JUNO SPACECRAFT

July 21, 2016


The following information was taken from the NASA web site and the Machine Design Magazine.

BACKGROUND:

After an almost five-year journey to the solar system’s largest planet, NASA’s Juno spacecraft successfully entered Jupiter’s orbit during a thirty-five (35) minute engine burn. Confirmation the burn was successful was received on Earth at 8:53 p.m. PDT (11:53 p.m. EDT) Monday, July 4. A message from NASA is as follows:

“Independence Day always is something to celebrate, but today we can add to America’s birthday another reason to cheer — Juno is at Jupiter,” said NASA administrator Charlie Bolden. “And what is more American than a NASA mission going boldly where no spacecraft has gone before? With Juno, we will investigate the unknowns of Jupiter’s massive radiation belts to delve deep into not only the planet’s interior, but into how Jupiter was born and how our entire solar system evolved.”

Confirmation of a successful orbit insertion was received from Juno tracking data monitored at the navigation facility at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, as well as at the Lockheed Martin Juno operations center in Littleton, Colorado. The telemetry and tracking data were received by NASA’s Deep Space Network antennas in Goldstone, California, and Canberra, Australia.

“This is the one time I don’t mind being stuck in a windowless room on the night of the 4th of July,” said Scott Bolton, principal investigator of Juno from Southwest Research Institute in San Antonio. “The mission team did great. The spacecraft did great. We are looking great. It’s a great day.”

Preplanned events leading up to the orbital insertion engine burn included changing the spacecraft’s attitude to point the main engine in the desired direction and then increasing the spacecraft’s rotation rate from 2 to 5 revolutions per minute (RPM) to help stabilize it..

The burn of Juno’s 645-Newton Leros-1b main engine began on time at 8:18 p.m. PDT (11:18 p.m. EDT), decreasing the spacecraft’s velocity by 1,212 miles per hour (542 meters per second) and allowing Juno to be captured in orbit around Jupiter. Soon after the burn was completed, Juno turned so that the sun’s rays could once again reach the 18,698 individual solar cells that give Juno its energy.

“The spacecraft worked perfectly, which is always nice when you’re driving a vehicle with 1.7 billion miles on the odometer,” said Rick Nybakken, Juno project manager from JPL. “Jupiter orbit insertion was a big step and the most challenging remaining in our mission plan, but there are others that have to occur before we can give the science team the mission they are looking for.”

Can you imagine a 1.7 billion (yes that’s with a “B”) mile journey AND the ability to monitor the process?  This is truly an engineering feat that should make history.   (Too bad our politicians are busy getting themselves elected and reelected.)

Over the next few months, Juno’s mission and science teams will perform final testing on the spacecraft’s subsystems, final calibration of science instruments and some science collection.

“Our official science collection phase begins in October, but we’ve figured out a way to collect data a lot earlier than that,” said Bolton. “Which when you’re talking about the single biggest planetary body in the solar system is a really good thing. There is a lot to see and do here.”

Juno’s principal goal is to understand the origin and evolution of Jupiter. With its suite of nine science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter’s intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet’s auroras. The mission also will let us take a giant step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system. As our primary example of a giant planet, Jupiter also can provide critical knowledge for understanding the planetary systems being discovered around other stars.

The Juno spacecraft launched on Aug. 5, 2011 from Cape Canaveral Air Force Station in Florida. JPL manages the Juno mission for NASA. Juno is part of NASA’s New Frontiers Program, managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems in Denver built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.

SYSTEMS:

Before we list the systems, let’s take a look at the physical “machine”.

Juno Configuration

As you can see, the design is truly remarkable and includes the following modules:

