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http://www.space.com/scienceastronom...ay_041018.html


The Problem with Gravity: New Mission Would Probe Strange Puzzle
By Robert Roy Britt
Senior Science Writer
posted: 18 October 2004
06:33 am ET

Imagine the weight of a nagging suspicion that what held your world together, a constant and consistent presence you had come to understand and rely on, wasn't what it seemed. That's how scientists feel when they ponder gravity these days.

For more than three centuries, the basics of gravity were pretty well understood.

Newton described the force as depending on an object's mass. Though it extends infinitely, gravity weakens with distance (specifically, by the inverse square of the distance). Einstein built on these givens in developing his theory of relativity.

Then more than a decade ago a researcher noticed something funny about two Pioneer spacecraft that were streaming toward the edge of the solar system. They weren't where they should have been.

Something was holding the probes back, according to calculations of their paths, speed and how the gravity of all the objects in the solar system -- and even a tiny push provided by sunlight -- ought to act on them.

Now scientists have proposed a new mission to figure out what's up with gravity.

Staggering possibilities

Pioneer 10 and 11 launched in 1972 and 1973. Today each is several billion miles away, heading in opposite directions out of the solar system.

The discrepancy caused by the anomaly amounts to about 248,500 miles (400,000 kilometers), or roughly the distance between Earth and the Moon. That's how much farther the probes should have traveled in their 34 years, if our understanding of gravity is correct. (The distance figure is an oversimplification of the actual measurements, but more on that in a moment.)

Scientists are quick to suggest the Pioneer anomaly, as they call it, is probably caused by the space probes themselves, perhaps emitting heat or gas. But the possibilities have been tested and modeled and penciled out, and so far they don't add up.

Which leaves open staggering possibilities that would force wholesale reprinting of all physics books:

* Invisible dark matter is tugging at the probes
* Other dimensions create small forces we don't understand
* Gravity works differently than we think

Devoted to the problem

Slava Turyshev at NASA's Jet Propulsion Laboratory is one of a handful of scientists who wrestle mentally with the Pioneer anomaly every day. He is not paid to work specifically on the problem, so he has to juggle the disturbing thought with his regular research, which involves other aspects of gravity and, significantly, whether theories that explain the glue of the whole universe might one day match neatly with those describing the invisible, subatomic world.

"I have been working on [the Pioneer anomaly] for more than 11 years now, and was never funded to do this job," Turyshev tells SPACE.com. "I guess this says a lot about my devotion to solve this mystery."

Data from the Galileo and Ulysses spacecraft suggest the anomaly may have affected them, too. But neither has been far enough from the Sun -- the dominant source of gravity in the solar system -- to firmly distinguish any possible discrepancy from noise in the data, Turyshev says. Galileo was crashed into Jupiter last year, and Ulysses will never go farther than it has.

That leaves two data points -- one from each Pioneer craft. Turyshev pointedly considers the pair as one data point, so as not to inflate the case for strange new physics. He looked at the two Voyager spacecraft, also exiting the solar system, but says their design involved "numerous attitude-control maneuvers" that "can overwhelm the signal of a small external acceleration."

NASA engineers have made their last communications with the Pioneer probes, so the two table-sized robots are carrying the unsolved mystery silently to the stars.

New mission proposed

The Pioneer anomaly was discovered by John Anderson, also of JPL, in the 1980s. For years he didn't publish what he'd noticed. Then he discussed it with physicist Michael Martin Nieto at the Los Alamos National Laboratory. Nieto says he "almost fell off my chair."

Nieto jumped into the investigation, and the two were later joined by Turyshev. They dug deeper into the data, even tracking down retired NASA scientists for some of it.

Unraveling the enigma will require a new mission, the researchers say. NASA, however, doesn't have such a project on its agenda and has not expressed much interest in one. Europeans, for reasons both historic and having to do with a current strong desire to better grasp gravity, seem more interested in investigating the problem.

So Anderson's team recently proposed to the European Space Agency a "mission to explore the Pioneer anomaly" using the latest accelerometers and advanced navigation methods. All possible sources of onboard radiation would be eliminated in "the most precisely tracked spacecraft ever to go into deep space," the group writes in the September issue of Physics World magazine.

The idea has "very high chances" of being chosen for future study, Turyshev thinks. If funded, it could launch as early as 2015.

