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Deep Impact Reveals Comet’s Components

Monday, July 17, 2006

Comet materials
Image: COURTESY OF NASA/JPL-CALTECH/R. HURT 200x175

The Fourth of July last year had some extra fireworks. NASA's Deep Impact spacecraft sent a hefty projectile--more than 800 pounds--into the body of the comet known as Tempel 1. The collision delivered 19 gigajoules of energy--the equivalent of nearly five tons of explosive TNT--into the wandering comet and ejected a plume of its innermost secrets. Roughly 10 million kilograms of comet stuff (more than 22 million pounds) spread out into space, giving scientists a rare glimpse of the ingredients that go into making a comet. Now researchers observing with the Spitzer Space Telescope have revealed their findings: comets contain a mix of materials that formed under widely divergent conditions.

Read more at SCIENCE NEWS -Deep Impact Reveals Comet's Components

Despite Balky Sensor, Venus Express Ready for Operations

Monday, July 17, 2006

Paris - Europe's Venus Express satellite, which entered Venus orbit in April, has cleared its commissioning phase and is ready to begin formal operations despite the fact that one of its seven observing instruments is not functioning, the European Space Agency (ESA) said July 12.

Venus Express satellite
Venus Express satellite
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The Planetary Fourier Spectrometer (PFS), which encountered problems in May, is stuck in "closed" position despite weeks of efforts to return the instrument to operations, ESA said.

"[A] series of activities and further in-orbit tests [will] be conducted in the next months, as well as a series of independent investigations, to examine the origin of the problem," ESA said in a July 12 statement on Venus Express' status. "In the meantime, other instruments will cover some of the PFS objectives."

The PFS is designed to measure Venus' surface and atmospheric temperature. Part of its mission is to hunt for volcanic activity on the planet.

Venus Express was launched in November 2005 and entered Venus orbit in April, after which it began adjusting its position to arrive at the highly elliptical orbit in which it will operate. The satellite will view Venus from distances of between 66,000 kilometers and 250 kilometers.

Credit: Space.com, Peter de Selding--Despite Balky Sensor, Venus Express Ready for Operations

NASA-Funded Study Says Saturn's Moon Enceladus Rolled Over

Monday, June 5, 2006

Saturn's moon Enceladus - an active, icy world with an unusually warm south pole - may have performed an unusual trick for a planetary body. New research shows Enceladus rolled over, literally, explaining why the moon's hottest spot is at the south pole.

Enceladus
Image right: This graphic illustrates the interior of Saturn's moon Enceladus. It shows warm, low-density material rising to the surface from within, in its icy shell (yellow) and/or its rocky core (red). Image credit: NASA/JPL/Space Science Institute 200x200

Enceladus recently grabbed scientists' attention when the Cassini spacecraft observed icy jets and plumes indicating active geysers spewing from the tiny moon's south polar region.

"The mystery we set out to explain was how the hot spot could end up at the pole if it didn't start there," said Francis Nimmo, assistant professor of Earth sciences, University of California, Santa Cruz.

The researchers propose the reorientation of the moon was driven by warm, low-density material rising to the surface from within Enceladus. A similar process may have happened on Uranus' moon Miranda, they said. Their findings are in this week's journal Nature.

More on Enceladus. Credit: NASA

Voyager 2 Detects Odd Shape of Solar System's Edge

Friday, May 26, 2006

VoyagerVoyager 2 could pass beyond the outermost layer of our solar system, called the "termination shock," sometime within the next year. The milestone, which comes about a year after Voyager 1's crossing, comes earlier than expected and suggests to scientists that the edge of the shock is about one billion miles closer to the Sun in the southern region of the solar system than in the north.
This implies that the heliosphere, a spherical bubble of charged low-energy particles created by our Sun's solar wind, is irregularly shaped, bulging in the northern hemisphere and pressed inward in the south.
Scientists determined that Voyager 1 was approaching the termination shock when it began detecting charged particles that were being pushed back toward the Sun by charged particles coming from outside our solar system. This occurred when Voyager 1 was about 85 AU from the Sun.
One AU is the distance between the Earth and the Sun, or 93 million miles.
In contrast, Voyager 2 began detecting returning particles while only 76 AU from the Sun.
"This tells us that the shock down where Voyager 2 is must be closer the sun than where Voyager 1 is," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena.
The researchers think that the heliosphere's asymmetry might be due to a weak interstellar magnetic field pressing inward on the southern hemisphere.
"The [magnetic] field is only 1/100,000 of the field on the Earth's surface, but it's over such a large area and pushing on such a faint gas that it can actually push the shock about a billion miles in," Stone explained.

