The BBC has finally pulled it’s finger out and made their iPlayer view-on-demand system work on Linux and Mac platforms. The iPlayer streaming service is now available via web-browser using the Adobe Flash plugin. The download service is not available as it has apparently still not been possible to port Verisign’s proprietary, DRM encumbered Kontiki software to other platforms.

Apparently, releasing a flash-based version will not be enough to appease the BBC Trust on cross-platform availability either.

The streaming iPlayer requires the latest flash version which is a minor version of Flash 9.x (9.0.115.0). The iPlayer will run with earlier flash 9.x versions but the full-screen mode is disabled. Apparently, users were formerly required to register before using iPlayer but when I went to try it, I was given direct access. The experience was somewhat underwhelming. The bitrate was obviously lower than required to maintain the quality and the frame rate felt like 15fps. That said, this is probably the best the BBC can do at the moment as services such as iPlayer require a huge amount of processing power and bandwidth due to the potential userbase.

The personal gripe that I had is probably more of a problem with the BBC in general rather than iPlayer itself. Despite the large iPlayer catalogue, there seems to be very little worth watching. I’m sure it appeals to the lowest common denominator (whoever he may be) but I’m left puzzled by what the modern BBC regard as ‘entertainment’.

Tags: bbc, flash, iplayer, kontiki, linux, mac osx

I just had a corking idea to help alleviate the UK’s dependence on oil for transport.

Quite simply; electrify the motorways!

The idea is simple. Working on the principal of ‘trolleybuses’ we have sections of motorway where lane 1 (slow lane) is covered by overhead power cables for ‘trolley’ pick-up. You would, of course, need to design the system to cater specifically for the motorways.

Series-hybrid vehicles (preferrably HGVs) would be equipped with trolley arms. Before joining the motorway, they would operate under their fuel-based power system whether that be diesel-electric or another fuel. To enter the motorway, they would pass under a bar to ensure that no vehicle is over-height. Overheight vehicles would collide with hanging ‘rattle’ poles as well as triggering emergency stop lights on the sliproad. The entering vehicle would then filter into traffic as normal and an on-board system would briefly communicate with road-side telemetry to ask for permission to join the overhead power system (this as to prevent overloading of the system if too many vehicles joing too quickly for example). Once authorised, the vehicle would raise it’s trolley arms and make a computer-controlled capture of the overhead cables and then deactivate it’s fuel-based power system, relying on electricity alone for propulsion. The supplied power could also be used to charge any on-board battery systems the vehicle may have to enable short road journeys off the motorway after the vehicle pulls off.

Safety features which I can think of off the top of my head would be the aforementioned height bar, intelligent emergency disconnect systems in the event of a severed cable or pylon-strike, intelligent trolley arm control to instantly disconnect from the cables in the event of a capture ‘miss’ or that emergency maneuvering is required and an intelligent power-load controlling system.

The power will need to come from somewhere and I would suggest that modern nuclear power combined with supplementary power from renewable sources would be the best solution. With no direct emissions and careful management of waste products, this would undoubtedly be a far cleaner system that individual internal combustion engines. Even were the system powered by a centralised hydrocarbon generator, the efficiency of scale would make it a cleaner and more economical solution. More importantly though, using nuclear and renewable power would help reduce our dependence on oil and save hauliers a fortune enabling us to enjoy cheaper goods.

Photo credit: Carl-Johan Aberger

Tags: electric motorway, electric vehicles, energy, oil, pantograph, power, trolleybus

The next launch attempt of Space Shuttle Atlantis for STS-122 has been postponed until January 2008 due to faults with the ECO sensors in the Liquid Hydrogen fuel tank of the Space Shuttle System.

Launch had originally be scheduled for last Thursday but two of the four Engine Cut-Off Sensors in the liquid hydrogen section of the external tank failed to respond during fuelling. NASA requires that all four ECO sensors respond during tanking prior to launch. On Sunday’s launch attempt one of the four sensors failed to respond during tanking and the launch was scrubbed.

The postponement to the 10th of January is to allow time for engineering teams to evaluate the sensor problem and I’d also hazard a guess, to avoid any possible issues with the Shuttle’s annual ‘Y2K bug’. The bug is a potential issue with on-board computers when the calendar rolls over from one year to the next. This wouldn’t directly be a problem for a Shuttle launched in the next few days but it could perhaps become a problem if damage to the orbiter required an STS-3xx crew rescue mission.

The ECO sensor issue is a tricky one, they can’t risk them not working properly as a turbopump failure could lead to a ‘catastrophic’ engine failure. As I understand it, when the Space Shuttle Main Engine (SSME) turbopumps are at operating speed, fuel flow must be maintained for safe operation. A normal shutdown would be a controlled throttle-back of the engines so the turbopumps would spin down gradually. A sudden cutoff of the fuel would actually cause an rpm increase and failure (presumably uncontained) of the turbopump.