If the mission were to find a natural, cosmic cause to the Pioneer anomaly, the revelation would rank right up there with other apple-on-the-head moments in the history of physics.

"If the anomaly is due to some new physical mechanism, this discovery would have a truly fundamental impact," Turyshev said.

Exotic candidates

One candidate is dark matter. This unknown stuff seems to infuse the universe and, though invisible, has a collective gravitational impact greater than all known matter, including stars and planets. Dark matter is inferred to exist because, without it, galaxies would fly apart. Every galaxy must be loaded with the stuff, astronomers conclude, based on how stars are bound to orbit the centers of the galaxies.

But dark matter's effects have been presumed to operate across large expanses, both within and between galaxies. There is no evidence of it controlling anything on a scale so small as our solar system.

Another idea is that gravity tugs slightly harder at things farther away. That radical suggestion, if proved true, would force a modification of Einstein's general theory of relativity and might eliminate dark matter as a player.

Yet one more exotic possibility: Dimensions exist beyond the four we know (three directions and time). Models of string theory propose that higher dimensions could provide weak forces that act in ways we don't yet comprehend.

No fancy theory in existence, however, properly explains the Pioneer data.

Drifting journeys

The Pioneer anomaly is not actually a measure of how far the Pioneer probes did or didn't travel.

Instead, scientists bounced microwave signals off each probe and noticed an unexpected drift in the Doppler frequency as the probes got farther away. The technique is akin to noting the sound change in a siren as an ambulance races first toward you, and then away from you. The Doppler effect is a shortening or lengthening of sound waves (or microwaves, or any waves) forced by an object's movement.

The drift showed that the Pioneers were being accelerated toward the Sun (or, rather, decelerated in their movement away from the Sun) by a tiny but inexplicable amount. The level of drift is equal to a gravitational effect 10 billion times weaker than the pull of Earth.

Though tiny, the signal is clear, other scientists agree.

Despite 11 years of devotion to the mystery, Turyshev is the first to admit that the "most obvious explanation" would be an unknown onboard effect. Perhaps excessive internal heat or leaks of propulsion gas are providing a wee bit of thrust that adds up over the years.

Yet despite a lot of testing, "no unambiguous, onboard systematic problem has been discovered," he said. "This inability to explain the anomalous acceleration of the Pioneer spacecraft with conventional physics has contributed to the growing discussion about its origin."

Even if the anomaly is caused by the Pioneer probes themselves, figuring it out will be useful says Turyshev, who is the proposal leader for the U.S. group.

"Finding it would help us to build a better spacecraft for the needs of fundamental physics," he said. "These craft would much more stable, quieter and would allow us to go even deeper in our quests of studying the fabric of fundamental and gravitational physics."

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The Heavy: Triple-sized Delta 4 rocket to debut

BY JUSTIN RAY
SPACEFLIGHT NOW
Posted: December 7, 2004

After years of development and 366 days standing on the launch pad, Boeing's behemoth Delta 4-Heavy rocket flies its maiden mission Friday to showcase its proficiency and character in hauling hefty cargos to space.

Although the demonstration flight lacks a real satellite payload -- fitted instead with an instrumented dummy craft -- the rocket's launch carries enormous importance for upcoming U.S. national security spacecraft looking for rides to orbit after retirement of the costly Titan 4 vehicle.

What's more, a successful debut is crucial to establishing a solid first impression of the heavy-lifter that may one day launch astronauts in NASA's proposed Crew Exploration Vehicle.


The Delta 4-Heavy rocket is ready for its inaugural flight. Credit: Boeing photo by Carleton Bailie

The 23-story rocket is scheduled for liftoff at 2:31 p.m. EST (1931 GMT) from pad 37B at Cape Canaveral Air Force Station, Florida. The day's available launch window extends two hours and 56 minutes to 5:27 p.m. EST (2227 GMT).

The rocket was erected on the seaside pad last December where it has since undergone an exhaustive program of tests and countdown rehearsals that built a database of knowledge for engineers and the launch team.

The Cape's Complex 37 is the same site used in the 1960s to fly unmanned Saturn 1 and 1B rockets that helped prepare for mankind's voyage to the moon. The site was rebuilt for the Delta 4 era, successfully supporting the previous three liftoffs in the next-generation vehicle family.

