When 'state of the art' is also years old

MHS The final MHS model will likely be 17 before it gets to do the job for which it was designed

It's possible to be brand new and old at the same time. That's the peculiarity of weather satellites and the way they're procured.

Because of the billions it costs to develop these special space systems, they're purchased in batches. The satellites then sit in storage until they're needed.

It means that newly launched spacecraft can in fact contain equipment which was delivered from the manufacturer years earlier.

This is the case with Europe's latest meteorological platform - Metop-B. It is the second in a three-satellite series and has just gone into orbit on a Soyuz rocket.

The first satellite, Metop-A, was launched back in 2006. The third platform, Metop-C, probably won't go up until about 2018. But all three of these spacecraft are circa early 2000s, and the industrial contracts that brought them into being were circa early 1990s.

So you have to wonder - how can anything that "old" deliver any sort of service that can be described as "new"?

It was a puzzle on my mind when I went to see one of the main British contributions to the Metop programme.

This is the Microwave Humidity Sounder (MHS), one of the eight meteorological instruments carried on each of the three identical Metop satellites.

UK engineers built these washing machine-sized objects to measure the water content sitting at different altitudes, including atmospheric ice, cloud cover and precipitation (rain, snow, hail and sleet).

It is fundamental information needed by the computer models to produce our daily forecasts.

The MHS batch model I saw will go up on that final 2018 Metop-C, a full 17 years after the instrument came off the "production line".

When you lay eyes on this remaining sounder, you immediately recognise its age. A little plate screwed to the side of the instrument announces the name of the manufacturer - Matra-Marconi Space. It is a famous name that no longer exists, subsumed years ago into the pan-European aerospace giant Astrium.

But, insists project manager Ian Stewart, "MHS was state of the art in '93, and it's state of the art today".

Brett Candy: "MHS data is critical for good weather forecasting"

He keeps an eye on things. Every year, he pulls the model out of its storage container to check everything is in good working order. If anything is playing up, it can be exchanged easily.

"We've built a lot of pre-assembled units in there. It's not quite plug and play, but it's as good as that. We don't have to go and de-wire boards - we have a replacement unit that we can just slot in."

Metop (Esa) The immense cost of these systems means it is impractical to buy a new version for every launch

But even if the hardware looks a bit quaint by today's standards, what about the science it can do? It's tip-top, maintains the UK Met Office; and like all the Metop instruments, MHS continues to stretch the models and the forecasters

"We're still in the situation where the data from this instrument is the topic of research," explains Nigel Atkinson, an expert scientist in satellite applications at the Met Office.

"Some of the data from the standard humidity channels, we know how to handle; and then there's the precipitation-affected channels that are a new area. So, we can exploit this data and improve weather models. We're not sitting there saying 'this is an obsolete instrument' - it is still something which can push forecasts forward."

In other words, the data MHS acquires is made to work harder and harder as the science of meteorology advances.

Metop-B In this pre-launch image of Metop-B, MHS is the big silver box two-thirds of the way up the satellite

Studies have compared all the different types of observations (including surface weather stations, balloons and aeroplanes, etc) ingested in weather models and found that Metop data makes the largest contribution to the accuracy of 24-hour lookahead, at around 25%.

Is is a big impact. Consider for a moment all the lives that have been saved and all the damage to property that has been prevented by Metop-supported weather forecasts. The value of those forecasts must equate to hundreds of millions of pounds every year across Europe.

Inevitably, though, the time comes when one must move to next-generation instruments. That is the discussion taking place right now, although the cost of a new and improved Metop system means the future satellites and their instruments will again be a batch-buy. The figure being quoted is just shy of 3bn euros for a series of spacecraft that would likely operate in the 2020s and 2030s.

The cost will fall on nations that are member states of the European Organisation for the Exploitation of Meteorological Satellites (Eumetsat), which operates Metop; and the European Space Agency (Esa), which leads weather satellite R&D in Europe.

British industry is keen to play its part and has put a case to government, through the UK Space Agency, to be allowed to develop the MHS follow-on instrument.

This will be known as MWS (MicroWave Sounder). It will do broadly the same as MHS but better (25 channels versus five channels).

It will also incorporate the observations of another current Metop instrument, Amsu (Advanced Microwave Sounding Units A1 and A2), which makes temperature profiles of the atmosphere.

"MHS is proven; it's a critical part of the forecast system. If we don't receive the data for some reason, the forecast degrades," says Brett Candy, a data assimilation scientist at the Met Office.

"For the future, we'd be looking for improved accuracy in the observations, hopefully improved resolution, perhaps more channels looking at different layers in the atmosphere - but really a continuation of the great instrument we've already got.".

And for Astrium, which now curates the Matra Marconi heritage, Mike Healy observed: "Sometimes, you put together a satellite instrument and there isn't a possibility of a follow-on.

"The nice thing here is that we have that possibility. The basis and all the lessons learned that were made for MHS - we can put that now into MWS, provided the UK subscription is big enough. This is about jobs and hi-tech manufacturing, so it should fit with the government's desire for growth," the director of the company's Portsmouth base said.

Jonathan Amos Article written by Jonathan Amos Jonathan Amos Science correspondent

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  • rate this

    Comment number 26.

    @sporpo The aim with satellites like these is to have them running side by side for a while so the new satellite can be calibrated against the existing one by measuring the same weather. This is true whether is is B replacing C or the next generation replacing C.

