NASA’s Dawn Asteroid Orbiter successfully spiraled down today to the closest orbit the probe will ever achieve around the giant asteroid Vesta, and has now begun critical science observations that will ultimately yield the mission’s highest resolution measurements of this spectacular body.
“What can be more exciting than to explore an alien world that until recently was virtually unknown!” Dr. Marc Rayman gushed in an exclusive interview with Universe Today. Rayman is Dawn’s Chief Engineer from NASA’s Jet Propulsion Lab (JPL) in Pasadena, Calif., and a protégé of Star Trek’s Mr. Scott.
Before Dawn, Vesta was little more than a fuzzy blob in the world’s most powerful telescopes. Vesta is the second most massive object in the main Asteroid Belt between Mars and Jupiter.
Dawn is now circling about Vesta at the lowest planned mapping orbit, dubbed LAMO for Low Altitude Mapping Orbit. The spacecraft is orbiting at an average altitude of barely 130 miles (210 kilometers) above the heavily bombarded and mysterious world that stems from the earliest eons of our solar system some 4.5 Billion years ago. Each orbit takes about 4.3 hours.
“It is both gratifying and exciting that Dawn has been performing so well,” Rayman told me.
Dawn arrived in orbit at Vesta in July 2011 after a nearly 4 year interplanetary cruise since blasting off atop a Delta II rocket from Cape Canaveral, Florida in September 2007. The probe then spent the first few weeks at an initial science survey altitude of about 1,700 miles (2,700 kilometers).
Gradually the spaceship spiraled down closer to Vesta using her ion propulsion thrusters.
See Vesta science orbit diagram, below, provided courtesy of Dr. Marc Rayman.
Along the way, the international science and engineering team commanded Dawn to make an intermediate stop this past Fall 2011 at the High Altitude Mapping orbit altitude (420 miles, or 680 kilometers).
“It is so cool now to have reached this low orbit [LAMO]. We already have a spectacular collection of images and other fascinating data on Vesta, and now we are going to gain even more,” Rayman told me.
“We have a great deal of work ahead to acquire our planned data here, and I’m looking forward to every bit!
Dawn will spend a minimum of 10 weeks acquiring data at the LAMO mapping orbit using all three onboard science instruments, provided by the US, Germany and Italy.
While the framing cameras (FC) from Germany and the Visible and Infrared Mapping spectrometer (VIR) from Italy will continue to gather mountains of data at their best resolution yet, the primary science focus of the LAMO orbit will be to collect data from the gamma ray and neutron detector (GRaND) and the gravity experiment.
GRaND will measure the elemental abundances on the surface of Vesta by studying the energy and neutron by-products that emanate from it as a result of the continuous bombardment of cosmic rays. The best data are obtained at the lowest altitude.
By examining all the data in context, scientists hope to obtain a better understanding of the formation and evolution of the early solar system.
Vesta is a proto-planet, largely unchanged since its formation, and whose evolution into a larger planet was stopped cold by the massive gravitational influence of the planet Jupiter.
“Dawn’s visit to Vesta has been eye-opening so far, showing us troughs and peaks that telescopes only hinted at,” said Christopher Russell, Dawn’s principal investigator, based at UCLA. “It whets the appetite for a day when human explorers can see the wonders of asteroids for themselves.”
After investigating Vesta for about a year, the engineers will ignite Dawn’s ion propulsion thrusters and blast away to Ceres, the largest asteroid which may harbor water ice and is another potential outpost for extraterrestrial life
Dawn will be the first spaceship to orbit two worlds and is also the first mission to study the asteroid belt in detail.
Read continuing features about Dawn by Ken Kremer starting here:
NASA’s long lived Opportunity rover has discovered the most scientifically compelling evidence yet for the flow of liquid water on ancient Mars. The startling revelation comes in the form of a bright vein of the mineral gypsum located at the foothills of an enormous crater named Endeavour, where the intrepid robot is currently traversing. See our mosaic above, illustrating the exact spot.
Update: ‘Homestake’ Opportunity Mosaic above has just been published on Astronomy Picture of the Day (APOD) – 12 Dec 2011 (by Ken Kremer and Marco Di Lorenzo)
Researchers trumpeted the significant water finding this week (Dec. 7) at the annual winter meeting of the American Geophysical Union (AGU) in San Francisco.
“This gypsum vein is the single most powerful piece of evidence for liquid water at Mars that has been discovered by the Opportunity rover,” announced Steve Squyres of Cornell University, Ithaca, N.Y., Principal Investigator for Opportunity, at an AGU press conference.
