Voyager 1's Back Thrusters Just Fired Up for the First Time in 37 Years

NASA/JPL-Caltech
NASA/JPL-Caltech

Imagine trying to start a car that's been sitting in a garage for decades—and the car is 13 billion miles away. That's what NASA attempted to do this week with the Voyager 1 spacecraft—and it worked.

Four of the thrusters on Voyager 1—the only human-made object ever to reach interstellar space—have been dormant since 1980, just three years after it and its twin probe, Voyager 2, were launched into the universe bearing the sights, sounds, and music of Earth on the Golden Record.

For the past 40 years, Voyager 1 has been using "attitude control thrusters" to keep the spacecraft's antenna oriented to Earth so that it can communicate with us, and us with it. The thrusters fire tiny pulses lasting for just milliseconds. For the past three years, they've been degrading, worrying the Voyager team.

Propulsion experts Carl Guernsey and Todd Barber, from NASA's Jet Propulsion Laboratory in Pasadena, California, considered different interventions and how the spacecraft might respond to them. They proposed attempting to start the four "trajectory correction maneuver," or TCM, thrusters located on the back of the spacecraft, hoping they could take over the job of correctly orienting Voyager. In the early days of the mission, these thrusters, identical in size and functionality to the attitude control thrusters, were used to keep the probe's instruments targeted on Jupiter, Saturn, and their moons as the spacecraft flew by them.

They pored over decades-old data and deciphered outdated software code to make sure they could attempt to turn on the TCM thrusters without causing damage to Voyager. Then, on Tuesday, engineers fired them up and tested their ability to orient the spacecraft, using 10-millisecond pulses. They had to wait 19 hours and 35 minutes for the data to make it to Earth, but eventually they got the good news: The TCM thrusters were up to snuff.

Now that the back thrusters are operational, Voyager 1 just got another two to three years of life, Suzanne Dodd, mission project manager at NASA's Jet Propulsion Laboratory, said in a statement. The plan is to shift the orientation work to the TCM thrusters in stages beginning in January. Each requires a heater to operate, and turning on the heaters requires power, which is a strain on the aging probe. So when there's no longer enough power for them, the job will switch back to the attitude control thrusters.

The engineers will likely attempt the same move with Voyager 2 when its attitude control thrusters start to break down; currently, they're in better shape than Voyager 1's. Now in the periphery of our solar system in what's known as the heliosheath, Voyager 2 will enter interstellar space in the next few years. As the twin crafts fly deeper into the universe at more than 36,000 mph, they'll keep talking to Earth for at least a little while longer. 

A Super Pink Moon—the Biggest Supermoon of 2020—Is Coming In April

April's super pink moon will be extra big and bright (but still white).
April's super pink moon will be extra big and bright (but still white).
jakkapan21/iStock via Getty Images

The sky has already given us several spectacular reasons to look up this year. In addition to a few beautiful full moons, we’ve also gotten opportunities to see the moon share a “kiss” with Venus and even make Mars briefly disappear.

In early April, avid sky-gazers are in for another treat—a super pink moon, the biggest supermoon of 2020. This full moon is considered a supermoon because it coincides with the moon’s perigee, or the point in the moon’s monthly orbit when it’s closest to Earth. According to EarthSky, the lunar perigee occurs on April 7 at 2:08 p.m. EST, and the peak of the full moon follows just hours later, at 10:35 p.m. EST.

How a supermoon is different.

Since the super pink moon will be closer to Earth than any other full moon this year, it will be 2020’s biggest and brightest. It’s also the second of three consecutive supermoons, sandwiched between March’s worm moon and May’s flower moon. Because supermoons only appear about 7 percent bigger and 15 percent brighter than regular full moons, you might not notice a huge difference—but even the most ordinary full moon is pretty breathtaking, so the super pink moon is worth an upward glance when night falls on April 7.

The meaning of pink moon.

Despite its name, the super pink moon will still shine with a normal golden-white glow. As The Old Farmer’s Almanac explains, April’s full moon derives its misleading moniker from an eastern North American wildflower called Phlox subulata, or moss pink, that usually blooms in early April. It’s also called the paschal moon, since its timing helps the Catholic Church set the date for Easter (the word paschal means “of or relating to Easter”).

[h/t EarthSky]

Are Any of the Scientific Instruments Left on the Moon By the Apollo Astronauts Still Functional?

Apollo 11 astronaut Neil Armstrong left the first footprint on the Moon on July 20, 1969.
Apollo 11 astronaut Neil Armstrong left the first footprint on the Moon on July 20, 1969.
Heritage Space/Heritage Images/Getty Images

C Stuart Hardwick:

The retroreflectors left as part of the Apollo Lunar Ranging Experiment are still fully functional, though their reflective efficiency has diminished over the years.

This deterioration is actually now delivering valuable data. The deterioration has multiple causes including micrometeorite impacts and dust deposition on the reflector surface, and chemical degradation of the mirror surface on the underside—among other things.

As technology has advanced, ground station sensitivity has been repeatedly upgraded faster than the reflectors have deteriorated. As a result, measurements have gotten better, not worse, and measurements of the degradation itself have, among other things, lent support to the idea that static electric charge gives the moon an ephemeral periodic near-surface pseudo-atmosphere of electrically levitating dust.

No other Apollo experiments on the moon remain functional. All the missions except the first included experiment packages powered by radiothermoelectric generators (RTGs), which operated until they were ordered to shut down on September 30, 1977. This was done to save money, but also because by then the RTGs could no longer power the transmitters or any instruments, and the control room used to maintain contact was needed for other purposes.

Because of fears that some problem might force Apollo 11 to abort back to orbit soon after landing, Apollo 11 deployed a simplified experiment package including a solar-powered seismometer which failed after 21 days.

This post originally appeared on Quora. Click here to view.

SECTIONS

arrow
LIVE SMARTER