NASA - Voyager 1 and 2 updates

• NASA - Voyager 1 and 2 updates by E_ E_ H on 20 Aug, 2007 16:50
• What an achievement. I have started this thread in "historical spaceflight", but I suppose it should be in current missions because they are still flying and transmitting data.
  
  I've started this for people to pass comment. I thought that Carl Sagan said it best in 1996 when he said,
  
  "We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it everyone you know, everyone you love, everyone you've ever heard of, every human being who ever was, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines. Every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there - on a mote of dust suspended in a sunbeam.
  
  The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.
  
  Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity -- in all this vastness -- there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish this pale blue dot, the only home we've ever known."
  
  The picture is a composite from Voyager 1 (NASA public domain).
  
  What an astonishing achievement by mankind. I hope we follow up with more. I believe it is worth it.
  
  Cheers.
  
  Richard.

  ---

  
• #1 by Analyst on 20 Aug, 2007 17:36
• I love these birds. Their mission should only be terminated by degrading RTG power, not by funding decisions. If you think about redundancy and reliable systems design, this is it.
  
  Analyst
• #2 by jacqmans on 20 Aug, 2007 17:46
• RELEASE: 07-205
  
  PIONEERING NASA SPACECRAFT MARK THIRTY YEARS OF FLIGHT
  
  WASHINGTON - NASA's two venerable Voyager spacecraft are celebrating
  three decades of flight as they head toward interstellar space. Their
  ongoing odysseys mark an unprecedented and historic accomplishment.
  
  Voyager 2 launched on Aug. 20, 1977, and Voyager 1 launched on Sept.
  5, 1977. They continue to return information from distances more than
  three times farther away than Pluto.
  
  "The Voyager mission is a legend in the annals of space exploration.
  It opened our eyes to the scientific richness of the outer solar
  system, and it has pioneered the deepest exploration of the sun's
  domain ever conducted," said Alan Stern, associate administrator for
  NASA's Science Mission Directorate, Washington. "It's a testament to
  Voyager's designers, builders and operators that both spacecraft
  continue to deliver important findings more than 25 years after their
  primary mission to Jupiter and Saturn concluded."
  
  During their first dozen years of flight, the spacecraft made detailed
  explorations of Jupiter, Saturn, and their moons, and conducted the
  first explorations of Uranus and Neptune. These planets were
  previously unknown worlds. The Voyagers returned never-before-seen
  images and scientific data, making fundamental discoveries about the
  outer planets and their moons. The spacecraft revealed Jupiter's
  turbulent atmosphere, which includes dozens of interacting
  hurricane-like storm systems, and erupting volcanoes on Jupiter's
  moon Io. They also showed waves and fine structure in Saturn's icy
  rings from the tugs of nearby moons.
  
  For the past 19 years, the twin Voyagers have been probing the sun's
  outer heliosphere and its boundary with interstellar space. Both
  Voyagers remain healthy and are returning scientific data 30 years
  after their launches.
  
  Voyager 1 currently is the farthest human-made object at a distance
  from the sun of about 9.7 billion miles. Voyager 2 is about 7.8
  billion miles from the sun. Originally designed as a four-year
  mission to Jupiter and Saturn, the Voyager tours were extended
  because of their successful achievements and a rare planetary
  alignment. The two-planet mission eventually became a four-planet
  grand tour. After completing that extended mission, the two
  spacecraft began the task of exploring the outer heliosphere.
  
  "The Voyager mission has opened up our solar system in a way not
  possible before the Space Age," said Edward Stone, Voyager project
  scientist at the California Institute of Technology, Pasadena, Calif.
  "It revealed our neighbors in the outer solar system and showed us
  how much there is to learn and how diverse the bodies are that share
  the solar system with our own planet Earth."
  
  In December 2004, Voyager 1 began crossing the solar system's final
  frontier. Called the heliosheath, this turbulent area, approximately
  8.7 billion miles from the sun, is where the solar wind slows as it
  crashes into the thin gas that fills the space between stars. Voyager
  2 could reach this boundary later this year, putting both Voyagers on
  their final leg toward interstellar space.
  
  Each spacecraft carries five fully functioning science instruments
  that study the solar wind, energetic particles, magnetic fields and
  radio waves as they cruise through this unexplored region of deep
  space. The spacecraft are too far from the sun to use solar power.
  They run on less than 300 watts, the amount of power needed to light
  up a bright light bulb. Their long-lived radioisotope thermoelectric
  generators provide the power.
  
  "The continued operation of these spacecraft and the flow of data to
  the scientists is a testament to the skills and dedication of the
  small operations team," said Ed Massey, Voyager project manager at
  NASA's Jet Propulsion Laboratory in Pasadena, Calif. Massey oversees
  a team of nearly a dozen people in the day-to-day Voyager spacecraft
  operations.
  
