Shuttle to reel out satellite on 12-mile line

AT THE turn of the century, Konstantin Tsiolkovsky, a Russian schoolteacher and space pioneer, proposed a 'cosmic railway' built from tethering a ring of unbelievably high towers - anchored to the ground - together in space.

The first real practical test of his ideas will come later this month, when one of the most dangerous experiments in space begins with the launch of a space shuttle that will reel out a satellite on a thin line 12 1/2 miles long.

The experiment will test the feasibility of using extremely long tethers in space, but scientists at the US National Aeronautical and Space Administration are nervous about what may happen if the satellite and line start swinging out of control.

The science fiction author Arthur C Clarke, writing 70 years after Tsiolkovsky, suggested that space tethers could be used to form a ring of satellites around the planet, with 'space elevators' taking people for rides in space. 'The distinction between Earth and space would be abolished, though the advantages of either could still be retained,' he wrote.

But it was an Italian space engineer, Giuseppe Colombo, who gave the ideas of tethered objects in space a firm practical basis. Colombo, who died in 1984, moved from Padua University in the late 1970s to Nasa's Goddard Institute in New York, where he proposed that tethers could be used to build giant structures, such as space stations, in orbit.

It is largely Colombo's ideas that have led Nasa, in conjunction with the Italian space agency, to test its first tethered satellite system, TSS-1, to be launched on 31 July on board the shuttle Atlantis.

The seven-strong crew will reel out the tethered satellite into a higher orbit - considered safer than lowering it into the rarefied atmosphere of Earth below.

Explosive bolts and other safety measures are ready to jettison the tethered satellite should the 'skip-rope effect' become uncontrollable. 'It's a squishy subject,' said Dave Bowlan, a Nasa scientist. 'We don't really know what will happen until we try.'

Nasa's tether, a mixture of copper wire, nylon and carbon fibres, is only a tenth of an inch in diameter but it can support 400lb. Even so, in the near weightlessness of the shuttle's orbit it is expected to experience a tension of no more than 15lb, despite being connected to a 100-ton shuttle and its one-ton satellite.

Nevertheless, there are plans for a second TSS mission, which involves lowering a tethered satellite below a shuttle to sample the upper regions of Earth's atmosphere. At this altitude the air is extremely rarefied, and as a result is much too high for the air- breathing engines of conventional aircraft. However, because there is enough air to cause quite severe aerodynamic drag, it is too low for a satellite to keep orbiting.

Scientists envisage testing the aerodynamics of future space planes by towing models from a shuttle overhead.

Even further into the future, there are tentative proposals to tether large landing platforms - 'shuttle ports' - to space stations orbiting high above. Space elevators would take crew and cargo from one to the other, cutting down on fuel.

If the tether is spring-loaded, it would absorb the shock of shuttles landing and taking off from the platform and prevent the space station from being disturbed too much.

Tethers from the space station, or other shuttles, could also take communications satellites or weather satellites into very high orbits at a fraction of the cost of getting them there using rockets.

Fuel depots tethered high overhead could be refuelled from below with the fuel taken up via the elevators. Nasa also envisages that two tethered objects could be spun around 'much like a set of bolas' to create artificial gravity - another fantasy of science fiction writers.

A further reason for using tethers is that they can be used as giant antennas to transmit radio signals around the globe. The mission later this month will use its tether as a rudimentary radio transmitter to test the idea.

Perhaps the most interesting phenomenon the TSS-1 experiment will test is whether it is possible to generate electricity as the tethered satellite and shuttle move through the Earth's magnetic field at 17,000mph.

Just as a dynamo generates electricity by the movement of wires in a magnetic field, so the tether - with its copper wire - is expected to produce up to 4 kilowatts of power as it hurtles through the Earth's field.

The generation of electricity also means that electrons will flow from the satellite on the end of the 12-mile line down the tether and on to the shuttle, causing it to become negatively charged. An unanswered question is whether enough electrons will jump off the shuttle to return to the positively charged satellite through the charged ionosphere of space.

Electron guns, which fire negative charge from the shuttle and the tether into the ionosphere, are ready to help complete the electric circuit and prevent a build-up of static electricity on the shuttle. If the experiment proves successful, scientists believe it may be possible to use tethers as the electrical generators of future space missions.