credit: Space.com, Ker Than

NASA to BLast the Moon in Search of Water

Tuesday, May 9, 2006

LCROSS

In this artist's rendering, the satellite and the launcher's second stage approach the moon. Meanwhile, the Lunar Reconnaissance Orbiter is orbiting the moon.
Credit: NASA/John Frassanito and Associates

NASA will send an impactor spacecraft to the moon with liftoff of the Lunar Reconnaissance Orbiter, scheduled for October 2008. The Lunar Crater Observation and Sensing Satellite (LCROSS) will travel independently of the orbiter and crash violently into the lunar surface, at a speed of 5,592 miles per hour (or about 2.5 kilometers per second) to search for water. It should blast out a crater about a hundred feet wide and 15 feet deep.

First, the craft will direct the upper stage used to leave Earth orbit to crash into a permanently-shadowed crater at the lunar south pole, creating a plume visible on Earth through a telescope. Next, the satellite will observe the plume and fly through it using several instruments to look for water. At the end of its mission, the satellite will itself become an impactor, creating a second plume visible to lunar-orbiting spacecraft and Earth-based observants.


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HiRise to the Red Planet

Wednesday, April 12, 2006

Newly Released Images

HiRISE images
First MRO HiRISE Image of Mars: Topographic Model from Photoclinometry.
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Employees of the USGS Astrogeology Research Program celebrate the public release of the first images productively captured by the High Resolution Imaging Science Experiment(HiRISE) camera, which is one of six instruments on board the Mars Reconnaissance Orbiter (MRO).

"I am VERY happy!" said Alfred McEwen, former employee of USGS, Principal Investigator and chief scientist of MRO,while viewing the images. "They are sharp, clear, and beautiful!"

The HiRISE camera is the most powerful telescopic camera ever sent to another planet. It productively took four images of Mars on March 23, 2006. The actual launch of MRO took place August 25, 2005.

Astrogeology Research Program personnel are major players in The HiRISE Operations Center (HiROC) at the University of Arizona's Lunar and Planetary Laboratory, who are responsible for the majority of the ground data system work for the HiRISE instrument. Astrogeology's programming group is developing software , which will encompass tools for any person who desires to work with HiRise data. Other personnel are co-investigators, coordinators, and leads in varying disciplines that are involved in the observation planning, uplink, downlink, data processing, and instrument monitoring. For example, Randolph Kirk (Co-Investigator geodesy, geometric calibration, and topographic mapping lead) has applied a technique called photoclinometry (or, more descriptively, "shape-from-shading") on a subset of AEB_000001_0000_Red, to produce a preliminary topographic map which covers a portion of this first image of Mars obtained by the HiRISE camera on March 24, 2006. Photoclinometry reveals the details of the smallest topographic features resolved by the image. Elevations can be reconstructed from an image by noting how surfaces sloping toward the sun appear brighter than areas that slope away from it.

Anyone who has seen the newly released HiRISE images will concur that they are simply dynamic! Here is how the images are captured: The HiRISE camera takes the image, and then transfers it to the MRO spacecraft electronics. MRO then sends the image to Earth using radio waves. It takes 13 minutes currently for images to travel to Earth, (the distance between the Earth and Mars varies with time due to their different orbits around the Sun) since radio waves travel at the speed of light. NASA's Deep Space Network receives the image data on Earth using its antennas in California, Spain and Australia, which cover the whole globe. The DSN then sends the images to the Jet Propulsion Laboratory, who reassembles the images and processes them.

Although we space enthusiasts may have to wait six months for more images, while MRO aerobrakes, we can look forward to user-friendly web tools available to both the science community and the public to view and/or analyze the HiRISE images. One thing interested parties shouldn't wait for is to make an observation request. What's more exciting is that processed images will be released soon after acquisition to allow everyone to share in the scientific HiRise to the Red Planet!