  • rate this

    Comment number 25.

    Surely it is a good thing to have identical satellites to replace existing ones when they expire? That way there is more chance that the data they collect will be directly comparable with their predecessor. Less chance of a subtle change in sensitivity being misinterpreted as an actual change in the environment.

  • rate this

    Comment number 24.

    I have a 1994 Proton Persona, and it works!

    If the old trusted equipment is doing the required work, than its age does not matter.

  • rate this

    Comment number 23.

    assuming that most weather patterns are coming along gulf stream pushed by jetstream a weather ship in atlantic could give 2,3,4 days notice,land fall on west coast 1\2 day 1\4 day notice.4 seasons 4 winds cold north + east, warm south, wet west

  • rate this

    Comment number 22.

    21.topcat - presumably you don't work in a job where the weather dictates what you can and cannot do & therein the work needs to be planned a few days ahead?

  • rate this

    Comment number 21.

    # yes science really does work for us all weather predictions great really,but one would have thought that if you can not change it,why look from above as we now the principal factors controlling patterns why note just phone a freind and say iie wind westerly clear and if you are down wind dry day,and does launching rockets improve or destabilise weather patterns most are set off near caribean sea

  • rate this

    Comment number 20.

    Predicting the weather and seasons is and always has been vital. From farmers to town planners to sun bathers all have a stake in the weather. That we make mistakes, in this field or any other, with predictions is nothing new, hence our desire to improve upon those techniques. I nearly went into weather prediction while I was studying AI at Reading. It's a fascinating area and very complex.

  • rate this

    Comment number 19.

    #8 at the time of manufacture the wood used was harvested by the violin maker who knew the tight grain of the wood,will give a superior clarity and better sound, that was caused "by the weather" a prolonged dry spell.which in all probabilty he stradavarius was unaware of,did u enjoy the concert,vivaldi the right of spring the red priest

  • rate this

    Comment number 18.

    For the record, as it seems to be one source of the confusion over Michael Fish's forecast that October '88 day - the severe storm that hit us was the remenants of a hurricane that had bounced off the eastern seaboard of the US.

    But as it travelled across the Atlantic it weakened, as these things do, and dropped in severity to a severe storm by the time it got here.....

  • rate this

    Comment number 17.


    ...we had a severe storm. You'd know that if you bothered checking the records and/or if you'd ever lived through a genuine hurricane/typhoon in the US/Far East etc....

    ...Michael Fish's forecast was spot on......

  • rate this

    Comment number 16.

    @ 11
    "Earlier on today, apparently, a woman rang the BBC and said she heard there was a hurricane on the way; well, if you're watching, don't worry, there isn't, but having said that, actually, the weather will become very windy, but most of the strong winds, incidentally, will be down over Spain and across into France."

    Afloat, we had 3 hours warning of "hurricane" force winds. Not enough!

  • rate this

    Comment number 15.

    Sometimes a consistent measurement system is preferable to getting the latest upgrade every year.
    Do you see anyone rushing to replace the Stevenson Screen?

  • rate this

    Comment number 14.

    Interesting that you chose weather satellites as an example. It doesn't matter how old it is, it wouldn't make much difference what data you got, they can only see or detect what is happening now

    They cost a packet to build and punt into orbit, but don't do more than give us a "bird's-eye-view." WE have to work it out from there, and we're still not that great at it ;o)

  • rate this

    Comment number 13.

    The main thing is that space technology is not trivial. It has to handle harsh radiation and extreme temperature fluctuations, be almost 100% maintenance-free on a timescale of decades (even a reboot is out of the question), operate on about the same sort of power levels as your mobile phone, evade space junk, guard against solar flares, and do all this continuously. Space tech is hard to improve.

  • rate this

    Comment number 12.

    #10. BluesBerry
    As it is theres currently a bit of a problem with building many one-offs and not building stuff (relatively) quickly and cheaply so getting them in batches makes sense.

    Also if the next model isnt significantly better then maybe an upgrade is not justified.

  • rate this

    Comment number 11.

    Before anyone mentions Michael/October '88 I'd like to point something out.

    He said we'd get a severe storm, not a hurricane....

    ....and that is exactly what we got - his forcast was absolutely spot on 100%......

    ....the forecast is more accurate than most folk realise, mainly because they don't listen to it properly.....

  • rate this

    Comment number 10.

    Excuse me, but methodology does not seem to make sense. If scientific enhancements are moving forard, even machine that is one year old probably could do with some updating.It's not just a matter of being able to use it; it's a matter of doing more, becoming more useful & accurate. Using the same machine, when needed, even if slightly adjusted, is not my idea of a great leap forward.

  • rate this

    Comment number 9.

    There's an important scientific point here. When you build up an ongoing data set like atmospheric measurements, they need to be measured consistently. If you bring in a new type of instrument every few years there is always an uncertainty regarding their comparability. Using the same instrument design on three successive satellites gives confidence in the long-term reliability of the data.

  • rate this

    Comment number 8.

    I went to a concert last week where the violin soloist played an instrument that was just shy of 300 years old ...

  • rate this

    Comment number 7.

    I have to say that I dont care whether the weather is too right or wrong as it adds spice to life. I dont care if I use US or EU data for my satnav. I do care that our EU pond life seem to want to duplicate whats up there already at great cost to the EU tax payer. Pretty soon we wont have a global warming problem as there will be so much junk up there we will be in the shade.


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