Inside the High Stakes Missions of NASA's Oldest Deep-Space Probes




  • In Science
  • 2020-02-18 10:08:39Z
  • By The Daily Beast
Inside the High Stakes Missions of NASA\
Inside the High Stakes Missions of NASA\'s Oldest Deep-Space Probes  

On Aug. 20, 1977, NASA launched the Voyager 2 probe on a mission to explore the outer planets of our solar system.

Twelve years later, having scanned Jupiter, Saturn, Uranus and Neptune, the 1,600-pound spacecraft completed its initial mission.

But it kept going. And going. And going. Nursed farther and farther into space by a small team at NASA's Jet Propulsion Laboratory in California, Voyager 2 is now more than 11 billion miles from Earth, making it the second-most-distant man-made object from Earth after its speedier twin Voyager 1.

In late January, Voyager 2's decades-long voyage almost came to an untimely end. The mishap underscores the delicacy of NASA's super-long-range space missions, as well as the ingenuity of the space agency's probe-operators.

After zipping past Neptune in 1989, Voyager 2 took on a new mission: working alongside Voyager 1 to investigate the "heliosphere," which NASA spokeswoman Calla Cofield described as "the bubble of particles and magnetic fields created by the sun."

On Jan. 25, Voyager 2 was supposed to execute a scheduled maneuver, turning 360 degrees in order to calibrate an on-board magnetic instrument. But the probe never made the turn.

Voyager 2's operators in California found out about the missed turn 17 hours later- the time it takes for a radio signal to travel the billions of miles from the spacecraft to Earth.

"Analysis of the telemetry from the spacecraft indicated that an unexplained delay in the onboard execution of the maneuver commands inadvertently left two systems that consume relatively high levels of power operating at the same time," NASA explained in a release. "This caused the spacecraft to overdraw its available power supply."

The Voyager probes carry plutonium-powered generators that can produce 470 watts of power-the equivalent of a handful of light bulbs. Any system that consumes even a few extra watts could shave years off the probes' lifespans.

To protect against a sudden battery drain, the Voyagers' software automatically shuts off the probes' science instruments whenever it detects a surge in power consumption. Of course, without instruments the spacecraft are just useless hunks of metal streaking 34,000 miles per hour into the cosmos.

The team in California got to work fixing Voyager 2. They'd done it before. In 2010 a single bit in Voyager 2's memory flipped from zero to one, introducing a flaw into the data the probe was sending back to Earth.

To diagnose the error, engineers at the Jet Propulsion Laboratory ran simulations on a computer running the same software as the distant probe. It took a few weeks, but they were able to transmit instructions to Voyager 2 to flip the bit back to zero.

But the 2010 fix perhaps seemed deceptively easy. In fact, the teams managing the Voyagers as well as NASA's other deep-space probe, New Horizons, can prevent or cause catastrophe with a single keystroke.

(New Horizons, which launched in 2006, is probing the Kuiper Belt, a region of the solar system beyond Neptune that scientists believe contains a large number of comets and asteroids.)

In 1982, a NASA team botched a software update on the Viking 1 Mars lander. The bad code caused the lander to point its antenna in the wrong direction, permanently cutting off all communication with Earth.

"They can never make a single mistake," Alan Stern, the principal investigator for the New Horizons mission, told The Daily Beast, referring to NASA's probe teams. And the teams have to maintain that flawless performance every day for decades as presidential administrations come and go, budgets rise and fall, old staff retire and new staff join up.

Fixing Voyager 2's January malfunction ended up being fairly straightforward. The engineers essentially rebooted a few key systems. Then waited 17 hours to hear back from the probe.

On Feb. 5, NASA announced the good news. "Mission operators report that Voyager 2 continues to be stable, and communications between Earth and the spacecraft are good," NASA's Cofield told The Daily Beast. "The spacecraft has resumed taking science data, and the science teams are now evaluating the health of the instruments following their brief shut-off."

Stern praised the engineers who saved the probe. "The Voyager guys, they were under the gun of time with high stakes," he said. "They discovered a problem and the clock was ticking to save the day."

With any luck, the Voyagers have another four or five years worth of power left. NASA plans for the probes to continue investigating the heliosphere until the day they finally power down, sometime in the mid-2020s. With its fresher batteries, New Horizons could last into the 2040s.

Read more at The Daily Beast.

Get our top stories in your inbox every day. Sign up now!

Daily Beast Membership: Beast Inside goes deeper on the stories that matter to you. Learn more.

COMMENTS

More Related News

NASA details how it plans to establish a sustained human presence on the Moon
NASA details how it plans to establish a sustained human presence on the Moon

NASA's Artemis program aims to bring humans back to the Moon, with the goal of staying there for good in the interest of pursuing additional science and exploration missions, including to Mars. NASA has provided some more detail about its plans with a sustainability concept it released describing some core components of the infrastructure it plans to put in place on the lunar surface.

NASA goes back to the future and revives its formerly forbidden
NASA goes back to the future and revives its formerly forbidden 'worm' logo

NASA is restoring a squiggly graphic representation of its acronym, known as "the Worm," to a place of prominence, 28 years after it was consigned to the dustbin of space history. NASA Administrator Jim Bridenstine declared that "the worm is back" today in a tweet - and revealed that it's been painted on the SpaceX Falcon 9 rocket that's due to launch NASA astronauts to the International Space Station as soon as next month. That demonstration mission will mark the first time U.S. astronauts have been launched to orbit from U.S. soil since the retirement of the space shuttle fleet in… Read More

NASA and SpaceX add some retro flair to the Falcon 9 rocket flying the first crewed Dragon launch
NASA and SpaceX add some retro flair to the Falcon 9 rocket flying the first crewed Dragon launch

NASA and SpaceX are moving ahead full-steam with the Demo-2 launch of SpaceX's Crew Dragon spacecraft - the first launch to carry astronauts to space aboard a private launch vehicle from American soil. The Falcon 9 rocket that will propel the Crew Dragon to space will include a NASA logo that has been - technically - retired from active duty since 1992. The 1970s-era "worm" logo is a take on NASA branding that has, for more than 20 years now, been relegated to souvenir status.

NASA received over 12,000 applications this year to be an astronaut in the Artemis program
NASA received over 12,000 applications this year to be an astronaut in the Artemis program

This marks the second-highest number of applicants NASA has ever received, surpassed only by its most recent class, despite tighter qualifications.

NASA call for astronauts draws 12,000 spaceflight hopefuls
NASA call for astronauts draws 12,000 spaceflight hopefuls
  • US
  • 2020-04-01 17:15:32Z

NASA said Wednesday that Americans from all 50 states, the District of Columbia and four U.S. territories applied to be part of the space agency's next astronaut class. NASA Administrator Jim Bridenstine said this next class of astronauts will help explore the moon and pave the way to Mars. NASA's previous call for astronauts, in 2017, attracted a record 18,300 applicants.

Leave a Comment

Your email address will not be published. Required fields are marked with *

Cancel reply

Comments

Top News: Science