At a recent Mission Management team press briefing, they discussed the possibilities for fixing the ECO sensor issue. The MMT are optimistic that the fault lies in the avionics which are contained within the orbiter and can be accessed while on the pad. If, however, the fault lies at the sensors themselves within the base of the external tank, a roll-back to the vehicle assembly building may be required, perhaps even with the tank being demated from the stack. The MMT did mention that they had gained access to the tank while on the pad on a previous mission “a long time ago” but pointed out that it was a very difficult process involving removing an area of insulation foam, removing a panel of the tank and then putting it all back together again. The foam would then have to be re-applied in situ.

In the mean time, station life goes on. Progress M-62 is scheduled to launch to the ISS on the 23rd of December. The unmanned cargo vessel is expected to dock with the station on the 26th.

Tags: atlantis, columbus, eco sensors, esa, january, space shuttle, sts-122

…the UK’s Energy Policy is full of wind.

Labour MP John Hutton stated on the BBC Politics Show that it is the UK government’s intention to build 7,000 or so new wind turbines for electricity generation around the UK. In a slightly inflammatory fashion, the BBC has pointed out that would be one turbine for every two miles of coastline but they fail to note that it would only be the case if they were set equidistantly around the coast. They will, of course, be arranged in ‘batteries’ to allow for easier installation, maintenance and shorter cable runs. The placement, however, is very far from the problem.

The real problem seems to be minister’s lack of basic understanding when it come to how the electricity grid is operated.

Mr Hutton said:

“There is the potential, we believe, out there, using the resources that there are around the UK to generate maybe all of the electricity that households need … from offshore wind sources,”

Certainly there is. When the wind is blowing.

7,000 wind turbines would be rather less than useful for electricity generation when there is no wind and they are all idling. This is why wind turbines will never be anything other than supplementary generators. We have to have base-load generation and that is only available from sources which are not dependent on uncontrollable external factors like wind. That limits the options for base load generation to hydroelectric, hydrocarbon (coal, gas, oil) and nuclear. Then we need load-following generation (the generation that takes up any difference between base and peak load), once again, this has to be provided by the controllable sources of hydroelectric, hydrocarbon and nuclear.

So, of the only options for base-load generation:

• Hydroelectric generation is limited in the UK. Once you’ve tapped all the available dams for power, you can’t build any more unless you intend to flood more valley/catchment areas. There is also a concern that non-tidal hydro is adversely affected by droughts. Hydroelectric dams can also load-follow at the risk of depleting the reservoir supply faster.
• Hydrocarbon generation is always the one to take a battering from environmentalists but, once again, that isn’t the real problem. The real issue is that we are running out of hydrocarbon supplies and as such, the price will continue to spiral upwards for this sort of generation
• Nuclear generation, also hated by environmentalists should provide the most effective method of base-load generation. The system itself is clean in operation and if we bought modern French reactors, we could minimise the radioactive waste. It is worth remembering that France generates so much power through it’s 50+ nuclear reactors, they can sell the power on to other nations (including the UK) and boost their economy in the process.

Wind can only supplement these base-load generators. It cannot be a base-load itself and it cannot load-follow reliably. The wind will do as it pleases. We cannot control it.

The people of the UK must ask whether they really want such massive expenditure on a generation system that could see them sat in darkness several days a week.

Photo Credit: André Karwath by-sa-2.5

Tags: base-load, government, uk, wind farms, wind generation

The first launch attempt of Space Shuttle Atlantis for STS-122 has been scrubbed due to two of four LH2 Engine Cutoff (ECO) sensors failing to respond during tanking. The ECO sensors detect when the Liquid Hydrogen tank is about to run dry and cause a main engine shutdown to protect the turbopumps from running dry which could lead to catastrophic engine failure.

LH2 and LOX fuels have now been detanked from the shuttle and there will be a launch countdown recycle with the next attempt at 20:43ZULU Saturday the 8th of December.

Update: Launch now postponed until January

I also discovered an alternative link for NASA TV via Yahoo! which appears to provide a better quality of video that the rather awful quality provided by the NASA TV landing page.

Tags: atlantis, columbus, eco sensors, esa, iss, scrubbed, space shuttle, sts-122

Space Shuttle mission STS-122 is scheduled to launch today from Kennedy Space centre in Florida at 21:31:44ZULU. The shuttle in use for this mission is Atlantis and it will be carrying the European Columbus pressurised module (shown in the cargo bay in the diagram) for the International Space Station.

Atlantis will also be carrying the EuTEF external payload facility for the ISS.

You can follow the launch on NASA TV via the web or if you’re in Europe with a suitable dish, you can get the ESA TV relay on Atlantic Bird 1 at 12.5 deg West.

Eutelsat Atlantic Bird 1 at 12.5 deg West, Transponder F5, Channel C, Horizontal, F=12.642,75 MHz, SR=6.1113 Ms/s, FEC=3/4, signal MPEG2 4:2:0 PAL in the clear.

I had a quick look in at NASA.GOV’s new web page for NASA TV. On playing back the wma stream, it appeared to be of decidedly worse quality than we are used to so I tried the RealPlayer stream which was far better. It may just be a transient reduction in the bandwidth of the stream by Yahoo so I’ll try again tomorrow on the WMA stream but remember that the RealPlayer stream may be worth a try if you can’t get a good stream otherwise.

Tags: atlantis, columbus, esa, iss, space shuttle, sts-122