The light-toned vein is apparently composed of the mineral gypsum and was deposited as a result of precipitation from percolating pools of liquid water which flowed on the surface and subsurface of ancient Mars, billions of years ago. Liquid water is an essential prerequisite for life as we know it.
“This tells a slam-dunk story that water flowed through underground fractures in the rock,” said Squyres. “This stuff is a fairly pure chemical deposit that formed in place right where we see it. That can’t be said for other gypsum seen on Mars or for other water-related minerals Opportunity has found. It’s not uncommon on Earth, but on Mars, it’s the kind of thing that makes geologists jump out of their chairs.”
The light-toned vein is informally named “Homestake”, and was examined up close by Opportunity’s cameras and science instruments for several weeks this past month in November 2011, as the rover was driving northwards along the western edge of a ridge dubbed ‘Cape York’ – which is a low lying segment of the eroded rim of Endeavour Crater.
Veins are a geologic indication of the past flow of liquid water
Opportunity just arrived at the rim of the 14 mile (22 kilometere) wide Endeavour Crater in mid-August 2011 following an epic three year trek across treacherous dune fields from her prior investigative target at the ½ mile wide Victoria Crater.
“It’s like a whole new mission since we arrived at Cape York,” said Squyres.
‘Homestake’ is a very bright linear feature.
“The ‘Homestake’ vein is about 1 centimeter wide and 40 to 50 centimeters long,” Squyres elaborated. “It’s about the width of a human thumb.”
Homestake protrudes slightly above the surrounding ground and bedrock and appears to be part of a system of mineral veins running inside an apron (or Bench) that in turn encircles the entire ridge dubbed Cape York.
In another first, no other veins like these have been seen by Opportunity throughout her entire 20 miles (33 kilometers) and nearly eight year long Martian journey across the cratered, pockmarked plains of Meridiani Planum, said Squyres.
The veins have also not been seen in the higher ground around the rim at Endeavour crater.
“We want to understand why these veins are in the apron but not out on the plains,” said the mission’s deputy principal investigator, Ray Arvidson, of Washington University in St. Louis. “The answer may be that rising groundwater coming from the ancient crust moved through material adjacent to Cape York and deposited gypsum, because this material would be relatively insoluble compared with either magnesium or iron sulfates.”
Opportunity was tasked to engage her Microscopic Imager and Alpha Particle X-ray Spectrometer (APXS) mounted on the terminus of the rover’s arm as well as multiple filters of the mast mounted Panoramic Camera to examine ‘Homestake’.
“The APXS spectrometer shows ’Homestake’ is chock full of Calcium and Sulfur,” Squyres gushed.
The measurements of composition with the APXS show that the ratio points to it being relatively pure calcium sulfate, Squyres explained. “One type of calcium sulfate is gypsum.”
Calcium sulfate can have varying amounts of water bound into the minerals crystal structure.
The rover science team believes that this form of gypsum discovered by Opportunity is the dihydrate; CaSO4•2H2O. On Earth, gypsum is used for making drywall and plaster of Paris.
The gypsum was formed in the exact spot where Opportunity found it – unlike the sulfate minerals previously discovered which were moved around by the wind and other environmental and geologic forces.
“There was a fracture in the rock, water flowed through it, gypsum was precipitated from the water. End of story,” Squyres noted. “There’s no ambiguity about this, and this is what makes it so cool.”
At Homestake we are seeing the evidence of the ground waters that flowed through the ancient Noachian rocks and the precipitation of the gypsum, which is the least soluble of the sulfates, and the other magnesium and iron sulfates which Opportunity has been driving on for the last 8 years.
“Here, both the chemistry, mineralogy, and the morphology just scream water,” Squyres exclaimed. “This is more solid than anything else that we’ve seen in the whole mission.”
It’s inconceivable that the vein is something else beside gypsum, said Squyres.
As Opportunity drove from the plains of Meridiani onto the rim of Endeavour Crater and Cape York, it crossed a geologic boundary and arrived at a much different and older region of ancient Mars.
The evidence for flowing liquid water at Endeavour crater is even more powerful than the silica deposits found by Spirit around the Home Plate volcanic feature at Gusev Crater a few years ago.
“We will look for more of these veins in the [Martian] springtime,” said Squyres.
If a bigger, fatter vein can be found, then Opportunity will be directed to grind into it with her still well functioning Rock Abrasion Tool, or RAT.
