Engineers successfully switch thrusters on Voyager-1
The routes the Voyager spacecraft have
taken since launch.
Because of an increasing number of clogged thrusters on the almost half-century old Voyager-1 spacecraft, now flying just beyond the heliosphere of the solar system, engineers needed to switch thrusters recently, and successfully did so in a complex dance of engineering.
They had to switch from one thruster, in which a fuel line has become increasingly clogged in the last few years due to age, to an another thruster in a different system. The switch however required other careful preparations, since Voyager-1’s nuclear power supply has dropped to a point where they have been forced to shut down almost all operations. Thus, the thrusters are not getting heated as they once were, and turning on the replacement thruster in this condition could damage it.
The team determined that the best option would be to warm the thrusters before the switch by turning on what had been deemed non-essential heaters. However, as with so many challenges the Voyager team has faced, this presented a puzzle: The spacecraft’s power supply is so low that turning on non-essential heaters would require the mission to turn off something else to provide the heaters adequate electricity, and everything that’s currently operating is considered essential.
Studying the issue, they ruled out turning off one of the still-operating science instruments for a limited time because there’s a risk that the instrument would not come back online. After additional study and planning, the engineering team determined they could safely turn off one of the spacecraft’s main heaters for up to an hour, freeing up enough power to turn on the thruster heaters.
It worked. On Aug. 27, they confirmed that the needed thruster branch was back in action, helping point Voyager 1 toward Earth.
While Voyager-1 still can do some science, the primvary purpose of this work is engineering. The goal is to keep the spacecraft running for as long as possible, until its power supply finally drops so low that it finally dies, something that is expected sometime in the next two years.
If this goal is achieved, it will be a masterpiece of exploration. Launched in 1977 along with its twin, Voyager-2, both spacecraft have been functioning non-stop now for almost a half century. Both have the longest continuously operating computer systems, and both are now beyond the edge of the solar system as influenced by the Sun’s solar wind. To get to 2027 and a full half century will be a magnificent testament not only to the engineers operating each now, but to the American engineers who built the spacecraft in the 1970s.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The routes the Voyager spacecraft have
taken since launch.
Because of an increasing number of clogged thrusters on the almost half-century old Voyager-1 spacecraft, now flying just beyond the heliosphere of the solar system, engineers needed to switch thrusters recently, and successfully did so in a complex dance of engineering.
They had to switch from one thruster, in which a fuel line has become increasingly clogged in the last few years due to age, to an another thruster in a different system. The switch however required other careful preparations, since Voyager-1’s nuclear power supply has dropped to a point where they have been forced to shut down almost all operations. Thus, the thrusters are not getting heated as they once were, and turning on the replacement thruster in this condition could damage it.
The team determined that the best option would be to warm the thrusters before the switch by turning on what had been deemed non-essential heaters. However, as with so many challenges the Voyager team has faced, this presented a puzzle: The spacecraft’s power supply is so low that turning on non-essential heaters would require the mission to turn off something else to provide the heaters adequate electricity, and everything that’s currently operating is considered essential.
Studying the issue, they ruled out turning off one of the still-operating science instruments for a limited time because there’s a risk that the instrument would not come back online. After additional study and planning, the engineering team determined they could safely turn off one of the spacecraft’s main heaters for up to an hour, freeing up enough power to turn on the thruster heaters.
It worked. On Aug. 27, they confirmed that the needed thruster branch was back in action, helping point Voyager 1 toward Earth.
While Voyager-1 still can do some science, the primvary purpose of this work is engineering. The goal is to keep the spacecraft running for as long as possible, until its power supply finally drops so low that it finally dies, something that is expected sometime in the next two years.
If this goal is achieved, it will be a masterpiece of exploration. Launched in 1977 along with its twin, Voyager-2, both spacecraft have been functioning non-stop now for almost a half century. Both have the longest continuously operating computer systems, and both are now beyond the edge of the solar system as influenced by the Sun’s solar wind. To get to 2027 and a full half century will be a magnificent testament not only to the engineers operating each now, but to the American engineers who built the spacecraft in the 1970s.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Here’s where the Voyagers be at: https://science.nasa.gov/mission/voyager/where-are-they-now/
164.71 AU #1, 137.16 AU #2.
“I don’t care about what anything was DESIGNED to do, I care about what it CAN do.”
Gene Kranz ‘Apollo 13’ Universal 1995
A while ago, while commenting on the Voyager Spacecraft, Mr Zimmerman mentioned that the longest lasting computers use magnetic tape. Incredible! The current Voyager Mission Specialists are amazing. I wonder if they could refurbish my 8-track player.
“”The Voyager Computer Command System (CCS) would have 70kb of memory. In-flight programming allowed for new routines and programs to be uploaded regularly in non-volatile memory and eliminated the need for large amounts of memory to be required onboard.
The original software for the Voyager probes was written using Fortran 5 then ported to Fortran 77, and today there is some porting in C. Low-level, light-weight software is increasingly important as the probes move farther and farther away from Earth and communication becomes slower.
The management side of the Voyager computer system also saw some changes to the typical structure; H. Kent Frewing, a spacecraft software engineer, would manage the engineers responsible for each computer system and up to four programmers would work together on the project at once. An On-Board Software Design Team was put together to guide software development, and software validation was completed by the Capability Demonstration Laboratory. Once the initial software had been developed, hardware that was set up in the same configuration that would be used onboard the spacecraft would then be used to test and continue development.””
https://www.allaboutcircuits.com/news/voyager-mission-anniversary-computers-command-data-attitude-control/
Just before the Voyagers go silent, wouldn’t it be fun to load more music? I realize there is the gold-plated phonograph record. Perhaps add Rockin In The Free World, or a Ronald Reagan speech.
There is a good visualization of spacecraft escaping the Solar System at
https://www.heavens-above.com/SolarEscape.aspx
Also a great site for seeing satellites & such . You can set it up with your location and get exact times & where to look.