Tiny bits of debris are a big problem in space, says Stanford professor in report on 'space junk'

Sep 07, 2011 By Louis Bergeron
The U.S. Air Force estimates that at any given time, there are about 22,000 pieces of debris 10 centimeters or larger in orbit around the Earth.

Many of us have too much junk shoved into our closets, but according to a report released Friday by the National Research Council, we Earthlings also have way too much junk orbiting our planet – and it is becoming a serious hazard.

Space debris – remnants of various human-made spacecraft, along with naturally occurring material, or meteoroids, shed by passing asteroids and comets – are threatening satellites and other spacecraft, as well as astronauts.

According to the U.S. Air Force, which is responsible for detecting and tracking human-made objects orbiting the Earth, at any given time there are somewhere in the neighborhood of 22,000 pieces of debris 10 centimeters or larger zipping along in orbit at speeds of seven kilometers per second.

Objects that large, moving that fast, can do serious damage to anything they hit. But Sigrid Close, an assistant professor of aeronautics and astronautics at Stanford, says there are billions of much tinier particles that can – and do – damage spacecraft, at roughly once per year – a number larger than that associated with space debris.

Close was a member of the 13-person panel that produced the report. She and Peter Brown, a professor of astronomy at the University of Western Ontario, wrote the section on meteoroids.

Meteoroids come in all different sizes, but most are usually tiny – weighing on the order of a billionth of a gram or less and measuring less than one five-hundredth of an inch – and Close has been studying them for years.

"One of the issues we raised was that everyone is focused on the impacts of the larger particles and nobody is looking at the mechanism for electrical failures and anomalies associated with small, fast particles, even though it appears as though this is how satellites are failing," Close said.

"This would occur from very fast-moving particles and could happen from particles as small as a nanogram. Why are spacecraft having anomalies during high-speed meteor showers?" The committee report recommended that NASA take the problem seriously.

Ivan Linscott, a senior Stanford researcher with Close's team, recently ran an experiment to try to detect radio frequency emission from plasmas, which are produced when a meteoroid or debris particle hits a spacecraft. Stanford Graduate students Theresa Johnson in aeronautics and astronautics and David Strauss in electrical engineering worked with Linscott. Their preliminary results suggest that radio frequency emissions are indeed produced when a particle weighing less than a billionth of a gram and traveling upward of 20 kilometers per second smacks into a spacecraft and produces ionization.

"Now the question is, what is the mechanism behind this? Can these emissions cause a satellite to fail or cause an anomaly on the satellite even when you never see a momentum transfer?" Close asked.

In other words, can a particle too tiny for its impact to be felt by a spacecraft still cause the spacecraft to malfunction?

That may sound like a question along the lines of, "If a tree falls in a forest and no one is around to hear it, does it make a sound?" But the answer to the meteoroid question has more than just philosophical implications, as the multibillion-dollar satellite and industry and NASA know all too well. Stay tuned for Close's further results.

Explore further: Orion spacecraft transfers to Launch Abort System Facility

add to favorites email to friend print save as pdf

Related Stories

Keeping astronauts safe from meteroids

Apr 01, 2011

Every day, about 100 tons of meteoroids bombard the Earth's atmosphere. These tiny particles can cause serious damage to spacecraft and astronauts alike. So how do we ensure the safety of space explorers and ...

Lunar Leonid Strikes

Dec 04, 2006

Meteoroids are smashing into the Moon a lot more often than anyone expected. That's the tentative conclusion of Bill Cooke, head of NASA's Meteoroid Environment Office, after his team observed two Leonids hitting ...

European space scout

Apr 01, 2011

The growing quantity of space debris is a serious threat to satellites and other spacecraft, which risk being damaged or even destroyed. A new European space surveillance system is being developed to ward ...

Recommended for you

NASA rocket has six minutes to study solar heating

2 hours ago

(Phys.org) —On Sept. 30, 2014, a sounding rocket will fly up into the sky – past Earth's atmosphere that obscures certain wavelengths of light from the sun—for a 15-minute journey to study what heats ...

Cassini watches mysterious feature evolve in Titan sea

17 hours ago

(Phys.org) —NASA's Cassini spacecraft is monitoring the evolution of a mysterious feature in a large hydrocarbon sea on Saturn's moon Titan. The feature covers an area of about 100 square miles (260 square ...

MOM eyes the limb of Mars after historic arrival

Sep 29, 2014

India's maiden interplanetary voyager, the Mars Orbiter Mission (MOM) has transmitted a breathtaking new image eyeing the limb of Mars and its atmosphere against the blackness of space.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

GDM
1 / 5 (1) Sep 07, 2011
I'm resonably sure NASA has done studies of small-particle, high-speed impacts on various target materials, but they have seen the results of a fleck of paint hitting a shuttle window. It's rather disturbing, anything larger might have taken the window out and caused the loss of the shuttle.
Nik_2213
not rated yet Sep 07, 2011
About time they orbited some fly-swatters, big blobs of aerogel constrained by netting, aka 'SplatNiks'...
Given that aerogels need freezing then vacuum evaporation, and the solvent is recycled, the ISS would seem to be a good place to make the stuff.
GDM
not rated yet Sep 10, 2011
Here is another presentation that is absolutely "on point"
http://www.star-t...Talk.pdf