The Voyager 1 spacecraft began its mission in 1977,
setting out to reach the edge of our solar system and beyond (Mission, 2015). It met its goal and continues on into deep
space with its mission planned to continue on around 2020 when its
thermoelectric nuclear generator will no longer create enough power to sustain
the mission (Operation, 2015). The
thermoelectric nuclear generator in Voyager 1 had a power output of around 420W
when first launched and makes use of an 8-track digital tape recorder for
storing data gained from science instruments (Voyager, 2012). The data storage strategy for Voyager 1 is to
mainly transmit data real time so as to avoid the need to store data on the
spacecraft, however some data from the Plasma Wave Investigation sensors are
stored long term on the spacecraft (Mission, 2015). The tape recorder has the ability to store
63.5 MB of data which is enough to store about 100 images or a few graphs worth
of data at a time (Voyager, 2012). Science
data is returned to Earth real time at 160 bps, and the Deep Space Network
(DSN) 34 meter antennas are used to capture around 16 hours of data a day
(Mission, 2015). Once a week the
spacecraft also records 48 seconds of high rate Plasma Wave Investigation (PWS)
data onto the digital tape recorder and every 6 months that data is sent back
to Earth (Mission, 2015). The 70 meter
antennas of the DSN have to be used to support that data capture (Mission, 2015). Voyager 1 has 10 science sensor systems on board that gather data in order to perform its mission of exploring our solar
system and beyond (Operation, 2015). These 10 systems are detailed below:
- Ultraviolet Spectrometer (UVS), 2.4 W – measures atmospheric properties of planets and UV radiation emitted from them (Operation, 2015).
- Photopolarimeter System (PPS), 1.2 W – telescope that measures the amount of light scattered or reflected by planets (Operation, 2015).
- Infrared Interferometer Spectrometer (IRIS), 6.6 W – measure infrared radiation emitted or reflected by planets (Operation, 2015).
- Low-Energy Charged Particle Detector (LECP), 4.7 W – measures low-energy charged particles (Operation, 2015).
- Triaxial Fluxgate Magnetometer (MAG), 2.2 W – investigates patterns of planetary magnetic fields (Operation, 2015).
- Planetary Radio Astronomy (PRA) and Plasma Wave Subsystem (PWS), 6.6 W – used to sample plasma behavior in and around planets (Operation, 2015).
- Cosmic Ray Subsystem (CRS), 6.5 W – records the number and energy of high-energy cosmic ray particles (Operation, 2015).
- Plasma Spectrometer (PLS), 4.2 W – measures the lowest-energy particles (Operation, 2015).
- Imaging Science Subsystem (ISS), 14 W – two cameras with attached telescopes to take pictures (Operation, 2015).
Unfortunately the thermoelectric nuclear generator
decays overtime and produces approximately 4.2 watts of power less each year (Operation,
2015). This decline has made it
necessary to end operation of 5 of these science instruments and their
supporting systems so far and the other 5 instruments will have to be turned
off one by one as well leading up to 2020 when there is no longer enough power
to support gyro operations which allow the spacecraft to make sure it’s antenna
points towards Earth to insure data is transmitted successfully (Operation,
2015). Consider Voyager 1 was built in
1977, it’s a marvel what it’s been able to accomplish however considering a
modern phone has many times its data storage capacity today it’s hard not to
wish it didn’t have a much greater amount of data storage onboard so that it
didn’t rely on having constant communication with Earth in order to transmit science
data.
References
The Mission. (2015). Retrieved from
http://voyager.jpl.nasa.gov/spacecraft/
Operation Plan to the End of the
Mission. (2015, May 18). Retrieved from
http://voyager.jpl.nasa.gov/science/thirty.html
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