Stories from the stores

Category: Space

The decline of WorldSpace

May 8th, 2012 | by | communication, meta, space

May
08

Last month I went to a conference marking 50 years of the UK in space. Some of the speakers reminded us many of us use space daily without even thinking about it when we watch satellite television or get directions from our GPS.

A snapshot from last month's conference (Credit: Alex Costa)

I recently took delivery of a new object for the collection that also uses space – a satellite radio made for WorldSpace. The WorldSpace company was founded in 1990 and used geostationary satellites to broadcast to Asia and Africa. At one point they had 170,000 paid up listeners.

This WorldSpace WSSR-11 satellite radio broadcast receiver we recently added to the Museum's collection (Credit: Charlotte Connelly)

The company also maintained a not-for-profit arm, using 5% of the satellite’s bandwidth to broadcast programs giving advice on HIV and AIDS, agriculture or providing information for women. It was tricky to make these programs localised enough to be really useful. For example, WorldSpace broadcast some Somali language programmes for use in classrooms in one region of one country, but anyone in Africa could tune in.

Satellite radio also faces technical challenges; I spoke to an engineer who explained that the signal is easily interrupted by concrete, glass, trees and even smoke.

“I had a guy in Ethiopia write me every day that his signal was lost at roughly 10am, 1pm, and 4pm daily. We couldn’t figure it out… It turned out the antenna was in a courtyard, and people took their smoke break in front of the antenna – effectively cutting the signal until they finished their break.”

Arial masts are a common feature of the landscape in Africa now. This picture was taken in Buea, Cameroon in March 2012 (Credit: Charlotte Connelly)

Unfortunately WorldSpace was unsustainable as a business and went into liquidation in 2008. It might be surprising that a business with 170,000 customers would struggle, but communications technology has changed rapidly since the service started. Back then mobile phones were only just getting going in developed countries, and satellite radio seemed to be a really good way forward. Now, however, mobile phones have completely changed telecommunications in Africa and Asia, and satellite technology is expensive and hard to localise.

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Space Debris

July 28th, 2010 | by | communication, engineering, materials, space

Jul
28

X3/Prospero thermal surfaces experiment

X3/Prospero thermal surfaces experiment (Doug Millard, 2005)

This box contains a flight spare set of experimental surfaces for the Prospero satellite that was launched in 1971. They were designed to tell scientists more about how different satellite materials and finishes – matt, shiny etc, would behave in the temperature extremes of space.

It has always reminded me of a much larger experiment flown by NASA (LDEF - which stands for Long Duration Exposure Facility) that was covered with all sorts of equivalent surfaces.

LDEF satellite during its six year stay in orbit

LDEF satellite during its six year stay in orbit (NASA)

The LDEF was brought back to Earth in the Shuttle and scientists discovered that its surfaces were covered with impact craters from micro-meteoroids.

Micro-meteoroid impact crater on the LDEF satellite

Micro-meteoroid impact crater on the LDEF satellite (NASA)

That was back in the 1980s but if the mission were to be repeated now it would almost certainly suffer many more collisions from the bits of space debris that we have put up there. There are thousands upon thousands of pieces of rocket and spacecraft circling Earth and it is becoming a big problem for satellite operators.

Computer representation of just some of the debris pieces orbiting Earth

Computer representation of just some of the debris pieces orbiting Earth (NASA)

At a meeting last week Air Commodore Stuart Evans RAF, Head of Joint Doctrine, Air and Space, DCDC, pointed out that ‘all nine sectors of the UK’s critical national infrastructure (communications, emergency services, government and public services, finance, energy, food, health, transport and water) all rely, to a greater or lesser degree, on space.

What to do about the debris problem, then? There is no simple answer at the moment and all the space players can do is ensure as little new debris is created as possible.

Prospero is still in orbit and next October scientists hope to re-contact it for its 40th anniversary. They won’t be able to examine those experimental surfaces but if they could I wonder what state they would be in now!

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FM: No Static At All

July 13th, 2010 | by | astronomy, communication, music, road transport, sound, space

Jul
13

Our car is still fitted with a cassette player. Albums from long ago (Steely Dan and Beatles are current favourites) provide regular entertainment on journeys and are also enjoyed by the younger members of the family. I suppose we should have moved over to a CD player or something more exotic still, but somehow it seems unnecessary while the cassettes hold out (now 25 years old plus and still working fine!)

8-Track audio tape

8-Track tapes like this one dominated the American in-car market between the 1960s and 1980s but were then killed off by the improved audio quality of the handy cassette. (Science Museum/Science & Society)

I suppose the same can now be said of the car’s FM radio, given government Culture Minister Ed Vaizey’s announcement last week that the digital radio switch-over will happen, but only when a vast majority of listeners have voluntarily adopted digital radio over analogue.