Those initial missions in 2002 and 2003 all flew in the Delta 4-Medium configuration with two stages. The lower stage, called the Common Booster Core, features the Rocketdyne RS-68 main engine that generates 650,000 pounds of thrust. The cryogenic upper stage has the Pratt & Whitney RL10B-2 powerplant.

The Delta 4-Heavy debuting this week is engineered from the foundation built by the Medium models, but is much larger and far more complex.

"The Delta 4-Heavy launch represents a remarkable American technological achievement," said Dan Marin, Boeing's director of Delta 4 Air Force programs.

The Heavy is created by taking three Common Booster Cores -- the liquid hydrogen-fueled motor that forms the Medium's first stage -- and strapping them together to form a triple-body rocket, and then adding the powerful upper stage.


An illustration of the Delta 4-Heavy rocket and payload. Credit: Boeing

"If you look at where the increased complexity of the Heavy vehicle is, it really plays into how these three large boosters interact and how the control system accommodates that interaction and keeps the rocket flying straight and true," said Boeing's Delta program manager, Dan Collins. "That's something we've worked since day 1 on this program -- so well over six years of the very best design people in the business making sure we understand those dynamics and how they play out."

The Delta 4-Heavy is capable of delivering 48,000 pounds of cargo into low-Earth orbits, including that of the International Space Station, 28,000 pounds into geosynchronous transfer orbit used by communications satellites, 22,000 pounds for Trans Lunar Injection routes to the moon and 17,600 pounds on Mars-bound trajectories.

The Air Force has ordered two Heavy rockets that will loft the final Defense Support Program missile-launch detection satellite next fall and sometime later a classified payload for the National Reconnaissance Office, which is the government agency responsible for the U.S. fleet for spy satellites.

During creation of the Delta 4 under the military's Evolved Expendable Launch Vehicle program, a healthy commercial satellite market was supposed to help offset development costs for the Air Force. But that dream fizzled and the potential to launch the first Heavy with a commercial cargo financing the trip went nowhere, prompting the government to purchase a test flight before the DSP and NRO craft are entrusted to the booster.

"The original strategy for demonstrating the Heavy capability was to utilize the perceived burgeoning commercial market. In 1998, this vehicle would have been a big player in what was projected back in those times. So the Air Force was in a great position. They were going to be able to benefit from the commercial launches," Collins said.

"When that commercial launch market started to go away and signs that it wasn't going to allow the demonstration to happen, the Air Force stepped in and said 'hey, we've got some important payloads to go. We want to get data before we put those on top of the rocket.' So they came in and purchased an amendment to the development of the contract for this mission."

In December 2000, the Air Force awarded a $141 million contract for the Delta 4-Heavy demonstration launch.


Boeing's 23-story tall Delta 4-Heavy rocket is scheduled for launch Friday. Credit: Boeing photo by Carleton Bailie

Beyond the two operational missions already slated, the Heavy's future manifest has no reservations yet.

The Air Force is preparing another batch of launch orders to be competed between Delta 4 and Lockheed Martin's Atlas 5. But program manager Lt. Col. James Planeaux says it is not yet known how many, if any, Heavy missions will be up for grabs.

Lockheed Martin, which had skipped plans to field its version of the Atlas 5-Heavy, changed course and is developing the vehicle that will resemble the Delta 4-Heavy with three booster cores tied together.

NASA is studying the Delta 4, Atlas 5, space shuttle-derived concepts and completely new space vehicles to launch missions in the agency's Vision for Space Exploration that aims to return astronauts to the moon and ultimately send the first humans to Mars.

"The biggest help we're being at this point is by providing (NASA) information about the system, what its growth possibilities are, where its limitations are, so that they have the best set of data to match up with planning an overall exploration program," Collins said of Boeing's ongoing discussions with NASA.

"We're working hard with them but really in an information exchange situation and helping them get educated and smart on what the existing Delta capabilities are and then how Delta can grow."

Collins said a key aspect in selecting a launch vehicle is the infrastructure -- manufacturing factories, processing hangars and pads -- already available to support the exploration vision.

"The reason that's a key is a big part of the job ahead of NASA is making the exploration program fit within a budget."

Boeing designers foresee a host of engine, upper stage and other upgrades to the existing Delta 4-Heavy design that would increase the rocket's payload-carrying capacity into low-Earth orbit for NASA. One configuration would ferry 100,000 pounds -- that's double the ability of the current system.

