Friday, February 18, 2011

Spaceman by Jonathan Amos,


Plotting a course for Europe's space freighter

It was a big moment in every sense. When the Ariane 5 shook and lifted skyward, it marked not only the heaviest payload carried into orbit to date by Europe's premier rocket but the 200th mission of the launcher series initiated back in 1979.
Ariane launch
Point perfect: Ariane delivered Johannes Kepler precisely into the 260km-high orbit demanded
Wednesday night's beefy passenger was the European space freighter, or Automated Transfer Vehicle (ATV). Nicknamed Johannes Kepler for this mission, the robotic truck tipped the scales at 20,062kg.
I've discussed the capabilities of the ATV on a number of occasions, especially its very smart rendezvous and docking technology that allows it to find its own way to a destination and attach itself without any human intervention.
The current ship is the second such vehicle (the first, "Jules Verne", went to the launch pad 600kg lighter than Kepler). Three more ATVs are in various stages of construction.
The freighters are a kind of subscription that Europe has to pay to be a member of the International Space Station "club". Instead of handing over cash to the Americans to get access to the orbiting laboratory for its astronauts, Europe has instead bartered a logistics role for itself.
So long as ATVs keep turning up at the station with several tonnes of food, water, air, fuel and equipment, European astronauts can claim a place on the platform for six months out of every 24.
ATV
The ATV production line requires a decision now on any future orders
The supplies that will fly on the next three ATVs should see Europe meet its end of the bargain through to about 2016. But as we know, the station now looks as though it will fly until at least 2020, and perhaps beyond.
So how should Europe continue to pay its subscription?
It's a very timely question right now because European industry has told Esa that if the production line for the freighters is to be kept open and economical then fresh orders must be placed very soon.
For a long time, the expectation was that Esa would request simply an ATV-6 and ATV-7, with little significant change in the basic design concept.
Then the idea was floated of having a return capability added to at least one of these vehicles.
At the moment, the ATVs are destroyed at the end of their mission by being commanded to burn up in the Earth's atmosphere with all the refuse off-loaded from the space station.
Feasibility work has been done to assess the implications of adding a re-entry capsule, one that could be used in the first instance to bring cargo safely down to Earth and then maybe, sometime in the future, even astronauts.
But this option, known as the Advance Re-Entry Vehicle, does not appear to have the momentum it once had.
ARV concept
Adding a return capsule to an ATV may not be the best option in a common transportation plan
Driving the thought process now is the need for a global transportation policy, the idea that the different partners in the space station club bring capabilities that enhance the overall effectiveness of their endeavours in orbit.
In other words, on space transportation they should all play as a team. And with a number of return capsules already in development in the US (such as Dragon, Boeing CST-100, etc), does Europe really need to be duplicating this function?
Should it instead try something different, something new? Shouldn't the next series of ATVs look to take that clever automatic rendezvous and docking technology into new roles?
Simonetta Di Pippo is the director of human spaceflight at Esa. She told me that Esa was looking at re-defining the ships:
"The idea is to procure up to ATV-5 and then to develop a new system. We want something new in order also to keep the expertise in our industry.

"We're discussing that in the context of the extension of ISS up to 2020 and beyond with our member states. It would be something that is a derivative of the ATV, with the requirements to be discussed with the station partners. Because whatever we develop, it has to be done on the basis of a common understanding of what is needed for the future.

"With the new commercial systems coming out, we need to revisit the overall picture; and this has to be done together with the partners. In the past, we've had co-ordination but not a common plan. Now we want to develop a common plan that allows us to co-operate while at the same time being autonomous in certain technologies.

"[The future vehicle] needs certain requirements. The space station needs to be de-orbited at a certain point; we need probably also on the longer term to be able to send some pressurised modules to the station, because we do believe that more space will be needed in the years to come; and it would need to have some features like a service module that could act as a tug.

"In June, we should have the requirements on the table, jointly agreed with Nasa and the other partners."
So, some new roles for the European space freighter are being defined and we'll find out what they are very shortly.
The issue of de-orbiting the space station is an interesting one. Currently, we've no clear idea when that might happen; it could be quite late in the 2020s if the modules receive the necessary certification or/and are updated.
But what is clear is that of all the vehicles out there at the moment, only the ATV has the propulsive might to bring the 400-tonne structure down into the atmosphere and a controlled burn-up.

