TEPCE...

Image source: Futurism/Dan Robitzski

Topics: Astrophysics, Instrumentation, Space, Space Junk

A massive cloud of space junk—containing more than 23,000 pieces larger than 10 centimeters across—is currently zooming around Earth with an average speed of about 36,000 kilometers per hour. And as companies such as SpaceX and OneWeb plan to launch tens of thousands of new satellites over the next few years, this hazardous clutter will likely pose an increasing threat to space missions and astronauts. One possible solution may be an electrodynamic tether, a device that could help prevent future satellites from becoming abandoned wrecks. The U.S. Naval Research Laboratory plans to test this technology in the next few weeks.

In early November the Tether Electrodynamic Propulsion CubeSat Experiment (TEPCE), already in orbit, is set to make its move under the watchful gaze of telescopes on the Hawaiian island of Maui. The Earth-bound control team is waiting for an ideal 10-minute period at dawn or dusk, when the dim sunlight will offer the best possible view of the shoe box-size spacecraft involved. Once the crew triggers the process, TEPCE should separate into two identical minisatellites joined by a kilometer-long tether as thick as several strands of dental floss. If deployment goes smoothly, the mission can observe how the tether interacts with Earth’s magnetic field in the ionosphere (where much of the space junk orbits) to change the satellites’ velocity and orbit; the results could possibly enable future spacecraft to move around while orbiting Earth—without having to carry unwieldy chemical propellant.

“In other words, it is the sailing ship of space,” says Enrico Lorenzini, a professor of energy management engineering at the University of Padova in Italy, who is not involved in the TEPCE mission. But instead of wind, the electrodynamic tether technology moves thanks to the physical laws that govern electric and magnetic fields. A tether in Earth’s ionosphere—an upper atmospheric layer filled with charged particles such as free electrons and positive ions—can collect electrons at one end and emit them at the other, generating an electric current through itself. The electrified tether’s interactions with Earth’s magnetic field produce an impetus known as the Lorentz force, which pushes on the tether in a perpendicular direction.

Kilometer-Long Space Tether Tests Fuel-Free Propulsion
Jeremy Hsu, Scientific American

Orbital WALL-E...

Image Source: Figure 3 Debris engine, see link below

Topics: Astrophysics, Instrumentation, Space, Space Junk, Taikonaut

I am always glad when good science is proposed and achieved. This is mostly a thorough application of Kepler and Newtonian physics as well as engineering rocketry. I give the poignant observation with some exception, this is happening LESS in the country of my birth, currently known for carnival barkers and xenophobes as presidential front runners, and some of my fellow citizens thinking "The Flintstones" instead of a parody of "The Honeymooners" was a documentary.

TECHNOLOGY REVIEW: At 16:56 UTC on August 29, 2009, an Iridium communications satellite suddenly fell silent. In the hours that followed, the U.S. Space Surveillance Network reported that it was tracking two large clouds of debris—one from the Iridium and another from a defunct Russian military satellite called Cosmos 2251.

The debris was the result of a high-speed collision, the first time this is known to have happened between orbiting satellites. The impact created over 1,000 fragments greater than 10 centimeters in size and a much larger number of smaller pieces. This debris spread out around the planet in a deadly cloud.

Space debris is a pressing problem for Earth-orbiting spacecraft, and it could get significantly worse. When the density of space debris reaches a certain threshold, analysts predict that the fragmentation caused by collisions will trigger a runaway chain reaction that will fill the skies with ever increasing numbers of fragments. By some estimates that process could already be underway.

An obvious solution is to find a way to remove this debris. One option is to zap the larger pieces with a laser, vaporizing them in parts and causing the leftovers to deorbit. However, smaller pieces of debris cannot be dealt with in this way because they are difficult to locate and track.

Another option is send up a spacecraft capable of mopping up debris with a net or some other capture process. But these missions are severely limited by the amount of fuel they can carry.

Today, Lei Lan and pals from Tsinghua University in Beijing, China, propose a different solution. Their idea is to build an engine that converts space debris into propellant and so can maneuver itself almost indefinitely as it mops up the junk.