Futuristic Delta 4 ideas that would require construction of new launch pad and ground infrastructure envision monster rockets with five-to-seven Common Booster Cores strapped together in a cluster. Some concepts built with lightweight materials and sporting an advanced main engine could loft upwards of 200,000 pounds of cargo.

But the current focus is proving the Delta 4-Heavy is trustworthy and reliable. Friday's demonstration flight will last nearly six hours from liftoff until deployment of the instrumented satellite mockup into geosynchronous orbit.


This dramatic view from the launch pad looks up to the towering Delta 4-Heavy rocket. Credit: Boeing photo by Carleton Bailie

The 13,383-pound DemoSat craft is a 6-foot tall, 4.5-foot diameter shiny aluminum barrel filled with 60 brass rods for ballast. Sensors on the satellite will collect data on the vibrations, temperatures and pressures during ascent, plus measure the shock felt at separation.

"It is tuned to demonstrate capabilities of the rocket," Collins said. "The Air Force and the Delta team have gotten together and designed the generic DemoSat to answer questions for many missions. It will do a very good job of that, but it isn't tied specifically to one certain payload. It is really tied to a broader sense of demonstrating the capabilities and getting data points from some of the critical aspects of the environment within the payload fairing."

Sensors placed throughout the rocket will obtain the crucial information on the vehicle's actions during launch.

"(There is) a huge amount of telemetry and special instrumentation on this vehicle, being the inaugural mission, looking to get all of the data that we can in order to understand exactly how the rocket has performed," Collins added.

Hitching a ride on the side of DemoSat will be a pair of 35-pound, six-sided nanosatellites nicknamed Ralphie and Sparky. Built in collaboration between Arizona State University, New Mexico State University and the University of Colorado at Boulder, the canister-like nanosats were originally supposed to launch aboard a space shuttle mission in 2003. But the Columbia accident and grounding of the shuttle fleet led to the Air Force proposing an alternate route to orbit on Delta 4.

The missions of Ralphie and Sparky to conduct imaging, micropropulsion and intersatellite communications experiments will last a few days, controlled via ground stations linked by the Internet, before the craft tumble into the atmosphere.


The payload for the Delta 4-Heavy rocket's demonstration launch includes a satellite simulator and two nanosats. The craft are mounted atop the black cone-shaped adapter that mounts to the rocket as seen in this image. Credit: U.S. Air Force

Getting to space all begins with 1.9 million pounds of rumbling thrust blasting the Delta 4-Heavy rocket ever so slowly off the ground. It will take more than 15 seconds for the vehicle to clear the launch pad tower.

About 50 seconds into flight, the center Common Booster Core's engine is throttled back to its minimum power level of 58 percent thrust to conserve fuel that becomes important later. The starboard and port boosters continue firing at full throttle -- 102 percent thrust -- through the launch's first four minutes before emptying their liquid hydrogen and liquid oxygen propellant tanks and shutting down the RS-68 engines. The 15-story boosters will peel away and plummet into the Atlantic Ocean.

"A lot of the risk is burnt down at that point in time when we get back the single-core flying," Collins said, noting that the rocket will resemble a Delta 4-Medium from this point forward.

Once the outer boosters are shed, the center stage finally throttles back up to 102 percent for more than a minute of propulsion, consuming that fuel supply saved during the period of reduced thrust. The stage is jettisoned five minutes, 41 seconds after liftoff, leaving the rocket's upper stage and payload to continue the journey to orbit.

The upper stage is a bit larger than ones flown previously on Delta 3 and Delta 4-Medium missions. It features wider liquid hydrogen and lengthened liquid oxygen tanks to carry additional propellants, enabling the RL10 engine to fire longer.

About 12 minutes, 48 seconds into flight, the upper stage completes its first burn to achieve a low-altitude parking orbit of 100 by 135 nautical miles above Earth. It is here that Ralphie and Sparky are deployed, each testing low-shock separation systems for possible future applications.


An artist's concept shows the nanosats separating from DemoSat and the Delta 4-Heavy rocket's upper stage. Credit: Boeing

After an eight-minute pause, the upper stage is re-ignited to reach a geosynchronous transfer orbit with a high point of 19,651 nautical miles, low point of 148 nautical miles and inclination of 27.3 degrees north and south of the equator.

The stage will coast in this orbit, eventually reaching the apogee where the RL10 engine is fired for a third time starting at T+plus 5 hours, 37 minutes. This three-minute burn circularizes the orbit and lowers the inclination to 10 degrees.