Show me more newly released images.

Status Report: NASA MESSENGER Passes the Billion-Mile Mark!

Wednesday, March 29, 2006

On March 23 MESSENGER reached the one-billion mile mark, placing the spacecraft about one-fifth of the way toward its destination to orbit Mercury. On that same day, in the early morning hours (UTC), the spacecraft's distance from the Sun was about the same as the Earth's distance to the Sun. "One billion miles and the team and spacecraft are doing well," says Mission Operations Manager Mark Holdridge of the Johns Hopkins Applied Physics Laboratory (APL), where the spacecraft is operated and where it was designed and built.

The MESSENGER spacecraft performed its final "flop" maneuver for the mission on March 8, pointing the back side of the spacecraft to the Sun until June 2006. This rotation about the X-axis is performed whenever the solar distance increases beyond approximately 0.95 astronomical units (AU), nearly the distance between the Earth and the Sun. At this distance, the solar arrays do not generate enough power to operate all spacecraft components simultaneously, including instruments and heaters. The "flop" is performed to heat the back side of the spacecraft with the Sun. A "flip" maneuver reverses the effect of the "flop" maneuver by pointing the sunshade toward the Sun. This solar heating reduces the need for multiple onboard heaters, providing the necessary power until the spacecraft is closer to the Sun again. Previous flip, flop, and flip maneuvers were performed on March 8, 2005, June 14, 2005, and September 7, 2005. The spacecraft is scheduled to flip back toward the Sun on June 21.

Even though the MESSENGER spacecraft is years away from entering its final destination of orbiting Mercury, the mission Science Team is already very busy collecting scientific data and sharing it with the larger scientific community. Those plans and results are now available on the team's new Web site: http://messenger.jhuapl.edu/soc/index.html.

For a complete look at MESSENGER's journey through the inner solar system, visit the Mission Design section of the Web site at http://messenger.jhuapl.edu/the_mission/mission_design.html.

To see where MESSENGER is now, visit http://messenger.jhuapl.edu/whereis/index.php.

More: NASA -Status Report on MESSENGER

NASA Reinstates the Dawn Mission

Wednesday, March 29, 2006

NASA senior management announced a decision Monday to reinstate the Dawn mission, a robotic exploration of two major asteroids. Dawn had been canceled because of technical problems and cost overruns.

The mission, named because it was designed to study objects dating from the dawn of the solar system, would travel to Vesta and Ceres, two of the largest asteroids orbiting the sun between Mars and Jupiter. Dawn will use an electric ion propulsion system and orbit multiple objects.

The mission originally was approved in December 2001 and was set for launch in June 2006. Technical problems and other difficulties delayed the projected launch date to July 2007 and pushed the cost from its original estimate of $373 million to $446 million. The decision to cancel Dawn was made March 2, 2006, after about $257 million already had been spent. An additional expenditure of about $14 million would have been required to terminate the project.

The reinstatement resulted from a review process that is part of new management procedures established by NASA Administrator Michael Griffin. The process is intended to help ensure open debate and thorough evaluation of major decisions regarding space exploration and agency operations.

"We revisited a number of technical and financial challenges and the work being done to address them," said NASA Associate Administrator Rex Geveden, who chaired the review panel. "Our review determined the project team has made substantive progress on many of this mission's technical issues, and, in the end, we have confidence the mission will succeed."

The Dawn decision document will be available on the Web at:http://www.nasa.gov/formedia

Story Credit: NASA-Erica Hupp/Dean Acosta

Mars Reconnaissance Orbiter Successfully Enters Orbit Around Mars!

Friday, March 10, 2006

Celebration photo of the team
Mars Reconnaissance Orbiter Successfully Enters Orbit Around Mars!

Mars Reconnaissance Orbiter mission manager Jim Graf raises his arms in celebration of the orbiter's successful entry into orbit around Mars. Behind him is Jet Propulsion Laboratory Director Dr. Charles Elachi, giving the "thumbs up."

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Credit: NASA
With a crucially timed firing of its main engines, NASA's new mission to Mars successfully put itself into orbit around the red planet.

The spacecraft, Mars Reconnaissance Orbiter, will provide more science data than all previous Mars missions combined.