Homestake was crunched with the wheels – driving back and forth over the vein – to break it up and expose the interior. Opportunity did a triple crunch over Homestake, said Arvidson.
Homestake was found near the northern tip of Cape York, while Opportunity was scouting out a “Winter Haven” location to spend the approaching Martian winter.
Arvidson emphasized that the team wants Opportunity to be positioned on a northerly tilted slope to catch the maximum amount of the sun’s rays to keep the rover powered up for continuing science activities throughout the fast approaching Martian winter.
“Martian winter in the southern hemisphere starts on March 29, 2012. But, Solar power levels already begin dropping dramatically months before Martian winter starts,” said Alfonso Herrera to Universe Today, Herrera is a Mars rover mission manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
“Opportunity is in excellent health,” said Bruce Banerdt, the Project Scientist for the Mars rover mission at JPL.
“This has been a very exciting time. We’ll head back south in the springtime and have a whole bunch of things to do with a very capable robot,” Squyres concluded.
Meanwhile, NASA’s next leap in exploring potential Martian habitats for life – the car sized Curiosity Mars Science Lab rover – is speeding towards the Red Planet.
Read Ken’s continuing features about Opportunity starting here:
[/caption]According to a new set of NASA computer simulations, solar storms and Coronal Mass Ejections (CMEs) can erode the lunar surface. Researchers speculate that not only can these phenomena erode the lunar surface, but could also be a cause of atmospheric loss for planets without a global magnetic field, such as Mars.
A team led by Rosemary Killen at NASA’s Goddard Space Flight Center, has written papers exploring different aspects of these phenomena and will appear in an issue of the Journal of Geophysical Research Planets. The team’s research was also presented earlier this week during the fall meeting of the American Geophysical Union.
What are CME’s? Corona Mass Ejections are intense outbursts of the Sun’s usually normal solar wind which consists of electrically charged particles (plasma). CME’s blow outward from the surface of the Sun at speeds in excess of 1.6 million kilometers per hour into space and can contain over a billion tons of plasma in a cloud larger than Earth.
Our Moon has the faintest traces of an atmosphere, which is technically referred to as an exosphere. The lack of any significant atmosphere, combined with the lack of a magnetic field, makes the lunar surface vulnerable to the effects of CME’s.
William Farrell, DREAM (Dynamic Response of the Environment at the Moon) team lead at NASA Goddard, remarked, “We found that when this massive cloud of plasma strikes the Moon, it acts like a sandblaster and easily removes volatile material from the surface. The model predicts 100 to 200 tons of lunar material – the equivalent of 10 dump truck loads – could be stripped off the lunar surface during the typical 2-day passage of a CME.”
While CME’s have been extensively studied, Farrell’s research is the first of its kind that attempts to predict the effects of a CME on the Moon. “Connecting various models together to mimic conditions during solar storms is a major goal of the DREAM project” added Farrell.
When intense heat or radiation is applied to a gas, the electrons can be removed, turning the atoms into ions. This process is referred to as “ionization”, and creates the fourth form of matter, known as plasma. Our Sun’s intense heat and radiation excites gaseous emissions, thus creating a solar wind plasma of charged particles. When plasma ions eject atoms from a surface, the process is called “sputtering”.
The lead author of the research paper Rosemary Killen described this phenomenon: “Sputtering is among the top five processes that create the Moon’s exosphere under normal solar conditions, but our model predicts that during a CME, it becomes the dominant method by far, with up to 50 times the yield of the other methods.”
In an effort to better test the team’s predictions, studies will be performed using NASA’s Lunar Atmosphere And Dust Environment Explorer (LADEE). Scheduled to launch in 2013 and orbit the Moon, the team is confident that the strong sputtering effect will send atoms from the lunar surface to LADEE’s orbital altitude (20 to 50 km).
Farrell also added, “This huge CME sputtering effect will make LADEE almost like a surface mineralogy explorer, not because LADEE is on the surface, but because during solar storms surface atoms are blasted up to LADEE.”
Affecting more than just our Moon, solar storms also affect Earth’s magnetic field and are the root cause of the Northern and Southern lights (aurorae). The effect solar storms have on Mars is a bit more significant, due in part to the Red Planet’s lack of a planet-wide magnetic field. It is widely theorized that this lack of a magnetic field allows the solar wind and CME’s to erode the martian atmosphere. In late 2013, NASA will launch the Mars Atmosphere and Volatile Evolution (MAVEN) mission. The goal of MAVEN is to orbit Mars and help researchers better understand how solar activity, including CMEs, affects the atmosphere of the red planet.