About five hours and 50 minutes after leaving Cape Canaveral, DemoSat is released from the Delta 4-Heavy rocket to fly 19,623 nautical miles above the planet, completing the launch.

"It takes quite a while to get there. It is a long mission for us," Collins said.

"It ends up a pretty good long day by the time it takes us about six hours to get everything (fueled for launch) and ready to go, and then it takes another six hours to go run the mission. But I'm sure when we get to successful (DemoSat) separation, everybody will not feel tired at all!"

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Arianespace will launch the Skynet military satcoms

ARIANESPACE NEWS RELEASE
Posted: January 4, 2005

EADS Astrium Ltd. has chosen Arianespace to launch the British Ministry of Defense's Skynet 5A and Skynet 5B military communications satellites.

Colin Paynter, Managing Director of EADS Astrium Ltd., and Jean-Yves Le Gall, CEO of Arianespace, today announced the signature of two launch contracts, for the Skynet 5A and 5B satellites.

These two satellites will be boosted into geostationary transfer orbit by Ariane 5 launchers from the Guiana Space Center, Europe's Spaceport in Kourou, French Guiana. Launches are scheduled for the second half of 2006 and the second half of 2007.

Skynet 5A and 5B, secure high-speed communications
Skynet 5A and 5B will be launched by Arianespace on behalf of EADS Astrium, which in turn will deliver the satellites in orbit to the commercial organisation Paradigm Secure Communications. Paradigm is contracted to provide secure communications services for the British armed forces, NATO and a number of other countries.

The Skynet 5 satellites, built by EADS Astrium, will weigh approximately 4,700 kilograms at launch.

Europe's Ariane launcher has already orbited the Skynet 4B, 4C, 4E and 4F satellites for the British Ministry of Defense.

Ariane 5, supporting defense and security
The Ariane 5 launcher is key to the development of a common European defense and security policy, for which the space segment is essential. Skynet 5A and 5B are the 24th and 25th military payloads entrusted to the European launch vehicle.

Arianespace to launch Pleiades satellites
French space agency CNES has awarded Arianespace a launch contract for two Pleiades Earth observation satellites.

The two Pleiades satellites will be placed in heliosynchronous orbit by Soyuz launchers from the Guiana Space Center in Kourou, French Guiana. The first satellite is to be launched in 2008 and the second in 2009.

Successors to Spot satellites
The Pleiades satellites comprise the high-resolution optical imaging component in the Franco-Italian Orfeo system. Italy is supplying the radar component. The satellites will perform both civil and military missions, providing continuity with the services available via the Spot satellites.

EADS Astrium is prime contractor and platform manufacturer for the satellites, which weigh about one metric ton each. Alcatel Space will supply the high-resolution and image telemetry systems. The size, image resolution, orbital agility and ground transmission capabilities of the Pleiades satellites represent a significant technological advance.

Arianespace to launch Corot satellite
French space agency CNES has awarded Arianespace a launch contract for the Corot stellar observation satellite.

The Corot satellite is a veritable space observatory designed to study stars and search for new planets. With a payload of 630 kg, the satellite will be launched by the maiden flight of the Soyuz 2-1b launch vehicle in mid-2006 from the Baikonur cosmodrome. This launch is part of the Guiana Space Center (CSG) Soyuz program and will be executed under the responsibility of Arianespace. For launch operations Arianespace will draw on Starsem expertise.

Corot, a world first in astronomy
This scientific mission will mark a world first, with two missions: study the internal structure of stars and detect plants outside our solar system.

The Corot satellite uses the Proteus multimission platform built by Alcatel Space. Corot will placed into a polar orbit at an altitude of 850 kilometers.

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http://www.repubblica.it/2005/b/sezi...ne/ariane.html

Guyana, lanciato il razzo Ariane 5.
Messi in orbita due satelliti

EVRY (FRANCIA) - Il razzo Ariane 5 Eca lanciato ieri dal Centro spaziale di Kourou, nella Guyana francese, ha messo in orbita i due satelliti che aveva a bordo. L'annuncio è stato dato dalla società Arianespace, nella sua sede di Evry (nella Francia centrale).

