Podcaster: Richard Drumm
Title: Space Scoop: Not All Those Who Wander Are Lost
Organization:365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1702/
Description: Space scoop, news for children
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Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is the 365 Days of Astronomy Podcast. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Not All Those Who Wander Are Lost
We’ve all heard it, and probably said it more than once: It’s not rocket science!
But, sometimes it IS rocket science, or science about spacecraft. These areas of science are notoriously difficult to get right and are very risky, but when everything works right they provide huge rewards.
In 2014, a comparatively tiny, 67 kilogram, spacecraft called PROCYON was launched into space. Procyon is the name of the brightest star in the constellation Canis Minor, but the spacecraft’s name stands for Proximate Object Close flYby with Optical Navigation.
Yeah, let’s just keep calling it PROCYON.
It had 2 missions:
The first mission was a test of the micro-spacecraft bus, the body of the probe, with all the communications, attitude controls, propulsion systems, star & Sun sensors and solar arrays.
PROCYON’s second mission was to fly past and study the binary asteroid 2000 DP107. The ion engine worked flawlessly for over 2 weeks but failed and the spacecraft became lost in space.
OK, not all THAT lost. JAXA, the Japanese Space Agency, knew where the probe was, they just couldn’t restart the main engine. So it’s wandering along in an orbit around the Sun.
The cold-gas attitude control thrusters were OK, so they could point the spacecraft’s instruments at targets just fine. And these thrusters had access to all of the Xenon fuel that the main engine would have used.
And JAXA is sure that they know what happened to the ion engine. They think that a small chip of metal left over from the construction of the spacecraft floated around in microgravity and got stuck in the electrical controls of the engine, shorting it out.
Since then, PROCYON has been put to work studying the Sun instead of the asteroid it was supposed to study. It’s a fairly low cost mission, having cost 500 million Yen, or about 4.4 million US dollars to build.
Launch costs were minimal as the PROCYON payload was able to piggy-back on the Hayabusa 2 mission launch. So they had a working spacecraft that needed a new mission.
The spacecraft has 2 instruments it can study a target with:
– An optical telescope of 50mm aperture to be used for navigation & imaging of the asteroid during the fly-by,
and the, uh, star of this show:
– LAICA, the Lyman Alpha Imaging CAmera intended for imaging Earth’s so-called “geocorona”, the luminous outermost part of our atmosphere.
Sunlight is reflected off neutral hydrogen gas in the ultraviolet part of the spectrum and this camera takes a picture in that invisible color of light.
The American physicist Dr. Theodore Lyman studied the spectroscopy of hydrogen gas and in 1906 discovered a series of spectral lines in the far ultraviolet, a series of lines that bear his name to this day. The lines are given greek letter designations, alpha, beta, gamma and so on. The LAICA camera just studies the lowest frequency line, the Lyman alpha line.
And then in September 2015, the Rosetta spacecraft was flying alongside the comet 67P/Churyumov-Gerasimenko. It was the last few weeks of Rosetta’s mission and they were flying close to the Sun.
Comets are commonly known as ‘dirty snowballs’ because they are made largely of ice and cosmic dust. When they travel too close to the Sun they heat up and some of their ices sublimate, or turn directly into gas without passing through a liquid phase.
This creates the striking ‘tail’ we often see. It also creates a foggy cloud around the comet called a ‘coma’.
Rosetta spent it’s last few weeks engulfed inside the coma, too close to the center to see the shape and size of the coma as it changes. You know, it’s a “Can’t see the forest for the trees!” kind of thing.
Unfortunately, when the comet passed by the Earth the observing conditions were bad, so telescopes on the ground couldn’t get a clear view of the coma either.
Luckily, PROCYON came to the rescue, providing observations of the comet’s coma from space. The results told us what the comet is made of and how much water it’s losing in the heat of the Sun.
It’s long been thought that water might first have been brought to Earth, billions of years ago, by impacting comets. Studying Comet 67P may help us figure out whether this is true.
PROCYON is called a micro satellite due to its tiny size – it’s slightly larger than a microwave and weighs about as much as a washing machine. This is the first scientific discovery made in deep space by such a small, cheap satellite.
Hey, Here’s A Cool Fact:
The original main objective of the LAICA telescope was to take wide field images from deep space of the Earth’s Lyman Alpha geocorona and geotail. The geotail is the part of the geocorona that has been pushed away by solar radiation pressure.
The goal was to supplement images originally taken during the Apollo 16 mission by a UV telescope the astronauts set up on the Moon in 1972.
The designer of this instrument was Dr. George R. Carruthers, a black physicist who was working at the NRL, the Naval Research Laboratory in Washington, DC.
That far ultraviolet telescope, with its 3″ diameter rhenium mirror, is still sitting there on the Moon. The images it acquired were captured on film, which was returned to Earth for processing.
The instrument studied more than Earth’s atmosphere, ionosphere and aurorae, though. The astronauts also pointed the scope at various nebulae, star clusters and the LMC, the Large Magellanic Cloud.
We at 365 Days of Astronomy, CosmoQuest and Astrosphere New Media salute you, Dr. Carruthers, on this Black History Month.
Thank you for listening to the 365 Days of Astronomy Podcast!
End of podcast:
365 Days of Astronomy
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