  • SOLAR PANELS—Juno requires 18,000 solar cells to gather enough energy for it’s journey, 508 million miles from our sun.  In January, Juno broke the record as the first solar-powered spacecraft to fly further than 493 million miles from the sun.
  • RADIATION VAULT—During its polar orbit, Juno will repeatedly pass through the intense radiation belt that surrounds Jupiter’s equator, charged by ions and particles from Jupiter’s atmosphere and moons suspended in Juno’s colossal magnetic field. The magnetic belt, which measures 1,000 times the human toxicity level, has a radio frequency that can be detected from Earth and extends into earth’s orbit.
  • GRAVITY SCIENCE EXPERIMENT—Using advanced gravity science tools; Juno will create a detailed map of Jupiter’s gravitational field to infer Jupiter’s mass distribution and internal structure.
  • VECTOR MAGNETOMETER (MAG)—Juno’s next mission is to map Jupiter’s massive magnetic field, which extends approximately two (2) million miles toward the sun, shielding Jupiter from solar flares.  It also tails out for more than six hundred (600) million miles in solar orbit.  The dynamo is more than 20,000 times greater than that of the Earth.
  • MICROWAVE RADIOMETERS–Microwave radiomometers (MWR) will detect six (6) microwave and radio frequencies generated by the atmosphere’s thermal emissions.  This will aid in determining the depths of various cloud forms.
  • DETAILED MAPPING OF AURORA BOREALIS AND PLASMA CONTENT—As Juno passes Jupiter’s poles, cameral will capture high-resolution images of aurora borealis, and particle detectors will analyze the plasmas responsible for them.  Not only are Jupiter’s auroras much larger than those of Earth, they are also much more frequent because they are created by atmospheric plasma rather than solar flares.
  • JEDI MEASURES HIGH-ENERGY PARTICLES–Three Jupiter energetic particle detector instruments (JEDIs) will measure the angular distribution of high-energy particles as they interact with Jupiter’s upper atmospheres and inner magnetospheres to contribute to Jupiter’s northern and southern lights.
  • JADE MEASURE OF LOW-ENERGY PARTICLES—JADE, the Jovian Aurora Distributions Experiment, works in conjunction with DEDI to measure the angular distribution of lower-energy electrons and ions ranging from zero (0) to thirty (30) electron volts.
  • WAVES MEASURES PLASMA MOVEMENT—The radio/plasma wave experiment, called WAVES, will be used to measure radio frequencies  (50 Hz to 40 MHz) generated by the plasma in the magnetospheres.
  • UVS,JIRAM CAPTURE NORTHERN/SOUTHERN LIGHTS—By capturing wavelength of seventy (70) to two hundred and five (205) nm, an ultraviolet imager/spectrometer (UVS) will generate images of the auroras UV spectrum to view the auroras during the Jovian day.
  • HIGH-RESOLUTION CAMERA—JunoCam, a high-resolution color camera, will capture red, green and blue wavelengths photos of Jupiter’s atmosphere and aurora.  The NASA team expects the camera to last about seven orbits before being destroyed by radiation.

CONCLUSION:

This technology is truly amazing to me.  Think of the planning, the engineering design, the testing, the computer programming needed to bring this program to fruition.  Amazing!

 

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I remain absolutely amazed at the engineering effort involving the space probe NASA calls “NEW HORIZONS”.  The technology, hardware, software and communication package allowing the flyby is truly phenomenal—truly.  One thing that strikes me is the predictability of planetary movements so the proper trajectory may be accomplished.   Even though we live in an expanding universe, the physics and mathematics describing planetary motion is solid.  Let us take a very quick look at several specifics.

THE MISSION:

PROJECT

SPECIFICS:

  • LAUNCH:  January 19, 2006
  • Launch Vehicle:  Atlas V 551, first stage: Centaur Rocket, second stage: STAR 48B solid rocket third stage
  • Launch Location:  Cape Canaveral Air Force Station, Florida
  • Trajectory:  To Pluto via Jupiter Gravity Assist
  • The teams had to hone the New Horizons spacecraft’s 3 billion plus-mile flight trajectory to fit inside a rectangular flyby delivery zone measuring only 300 kilometers by 150 kilometers. This level of accuracy and control truly blows my mind.
  • New Horizon used both radio and optical navigation for the journey to Pluto.  Pluto is only about half the size of our Moon and circles our Sun roughly every 248 years. (I mentioned predictability earlier.  Now you see what I mean. )
  • The New Horizon craft is traveling 36,373 miles per hour and has traversed 4.67 billion miles in nine (9) years.
  • New Horizon will come as close as 7,800 miles from the surface of Pluto.
  • Using LORRI (Long Range Reconnaissance Imager) — the most crucial instrument for optical navigation on the spacecraft; the New Horizon team took short 100 to 150 millisecond exposures to minimize image smear. Such images helped give the teams an estimate of the direction from the spacecraft to Pluto.
  •  The photographs from the flyby are sensational and very detailed relative to what was expected.
  • The spacecraft flew by the Pluto–Charon system on July 14, 2015, and has now completed the science of its closest approach phase. New Horizons has signaled the event by a “phone home” with telemetry reporting that the spacecraft was healthy, its flight path was within the margins, and science data of the Pluto–Charon system had been recorded.