Un portavoce della società ha spiegato che tutto è andato come previsto: il satellite per telecomunicazioni Xtar-Eur, che coprirà una regione che va dalla costa del Brasile al Sudest asiatico, e il microsatellite Sloshsat-Flevo, progettato per esperimenti sulla dinamica dei fluidi in microgravità, si sono separati dallo stadio superiore del razzo alla quota prevista.

Quello di ieri era il secondo lancio - il primo coronato da successo - di un vettore Ariane 5 Eca, in grado di trasportare un carico utile di 10 tonnellate (contro le 6 della versione generica). L'11 dicembre 2002 i responsabili del volo erano stati costretti a distruggere in volo il primo Ariane 5 Eca, poco dopo il decollo, a causa di un difetto al sistema di raffreddamento di un ugello.

La partenza da Kourou è avvenuta alle 18.03 ora locale (le 22.03 in Italia), in condizioni di bel tempo. Il conto alla rovescia era stato temporaneamente interrotto - il lancio è avvenuto circa un'ora dopo il previsto - a causa della necessità di verificare alcune misurazioni di un rilevatore di pressione. Quello di ieri era il 165esimo lancio di un razzo Ariane e il 21esimo di un Ariane 5.

Il presidente francese Jacques Chirac ha espresso "la sua grande soddisfazione dopo il successo" del lancio di Ariane 5. Ciò costituisce, ha detto, "una tappa essenziale" per "garantire l'accesso dell'Europa allo spazio". Chirac ha fatto anche i complimenti a "tutti i gruppi dell'industria europea che, con il loro impegno esemplare, hanno superato le difficoltà incontrate al primo tentativo, due anni fa". Quindi, ha concluso, "è stato superato un traguardo essenziale per garantire all'Europa accesso allo spazio. Questo successo è di buon auspicio per i prossimi voli di Ariane 5 che avranno luogo quest'anno".


(13 febbraio 2005)

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Arianespace:

The heavy-lift Ariane 5 enters commercial service with an on-target flight

Arianespace's increased-performance Ariane 5 ECA is now in full commercial service following today's successful mission from the Spaceport in French Guiana, which deployed a multi-element payload in orbit.

Climbing on the power of its up-rated Vulcain 2 cryogenic main engine and its increased-thrust solid propellant boosters, Flight 164's Ariane 5 left the ELA-3 launch zone and climbed into clear skies.

The launch vehicle's impressive ascent, which was video streamed live on the www.arianespace.com Website, clearly showed the first phase of flight, including separation of Ariane 5's two solid boosters approximately 2 min. 21 sec. into the flight.

The primary payload for today's mission was the XTAR-EUR a governmental X-band telecommunications satellite. XTAR-EUR will be operated by XTAR - a joint venture of Loral Space & Communications and HISDESAT, S.A., Its telecommunications relay services will be offered to government users in the United States, Spain and other friendly and allied nations. The spacecraft was produced by Space Systems/Loral and uses the company's 1300 satellite bus.

Eric Zhaler, President and Chief Operating Officer of Loral Space & Communications, said the XTAR-EUR joint venture partners had such confidence in Arianespace and Ariane 5 ECA that no insurance was taken for the spacecraft. Speaking at a Washington, D.C. live video broadcast of Flight 164, Zahler warmly thanked Arianespace for the successful launch - which will enable XTAR-EUR to begin the introduction of commercial X-band telecommunications relay capacity.

Flight 164 also deployed Sloshsat, a small cube-shaped spacecraft developed to study fluid dynamics in microgravity conditions by monitoring the behavior of water in an instrumented tank. This 125-kg. satellite was developed by the European Space Agency and Holland's NLR National Aerospace Laboratory, and carries 33.5 liters of de-ionized water.

An instrumentation payload called Maqsat-B was carried as well on Ariane 5, with the goal of logging parameters during the Ariane 5 ECA's flight and recording video images using a pair of cameras. Maqsat-B was designed to remain mounted to the Ariane 5 launcher throughout the mission. Germany's Kayser-Threde produced the Maqsat B2 system, while France's CNES space agency and Astrium of Europe developed the fluid loop and heat pipe which are included in the cylinder-shape payload.

Also incorporated in Maqsat-B is the dual-camera DVCAM system that was designed to image Ariane 5's liftoff and separation sequences using cameras outside and inside the payload fairing. The DVCAM system was developed by a team of CNES, Dassault and Arianespace.