Suggested Topics
More than 90 years of car history are coming to an end with the abolition of the paper car-tax disc
newsThis and other facts you never knew about the paper circle - completely obsolete tomorrow
people'I’d rather have Fred and Rose West quote my characters on childcare'
Kim Jong Un gives field guidance during his inspection of the Korean People's Army (KPA) Naval Unit 167
newsSouth Korean reports suggest rumours of a coup were unfounded
Arts and Entertainment
You could be in the Glastonbury crowd next summer if you follow our tips for bagging tickets this week
Have you tried new the Independent Digital Edition apps?
ebooksAn unforgettable anthology of contemporary reportage
Arts and Entertainment
Kylie performs during her Kiss Me Once tour
musicReview: 26 years on from her first single, the pop princess tries just a bit too hard at London's O2
peopleSwimmer also charged with crossing double land lines and excessive speeding
Arts and Entertainment
A new Banksy entitled 'Art Buff' has appeared in Folkestone, Kent
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Senior Marketing Manager - Central London - £50,000

£40000 - £50000 per annum: Ashdown Group: Marketing Manager (Campaigns, Offlin...

Head of Marketing - Acquisition & Direct Reponse Marketing

£90000 - £135000 per annum: Ashdown Group: Head of Marketing (B2C, Acquisition...

1st Line Service Desk Analyst

£27000 - £30000 Per Annum: Clearwater People Solutions Ltd: Our client who are...

Trainee Recruitment Consultant - Birmingham - Huxley Associates

£18000 - £23000 per annum + Commission: SThree: Huxley Associates are currentl...

Day In a Page

Isis is an hour from Baghdad, the Iraq army has little chance against it, and air strikes won't help

Isis an hour away from Baghdad -

and with no sign of Iraq army being able to make a successful counter-attack
Turner Prize 2014 is frustratingly timid

Turner Prize 2014 is frustratingly timid

The exhibition nods to rich and potentially brilliant ideas, but steps back
Last chance to see: Half the world’s animals have disappeared over the last 40 years

Last chance to see...

The Earth’s animal wildlife population has halved in 40 years
So here's why teenagers are always grumpy - and it's not what you think

Truth behind teens' grumpiness

Early school hours mess with their biological clocks
Why can no one stop hackers putting celebrities' private photos online?

Hacked photos: the third wave

Why can no one stop hackers putting celebrities' private photos online?
Royal Ballet star dubbed 'Charlize Theron in pointe shoes' takes on Manon

Homegrown ballerina is on the rise

Royal Ballet star Melissa Hamilton is about to tackle the role of Manon
Education, eduction, education? Our growing fascination with what really goes on in school

Education, education, education

TV documentaries filmed in classrooms are now a genre in their own right
It’s reasonable to negotiate with the likes of Isis, so why don’t we do it and save lives?

It’s perfectly reasonable to negotiate with villains like Isis

So why don’t we do it and save some lives?
This man just ran a marathon in under 2 hours 3 minutes. Is a 2-hour race in sight?

Is a sub-2-hour race now within sight?

Dennis Kimetto breaks marathon record
We shall not be moved, say Stratford's single parents fighting eviction

Inside the E15 'occupation'

We shall not be moved, say Stratford single parents
Air strikes alone will fail to stop Isis

Air strikes alone will fail to stop Isis

Talks between all touched by the crisis in Syria and Iraq can achieve as much as the Tornadoes, says Patrick Cockburn
Nadhim Zahawi: From a refugee on welfare to the heart of No 10

Nadhim Zahawi: From a refugee on welfare to the heart of No 10

The Tory MP speaks for the first time about the devastating effect of his father's bankruptcy
Witches: A history of misogyny

Witches: A history of misogyny

The sexist abuse that haunts modern life is nothing new: women have been 'trolled' in art for 500 years
Shona Rhimes interview: Meet the most powerful woman in US television

Meet the most powerful woman in US television

Writer and producer of shows like Grey's Anatomy, Shonda Rhimes now has her own evening of primetime TV – but she’s taking it in her stride
'Before They Pass Away': Endangered communities photographed 'like Kate Moss'

Endangered communities photographed 'like Kate Moss'

Jimmy Nelson travelled the world to photograph 35 threatened tribes in an unashamedly glamorous style