BBC to Launch Five New HD Channels

NASA Successfully Test 3D Printed Rocket Engine Part Posted: 20 Jul 2013 05:00 AM PDT NASA has announced that it has successfully tested a 3D printed part for a rocket engine. The technique called selective laser melting (SLM) was used and resulted in the part being produced quicker and cheaper. The California based Aerojet Rocketdyne were able to make an injector component, a part that is used to deliver liquid oxygen and hydrogen gas to an engine’s combustion chamber. Using the SLM method, a computer-designed object is turned into a real part  by using high-powered laser beams that melt and fuse thin layers of metallic powders into the designed shape. According to NASA an injector component would normally take a year to make but by using this technique, they have been able to cut production time to less than four months and reduce the cost by more than 70 per cent. The test part is not full scale, it is smaller than what would normally be used in a full-size rocket but it is still big enough to give proof that the part is able to withstand the pressure and heat it would be exposed to. “Nasa recognises that on Earth and potentially in space, additive manufacturing can be game-changing for new mission opportunities, significantly reducing production time and cost by ‘printing’ tools, engine parts or even entire spacecraft,” said Michael Gazarik, Nasa’s associate administrator for space technology. The space agency are also exploring other techniques. It has asked researches at Washington University to explore the possibilites of producing 3D printed objects from lunar rocks. It is also testing a process called electron beam freeform fabrication (EBF3), which uses a computer controlled electron beam gun in a vacuum that  then welds metal wires into complex shapes and patterns. All these techniques are making steps towards NASA’s astronauts being able to produce spare parts in space, thus saving more time and money during space exploration.

BBC to Launch Five New HD Channels Posted: 20 Jul 2013 03:00 AM PDT The BBC has announced it plans to launch five new high definition channels by early next year.  There will be High Definition versions of BBC News, CBBC, CBeebies, BBC Three and BBC Four. These channels will be available over rooftop aerials via Freeview receivers as well as cable and satellite services. This news coincides with the regulator Ofcom‘s announcement that is making it possible to launch a total of 10 new HD channels using airwaves freed up by the switch off of the old analogue TV signals.  ITV, Channel 4 and Channel 5 had no statement at this time as to whether they intended to take advantage of Ofcom’s move.  Surprisingly BSkyB said it had no plans to launch an HD service on Freeview.    BBC’s director general Tony Hall said “BBC One HD and BBC Two HD have already proved to be highly valued by our audiences and I’m delighted that we’re able to follow this with the launch of five new subscription-free BBC HD channels by early 2014…These new channels will allow us to showcase more of our programming at its very best.”  Currently there are four HD channels offered over Freeview, which launched its High Definition service in 2010.  They are BBC One HD, BBC Two HD, ITV HD and Channel 4 HD. These include variants of the BBC One HD service for Scotland, Wales and Northern Ireland. Two of the BBC’s new channels, BBC Three HD and CBBC HD, will utilise existing unused capacity, and CBeebies HD and BBC Four HD will share a channel since they will not be broadcast at the same time.  As a result there is still the potential for up to a further eight new HD channels to be offered over Freeview as a result of Ofcom’s move.  Transmission company Arqiva will provide the infrastructure behind the new Freeview services, having being awarded a licence to do so by the regulator. It will handle other applications for the added capacity.  The company has indicated that up to 70% of the UK population should be able to receive the new channels over their aerials. The 550-606MHz spectrum band being used was freed up as a result of the UK’s digital TV switchover, which was completed last year.  Ofcom has said it reserves the right to take back the bandwidth from December 2018 if it needs to prevent a “capacity crunch” caused by the roll-out of future mobile broadband services.  The BBC has indicated it also wants to launch English regional variants of its existing BBC One HD service as well as Wales, Scotland and Northern Ireland editions of BBC Two HD. This would not need any of the new capacity, it would, however, need to be approved by the BBC Trust. Currently more than 50% of homes in the United Kingdom are already HD-enabled. The BBC said it expected that figure to grow a further 40% to around 90% by 2019.