NASA's Orbiting Carbon Observatory(OCO) prepared for its scheduled launch on Tuesday, February 24 2009 at Vandenberg Air Force Base in California. It had been seven years in the building and its purpose was to solve the mystery of the earth’s ‘missing’ carbon sinks, which have so far eluded detection by earth-bound instruments. But this important mission was not to be.
Minutes into the launch, the fairing enclosing the OCO satellite in the nose of the Taurus XL rocket failed to deploy properly, removing all chances of the satellite gaining orbit, and the multi-million dollar instrument ended up in the Southern Ocean. Failures of this kind are, fortunately, rare; though this sop will offer little consolation to NASA and the international team of OCO project collaborators whose hard work has apparently come to nought.
Rarer still are collisions between existing orbiting craft. The first widely reported incident of this nature occurred only last month when the US commercial ‘Iridium’ satellite collided with a defunct Russian ‘Cosmos’ military communications craft over Siberia. With an estimated 6,000 manmade satellites - from fully-functioning to spent hulk - currently in orbit around the earth, the risk of collisions and their ensuing hazards must surely become more cause for concern.
The US military authorities are said to track around 18,000 pieces of ‘space junk’ - a figure that suddenly jumped by an estimated 600 pieces of significant size (100mm diameter or more) following last month’s collision. Unknown are the countless numbers of much smaller particles that may have sufficient momentum to damage manned craft such as the International Space Station (350km above earth's surface), scientific instruments like the Hubble orbiting telescope (559km above the earth's surface) and, of course the Space Shuttle, which often needs to rendezvous with these craft. The official line is: the risk is “very small, though elevated”.
The NASA Orbital Debris Program (ODP) has been running for thirty years and is responsible for the detailed mapping and analysis of thousands of pieces of space debris in low earth orbit (up to 2,000km from earth’s surface) where the bulk of it exists.
According to the ODP, more than 190 manmade objects in earth orbit have undergone moderate to serious breakups since 1961, with another 50 undergoing “less energetic debris-producing events”. The debris from what NASA euphemistically terms “fragmentations” now accounts for over 45% of all space junk that has so far escaped destruction as a result of re-entry into the earth’s atmosphere. Only three of these fragmentations are known to have been caused by accidental collisions. The ODP believes the vast majority of them appear to have arisen from explosions involving residual propellants or other pressurised gases, battery malfunctions, self-destruction charges, or space defence trials.
We might be forgiven for being a little disconcerted at all these statistics, particularly as we enter the era of ‘affordable’ space tourism. While the vast, vast majority of us will not be tempted to spend a couple of hundred thousand dollars on the space equivalent of a ‘circuit-and-bump’, Virgin Galactic is expecting its ‘pioneering’ run to attract at least a thousand punters in the first year.
Admittedly, Virgin’s initial Galactic expeditions are unlikely to climb to more than a 110km above the earth’s surface, so perhaps low earth orbiting objects (generally well above 160km) are not a perceived danger. But as the appetite of wealthy individuals is whetted by these trips, I suppose we must expect deeper excursions into the earth’s exosphere.
Meanwhile, on terra firma, scientific instruments designed to probe deeply beyond our galaxy probably stand a better chance of survival than their orbiting counterparts. Cambridge Consultants recently signed a framework agreement with the University of Oxford to provide design services to the Square Kilometre Array (SKA) programme, an international project to develop the world’s largest earth based telescope.
When completed in 2020, the SKA radio telescope will be thousands of times more powerful than the existing radio telescopes at Green Bank in the US and Jodrell Bank in the UK. With a collecting area of one million square metres, the compact core of the instrument will comprise more than half of the telescope’s antennas and a major supercomputer installation for processing the signals. Spiralling out from the core, further antenna stations will extend out to 3,000 km across a continent.
The revolutionary design includes an all-electronic system of 250 ‘aperture array’ stations, each of which will be composed of tens of thousands of small antennae fixed to the ground. And unlike traditional parabola dishes, this sophisticated system can produce many beams for unprecedented flexibility and performance limited only by the processing power available.
Women in engineering
Just before this week's newsletter was finalised, the IET announced the winner of the Young Woman Engineer of the Year Award, a competition which it has run in conjunction with various sponsors for the past 30 years. She is Hanna Sykulska, a 26 year old from Oxford who has been working at Imperial College's Electrical Engineering Department for the past four years. The runner up was Bijal Thakore, global client development and technical consultant at LEGO Systems in Denmark. She was awarded the Womens' Engineering Society Prize.
Three other finalists included Katie Lester, a 20 year old from Southend who is currently undertaking an apprenticeship with RWE N-Power; she is awarded the Mary George Memorial Prize for Apprentices. Elaine Hislop, a 21 year old Glaswegian who works as a technical apprentice at BVT Fleet was awarded the Womens' Engineering Society Doris Gray Award. Last, but by no means least, Laura Campbell a 25 year old from Glasgow who has just completed a two-year graduate programme at BVT Surface Fleet, was awarded the Special Prize for Merit.
We extend our warmest congratulations to all five finalists.
Les Hunt
Editor
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