Tue November 27, 2012
Small Satellites from Utah Help Measure Impact of the Sun's "Ejections" Toward Earth
Imagine a spacecraft as light as your laptop and small enough to fit in your hand. Small satellites, ranging in size from a smart phone to a loaf of bread, are making access to space cheaper and faster. They typically cost 100 times less than traditional satellites that are as large as a school bus.
Small sats are being built for a plethora of practical uses including the ability to quickly zoom in on potential catastrophic weather systems like hurricanes, floods, and earthquakes. And for studying solar storms that can disrupt everything from communications to airline navigation and GPS systems.
According to Pat Patterson, Director of the Space Dynamics Laboratory Military Space Division at Utah State University, small sats are also making a difference on the ground in the classroom.
"Probably the biggest assistance that small satellites have provided has really been as a training tool to university students because they can do hands-on work on these small space craft. In 2 or 3 years in school they can start with design, build-up of the thing, testing, all the way to the launch vehicle. These bigger spacecraft takes many many years so a student can't get through a whole cycle in the time they're at a university."
"It's been awesome to learn something in class and to be able to physically apply it. I started out doing the mechanical design. I helped hand wind tort coils and doing the program management and writing software for our ground station," says Eric Stromberg, one of a dozen graduate students at Utah State University, who worked on the project called DICE, which stands for Dynamic Ionosphere Cube-Sat Experiment.
DICE is orbiting the earth's upper atmosphere. It consists of two identical spinning satellites that are taking measurements of the density and magnetic strength at a particular point in space to ultimately create a 3 dimensional map of the space environment. The goal is to learn more about magnetic storms caused by solar flares from the sun.
Chad Fish is the space environment manager at the Space Dynamics Lab: "The earth has a magnetic field around it and it's actually a protective barrier around from what comes out of the sun. These spacecraft can be affected, they can be charged up or they can have trouble communicating with the ground, so our mission is to help understand what is going and to help what is going to go on in the future."
The sun is made up of plasma -- hot ionized gas -- interlaced with a maze of magnetic fields. The core of this fiery star is 27 million degrees. This massive furnace makes a lot of noise. This is the sound of its vibrations rippling across the surface, recorded by NASA. It pulsates to set rhythms, ranging from an 11 year solar flare cycle to other ones that span centuries.
Satellite pioneer Gil Moore explains, "The sun starts throwing out these coronal mass ejections." Coronal mass ejections are balloon-shaped bursts of solar wind rising above the sun's outer atmosphere. "Now we've only had a couple of them so far in this solar cycle. This is a pretty quiet cycle. This solar max is not really very exciting. I was hoping,there would be a lot more stuff going on. Next March or April you will see them every week."
Solar winds stream off the sun at speeds hovering around 1 million miles per hour and solar flares -- a sudden burst of brightness on the sun's surface -- pack the same amount of energy as millions of hydrogen bombs exploding at the same time.
Moore is working on a project similar to DICE referred to as POPACS (Polar Orbiting Passive Atmospheric Calibration Sphere). The goal is to measure the effects of solar flares and coronal mass ejections on the earth's upper atmosphere. The eventual hope is to use this information to decrease satellite collisions and improve the safety of orbiting crew and spacecraft.
"Electronic devices get smaller and smaller and so they can be damaged by cosmic rays and high energy protons and stuff coming in from solar storms more than the satellites did way back when, back in the beginning of the space age. Now from the debris up there, everything is susceptible. Something the size of your thumbnail can take out a satellite because it is whistling along at 7.5 miles a second," says Moore.
Even though the sun is 93 million miles away, the radiation it emits hits the earth every day. Severe solar storms are what cause the concern.
There is a whole range of potential effects, the most feared one is failure of the power grid. A solar storm in 1989 caused a blackout in the northeastern U.S. and parts of Canada.
"Now, if you don't know about it, it can pop all your breakers in your big distribution network," says Moore, "We are in a particular one here called the Bonneville network and it can shut down Salt Lake City. It can burn down lines, it's just a huge surge of power."
Electroctromagnetic pulses racing into earth from violent space weather cause the damage. They can also disable global positioning system satellites that we rely so heavily on for communication, surveillance, and navigation on earth and in space.
Moore says, "The more we understand about solar terrestrial physics, the better off the people are on earth are."
DICE was funded by a $1.2 million grant from the National Science Foundation and was launched in October 2011. It is sending data back to earth five days a week.
Eric Stromberg: "We've been able to show that our satellite and our measurements are seeing things that other missions are seeing which is a nice feel-good feeling that what we are doing is right. And from there we are moving forward and trying to analyze the data to figure out if we have seen anomalies."
Chad Fish: "We've seen some very interesting things that are related to interactions between the sun and the earth, things that are not standard that happen because something interesting is going on. We're going to start presenting them at conferences. There's a lot of work to go forward, a lot of science benefit and benefit to the community in general regarding space weather that we expect to come out of this."
The project well surpassed its six month mission requirements and the satellites will re-enter the atmosphere and disintegrate within 25 years. POPACS will hitch a ride on Space Exploration's Falcon 9 rocket from the Vanderberg Air Force base in California some time in spring of 2013.