Voyager Missions in Interstellar Space
In August and September 1977 respectively, NASA launched spacecrafts Voyager 2 and Voyager 1, and now they have flown into interstellar space, returning images that have given us our first glimpse of what this mysterious space is really like.
As the first human-built objects to leave the solar system, the two spacecrafts are exploring uncharted territories billions of miles from Earth.
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Their original purpose was only to perform a five-year mission, but they have been operating to this day.
Voyager 1 entered interstellar space in 2012, and Voyager 2, which departed half a month earlier, entered interstellar space in 2018.
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The first finding is about the thickness of heliopause which refers to the boundary of the solar system.
Voyager 2 and Voyager 1 passed through the heliopause in less than a day, confirming that this area is very thin.
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When Voyager 2 passed through the heliopause, its plasma wave instrument detected that the density of plasma there increased sharply by 20 times, just like the interaction of two different liquids, and continued to detect particles from the solar system spreading outward.
People used to think in the past that the solar wind would slowly fade away as it entered interstellar space from the solar system, but Voyager 2’s findings show that there is a very clear boundary there.
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Voyager 1 detected the frequency of plasma waves.
After analyzing the data, a research team led by Cornell University discovered weak but persistent sounds of interstellar gas.
These findings make researchers believe that there are more low-level activities going on in the interstellar gas, prompting them to further explore the distribution of plasma in space, and help scientists gain a deeper understanding of the interaction between the interstellar medium and the solar wind.
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When Voyager 1 crossed the boundary of the heliosphere, the heliosphere was shrinking, but when Voyager 2 crossed the boundary, the heliosphere was expanding.
That shows a pretty dynamic boundary.
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Voyager spacecrafts use nuclear batteries.
The efficiency of plutonium fuel has limits.
As the nuclear battery power continues to decline, some instruments on the spacecrafts must be shut down.
NASA hopes to be able to communicate with them till 2027.
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Warning: these questons and answers are not all representative of the way questions will be asked and answered in the pilot, because some questions are compound and some answers do not include citations.

Q: What are Voyager 1 and Voyager 2?
A: Two spacecrafts that have entered interstellar space.  

Q: When were they launched?
A: In August and September 1977 respectively.

Q: What is the original purpose of the projects?
A: It was only to perform a five-year mission. 

Q: Where are they now?
A: - They have both entered interstellar space.

Q: What is heliopause?
A: It is the boundary of the solar system.

Q: What did Voyagers find about heliopause?
A: They found it was very thin.

Q: Other findings in interstellar space:
A: Voyager 1 detected the frequency of plasma waves.

Q: Other findings in interstellar space:
A: Voyager 2 detected a very clear boundary of the solar system in terms of solar wind’s strength.

Q: Different findings:
A: Voyager 1 found the heliosphere shrinking while Voyager 2 found it expanding.

Q: What powers the two spacecrafts?
A: Nuclear batteries.

Q: How hong might the nuclear batteries continue to support the operation?
A: Likely till 2027.