He went on to highlight in-car radio as one of the biggest challenges facing the digital switch-over. This because of the difficulty in receiving digital signals while moving at speed. Once again, why bother to spend money on new technology when the old still works just fine.  He threw down the gauntlet to the car manufacturers to work towards some solutions.

But, although we choose perhaps to forget it, this tendency to delay novelty in favour of that which already works is by no means uncommon.

Smoothwell electric iron, 1935

Smoothwell electric iron, 1935 (Science Museum/Science & Society)

Take another domestic technology – the electric iron: it’s changed little over at least 70 years. Neither, by and large, has the basic form of the bicycle, now well into its second century of pedalling.

Rover 'Safety' Bicycle, 1885
Rover ‘Safety’ Bicycle, 1885 (Science Museum/Science & Society)

And at the other end of the cost spectrum – we still use rockets adapted from 1950s inter continental ballistic missiles to launch satellites and probes into space – they exist, we know lots about them, they do the job – why fix things that aren’t bust?

A Delta 2 Rocket launches the Kepler space observatory in 2009

A Delta 2 Rocket launches the Kepler space observatory in 2009 (NASA/Regina Mitchell-Ryall, Tom Farrar)

So novelty is no guarantee of successful innovation. Maybe Steely Dan had something to say about it in one of the songs we were listening to in the car: ‘FM – No Static at All.’

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No Laughing Matter

July 6th, 2010 | by | chemistry, climate science, medicine, space

Jul
06

A Scientific Lecture, 1802

Gilray's 'A Scientific Lecture', 1802, depicts Humphry Davy 'bellowing' laughing gas

What have Humphry Davy, Mike Melvill and my dentist got in common? Answer: They’ve all exploited the chemistry of nitrous oxide, popularly known as ‘laughing gas’.

Davy experimented with euphoria-inducing properties of the gas with his friends Samuel Taylor Coleridge and James Watt. Davy was working at the Pneumatic Institution, set up by Thomas Beddoes to investigate the medical properties of inhaled or ‘factitous airs’. Davy pursued his experiments – part scientific, part recreational – with his normal con brio and was fortunate not to have seriously damaged his and others’ health.

Lucy Baldwin's Analgesic Apparatus, 1955-80

Lucy Baldwin's Analgesic Apparatus, 1955-80, mixed oxygen and nitrous oxide during midwifery (Science Museum/Science & Society)

My dentist, alongside doctors and medics, has long employed nitrous oxide as an analgesic, to relax patients and as a prelude to anaesthesia.

And Mike Melvill? Well, as pilot of SpaceShipOne, the world’s first privately developed spacecraft, he depended on its ability to oxidise rocket fuel for the thrust that carried him spaceward on his pioneering sub-orbital flight of 2004.

Dobson Ozone spectrometer, 1926

Dobson Ozone spectrometer, 1926. Dobson's technique for detecting ozone led to the discovery of the ozone hole over Antartica in 1985. (Science Museum/Science & Society)

So nitrous oxide has a variety of uses but it also has a dark side. Whether produced naturally or by industrial activity it leads to ozone depletion of the upper atmosphere. This lets in more of the Sun’s harmful ultra-violet radiation which the ozone molecules normally absorb. Plus, nitrous oxide acts as a particularly effective greenhouse gas, trapping the heat re-radiated from the Earth’s surface and causing global temperature rises.

No laughing matter indeed.

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From Planck to pigeon poo

July 5th, 2010 | by | astronomy, physics, quirky, space

Jul
05

The European Space Agency has just released the first all-sky map from the Planck satellite. The centre of the map is dominated by purple swirls from the dust around our Galaxy, but Planck’s main business is to look closely at the blobby structures visible in the map’s outer regions. These ’blobs’ show temperature fluctuations in the Cosmic Microwave Background (CMB), the remnant radiation from the Big Bang. Irregularities in the CMB became the seeds of today’s galaxies.

Planck's all sky survey (ESA, HFI and LFI consortia)

The fluctuations in the background radiation were first mapped by NASA’s COBE satellite, launched in 1989. An instrument on board also measured the CMB’s spectrum. FIRAS’s moving mirrors created interference patterns in a radiation beam, enabling the precise spectrum to be reconstructed. To the delight of scientists, the results perfectly matched the predictions of Big Bang theory.

This prototype mirror mechanism for the FIRAS instrument is on display in Cosmos & Culture (Science Museum).

The FIRAS prototype is on loan to us from the kind folks at the Smithsonian Institution’s National Air and Space Museum in Washington DC.  NASM’s display about the 1964 discovery of the microwave background features one of my favourite objects in any museum, anywhere. Arno Penzias and Robert Wilson initially thought that an annoying background hiss from their radio antenna was caused by pigeon droppings, and used this trap to try and capture the pesky critters. It turned out they’d accidentally found what other scientists had been looking for – the Big Bang’s echo.

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