Space garbage men: Tracking the movement and spin of orbiting space junk

When we are in the process of colonising space, or even getting out of our Earth’s orbit, there will be a danger of the rubbish circling the planet damaging spacecraft or even stopping us getting away from the planet.

Previously NASA has said that the amount or trash that is in orbit around the world includes more than 500,000 objects. 

It has even gone as far as to say that we have lost control of the environment. 

Now researchers from MIT, in a DARPA funded project, have concocted an algorithm tested at the International Space Station that will help the space rubbish collectors of the future to do their jobs.

It allows them to track the movement and rotation of an object in space.

The algorithm is intended to allow those in space to see how a piece of debris, or one day something as big as a comet, is spinning in space.

Being able to track its movements accurately will allow those who are going to remove it from space to be able to do so safely.

Alvar Saenz-Otero, from MIT, explained the importance of being able to predict the movements: “There are thousands of pieces of broken satellites in space. If you were to send a supermassive spacecraft up there, yes, you could collect all of those, but it would cost lots of money.

“But if you send a small spacecraft, and you try to dock to a small, tumbling thing, you also are going to start tumbling. So you need to observe that thing that you know nothing about so you can grab it and control it.”

The algorithm uses only visual information, and was deployed using MIT’s SPHERES project, which is focused on using herds of volleyball-sized satellites to help humans on future space missions.

When testing the algorithm in space, one SPHERES satellite spun in place while another photographed it.

The algorithm needs to use trial and error to build up a visualisation of the object and accurately be able to track and predict its movements.

When developed further, it may be able to help humans – or robots – be able to capture the rubbish that is circling the Earth.

nasa2

The issue of how we can tackle space debris is one that has been discussed for many years and although a situation like that in the movie Gravity is probably unlikely to occur, the issue still needs to be tackled.

In 2009 a DARPA study said that “debris mitigation alone will not be sufficient to prevent a continual increase in the number of debris objects.”

Japan’s space agency JAXA was set to launch a spacecraft with a giant magnetic net to collect debris orbiting the earth.

Tackling the issue of space trash in the Earth’s orbit is crucially important as if it keeps on growing then it could prevent the launch of future space missions and also endanger working satellites that are in orbit.

If it is not dealt with then it may also give rise to the Kessler Syndrome, a theory created in the late 1970s by Donald Kessler, which says that once derbris in orbit collides it will create a chain reaction of more debris and then more collisions.


Featured image and image two courtesy of NASA


Space elevators: Sci-Fi dream or future reality?

issue-3-top-promo

Space elevators have existed as a concept for more than a century, but without sufficient material technologies they have been relegated to the world of science fiction.

However, this could be set to change, as the idea is seeing renewed interest from commercial companies.

Simply put, a space elevator is system that runs from a point on the Earth’s equator right up past geostationary orbit to a counterweight located in space.

These two points are connected by a 100,000km long tether – a very thin ribbon-like material with enough strength to maintain the connection while supporting 20t of cargo.

Attached to the tether is some form of pulley system that would allow cargo – and humans – to move easily into space, without the need for rockets to escape the clutches of Earth’s gravity.

Such a system would be revolutionary, turning space travel into a relatively low-cost endeavour and greatly increasing the number of people who could leave Earth. Estimates by the International Academy of Astronautics (IAA) even suggest that the cost- per- kilogram of launching items into space could drop from the current rate of $20,000 to the bargain price of $500.

“It could take you from ground to orbit with a net of basically zero energy. It drives down the space-access costs, operationally, to being incredibly low,” explained Google X rapid evaluation team leader Richard DeVaul in an interview with Fast Company.

shutterstock_98812298

A Matter of materials

The biggest issue that is preventing the development of space elevators is the lack of a suitable material to function as a tether.

Earlier this year it emerged that Google X, the technology giant’s secretive research lab for extreme future technologies, had undertaken serious research to determine if development of space elevators was feasible.

Their conclusion was that the tether needed to be at least 100 times stronger than the best steel ever developed, and only one material fitted the bill: carbon nanotubes.

Unfortunately, material science is still working on making carbon nanotubes long enough; at present the most that has been achieved is 1m, a far cry from the 100,000,000m needed.

However, materials science is seeing something of a revolution at present, which is accelerating the development of a whole host of nanoscale materials.

Carbon nanotubes in particular have already been recognised as a key material for a slew of applications across electronics, medicine, energy generation and the military, so there is likely to be strong long-term support for research.

It is quite possible, perhaps even likely, that the generation of suitably long carbon nanotubes is just a matter of time.

shutterstock_93165985

Finding a timescale

How long it will be before space elevators are possible to build is a matter of considerable debate.

The International Academy of Astronautics IAA recently released a report outlining the value and challenges of space elevators, in which the organisation argued that the technology could be possible by 2035. For many, however, such an ambitious estimate is way off the mark.

Peter Debney, engineer for global construction firm Arup, believes the technology is on its way, but will take far longer to be realised.

“I believe that they could be built cost-effectively within a century, and pay for themselves within just a few years,” he said in a post on the company’s website.

“While we have not quite got all the technology in place, and there are still engineering challenges to be overcome, the space elevator has nearly arrived.”