecraft will be dedicated to environment and security monitoring.

They will have many tasks but a key one will be to help enforce EU and member state legislation.

Two good current examples give a glimpse of where this trend is going.

One concerns the Common Agricultural Policy and the direct payments made to Europe's agricultural businesses.

Farmers will receive some 43bn euros this year to look after the continent's land. A small portion of this cash is directed at supporting particular crops but the vast majority of it goes into ensuring farmers manage the countryside properly - to maintain soil quality and natural habitats, and meet certain animal welfare standards, etc.

To check they haven't put a golf course on a piece of land they took money to maintain as pasture, satellites are tasked with taking pictures of the farmland. Something like 430,000 farms across 24 EU member states will be monitored in this fashion this year.

The number is actually quite a small fraction of the total number of farms but because farmers have no idea when a satellite might pass overhead, there is very little non-compliance, the European Commission reports.

Nonetheless, lawyers will go after fraudsters with the satellite imagery in hand.

Sentinel-1

Europe will soon launch its Sentinels

Likewise, radar spacecraft are used by the European Maritime Safety Agency (EMSA) to monitor for any illegal discharges of waste oil by ships.

The presence of oil in the water works to flatten the sea-surface somewhat and if wind conditions are just right, radar can sense this damping effect.

The discharge will appear as a long dark band in a radar image. A ship "caught in the act" will appear as a bright spot at the head of the trail.

Aircraft are scrambled to check out a possible infringement; and since the CleanSeaNet system was set up in 2007, about a quarter of the 2,000 potential spills investigated up to 2009 were confirmed as transgressions. Subsequent prosecutions would have been taken up in member state jurisdictions.

To be honest, most of this is fairly straightforward, and the satellite evidence in these instances tends to be secondary or complementary anyway to other material presented in cases.

Where the arguments are likely to get more intense is in those cases that rely on information from very complex or novel observation approaches.

For example, litigators dealing in subsidence claims will resort to Persistent Scatterer Interferometry, a smart but tricky radar technique capable of sensing millimetric changes in the elevation of the land or cityscape over several years.

It's powerful stuff, but you can see how an opposing lawyer might want to cast doubt on the calibration of the satellite instrument, query the atmospheric conditions that can introduce noise into the radar signal, and even question the modelling that underpins the processing of the raw data squirted out the back of that instrument. And who wrote the software and how many errors does it contain?

As Dr Kevin Madders, an expert in space policy and law, explained to me, using satellite data in a legal context requires very exacting standards:

"This is all about a technology which is still new and we're still getting to grips with it in an environment where it really matters because you're affecting peoples' rights and duties, both before courts which are very obvious but also before administrative tribunals which have these days an enormous role to play in society. When that happens, the kind of scientific-research, public-service uses we've traditionally employed the satellite data for recede to a different level. The level we're talking about here is one of the most testing in terms of what you mean by 'fact', because you have to prove that under standards where it's not just something which will go into a science journal or textbook, however important that might seem. This is where you can change someone's position in relation to the state or another person."

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