🚀 Science
Voyager 1 back in contact after brief silence; will be one light-day from Earth on 18 November
In 60 seconds: NASA says Voyager 1 is back in steady contact after its radio signal went missing on 18 and 19 October. A group of thrusters went offline, backups took over, and the spacecraft's fault protection put it in a safe configuration. Engineers had already swapped three devices for lower-power ones to save energy. On 18 November the probe, launched in 1977, will be one light-day, about 25.89 billion km, from Earth.
Why it matters
Voyager 1 is the farthest human-made object and the only one directly studying interstellar space from this far. Keeping it alive extends a unique scientific record.
Explain it simply
Send Voyager 1 a WhatsApp message and you wait a full day for the blue ticks, then another day for its reply.
The 3-minute read
What happened
NASA's Deep Space Network could not detect Voyager 1 in two contact attempts 24 hours apart. The signal returned on 20 October, and the root cause of the thruster fault is still being investigated.
Background
The probe draws power from radioisotope thermoelectric generators, which turn heat from decaying plutonium into electricity. Each Voyager loses about 4 watts a year, so power margins are thin.
How it works
In early September, in a swap the team called the 'Big Bang', three devices that help keep the craft warm were replaced by lower-power ones, all at once to keep heat balanced.
What's next
Without the swap, another instrument might have been switched off as early as summer 2027. At one light-day, a command and its reply will take 48 hours for a round trip.
What it means for you
Voyager 1 travels at about 61,155 km/h. Try working out how many years light-speed signals would take to reach the nearest star compared with one day to Voyager.
Key numbers
- 25.89 billion km: Distance on 18 Nov: one light-day
- 48 hours: Round trip time for a radio signal
- ~4 W: Power lost each year
- 1977: Launch year
Both sides
- NASA's Voyager team: The power swap buys the remaining instruments more time, and contact is stable again.
- Cautious observers: A first-ever thruster fault on a 49-year-old craft shows how fragile the mission now is.
Key terms explained
- Light-day
- The distance light travels in one day, about 25.9 billion km.
- Fault protection
- Onboard software that spots a problem and automatically puts a spacecraft into a safe state.
The story so far
- Sep 1977: NASA launches Voyager 1 to study the outer planets. Voyager 1 flew past Jupiter and Saturn and then kept heading out of the solar system, carrying 10 science instruments at launch.
- Aug 2012: Voyager 1 becomes the first spacecraft to enter interstellar space. It crossed the heliopause, the outer edge of the heliosphere, the bubble of solar wind that surrounds the Sun and planets.
- Today: Voyager 1 recovers from signal loss, nears one light-day mark
Exam notes (UPSC, SSC, Banking, PSC)
- Voyager 1 and Voyager 2 were launched by NASA in 1977; Voyager 1 entered interstellar space in 2012 and Voyager 2 in 2018.
- The heliosphere is the bubble of solar wind around the Sun; its outer boundary is called the heliopause.
- A radioisotope thermoelectric generator (RTG) produces electricity from the heat of decaying plutonium-238.
- A light-year, like a light-day, is a unit of distance, not of time.
Likely exam question: What challenges do deep-space missions face in power and communication? Discuss with reference to Voyager 1.