Do you know Voyager's primary purpose was to explore outer solar system planets in which Voyager 1
designed for planet Jupiter, Saturn and their satellites and Voyager 2 designed for planets Uranus, Neptune.
Voyager mission's twin spacecraft launch on 5 September (Voyager 1) and 20 August (Voyager 2 ) in the year 1977 and both arrived at Jupiter and other planets after 1979 with few months apart.
Before we start I just want to say this is based on my knowledge in the field. You might have different opinion in this which is completely fine too.
In this blog, we are going to focus on 5 major technological advancement that NASA might include if Voyager program was made after 2000s.
5 Major Technologies
- Particle Detector
- Imaging System
- Data Processors
- Power System
- Communication Network
Particle Detector is an instrument in spacecraft that detects cosmic rays and different types of particles from space. We will compare Voyegar's CRS with our most advanced instrument that recent spacecraft has - Solar Parker Prob.
Voyager Mission CRS ((Cosmic Ray Telescopes)) looks only for very energetic particles in plasma, and has the highest sensitivity of the three-particle detectors. To measure particle charge composition in the magnetosphere of Jupiter, Saturn, Uranus, and Neptune.
Solar Parker Prob - Energetic Particle Detector (EPD) - It measure electrons, protons, and heavy ions with high temporal resolution over a wide energy range, from suprathermal energies up to several hundreds of megaelectronvolts/nucleons.
It specifies the type of camera and imaging instrument used in the spacecraft. As Voyagers are planetary science mission at first so we will compare it with our latest planetary mission JUNO.
In Voyager - Imaging Science System (ISS) - is a modified version of the slow scan vidicon camera designs that were used in the earlier Mariner flights. The ISS consists of two television-type cameras, each with 8 filters in a commandable Filter Wheel mounted in front of the vidicons.
One has a low resolution 200 mm wide-angle lens with an aperture of f/3, while the other uses a higher resolution 1500 mm narrow-angle f/8.5 license.
In JunoCam - The JunoCam camera head has a lens with a 58-degree cross-scan field of view. It acquires images by sweeping out that field while the spacecraft spins to cover an along-scan field of view of 360 degrees. Lines containing dark sky are subsequently compressed to an insignificant data volume.
It takes images mainly when Juno is very close to Jupiter, with a maximum resolution of up to 1 to 2 miles (2 to 3 kilometers) per pixel. The wide-angle camera will provide new views of Jupiter’s atmosphere.
It is a kind of computer in spacecraft that runs the whole spacecraft and for every mission, we require different processors so we are again going to compare it with our latest planetary spacecraft mission JUNO.
In Voyager - Voyager used the same computer as the Viking Orbiter in only one of its 3 computerized subsystems (the Command and Control Subsystem). The Attitude and Articulation Control Subsystem used an augmented version of the CCS computer that inserted a unit between the CPU and RAM, which intercepted instructions to add indexed addressing capability, and accelerated instructions that used idle cycles.
The third computer, used in the Flight Data Subsystem, was a new custom design in CMOS with a 128 register, nibble-serial CPU, and 8096 words of 16-bit RAM. It ran about 80,000 instructions per second.
In JUNO - Juno features a data handling system that is based on the RAD750 flight processor with 256 megabytes of flash memory and 128 megabytes of DRAM local memory. RAD750 is a flight processor designed to operate in the strongest radiation environments.
The RAD750 processors operate at up to 200 megahertz. With RAD750, Juno can support up to 100Mbps of total instrument throughput which is more than sufficient for the payload suite.
Power System of Spacecraft
As its name suggests it is a system that gives spacecraft running. As Voyager was outer planet spacecraft it hardly depends on Sun so it has its in-built power system. So we are going to compare what is advancement in In-Built power system throughout these years.
In VoyagerIt has 3 MHW-RTGs with heat from 9 RHUs.
Multi-Hundred Watt (MHW) RTG - Radioisotope Thermoelectric Generators (RTGs) are lightweight, compact spacecraft power systems that are extraordinarily reliable. Output 158 Watts electric at beginning of mission and RTGs still operating over 30 years later at the edge of the solar system.Radioisotope Heater Units (RHUs) - RHUs are small devices that use the decay of plutonium-238 to provide heat to keep spacecraft components and systems warm.
In Mars2020 - The electricity needed to operate NASA's Mars 2020 rover is provided by a power system called a Multi-Mission Radioisotope Thermoelectric Generator or MMRTG. The MMRTG will be inserted into the aft end of the rover between the panels with gold tubing visible at the rear, which is called heat exchangers.
Essentially a nuclear battery, an MMRTG uses the heat from the natural radioactive decay of plutonium-238 to generate about 110 watts of electricity at the start of a mission.
How spacecraft communicate with earth after going out in space hasn't changed yet. All the spacecraft use the same communication network - DSN.
What is DNS ? - Deep Space Network (DSN)
Spacecraft send information and pictures back to Earth using the Deep Space Network or DSN. The DSN is a collection of big radio antennas in different parts of the world.
There are DSN locations near Canberra, Australia; Madrid, Spain; and Goldstone, California. Those sites are almost evenly spaced around the planet. That means as the Earth turns, we never lose sight of a spacecraft.
The farther away a spacecraft is, the larger the antenna you need to detect its signal. The largest antenna at each DSN site is 70 meters (230 feet) in diameter.
Because the Voyagers are so far away, their signals to the antennas are very weak. The power that the DSN antennas receive from the Voyager signals is 20 billion times weaker than what is needed to run a digital watch! Engineers have figured out ways to boost those signals so they can be “heard” loud and clear.