Tag: orbital debris

The Future of Space Travel: Stamp-Sized Thrusters

MIT_microthrustersReducing the cost of space missions is one of the greatest challenges facing engineers and technicians today. With a myriad of planned missions, ranging from everything to a settlement on the Moon, sending satellites to Near-Earth asteroids, and manned missions to Mars, the goal of making space travel more affordable is a persistent and important one.

As it stands, most efforts are directed towards created craft that are either reusable, repurposed, or simply don’t rely on big, expensive and disposable rockets to get them into orbit. But another angle at bringing the cost of missions down is focusing on the size of the space craft themselves. If they could be shrunk down to the point where they are no larger than a paperweight, sending them into space could be done on the cheap.

cubesatAlready we are seeing this idea at work with CubeSats, a new breed of satellites that are roughly the size of a Rubik’s cube. Over the past decade, dozens of these satellites have been sent into space, often as part of University projects. Since most sensor and survey equipment is now small enough that it can fit into a shoebox, the CubeSat design is ideal for departments that cannot afford to mount multimillion dollar space missions.

Expanding on this concept, MIT’s Poalo Lozano, a professor and the director of the Institute’s Space Propulsion Laboratory, has unveiled a new type of “microthruster” which, when added to the scaled-down satellites, could radically reduce the cost of space missions even further.  Roughly the size of a stamp, these tiny ion-engines would prolong the use of satellites by ensuring they could maneuver in space.

CubeSatsUp until now, CubeSat’s have had a limited life expectancy as their orbits inevitably decay and they burn up in the Earth’s atmosphere. But by equipping them with an Electrospray Propulsion System (iEPS), these pint-sized satellites would be able to conduct life-saving maneuvers that would extend their period of service and give them new functionality.

The thrusters are basically a liquid-fuel system that, when a voltage is applied, emit a stream of ions through tiny nozzles that propel the satellite forward. According to Lozano, four of these thrusters could provide attitude control and main propulsion for standard solar-powered “1U” CubeSat, which measures about 10 centimeters (4 inches) on a side and weighs 1 kilogram (2.2 pounds).

europa-lander-2But more exciting are the long-term prospects created by the addition of these tiny thrusters. For the price of sending a large spacecraft, a fleet of CubeSats could be dispatched to explore the moons of Jupiter. Other possible missions include clearing the massive pile of orbital debris floating around the Earth, de-orbiting satellites at the end of their service lives, and correcting atmospheric drag in low Earth orbit.

Part of what makes plans like these so feasible is the fuel-to-weight ratio it allows for spacecraft, something which astronauts and space agencies always have to take into account. As the Space Propulsion Laboratory claims on their website:

Less than 150 g of propellant would be required by a 1U CubeSat to reach Earth’s escape velocity from [low Earth orbit] and explore interplanetary space.

cubesats2Other possibilities arise from the fact that iEPS units require very little in the way of fuel, so even scaled-up versions can be fitted to small satellites to provide cost-effective and fuel-efficient thrust. Scientists in Switzerland, for instance, say they can send a shoebox-size satellite to the moon in six months with only a few drops of fuel.

As Professor Lozano said, in regards to the long term plans for the iEPS concept:

The goal is to make [CubeSats] do most of the things we already do with big satellites, except in a less expensive way. People have very big plans for these very small spacecraft.

cubesats1But in reality, even the outer Solar System is not limit when it comes to this scaled-down satellite technology. Looking even further abroad, tiny satellites could be sent into deep space to map out what lies between our Solar System and other stars, or investigate the mysteries of the Milky Way. Asteroid prospecting could also benefit from small, cost-effective probes that are capable of navigating between rocks.

And when the technology is scaled down even further, perhaps even to the nano level, millions of tiny probes could be sent out into space to study dark matter, high-energy particles, and seek out new life. Combined with new technologies like space penetrators, entire solar systems and even galaxies could be seeded with tiny space sats. Exciting possibilities indeed!

And in the meantime, be sure to check out this video on CubeSat’s, courtesy of Singularity HUB:


Sources: news.cnet.com, web.mit.edu, singularityhub.com

Space Junk: The of Bane of the Space Age

janitorOneSpace, or at least the portion which sits in low orbit around our planet, is quite literally a junkyard. Currently, it is estimated that there over 500,000 bits of debris floating above our world, which takes the form of satellite and rocket components, as well as broken down satellites that ceased functioning long ago. Naturally, these objects pose hazards for space flight, and collisions between objects have been known to occur.

In fact, just three years ago, a U.S. and Russian satellite collided over Siberia, generating an estimated 1,000 pieces of new debris at least 4 inches across. In addition, the International Space Station has to periodically adjust its orbit just to get out of the way of traffic. And since exploration and commercial travel to and from the Moon is expected within the near future, something needs to be done to take the garbage out.

cubesatAnd that’s where CleanSpace One comes into play, a janitor satellite that the Swiss Space Center in the Swiss Federal Institute for Technology (EPFL) began developing last year. Specifically designed to target derelict satellites that threaten our communications and information networks. The satellite has a price tag of 11 million dollars, and is expected to be deployed in three to five years.

Naturally, the task before it is a tricky one. In order to do a “launch and seize” operation, the satellite would have to get onto the same orbital plane as its target, latch onto it at high speed, and then de-orbit it. To do this, EPFL is working on an “ultra-compact motor” to get the janitor onto the right track, as well as a grasping mechanism to grab hold of the space junk once its aligned and within distance of it.


And then there’s the efficiency factor. As it stands, a vessel like the CleanSpace One is a one-shot deal design. Once it’s latched onto space junk, it essentially re-enters the atmosphere with it and drops it below, meaning it is unable to gather up multiple pieces of debris and dispose of them discreetly. As such, it would take even a large fleet of janitor satellites quite a long time before they made a dent in all the space junk.

Luckily, there’s another option that has been on the table even longer than the janitor satellite. The reasoning behind this concept is, if you don’t the means to de-orbit all that space junk, just hit it with some photons! When you consider all the debris in orbit and the havoc it plays with the space lanes, not to mention how its only getting worse, a “targeted” approach may just be what the doctor ordered.

space_laserBack in 2011, James Mason, a NASA contractor at the Universities Space Research Association in Moffett Field, Calif., and his colleagues presented a paper claiming that an anti-collision laser system which would target space debris was feasible. Although they acknowledged that more study was required before it could be implemented, they also claimed that lab simulations suggested that the idea would work in practice.

The idea would center around the deployment of a medium-powered laser of 5 to 10 kilowatts to essentially nudge debris off a potential collision course. Rather than eradicate the junk that clutters up the space lanes, this system would be responsible for anticipated crashes and preventing them by ensuring space junk didn’t cross paths with the ISS, satellites, or orbiting shuttles.

space_debrisAnd even that doesn’t represent the entirety of proposed solutions. In addition to janitor satellites and laser, the Russian Space Agency has also been batting around an idea for an orbital pod that would sweep away satellite debris. Details remain sketchy and little information has been released to the public, but the RSA has claimed that they hope to have such a craft ready to go no later than 2023.

Yes, it seems we as a species are entering into phase two of the Space Age. And in this segment of things, orbital pods, offworld habitations, and exploration into the outer Solar System may very well be the shape of things to come. As such, we’re going to need clearer skies above our heads if anything hopes to make it off of Earth without a series fender bender!

space_debris_wide

Sources: news.cnet, cbsnews.com