The Liberty rocket and the 'genetics' of human spaceflight


I wondered how long it would take before we saw Europe's biggest space company, Astrium, step into the race to develop a follow-on to the soon-to-be retired space shuttle.
It needs a US partner to get involved in the Nasa commercial crew development programme, of course, and in ATK it has one of the key companies in human spaceflight rocketry.
The firms' proposed Liberty rocket would mesh elements from the shuttle launch system with Europe's Ariane 5.
The new vehicle would incorporate a shuttle-derived, five-segment, solid-fuelled booster provided by ATK as the first stage, with an Ariane 5 cryogenic-core-stage and Vulcain-2 engine from Astrium making up the second stage (Vulcains are produced by French firm Snecma).
ATK is emphasising proven flight heritage, inherent safety, and speed of development
ATK is emphasising proven flight heritage, inherent safety, and speed of development
It's a meaty combination that could put 20 tonnes in low-Earth orbit. The companies say Liberty could launch any of the commercial crew capsules now in development.
I've written about quite a few of these concepts, most recently the Sierra Nevada Corporation's Dream Chaser. Back in the summer I also looked at the Boeing CST-100 vehicle.
ATK, as the lead in the partnership, has entered the Liberty proposal into the second round of Nasa's Commercial Crew Development Program (CCDev), hoping to secure some funding assistance. We'll find out in the coming weeks just how successful that's been.
Nasa is likely to be investing hundreds of millions of dollars in various concepts over the coming years in a bid to seed operators that can then sell crew launch services back to the agency and anyone else who might want to go into orbit.
Companies like Boeing are developing new capsules which could launch on Liberty
The "anyone else" could be other government bodies like the European, Japanese and Canadian space agencies, which do not currently possess indigenous human launch capabilities, or privateers looking to establish new space enterprises.
Here, tourism is an obvious contender.
Just looking at the artist's impression of Liberty rolling out to the launch pad at Kennedy on a crawler-transporter, I'm immediately reminded of the Ares-1 rocket that Nasa was pursuing as a crew launcher until President Obama and the US Congress decided to abandon the project.
Ares and Liberty are both stick thin; and of course ATK would have provided the Ares first stage as well.
ATK is hoping this will be part of the appeal of the Liberty concept - the new vehicle would be seen as taking advantage of all the investment that US taxpayers put into Ares before its cancellation. That investment included the test firing of two giant five-segment boosters on ATK's range in its home state of Utah. In that sense, Liberty can be said to be off and running already.
Kent Rominger is a former Nasa Chief of the Astronaut Corps who now works for ATK. Speaking to the BBC on Tuesday, he was keen to emphasise the safety aspects of the Liberty design:
"In my mind one of the most important attributes is providing a launcher that is very, very safe, and reliable. Our Liberty rocket is inherently reliable. You do that by starting with a system that is as simple as can be.
You minimise the number of areas where we've learnt in the past that failures can result in a catastrophe. So an as example, we have only two stages, meaning we have just one staging event. Each stage has only one engine - so there's only one place that can fail there.
In addition to that, we're leveraging all the experience that both companies have - and the hardware that has been proven."



Liberty rocket

For ATK's employees also, the announcement of the Liberty project must be most welcome. The company has indicated it would have to slim down given that its shuttle boosters are no longer required beyond this year.
For European commentators like myself, the Astrium involvement is most interesting. I was in the company's Les Mureaux facility near Paris just last month, walking around the Ariane 5 core stages as they were joined to their Vulcain engines just prior to shipment to the Kourou spaceport in French Guiana.
The Ariane 5 is "a vehicle that has human spaceflight in its genes". That's how Silvio Sandrone, Astrium's vice-president of launcher sales and business development, described the rocket to me today.
The Ariane 5 core stage with its Vulcain-2 engine has proven its reliability in recent years