Signals received from the spacecraft at 2:16 p.m. Pacific Time on 10 March 2006, after it emerged from its first pass behind Mars set off cheers and applause in control rooms at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and at Lockheed Martin Space Systems, Denver.

"This is a great milestone to have accomplished, but it's just one of many milestones before we can open the champagne," said Colleen Hartman, deputy associate administrator for NASA's Science Mission Directorate. "Once we are in the prime science orbit, the spacecraft will perform observations of the atmosphere, surface, and subsurface of Mars in unprecedented detail."

The spacecraft traveled about 500 million kilometers (310 million miles) to reach Mars after its launch from Florida on Aug. 12, 2005. It needed to use its main thrusters as it neared the planet in order to slow itself enough for Mars' gravity to capture it. The thruster firing began while the spacecraft was still in radio contact with Earth, but needed to end during a tense half hour of radio silence while the spacecraft flew behind Mars.


More: NASA -Robotic NASA Craft Begins Orbiting Mars for Most-Detailed Exam

NASA's Cassini Discovers Potential Liquid Water on Enceladus

Thursday, March 9, 2006

Enceladus
Plumes of icy material extend above the southern polar region of Saturn's moon Enceladus as imaged by the Cassini spacecraft in February 2005. The monochrome view is presented along with a color-coded version on the right. The latter reveals a fainter and much more extended plume component.

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Credit: NASA/JPL/SSI
NASA's Cassini spacecraft may have found evidence of liquid water reservoirs that erupt in Yellowstone-like geysers on Saturn's moon Enceladus. The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon.

"We realize that this is a radical conclusion --that we may have evidence for liquid water within a body so small and so cold," said Dr. Carolyn Porco, Cassini imaging team leader at Space Science Institute, Boulder, Colo. "However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms."

High-resolution Cassini images show icy jets and towering plumes ejecting large quantities of particles at high speed. Scientists examined several models to explain the process. They ruled out the idea that the particles are produced by or blown off the moon's surface by vapor created when warm water ice converts to a gas. Instead, scientists have found evidence for a much more exciting possibility -- the jets might be erupting from near-surface pockets of liquid water above 0 degrees Celsius (32 degrees Fahrenheit), like cold versions of the Old Faithful geyser in Yellowstone.

In the spring of 2008, scientists will get another chance to look at Enceladus when Cassini flies within 350 kilometers approximately 220 miles), but much work remains after Cassini's four-year prime mission is over.

Mission scientists report these and other Enceladus findings in this week's issue of Science.

More: NASA - Potential Liquid Water on Enceladus

Dawn Mission Killed

Friday, March 3, 2006

Dawn mission
The mission would have studied the asteroids Ceres and Vesta, both relics from the early solar system

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Artist's impression: W Hartmann/JPL/NASA
In early February, Dawn principal investigator Christopher Russell, at the University of California Los Angeles, said "We were going full bore toward launch, running as fast as we could. We saw the finish line in sight and then someone shot the gun and said we're cancelling the race for a bit."

Apparently the mission was stopped after a US congressional hearing on NASA's science budget, reports NASAWatch.com, a website run by former NASA employee Keith Cowing.

Both asteroids were thought to be remnants of the first objects formed in the solar system. But they show mysterious differences in their structures – Vesta has melted and separated into layers, while Ceres has not. Dawn was to probe these differences, using close-range scrutiny.

The decision to cancel the mission came after ,more than a month, the agency was expected to complete an extensive review of the mission's progress. In October 2005, NASA ordered Dawn managers to stop work on the mission, citing excessive technical problems and a budget overrun.

More: Dawn asteroid mission killed.
Story Credit: NewScientist.com news service; Kimm Groshong

Deep Impact Team Reports First Evidence of Cometary Ice

Friday, March 3, 2006

Comet Tempel 1, which created a flamboyant Fourth of July fireworks display in space last year, is covered with a small amount of water ice. These results, reported by members of NASA’s Deep Impact team in an advanced online edition of Science, offer the first definitive evidence of surface ice on any comet.