The giant Asteroid Vesta is among the most colorful bodies in our entire solar system and it appears to be much more like a terrestrial planet than a mere asteroid, say scientists deciphering stunning new images and measurements of Vesta received from NASA’s revolutionary Dawn spacecraft. The space probe only recently began circling about the huge asteroid in July after a four year interplanetary journey.
Vesta is a heavily battered and rugged world that’s littered with craters and mysterious grooves and troughs. It is the second most massive object in the Asteroid Belt and formed at nearly the same time as the Solar System some 4.5 Billion years ago.
“The framing cameras show Vesta is one of the most colorful objects in the solar system,” said mission scientist Vishnu Reddy of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany. “Vesta is unlike any other asteroid we have visited so far.”
Scientists presented the new images and findings from Dawn at the American Geophysical Union meeting this week in San Francisco.
“Vesta is a transitional body between a small asteroid and a planet and is unique in many ways,” Reddy said. “We do not know why Vesta is so special.”
Although many asteroids look like potatoes, Reddy said Vesta reminds him more of an avocado.
Asteroid Vesta is revealed as a ‘rainbow-colored palette’ in a new image mosaic (above) showcasing this alien world of highly diverse rock and mineral types of many well-separated layers and ingredients.
Researchers assigned different colors as markers to represent different rock compositions in the stunning new mosaic of the asteroid’s southern hemisphere.
The green areas in the mosaic suggest the presence of the iron-rich mineral pyroxene or large-sized particles, according to Eleonora Ammannito, from the Visible and Infrared (VIR) spectrometer team of the Italian Space Agency. The ragged surface materials are a mixture of rapidly cooled surface rocks and a deeper layer that cooled more slowly.
What could the other colors represent?
“The surface is very much consistent with the variability in the HED (Howardite-Eucritic-Diogenite) meteorites,” Prof. Chris Russell, Dawn Principal Investigator (UCLA) told Universe Today in an exclusive interview.
“There is Diogenite in varying amounts.”
“The different colors represent in part different ratios of Diogenite to Eucritic material. Other color variation may be due to particle sizes and to aging,” Russell told me.
No evidence of volcanic materials has been detected so far, said David Williams, Dawn participating scientist of Arizona State University, Tucson.
Before Dawn arrived, researchers expected to observe indications of volcanic activity. So, the lack of findings of volcanism is somewhat surprising. Williams said that past volcanic activity may be masked due to the extensive battering and resultant mixing of the surface regolith.
“More than 10,000 high resolution images of Vesta have been snapped to date by the framing cameras on Dawn,” Dr. Marc Rayman told Universe Today. Rayman is Dawn’s Chief Engineer from NASA’s Jet Propulsion Lab (JPL) in Pasadena, Calif.
Dawn will spend a year in orbit at Vesta and investigate the asteroid at different altitudes with three on-board science instruments from the US, Germany and Italy.
The probe will soon finish spiraling down to her lowest mapping orbit known as LAMO (Low Altitude Mapping Orbit), approximately 130 miles (210 kilometers) above Vesta’s surface.
“Dawn remains on course to begin its scientific observations in LAMO on December 12,” said Rayman.
The German Aerospace Center and the Max Planck Institute for Solar System Research provided the Framing Camera instrument and funding as international partners on the mission team. The Visible and Infrared Mapping camera was provided by the Italian Space Agency.
In July 2012, Rayman and the engineering team will fire up Dawn’s ion propulsion system, break orbit and head to Ceres, the largest asteroid and what a number of scientists consider to be a planet itself.
Ceres is believed to harbor thick caches of water ice and therefore could be a potential candidate for life.
Read continuing features about Dawn by Ken Kremer starting here:
Voyager 1 is in uncharted territory. The long-lived spacecraft has entered a new region of space that lies between where our solar system ends and where interstellar space begins. This area is not a place of sightseeing however, as a NASA press release referred to it as a kind of “cosmic purgatory.”
Here, the solar winds ebb somewhat, the magnetic field increases and charged particles from within our solar system – is leaking out into interstellar space. This data has been compiled from information received from Voyager 1 over the course of the last year.
“Voyager tells us now that we’re in a stagnation region in the outermost layer of the bubble around our solar system,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “Voyager is showing that what is outside is pushing back. We shouldn’t have long to wait to find out what the space between stars is really like.”
Despite the fact that Voyager 1 is approximately 11 billion miles (18 billion kilometers) distant from the sun – it still has not encounter interstellar space. The information that scientists have gleaned from the Voyager 1 spacecraft indicates that the spacecraft is still located within the heliosphere. The heliosphere is a “bubble” of charged particles that the sun blows around itself and its retinue of planets.