It was conceived with the intention of launching Europe's Hermes crew ship, before that project - like the US Ares rocket - was cancelled on the grounds of cost.
It's as if Ariane 5 has been waiting, though, for those genetics to be re-discovered. Most of us thought that if it happened it would come through European governments deciding to upgrade Esa's robotic freighter, ATV, into a crew ship and launching it off the top of an Ariane 5.
That idea still looks a long, long way away, especially in the current economic climate across Europe.
Taking the Ariane 5 core stage and sticking it atop a shuttle solid-rocket-booster is not entirely left-field but I doubt it would be many people's first suggestion.
The idea came from ATK, apparently, which first approached Arianespace, the company that sells Ariane launch services. Arianespace then spoke to Astrium, which leads the European Ariane manufacturing consortium. They love the idea.
The core stage will necessarily need some modifications. For a start, the Vulcain engine will have to be made to ignite in a vacuum - something it doesn't have to do currently. But the big thought running through my head today is not technical but philosophical.
Europeans often bemoan reliance on US systems and talk about developing an independent crew launch capability. But isn't this a rather outmoded idea? Surely, the direction in which "new space" is taking us is one where big multi-national concerns dominate, buying and selling services in ways that cut across borders and traditional government lines and ties.
This is true of the wider economy. Oil, pharmaceuticals, agribusiness, media - the biggest companies operate globally. They may have a HQ in a particular country but their outlook is trans-national. Silvio Sandrone told me:
"It's a good question. From Europe's point of view, you want to be independent to do in space the things you really want to do.
One can think of navigation, Earth observation - those kinds of things. These we would want to do on our own, and for me it is clear that these types of applications are necessarily linked to European sovereignty and have to have their own launcher.
It's up to the politicians to decide if human spaceflight is something we want to do on our own or in some sort of international cooperation. Only European governments can tell us what they want.
But maybe Liberty will be an intermediate step. If there were an American launcher with significant European industrial participation, this might spur Europe to think again and to think more proactively about affording itself a crew capability, at least with a capsule first."

 European space prepares to make a really big decision
More than 300 of Europe's leading space scientists gathered in Paris this week to discuss how to spend more than a billion euros. The options? Well, try to choose between these three:
IXO artist's impression
IXO would be compressed into a smaller shape to fit in its launch rocket
(1) a 20m-long telescope called IXO that could see the very "edge" of a black hole; or (2) a trio of satellites collectively known as LISA which might be able to detect the ripples in space-time left by the moment of creation itself; or (3) a pair of spacecraft that would visit two of the most promising locations for life beyond Earth in our Solar System. This is called EJSM/Laplace.
The European Space Agency is working through the process of selecting a large mission to do something extraordinary, with the idea of launching the venture in 2020 or soon after. The start of the next decade might seem a long way away, but in the business of space this type of extended planning is very common.
The mission concepts being considered in this instance stretch what we know scientifically and challenge what we think we're capable of achieving technologically. And the reality is that in the case of two of the three missions I'll discuss on this page, several million euros will be spent just to say "no, we're not going to do that this time".
This week's meeting was a beauty pageant, if you like. It was a chance for the proponents of each mission concept to sell their idea to the wider community, and, very importantly, to the committee members in the audience who will make the final decision.
So what exactly is on offer?
Meeting in Paris
The meeting was held in the grand surroundings of the Institut Oceanographique in Paris
IXO [7MB PDF]: The International X-ray Observatory would be another of the grand telescopes, in the mould of Hubble, Herschel and James Webb. Like James Webb, it would be so big that it would need to be compressed, accordion-like, to fit inside its Atlas 5 launch rocket.
Only when it got into orbit could this 6.5 tonne beast extend to full length. Carrying advanced optics, it would deliver sensitivity and resolution 10 to a 100 times better than the current state-of-the art machines - Nasa's Chandra telescope and Esa's XMM. What could it do? Well, X-rays are a signal from the energetic Universe - from places where matter is being accelerated to great speeds, heated, or even torn apart.
To a science journalist one might even say it's a signal from the "exciting Universe" because the sources of X-rays are often those staples of gripping astronomy stories - black holes. Indeed, IXO would allow us to probe these objects in ways the current generations of astronomers could only dream of.
IXO would hunt for the first supermassive black holes to form in the Universe, and learn how they evolved through cosmic time. It would also allow us to peer right at the event horizons of black holes, locations where some really weird relativistic effects are predicted to occur as matter is pulled "inside". Paul Nandra, from the Max Planck Institute for Extraterrestrial Physics in Garching, is an IXO champion. He told me:
"We think we've already seen some of these effects with the current generation of telescopes; evidence that time slows down close to a black hole. That causes the light to shift. But even weirder things happen when you get close to a black hole: you get effects that light is bent so that you can almost see the back of your head. That sort of thing can become observable if you've got enough sensitivity like you'll have with IXO. So, we want to see these effects; we've got hints of them already. But now we know we are close to a breakthrough and that if we get this increase in sensitivity from IXO, we can see these effects predicted by Einstein's general relativity."