  The Voyagers call home via NASA's Deep Space Network, a system of
  antennas around the world. The spacecraft are so distant that
  commands from Earth, traveling at light speed, take 14 hours one-way
  to reach Voyager 1 and 12 hours to reach Voyager 2. Each Voyager logs
  approximately 1 million miles per day.
  
  Each of the Voyagers carries a golden record that is a time capsule
  with greetings, images and sounds from Earth. The records also have
  directions on how to find Earth if the spacecraft is recovered by
  something or someone.
  
  NASA's next outer planet exploration mission is New Horizons, which is
  now well past Jupiter and headed for a historic exploration of the
  Pluto system in July 2015.
  
  For a complete listing of Voyager discoveries and mission information,
  visit the Internet at:
  
  http://www.nasa.gov/voyager
  
• #3 by brihath on 20 Aug, 2007 17:50
• Let's hear it for the RTG's that power these vehicles.  I know the ani-nuke crowd always get worked up about sending them up on a rocket, but they are safe and reliable.  As I recall, several other RTG powered experiments were eventually shut down for lack of funds.  If they keep providing good science, then keep the data coming.  What an awesome achievement!
• #4 by jmjawors on 20 Aug, 2007 18:20
• The Voyagers really hold a special place for me.  I was first old enough to understand what they were and what they were doing when Voyager 2 flew by Saturn and I've been hooked on astronomy (and later spaceflight itself) ever since.
  
  I especially remember what passed as "NASA - TV" back in those days... seeing the images come onto the TV screen one by one just as the scientists at JPL did.  Total excitement.  
  
  Here's to 30 more years!
  
  *raises glass*
• #5 by Kaputnik on 20 Aug, 2007 21:11
• I think the Neptune encounter is one of my most vivid early childhood memories- we had no VCR so if I wanted to see anything about Voyager on the TV, I had to make sure I was there with my Dad watching it. I got caught up in all the excitement and I think I've been hooked ever since!
  Maybe my own kids will have New Horizons as their own deep-space craft?
• #6 by Shadow Spork on 20 Aug, 2007 21:25
• I know that someday, we humans may be able to "fly-by" the Voyager probes as a nod to what we have accomplished. I'm glad these probes are still alive and ticking.
• #7 by wingod on 23 Aug, 2007 02:42
• Quote

  Gary - 20/8/2007  4:15 PM
  
  I remember the Saturn Encounter and just how amazing it was that these probes were that far out. They still amaze me to this day with just how much they have acomplished and how much we have learnt about the Solar System. I, for one, look forward to many more discoveres.
  

  
  I was at the Pasadena CA civic center for the Planetfest celebration for the Jupiter, Saturn, and Neptune encounters.  They were a LOT of fun and a total geekfest.
  
  I will never forget the first images that came back from Saturn showing the twisted rings and hearing Carl Sagan exclaim "thats impossible!".
  
  
  
  
• #8 by simonbp on 23 Aug, 2007 03:25
• What's even more incredible is that Ed Stone has been PI for the mission continuously since 1972! I'm sure that's a record...
  
  Simon
• #9 by Lee Jay on 23 Aug, 2007 03:37
• While I'm sure the position didn't become formal until much later (and I don't know when), you could argue that Francis Everitt has been the PI on Gravity Probe B since 1962.
• #10 by mikeh on 23 Aug, 2007 11:54
• Let's not forget the people that run the deep space communications network.  Imagine the engineering that it takes to "talk and listen" to a spacecraft where the one way light time is 14 hours.  It doesn't matter if the probes last for another decade if you can't "talk" to them.  It's about the system not just the spacecraft.
• #11 by E_ E_ H on 23 Aug, 2007 12:29
• I wonder how much interference will occur when Voyager 1 reaches the outer heliosphere.
• #12 by brahmanknight on 23 Aug, 2007 14:13
• Along with Challenger, one of my earliest space memories was the Neptune fly by.  And, yes, I remember how exciting it was for one image to download in about 20 seconds ( I get mad now if my laptop doesn't load a webpage in 3 seconds).  I couldn't fathom then or now how far that is out there, and how cold it is.  Just remarkable that they are even FARTHER out now.  Incredible.
• #13 by Andy USA on 13 Sep, 2007 00:03
• Very special spacecrafts. Will they speed up or slow down when they breach the heliosphere?
• #14 by Maverick on 17 Sep, 2007 21:38
• Quote

  Andy USA - 12/9/2007  7:03 PM
  
  Very special spacecrafts. Will they speed up or slow down when they breach the heliosphere?