The latest findings were made using Voyager’s Low Energy Charged Particle instrument, Cosmic Ray Subsystem and Magnetometer.
Experts are not certain how long it will take the Voyager 1 spacecraft to finally breach this bubble and head out into interstellar space. Best estimates place the length of time when this could happen anywhere from the next few months – to years. These findings counter findings announced in April of 2010 that showed that Voyager 1 had essentially crossed the heliosphere boundary. The discoveries made during the past year hint that this region of space is far more dynamic than previously thought.
The magnetometer aboard Voyager 1 has picked up an increase in the intensity of the magnetic field located within this “stagnation field.” Essentially the inward pressure from interstellar space is compressing the magnetic field to twice its original density. The spacecraft has also detected a 100-fold increase in the intensity of high-energy electrons diffusing into our solar system from outside – this is yet another indicator that Voyager 1 is approaching the heliosphere.
The interplanetary probe was launched from Cape Canaveral Air Force Station’s Space Launch Complex 41 (SLC-41) on Sept. 5, 1977, Voyager 1’s sister ship, Voyager 2 is also in good health and is about 9 billion miles (15 billion kilometers) from the sun (it too was launched in 1977). The spacecraft itself was built by NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
“Voyager is a mission of discovery and it’s at the edge of the solar system still making discoveries,” said Stone said. “The stagnation is the latest in the whole journey of discovery. We are all excited because we believe it means we’re getting very close to boundary of heliosphere and the entry into interstellar space.”
For a birds-eye view of where it all started, watch the cool close-up launch video, below taken from within the Atlas pad security fence.
Indeed the launch precision was so good that mission controllers at NASA’s Jet Propulsion Lab in Pasadsena, Calif., have announced they postponed the first of six planned course correction burns for the agency’s newest Mars rover by at least a month. The firing had been planned for some two weeks after liftoff.
Curiosity is merrily sailing on a 254 day and 352-million-mile (567-million-kilometer) interplanetary flight from the Earth to Mars that will culminate on August 6, 2012 with a dramatic first-of-its-kind precision rocket powered touchdown inside Gale Crater.
“This was among the most accurate interplanetary injections ever,” said Louis D’Amario of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. He is the mission design and navigation manager for the Mars Science Laboratory.
Video Caption: View from inside the Pad 41 Security Fence at Cape Canaveral. Shot by a Canon 7D still camera during the launch of the Atlas V rocket carrying the MSL Curiosity rover to Mars. Thanks to a sound trigger my camera started firing at three frames per second from just after main engine ignition up until the exhaust plume finally envelops the camera and deadens all sound around it. The frames have been slowed down quite a bit for dramatic effect. Enjoy seeing what it is like for us media personnel who set out our remote cameras for launches at Kennedy Space Center and Cape Canaveral, Florida. Credit: Chase Clark/shuttlephotos.com
As of midday Friday, Dec. 2, the spacecraft had already traveled 10.8 million miles (17.3 million kilometers) and is moving at 7,500 mph (12,000 kilometers per hour) relative to Earth and at 73,800 mph (118,700 kilometers per hour) relative to the sun.
An interesting fact is that engineers deliberately planned the spacecraft’s initial trajectory to miss Mars by about 35,000 miles (56,400 kilometers) so that the Centaur upper stage does not hit Mars by accident. Both Centaur and Curiosity are currently following the same trajectory through the vast void of space and the actual trajectory puts them on course to miss Mars by about 38,000 miles (61,200 kilometers).
The Centaur has not been thoroughly cleaned of earthly microbes in the same way as Curiosity – and therefore cannot be permitted to impact the Martian surface and potentially contaminate the very studies Curiosity seeks to carry out in searching for the “Signs of Life”.
For the 8.5 month voyage to Mars, Curiosity and the rocket powered descent stage are tucked inside an aeroshell and are attached to the huge solar powered cruise stage.
The cruise stage is rotating at 2.05 rounds per minutes and is continuously generating electric power – currently about 800 watts – from the gleaming solar arrays. It also houses eight miniature hydrazine fueled thrusters. The propellant is stored inside titanium tanks.
The historic voyage of the largest and most sophisticated Martian rover ever built by humans seeks to determine if Mars ever offered conditions favorable for the genesis of microbial life.
Curiosity is packed to the gills with 10 state of the art science instruments that are seeking to detect the signs of life in the form of organic molecules – the carbon based building blocks of life as we know it.