Physics arXiv: Debris Engine: A Potential Thruster for Space Debris Removal
Lei Lan, Jingyang Li, Hexi Baoyin

#P4TC WALL-E mentions:
Predicted, but still kind of gross when you think of it...
NASA Going Green...

WT1190F...

The object is only 1 to 2 meters in size, and its trajectory shows that it has a low density, and is perhaps hollow. That suggests an artificial object.

Credit: Johannes Gerhardus Swanepoel ©iStock.com

Topics: Economy, Jobs, Space Exploration, Space Junk

As I said in the post "Space Faring Species":

"Space Junk: Not a sexy topic, but we've been chucking things to the Clarke Orbit since Sputnik. There's a lot of debris floating above us, and with the right training, the opportunity to employ people and possibly recycle the metals and materials used to build probes that outlive their usefulness and technology." Now's a good time to start thinking about the subject.

Researchers call it sheer coincidence that a newly discovered piece of space junk is officially designated WT1190F. But the letters in the name, which form the acronym for an unprintable expression of bafflement, are an appropriate fit for an object that is as mysterious as it is unprecedented.

Scientists have worked out that WT1190F will plunge to Earth from above the Indian Ocean on November 13, making it one of the very few space objects whose impact can be accurately predicted. More unusual still, WT1190F was a 'lost' piece of space debris orbiting far beyond the Moon, ignored and unidentified, before being glimpsed by a telescope in early October.

Scientific American:
Mysterious Space Junk Will Plunge to Earth in November
Traci Watson and Nature Magazine

Space Faring Species..

CGI by XIXO

Topics: International Space Station, Moon Base, NASA, Space Exploration, Spaceflight, Space Junk, Tribalism

In no particular order - inspired by both Interstellar and The Martian - this is a purely speculative post regarding becoming a space faring species, i.e. no longer confined to Earth and what that could possibly mean. A math nerd note: Jessica Chastain and Matt Damon are the Venn diagram intersection points of both space opera features. I have no qualifications other than a STEM background, enthusiasm, imagination and wonder.

International Space Station: Some projections have it going beyond 2020, and it is international with 15 member nations participating. It's not only the longest-running science experiment on human endurance, it's the best thing we have so far of mutual cooperation, the UN notwithstanding.

Moon Base: This is a possibility, only in the fact the moon has far less gravity than on Earth, therefore it would be easier to launch vehicles into space from here. The caveat is radiation from the sun and far-away sources in the form of cosmic rays and meteors - some really big, and others the size of boulders. A sturdy, 3-D printed domicile for mostly surface sensors would have to be piezoelectric - perhaps a combination of lead zirconate titanate and titanium. The humans could use volcanic caverns underneath that could be made reasonably habitable. Launches from platforms beneath the surface would be just as easy as on the surface with bay doors made of the same previously speculated material.

NASA: The agency and its viability will last as long as we have the vision to fund it. The spin off technologies fuel economies, and if the United States didn't do that, European or Asian countries are more than poised to take the lead in that sphere, and profit from the venture. This will create jobs for their fellow countrymen in an ever-changing employment landscape.

Space Exploration: A lot is made of Exoplanets in the Goldilocks habitable zone, but not much regarding Exomoons: like our own companion, a moon or moons in orbit would stabilize a planet's climate, giving it predictable seasons that are hopefully suitable for us as well. In the movies Interstellar and The Martian, since we can't create artificial gravity like Star Trek, parts of our spacecraft (as each illustrated quite well) will have to rotate, using centrifugal force to create surfaces on a rotating ring, or in a Bernal Sphere in a planet's geosynchronous orbit so we can stand up and bear our own weight. Experiment Example: Take a bucket of water with a wire handle and attach the handle to a rope. Fill it halfway with water and swing it above your head by the rope - I promise as long as you're swinging it, you won't get wet (that will likely happen when and how you stop). This of course, eliminates the great space battles we've come to thrill to in the movies - in light of our aggressive tendencies, I don't think this is a bad idea, really. Part of what we've learned so far is that in a weightless environment, astronauts loose bone density and muscle mass very rapidly. It is also a good thing if you're going to have deep space missions whereby it may take a few lifetimes to get to say, Alpha Centauri. Newton's Third Law of motion is the likely reason despite attractions astronauts in weightless environments have never been as "frisky" as Captain Kirk or Commander Riker. It would be...awkward.