LISA artist's impression
The LISA satellites would fire lasers across five million km of space
LISA [12MB PDF]: The Laser Interferometer Space Antenna has been studied as a mission concept in some form for at least 18 years. Its purpose would be to detect gravitational waves. The movement of truly massive bodies, such as merging black holes, are expected to disturb the space-time around them, sending this energy radiating outwards. It's a very small signal, however, and to identify it requires extraordinary sensitivity.
LISA would fly three satellites five million km apart in an equilateral triangle formation. Laser beams travelling between the spacecraft would measure distances between free-floating gold blocks. The trick to detecting a wave washing over the observatory would be to see the laser beams deviate in a very characteristic way.
Measuring that, though, means observing changes as small as about 10 picometers, or 10 million millionths of a metre, a length smaller than the diameter of the smallest atom. Astonishing. But if this is possible - and everyone seems to think it is - it will turn astronomy on its head because it means we will be able to probe the Universe in ways that do not depend on detecting light. Professor Bernie Schutz from the Max Planck Institute for Gravitational Physics in Potsdam told me:
"Light is a wonderful medium for exploring the Universe and our own neighbourhoods, but the problem with light is that it's pretty easy to block it; and when you're talking about getting light from very distant regions of the Universe, there are too many things in the way. The light gets scattered or absorbed. Gravitational waves don't do that; they go through absolutely everything. Ordinary gravity does; you can't screen gravity out. You know that you weigh as much when you're standing inside a building as when you're standing outside. You can always block radio waves and the transmission to your phone - that's electromagnetic waves, that's light. But you can't do that with gravity. So if we can detect gravitational waves then we can observe things that we can't reach any other way."

Like IXO, LISA will open up black holes to study in ways that are simply not possible currently, but what really fascinates me is what it could do for the study of the really early Universe.
There should be a background of gravitational waves rippling across the Universe from the Big Bang. LISA just might have the sensitivity to pick this up, or certainly some of the other key events predicted to have occurred in the first fractions of a second after the cosmos came into being.
Jupiter Ganymede Oribiter
Europe would concentrate on Ganymede, putting a spacecraft in orbit around the moon
EJSM/Laplace [9MB PDF]: This is a two-spacecraft mission that would go out to Jupiter, to study the planet and its Galilean moons. Particular emphasis would be paid to Europa and to Ganymede. I'll talk to the importance of international collaboration in just a moment, but this endeavour would see the Americans concentrate on Europa with one spacecraft and the Europeans concentrate on Ganymede with the other.
Each satellite would conduct a stream of independent science in the Jupiter system. BUT, the two spacecraft would also work in tandem, gathering data together from different standpoints around the gas giant that would give scientists a totally new perspective on the Solar System's biggest planet.
Jupiter's significance has grown in recent years as we've discovered more and more planets around distant stars. Jupiter is an archetype, a model, for those far-flung systems, not least because it is on the rocky and icy moons of giants planets that life may exist. And this is the real draw of going to Europa and Ganymede. These two bodies probably harbour deep sub-surface layers of liquid water, and, as such, are considered prime locations for biology to perhaps take hold. Professor Michele Dougherty from Imperial College London said:
"You need essential elements; you need water; you need stability over time; and you need energy as well. What we want to do is to try to understand the details of those four different areas [at these moons]. And you can't do that if you have flybys. Nasa's Galileo spacecraft spent years in the vicinity of Jupiter but it didn't spend more than three or four hours on a flyby of each of the moons. To separate out all of the different effects, you need to spend time in orbit. You need to be able to see the same piece of surface time and time again, to see how it might change."

IXO, LISA and EJSM/Laplace would cost well in excess of a billion euros to implement. The European Space Agency says it can spend no more than 700m euros on any one venture.
That's realistic if the member states of the agency pick up the costs of building instruments (which they would normally do) and Nasa (and Japan in the case of IXO) also joins the party. And here's the tricky part. While Esa works through its selection process, the US is also working through a separate selection process, too.
The priorities of the two agencies - or at least their scientific communities - have to align; so too do the timelines for making decisions.
It's rather like organising a multi-billion euro wedding and trying to get the bride and groom to the church on the same day to say "I do". But watch out in June because we should at least get some indication then from the Science Programme Committee of Esa on how it views the big choices above.

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