The car sized robot is equipped with a drill and scoop at the end of its 7 ft long robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into two distinct analytical laboratory instruments inside the rover.
It may not have noticed anything different as it continued its high-speed trek through interplanetary space, but today New Horizons passed a new milestone: it is now (and will be for quite some time) the closest spacecraft ever to Pluto!
This breaks the previous record held by Voyager 1, which came within 983 million miles (1.58 billion km) of the dwarf planet on January 29, 1986.
New Horizons has been traveling through the solar system since its launch on January 19, 2006 and is now speeding toward Pluto at around 34,500 mph (55,500 km/hr). It has thus far traveled for 2,143 days and is just over halfway to the distant icy world.
“Although we’re still a long way — 1.5 billion kilometers from Pluto — we’re now in new territory as the closest any spacecraft has ever gotten to Pluto, and getting closer every day by over a million kilometers.”
– Alan Stern, New Horizons Principal Investigator
A gravity boost obtained by a close pass of Jupiter in 2007 gave the spacecraft the extra speed needed to make it to Pluto by 2015. (Without that, it wouldn’t have been reaching Pluto until 2036!)
Achievements like this are wonderful indicators that New Horizons is alive and well and that its historic goal is getting increasingly closer every day.
“We’ve come a long way across the solar system,” said Glen Fountain, New Horizons project manager at the Johns Hopkins University Applied Physics Laboratory (APL). “When we launched it seemed like our 10-year journey would take forever, but those years have been passing us quickly. We’re almost six years in flight, and it’s just about three years until our encounter begins.”
See answers to some FAQs about Pluto
New Horizons will pass by Pluto and its moons on July 14, 2015, becoming the first spacecraft ever to visit the distant system. It will image Pluto’s surface in unprecedented detail, resolving features as small as 200 feet (60 meters) across.
New Horizons will not land or enter orbit around Pluto but instead quickly pass by and continue on into the Kuiper Belt, where even more distant frozen worlds await. The New Horizons team is currently investigating further exploration targets should its mission be extended.
It’s time to put on your 3-D glasses and go soaring all over the giant asteroid Vesta – thanks to the superlative efforts of Dawn’s international science team.
Now you can enjoy vivid ‘Vestan Vistas’ like you’ve never ever seen before in a vibrant 3 D video newly created by Dawn team member Ralf Jaumann, of the German Aerospace Center (DLR) in Berlin, Germany – see below.
To fully appreciate the rough and tumble of the totally foreign and matchless world that is Vesta, you’ll absolutely have to haul out your trusty red-cyan (or red-blue) 3 D anaglyph glasses.
Then hold on, as you glide along for a global gaze of mysteriously gorgeous equatorial groves ground out by a gargantuan gong, eons ago.
Along the way you’ll see an alien ‘Snowman’ and the remnants of the missing South Pole, including the impressive Rheasilvia impact basin – named after a Vestal virgin – and the massive mountain some 16 miles (25 kilometers) high, or more than twice the height of Mt. Everest.
Video Caption: This 3-D video incorporates images from the framing camera instrument aboard NASA’s Dawn spacecraft from July to August 2011. The images were obtained as Dawn approached Vesta and circled the giant asteroid during the mission’s survey orbit phase at an altitude of about 1,700 miles (2,700 kilometers). To view this video in 3-D use red-green, or red-blue, glasses (left eye: red; right eye: green/blue). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“If you want to know what it’s like to explore a new world like Vesta, this new video gives everyone a chance to see it for themselves,” Jaumann said. “Scientists are poring over these images to learn more about how the craters, hills, grooves and troughs we see were created.”
NASA’s Dawn spacecraft is humanity’s first probe to investigate Vesta, the second most massive body in the main Asteroid Belt between Mars and Jupiter.
Video caption: 2 D rotation movie of Vesta. Compare the 2 D movie to the new 3 D movie. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.
Indeed Dawn was just honored by Popular Science magazine and recognized as one of three NASA Planetary Science missions to earn a ‘Best of What’s New in 2011’ for innovation in the aviation and space category – along with the Curiosity Mars Science Laboratory (MSL) and MESSENGER Mercury orbiter.
The images in the 3 D video were snapped between July and August 2011 as Dawn completed the final approach to Vesta, achieved orbit in July 2011 and circled overhead during the mission’s initial survey orbit phase at an altitude of about 1,700 miles (2,700 kilometers) in August.
How was the 3 D movie created?