HARDWARE:

The hardware for the mission is given with the graphic below.  From this pictorial we see the following sub-systems:

  • PEPSSI
  • SWAP
  • LORRI
  • SDC
  • RALPH
  • ALICE
  • REX(HGA)

The explanation for each sub-system is given with the graphic.   As you can see:  an extremely complex piece of equipment representing many hours of engineering design and overall effort.

 

HARDWARE

GOALS FOR THE MISSION:

The goal of the mission is to understand the formation of the Pluto system, the Kuiper belt, and the transformation of the early Solar System.  This understanding will greatly aid our efforts in understanding how our own planet evolved over the centuries.  New Horizon will study the atmospheres, surfaces, interiors and environments of Pluto and its moons.  It will also study other objects in the Kuiper belt.  By way of comparison, New Horizons will gather 5,000 times as much data at Pluto as Mariner did at Mars.  Combine the data from New Horizons with the data from the Mariner mission and you have complementary pieces of a fascinating puzzle.

Some of the questions the mission will attempt to answer are: What is Pluto’s atmosphere made of and how does it behave?  What does its surface look like? Are there large geological structures? How do solar wind particles interact with Pluto’s atmosphere?

Specifically, the mission’s science objectives are to:

  • map the surface composition of Pluto and Charon
  • characterize the geology and morphology of Pluto and Charon
  • characterize the neutral atmosphere of Pluto and its escape rate
  • search for an atmosphere around Charon
  • map surface temperatures on Pluto and Charon
  • search for rings and additional satellites around Pluto
  • conduct similar investigations of one or more Kuiper belt objects

NOTE:  Charon is also called (134340) Pluto I and is the largest of the five known moons of Pluto.  It was discovered in 1978 at the United States Naval Observatory in Washington, D.C., using photographic plates taken at the United States Naval Observatory Flagstaff Station (NOFS). It is a very large moon in comparison to its parent body, Pluto. Its gravitational influence is such that the center of the Pluto–Charon system lies outside Pluto.

HISTORY:

When it was first discovered, Pluto was the coolest planet in the solar system. Before it was even named, TIME that “the New Planet,” 50 times farther from the sun than Earth, “gets so little heat from the sun that most substances of Earth would be frozen solid or into thick jellies.”

The astronomer Clyde W. Tombaugh, then a 24-year-old research assistant at the Lowell Observatory in Flagstaff, Ariz., was the first to find photographic evidence of a ninth planet on this day, February 18, 85 years ago.  His discovery launched a worldwide scramble to name the frozen, farthest-away planet. Since the astronomer Percival Lowell had predicted its presence fifteen (15) years earlier, per TIME, and even calculated its approximate position based on the irregularity of Neptune’s orbit, the team at Lowell Observatory considered his widow’s suggestion of “Percival,” but found it not quite planetary enough. The director of the Harvard Observatory suggested “Cronos,” the sickle-wielding son of Uranus in Greek myth.  But the team opted instead for “Pluto,” the Roman god of the Underworld — the suggestion of an 11-year-old British schoolgirl who told the BBC she was enthralled with Greek and Roman mythology. Her grandfather had read to her from the newspaper about the planet’s discovery, and when she proposed the name, he was so taken with it that he brought it to the attention of a friend who happened to be an astronomy professor at Oxford University. The Lowell team went for Pluto partly because it began with Percival Lowell’s initials.

Pluto the Disney dog, it should be noted, had nothing to do with the girl’s choice. Although the cartoon character also made its first appearance in 1930, it did so shortly after the planet was named, as the BBC noted. While Pluto was downgraded to “dwarf planet” status in 2006, it remains a popular subject for astronomers. They began discovering similar small, icy bodies during the 1990s in the same region of the solar system, which has become known as the Kuiper Belt. Just because Pluto’s not alone doesn’t make it any less fascinating, according to Alan Stern, director of a NASA mission, New Horizons that will explore and photograph Pluto in an unprecedented spacecraft flyby on July 14 of this year.

“This epic journey is very much the Everest of planetary exploration,” Stern wrote in TIME last month. “Pluto was the first of many small planets discovered out there, and it is still both the brightest and the largest one known.”

NASA released its first images of Pluto from the New Horizons mission earlier this month, although the probe was still 126 million miles away from its subject; the release was timed to coincide with Tombaugh’s birthday. Stern wrote, when the pictures were released, “These images of Pluto, clearly brighter and closer than those New Horizons took last July from twice as far away, represent our first steps at turning the pinpoint of light Clyde saw in the telescopes at Lowell Observatory eighty-five (85) years ago, into a planet before the eyes of the world this summer.”