Spaceflight: Voyager leaving our solar system (or, at least the heliosphere of the sun) actually made us officially an interstellar space faring species! I don't think the transition was appreciated much by the media. I know EVERY Trekkie wants to go warp drive! However, we're not even at the level as a species just yet to generate a craft going at 0.10 c (one-tenth the speed of light) that would have us to Alpha Centauri - if it has habitable planets - in about 40 years. Hence the need for using Newton's Third Law to our advantage! This star ship would have to be shielded from cosmic radiation and meteorites (tricks we'd have learned from our Moon Base). Either fission, fusion or a very large solar powered sail would propel our craft. The sail would have to be propelled by lasers or masers we'd bring with us. For those of you that are interested, the 100 Year Star Ship project by former NASA astronaut Dr. Mae C. Jemison may give you vision for at least our great-grandchildren making the journey.

Popular Mechanics - How To Build a Starship

Space Junk: Not a sexy topic, but we've been chucking things to the Clarke Orbit since Sputnik. There's a lot of debris floating above us, and with the right training, the opportunity to employ people and possibly recycle the metals and materials used to build probes that outlive their usefulness and technology. Subset: We have a lot of Earth junk we need to clean up, both physical and atmospheric. I've often said, before we attempt Terraforming another planet, we ought to try Terraforming Earth.

Tribalism: We're in a special time in human history I kind of talked about in Terms of Indifference. This is the basis of our historic and current woes; geopolitics has always balanced on a knife's edge, especially as many of us long for a nostalgic utopia (literally "nowhere place") that never was, fearing constantly what's ahead. Many are resorting to either political fiat or violence to realize their vision on their respective populations using authoritarian means that inevitably restrict the rights of certain groups. The past cannot change, nor is time travel (except in certain relativistic cases) possible, but the future - relentlessly coming - we can plan for. "Failure to plan is planning to fail."

As things come to light, now briny water on Mars may point to a life form: a closer microscopic analysis of the Martian salt water might have a Tardigrade/Water Bear staring back at us! Such a discovery would change our collective history, our culture, our poetry and literature; our sense of ourselves. Part of being a space faring species would hopefully break down the artificial barriers we've erected separating us from our fellow humans. On a Martian or Moon Base - I've wondered - if you're an Imam conducting prayers: what then would be your reference to Mecca? Or, for any of the various human faiths, a large part of their identity is "where" they began, as then the humans there said: "we are the people of"... As more of us experience the Overview Effect, like our astronauts - a very limited group for now - more of us (I hope) will view the whole Earth as our home; ourselves as Earthlings.

About That Death Star...

The proposal, which was announced by press release and press conference, comes from cosmologist Philip Lubin of the University of California at Santa Barbara and engineer Gary Hughes of California Polytechnic State University. Calling it a Death Star immediately makes the idea sound both sexy and goofy. The researchers use the term Directed Energy Solar Targeting of Asteroids and exploRation (DE-STAR), which isn’t much better. Setting aside the name, though, the idea is interesting.

Lubin and Hughes envision building a scalable, phased array, space-based laser system, powered by large solar panels. Solar power is abundant and uninterrupted in space; developing large, lightweight photovoltaic arrays would be a useful technology for future space stations or power-hungry scientific experiments. Laser beams could be useful for characterizing the composition of near-earth asteroids, and for conducting experiments on how laser heating or laser vaporization could alter an asteroid’s orbit. And phased arrays are an intriguing way to create a steerable light beam from a flat surface without turning it.

Discovery: The Case for Building a Death Star

Predicted, but still kind of gross when you think of it...

Where's WALL-E when you need him?

The Air Force has a commercial of a satellite avoiding collision with debris involving an impressive maneuver, but after 4,500 or so launches, I'm not holding my breath that we won't have a communications satellite dented by all this space stuff.  Newton's Laws of Motion dominate orbital physics.  Plus, if we don't solve our debris in orbit, it could halt space missions  for generations.

Discovery Magazine online: The Trouble With Trash

'78 paper on: The Kessler Effect