“The Dawn team consists of a bunch of talented people. One of those talented people is Ralf Jaumann, Dawn co-Investigator from the DLR in Berlin,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.
“Jaumann and the team behind him have stitched together the mosaics we see and they have made shape models of the surface. They are also skilled communicators and have been heroes in getting the Dawn Image of the Day together. I owe them much thanks and recognition for their efforts.”
“They wanted to make and release to the public an anaglyph of the rotating Vesta to share with everyone the virtual thrill of flying over this alien world.”
“I hope everyone who follows the progress of Dawn will enjoy this movie as much as I do.”
“It is just amazing to an old-time space explorer as myself that we can now make planetary exploration so accessible to people all over our globe in their own homes and so soon after we have received the images,” Russell told me.
Dawn is now spiraling down to her lowest mapping orbit known as LAMO (Low Altitude Mapping Orbit), barely 130 miles (210 kilometers) above Vesta’s surface.
“Dawn remains on course and on schedule to begin its scientific observations in LAMO on December 12,” says Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif.
“The focus of LAMO investigations will be on making a census of the atomic constituents with its gamma ray and neutron sensors and on mapping the gravity field in order to determine the interior structure of this protoplanet.”
“Today, Dawn is at about 245 km altitude,” Rayman told Universe Today.
The 3 D video is narrated by Carol Raymond, Dawn’s deputy principal investigator at JPL.
“Dawn’s data thus far have revealed the rugged topography and complex textures of the surface of Vesta, as can be seen in this video”.
“Soon, we’ll add other pieces of the puzzle such as the chemical composition, interior structure, and geologic age to be able to write the history of this remnant protoplanet and its place in the early solar system.”
Read continuing features about Dawn by Ken Kremer starting here:
A trio of NASA’s Planetary Science mission’s – Mars Science Laboratory (MSL), Dawn and MESSENGER – has been honored by Popular Science magazine and selected as ‘Best of What’s New’ in innovation in 2011 in the aviation and space category.
The Curiosity Mars Science Laboratory was just launched to the Red Planet on Saturday, Nov. 26 and will search for signs of life while traversing around layered terrain at Gale Crater. Dawn just arrived in orbit around Asteroid Vesta in July 2011. MESSENGER achieved orbit around Planet Mercury in March 2011.
Several of the top mission scientists and engineers provided exclusive comments about the Popular Science recognitions to Universe Today – below.
“Of course we are all very pleased by this selection,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.
Dawn is the first mission ever to specifically investigate the main Asteroid Belt between Mars and Jupiter and will orbit both Vesta and Ceres – a feat enabled solely thanks to the revolutionary ion propulsion system.
“At the same time I must admit we are also not humble about it. Dawn is truly an amazing mission. A low cost mission, using NASA’s advanced technology to enormous scientific advantage. It is really, really a great mission,” Russell told me.
Vesta is the second most massive asteroid and Dawn’s discoveries of a surprisingly dichotomous and battered world has vastly exceeded the team’s expectations.
“Dawn is NASA at its best: ambitious, exciting, innovative, and productive,” Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif., told Universe Today.
“This interplanetary spaceship is exploring uncharted worlds. I’m delighted Popular Science recognizes what a marvelous undertaking this is.”
JPL manages both Dawn and Mars Science Laboratory for NASA’s Science Mission Directorate in Washington, D.C.
Dawn is an international science mission. The partners include the German Aerospace Center (DLR), the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute.
“Very cool!”, John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.
“MSL packs the most bang for the buck yet sent to Mars.”
Curiosity is using an unprecedented precision landing system to touch down inside the 154 km (96 miile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering mountain.
“10 instruments all aimed at a mountain higher than any in the lower 48 states, whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life.”
“It’s like a trip down the Grand Canyon 150 years ago, with the same sense of adventure, but with a lot of high tech equipment,” Grotzinger told me.
MSL also has an international team of over 250 science investigators and instruments spread across the US, Europe and Russia.
MESSENGER is the first probe to orbit Mercury and the one year primary mission was recently extended by NASA.
Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.
“Planetary has 3 missions there… Dawn, MESSENGER, and MSL,” Jim Green proudly said to Universe Today regarding the Popular Science magazine awards. Green is the director, Planetary Science Division, NASA Headquarters, Washington
“Three out of 10 [awards] is a tremendous recognition of the fact that each one of our planetary missions goes to a different environment and takes on new and unique measurements providing us new discoveries and constantly changes how we view nature, ourselves, and our place in the universe.”
Read more about the Popular Science citations and awards here
.