CONCLUSION:

AMAZING ENGINEERING ACCOMPLISHMENT!

THE VEGA CHRONICLES

March 14, 2012


THE VEGA CHRONICLES

Evidence for Planets Around the Star Vega

Before we discuss the possibilities of any planet or planets existing around the star system Vega, let’s take a look at the star itself.  The following bullets will give some perspective as to position, size, mass, temperature, luminosity, etc relative to this celestial body.

  • Vega is also know as Alpha Lyrae and is the brightest star in the Constellation Lyra.  The name itself is derived from “Wega” and is Arabic for “Swooping Eagle” (Al Nasr al Waki).  It is the lower right member of the Summer Triangle and is actually visible with the naked eye from the Northern Hemisphere.  The photograph below will show the position relative to other constellation
  • Vega is the fifth (5th) brightest star visible from Earth and the third (3rd) brightest visible from mid-northern latitudes, after Sirius and Arcturus.
  • It is 25.3 light-years from Earth and is the sixth (6th) closest of the bright start if you exclude Alpha Centauri, which is not easily visible from most of the Northern Hemispheres.
  • It has a very distinct blue color with an estimated surface temperature of 17,000 degrees F, making it about 7,000 degrees F hotter than our own Sun.
  • Vega has a diameter roughly 2.5 times greater than our Sun and is slightly less in mass.  The internal pressures and temperature make it burn much faster, thus producing thirty-five to forty times the energy of the Sun.
  • Around 500 million years old, it is already middle-age and will run out of fuel in another one-half billion years. 
  • Vega radiates between thirty-seven (37 %) and fifty-eight (58 %) percent more ultraviolet light than our Sun, demonstrating a sixty-three (63%) greater abundance of elements heavier than hydrogen.

On January 10, 2005, astronomers using the infrared Spitzer Space Telescope announced that the dust ring around Vega was much larger than previously estimated.  The disk appears to be mostly composed of very fine dust particles that were probably created from collisions of protoplanetary bodies around 90 AUs (astronomical units) from the star but blown away by its intense radiation.  On the other hand, the mass and short lifetime of these small particles indicate the disk detected was created by a large and relatively recent collision that may have involved objects as big as the planet Pluto.   The irregular shape of the disk is the clue that it likely contains planets, maybe habitable planets.  Modeling suggests that a Neptune-like planet actually formed much closer to the star than its current position.  As it moved out to its current wide orbit over 56 million years, many comets were swept out with it, causing the dust ring to become “clumpy”.  This is exactly the same process that occurred during the formation of our own solar system.  The model estimates that the “clumps” in the disk will rotate around Vega once every three hundred years.  A rendition of this ring is given as follows:

It is very conceivable that this Neptune-like planet harbors some form of life.  Intelligent life, probably not as we define the term here on Earth, but life.   The irregular shape of the disk is the clue that it is likely to contain planets explains astronomer Mark Wyatt.   Although we can’t directly observe the planets, they have created clumps in the disk of dust around the star.  Another rendition of those “bumps” may be seen below.   This is an infrared photograph of the system with the position of the suggested planet being very prominent. 

Let us now take another look.  In March 2009, NASA launched the Kepler space telescope and as a result, astronomers have spotted two small, Earth-like planets orbiting, one called Kepler-20e and the other Kepler-20f.  Kepler 20-e is 1,000 light years away and in the constellation Lyra.  The very same constellation as Vega.   A graphic of the Kepler telescope is given below:

   Planet Kepler-20e is 1.03 times the diameter of Earth and three (3%) percent larger.   Researchers believe Kepler 20e orbits its sun every six days and is a blend of silicates and iron.  Kepler 20f, which orbits its sun every 20 days, is bigger and very well could have developed an atmosphere of water vapor.     Could it be possible that the star-system Vega is rightly positioned to support some form of life—intelligent or otherwise?   It would be a significant history-making event if life could be found on another planet.  The thought that we are really not alone in the universe would be shattering to some people—maybe most people.  I do think it is imperative that we continue looking with marvelous instruments like Hubble, Kepler and deep-space probes.  I also think SETI offers some aid although the Cosmos is expansive and one has to wonder where to look.  The age-old question of “why are we here”—“where did we come from” has yet to be answered.  Maybe Dr. Sagan was correct when he stated, “We are all made from star-stuff”. 

 

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