“We have known for a long time that water ice exists in comets, but this is the first evidence of water ice on comets,” said Jessica Sunshine, Deep Impact co-investigator and lead author of the Science article. Tempel I A chief scientist with Science Applications International Corporation who holds three Brown University degrees, Sunshine said the discovery offers important insight into the composition of comets – small, Sun-orbiting space travelers that are believed to be leftovers from the formation of the solar system.

“Understanding a comet’s water cycle and supply is critical to understanding these bodies as a system and as a possible source that delivered water to Earth,” she said. “Add the large organic component in comets and you have two of the key ingredients for life.”

More: NASA - Deep Impact Team Reports First Evidence of Cometary Ice

How We'll Get Back to the Moon

Wednesday, February 1, 2006

Before the end of the next decade, NASA astronauts will again explore the surface of the moon. And

this time, we're going to stay, building outposts and paving the way for eventual journeys to Mars and

Artist's concept of NASA's new crew exploration vehicle in lunar orbit.
Credit: NASA: John Frassanito and Associates
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beyond. There are echoes of the iconic images of the past, but it won't be your grandfather's moon shot.

Image left: NASA's new crew exploration vehicle in lunar orbit. Click to enlarge. Artist's concept by John Frassanito and Associates.

This journey begins soon, with development of a new spaceship. Building on the best of Apollo and shuttle technology, NASA's creating a 21st century exploration system that will be affordable, reliable, versatile, and safe.

The centerpiece of this system is a new spacecraft designed to carry four astronauts to and from the moon, support up to six crewmembers on future missions to Mars, and deliver crew and supplies to the International Space Station.

The new crew vehicle will be shaped like an Apollo capsule, but it will be three times larger, allowing four astronauts to travel to the moon at a time.

Coupled with the new lunar lander, the system sends twice as many astronauts to the surface as Apollo, and they can stay longer, with the initial missions lasting four to seven days. And while Apollo was limited to landings along the moon's equator, the new ship carries enough propellant to land anywhere on the moon's surface.

Once a lunar outpost is established, crews could remain on the lunar surface for up to six months. The spacecraft can also operate without a crew in lunar orbit, eliminating the need for one astronaut to stay behind while others explore the surface.

More:NASA How We'll Get Back to the Moon

Predicting the weather on Titan?

Monday, January 30, 2006

False-colour Images of Titan
False-colour Images of Titan (obtained by the Cassini-Huygens Visual Infrared Mapping Spectrometer)
Credits: NASA/JPL/University of Arizona
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Using recent Cassini, Huygens and Earth-based observations, scientists have been able to create a computer model which explains the formation of several types of ethane and methane clouds on Titan.
Clouds have been observed recently on Titan, Saturn’s largest moon, through the thick haze, using near-infrared spectroscopy and images of the south pole and temperate regions near 40° South. Recent observations from Earth-based telescopes and the NASA/ESA/ASI Cassini spacecraft are now providing an insight into cloud climatology.

More:ESA Science-Predicting the weather on Titan

Disembodied Space Suit

Monday, January 30, 2006

Using a simple police scanner or ham radio, you can listen to a disembodied spacesuit circling Earth.

January 26, 2006: One of the strangest satellites in the history of the space age is about to go into orbit. Launch date: Feb. 3rd. That's when astronauts onboard the International Space Station (ISS) will hurl an empty spacesuit overboard.

SuitSat in Flight Configuaration
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The spacesuit is the satellite -- "SuitSat" for short.

"SuitSat is a Russian brainstorm," explains Frank Bauer of NASA's Goddard Space Flight Center. "Some of our Russian partners in the ISS program, mainly a group led by Sergey Samburov, had an idea: Maybe we can turn old spacesuits into useful satellites." SuitSat is a first test of that idea.

"We've equipped a Russian Orlan spacesuit with three batteries, a radio transmitter, and internal sensors to measure temperature and battery power," says Bauer. "As SuitSat circles Earth, it will transmit its condition to the ground."

Unlike a normal spacewalk, with a human inside the suit, SuitSat's temperature controls will be turned off to conserve power. The suit, arms and legs akimbo, possibly spinning, will be exposed to the fierce rays of the sun with no way to regulate its internal temperature.

"Will the suit overheat? How long will the batteries last? Can we get a clear transmission if the suit tumbles?" wonders Bauer. These are some of the questions SuitSat will answer, laying the groundwork for SuitSats of the future.


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