Read continuing features about Curiosity, Dawn and MESSENGER by Ken Kremer starting here:
Launch video provided courtesy of United Launch Alliance
CAPE CANAVERAL, Fla – It is a mission years in the making. However, it would not be possible without the hard work of an army’s worth of engineers – and the systems that they built. How many different systems and engines are required to get the Mars Science Laboratory (MSL) rover named Curiosity to the surface of the Red Planet? The answer might surprise you.
Including the two engines that are part of the Atlas V 541 launch vehicle, it will take 50 different engines and thrusters in total to work perfectly to successfully deliver Curiosity to the dusty plains of Mars.
Starting with the launch vehicle itself, there are six separate engines that power the six-wheeled rover, safely ensconced in its fairing, out of Earth’s gravity well. For the first leg of the journey four powerful Solid Rocket Boosters (SRBs) provided by Aerojet (each of these provides 400,000 lbs of thrust) will launch the rover out of Earth’s atmosphere.
The United Launch Alliance (ULA) Atlas launch vehicle has two rocket engines that provide the remaining amount of thrust required to get MSL to orbit and send the rover on its way to Mars. The first is the Russian-built RD-180 engine (whose thrust is split between two engine bells) the second is the Centaur second stage. There are four Aerojet solid rocket motors that help the booster and Centaur upper stage to separate.
The Centaur’s trajectory is controlled by both thrust vector control of the main engine as well as a Reaction Control System or RCS comprised of liquid hydrazine propulsion systems (there are twelve roll control thrusters on the Centaur upper stage).
MSL’s cruise stage separates entirely from the Centaur upper stage and is on the long road to the Red Planet. The cruise stage has eight one-pound-thrust hydrazine thrusters that are used for trajectory maneuvers for the nine-month journey to Mars. These are used for minor corrections to keep the spacecraft on the correct course.
Curiosity’s first physical encounter with the Martian environment is referred to as Entry, Descent and Landing (EDL) – more commonly known as “six minutes of terror” – the point when mission control, back on Earth, loses contact with the spacecraft as it enters the Martian atmosphere.
Video courtesy of Lockheed Martin
Even though Mars only has roughly one percent of Earth’s atmosphere, the friction of the atmosphere caused by a spacecraft impacting it at 13,200 miles per hour (about 5,900 meters per second) – is enough to melt Curiosity if it were exposed to these extremes. The heat shield, located at the base of the cruise stage, prevents this from happening.
The heat shield, provided by Lockheed-Martin, on MSL’s cruise stage is 14.8 feet (4.5 meters) in diameter. By comparison, the heat shields that were used on the Apollo manned missions to the Moon were 13 feet (4 meters) in diameter and the ones that allowed the Mars Exploration Rovers Spirit and Opportunity to safely reach the surface of Mars were 8.7 feet (2.65 meters) in diameter.
[/caption]
At this point in the mission eight engines, each providing 68 pounds of thrust come into play. These engines provide all of the trajectory control during EDL – meaning they will fire almost continuously.
Shortly thereafter – BOOM – the parachute deploy. Then the heat shield is ejected. After the parachute slow the spacecraft down to a sufficient degree, both they and the back aeroshell depart leaving just the rover and its jet pack.
During the landing phase the “SkyCrane” comes alive with eight powerful hydrazine engines, each of which give Curiosity 800 pounds of thrust. Aerojet’s Redmond Site Executive, Roger Myers, talked a bit about this segment of the landing, considered by many to be the most dramatic method of getting a vehicle to the surface of Mars.
“Because of the control requirements for the SkyCrane these engines had to be very throttleable,” Myers said. “Keeping the SkyCrane level is a must, you must have very fine control of those engines to ensure stability.”
If all has gone well up to this point, the Curiosity rover will be lowered the remaining distance to the ground via cables. Once contact with the Martian surface is detected, the cables are cut, the SkyCrane’s engines throttle up and the jet pack flies off to conduct a controlled crash (approximately a mile or so away from where Curiosity is located).
Every powered landing on Mars conducted in the U.S. unmanned space program has utilized Aerojet’s thrusters. The reliability of these small engines was recently proven – in a mission that is now almost three-and-a-half decades old.
Voyager recently conducted a course correction some 34 years after it was launched – highlighting the capability of these thrusters to perform well after launch.
“Our engines have allowed missions to fly to every planet in the solar system and we are currently on our way to Mercury and Pluto,” Myers said. “When NASA explores the solar system – Aerojet provides the propulsion components.”