  
  I don't think anyone really knows. That's the cool mystery surrounding this.
• #15 by hmh33 on 17 Sep, 2007 21:57
• I'm pretty sure the plasma densities involved are much too thin to actually decelerate the spacecraft.  So it will continue to experience the same (very weak, ~5E-7 m/s^2) deceleration because of the influence of the Sun's gravity as it does at present.
  The plasma science instruments on board should notice changes though, which will be interesting.
• #16 by Moon King on 18 Sep, 2007 01:37
• They are slowing down??? So they will never really escape the sun's gravity? Could Voyager 1 and 2 eventually return to the inner solar system in several thousands of years?
• #17 by hmh33 on 18 Sep, 2007 05:15
• Yes they are slowing down, but they will still escape the sun's gravity and never return.
  The deceleration is a very small number and will continue to shrink.
  Currently Voyager 1 is at a distance of about 103 AU from the Sun and is travelling at about 17km/s.  This is much more than solar escape velocity at that distance (4.1km/s) so we know it will escape.
  
  The spacecraft's velocity relative to the sun is about 17000m/s.  The deceleration due to the sun's gravity at this distance is about 0.00000055m/s^2 so it loses 0.05m/s of velocity per day, or 18m/s per year.  After e.g. a year, it will have slowed by approximately 18m/s but it will also have travelled another 3.5 AU, the sun's gravity will be weaker and the deceleration will be less so over the following year its speed will decrease by only ~16m/s.
  
  To correctly prove that it will escape you should use differential calculus (this is how you derive escape velocity) but hopefully you get the picture.
  
  
  n.b. 1 AU is the radius of the Earth's orbit, about 150 million km or 93 million miles.
• #18 by Bruth on 16 Oct, 2009 21:04
• Yes, quite, that Golden Record on board should give any Intelligent Life that retrieves an indication as to the level of intelligence held by earthlings.
• #19 by jacqmans on 12 Feb, 2010 19:08
• Feb. 12, 2010
  
  
  Voyager Celebrates 20-Year-Old Valentine to Solar System
  
  The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/news.cfm?release=2010-048&cid=release_2010-048
  
  
  Twenty years ago on February 14, NASA's Voyager 1 spacecraft had sailed beyond the outermost planet in our solar system and turned its camera inward to snap a series of final images that would be its parting valentine to the string of planets it called home.
  
  Mercury was too close to the sun to see, Mars showed only a thin crescent of sunlight, and Pluto was too dim, but Voyager was able to capture cameos of Neptune, Uranus, Saturn, Jupiter, Earth and Venus from its unique vantage point. These images, later arranged in a large-scale mosaic, make up the only family portrait of our planets arrayed about the sun.
  
  The Apollo missions in the 1960s and 70s had already altered our perspective of Earth by returning images of our home planet from the moon, but Voyager was providing a completely new perspective, said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena.
  
  "It captured the Earth as a speck of light in the vastness of the solar system, which is our local neighborhood in the Milky Way galaxy, in a universe replete with galaxies," Stone said.
  
  In the years since the twin Voyager spacecraft were launched in 1977, they had already sent back breathtaking, groundbreaking pictures of the gas giants Jupiter, Saturn, Uranus and Neptune. It took Voyager 1 more than 12 years to reach the place where it took the group portrait, 6 billion kilometers (almost 4 billion miles) away from the sun. The imaging team started snapping images of the outer planets first because they were worried that pointing the camera near the sun would blind it and prevent more picture-taking.
  
  Candy Hansen, a planetary scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who worked with the Voyager imaging team at the time, remembers combing through the images and finally finding the image of Earth. She had seen so many pictures over the years that she could distinguish dust on the lens from the black dots imprinted on the lens for geometric correction.
  
  There was our planet, a bright speck sitting in a kind of spotlight of sunlight scattered by the camera. Hansen still gets chills thinking about it.
  
  "I was struck by how special Earth was, as I saw it shining in a ray of sunlight," she said. "It also made me think about how vulnerable our tiny planet is."
  
  This was the image that inspired Carl Sagan, the the Voyager imaging team member who had suggested taking this portrait, to call our home planet "a pale blue dot."
  
  As he wrote in a book by that name, "That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world."
  
  After these images were taken, mission managers started powering down the cameras. The spacecraft weren't going to fly near anything else, and other instruments that were still collecting data needed power for the long journey to interstellar space that was ahead.
  
  The Voyagers are still transmitting data daily back to Earth. Voyager 1 is now nearly 17 billion kilometers (more than 10 billion miles) away from the sun. The spacecraft have continued on to the next leg of their interstellar mission, closing in on the boundary of the bubble created by the sun that envelops all the planets. Scientists eagerly await the time when the Voyagers will leave that bubble and enter interstellar space.
  
  "We were marveling at the vastness of space when this portrait was taken, but 20 years later, we're still inside the bubble," Stone said. "Voyager 1 may leave the solar bubble in five more years, but the family portrait gives you a sense of the scale of our neighborhood and that there is a great deal beyond it yet to be discovered."
  
  The Voyagers were built by JPL, which continues to operate both spacecraft. Caltech manages JPL for NASA.