Arianespace CEO Jean-Yves Le Gall thanked the Ariane industrial team involved in today's flight and confirmed that Arianespace will have a busy year of missions in 2005. He announced the next Ariane 5 launch will be April 14, which will carry the French Syracuse 3A military telecommunications satellite and Indonesia's Telkom 2 telecom spacecraft. This upcoming mission will use an Ariane 5 Generic launcher version.

The heavy-lift Ariane 5 ECA version that was qualified today has a payload lift capability to geostationary transfer orbit (GTO) of 9,600 kg., compared to 6,700-kg. for the baseline Ariane 5 Generic.

Upgrades to the Ariane 5 ECA include a more powerful Vulcain 2 cryogenic main engine (which has its thrust increased by 20 percent from the Ariane 5 Generic's Vulcain engine); the use of a cryogenic upper stage powered by the HM7B engine (which was the engine used in the Ariane 4's third stage); and the incorporation of solid rocket boosters with a increased propellant load in the S1 segment for more thrust at liftoff and a lighter-weight nozzle

This evening's liftoff was briefly delayed due to a problem with a pressure sensor reading. The countdown resumed within the remaining time for the launch window, and Ariane 5 successfully roared away from the ELA-3 launch complex at 6:03 p.m. (local time at the Spaceport), trailing the bright flames and exhaust from the Vulcain 2 and solid boosters.

Flight 164's multi-payload deployment sequence began with XTAR-EUR's release approximately 26 min. later at an altitude of 897 km. The jettisoning of the SYLDA dispenser system followed by about 2 min., with the separation of Sloshsat completing the deployment sequence approximately 3 minutes later.

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Michael Griffin takes the helm as NASA administrator

NASA NEWS RELEASE
Posted: April 14, 2005

Michael D. Griffin reported to work today as NASA's 11th Administrator. Administrator Griffin becomes the leader of the agency on the day the Expedition 11 crew is set to launch to the International Space Station. The Administrator was confirmed late Wednesday night by the U.S. Senate. An official swearing-in ceremony will be scheduled later.


Michael Griffin appears at Senate hearing. Credit: NASA/Renee Bouchard

"I have great confidence in the team that will carry out our nation's exciting, outward-focused, destination-oriented program," said Griffin. "In the coming days, I'll be spending a good deal of my time reviewing our progress toward returning the Space Shuttle safely to flight. I will also be reviewing the activities of our mission directorates and our various supporting functions. I share with the agency a great sense of privilege that we have been given the wonderful opportunity to extend humanity's reach throughout the solar system."

During his confirmation hearing Tuesday before the U.S. Senate, the Administrator stated his priorities, consistent with the President's Vision for Space Exploration will be: * Fly the Space Shuttle as safely as possible until its retirement, not later than 2010 * Bring a new Crew Exploration Vehicle into service as soon as possible after the Space Shuttle is retired * Develop a balanced overall program of science, exploration and aeronautics at NASA, consistent with the redirection of the human spaceflight program to focus on exploration * Complete the International Space Station in a manner consistent with our international partner commitments and the needs of human exploration * Encourage the pursuit of appropriate partnerships with the emerging commercial space sector * Establish a lunar return program having the maximum possible utility for later missions to Mars and other destinations

President George W. Bush nominated Griffin as NASA Administrator in March, while he was serving as the Space Department Head at Johns Hopkins University's Applied Physics Laboratory in Baltimore.

Griffin was President and Chief Operating Officer of In-Q-Tel, Inc., before joining Johns Hopkins in April 2004. He also served in several positions within Orbital Sciences Corporation, Dulles, Va., including Chief Executive Officer of Magellan Systems, Inc.

Earlier in his career, Administrator Griffin served as Chief Engineer at NASA and as Deputy for Technology at the Strategic Defense Initiative Organization. He has served as an adjunct professor at the University of Maryland, Johns Hopkins University and George Washington University.

He taught courses in spacecraft design, applied mathematics, guidance and navigation, compressible flow, computational fluid dynamics, spacecraft attitude control, astrodynamcis and introductory aerospace engineering. He is the lead author of more than two dozen technical papers, as well as the textbook, Space Vehicle Design.

A registered professional engineer in Maryland and California, the Administrator is a fellow of the American Institute of Aeronautics and Astronautics (AIAA). He is a recipient of the NASA Exceptional Achievement Medal, the AIAA Space Systems Medal and the Department of Defense Distinguished Public Service Medal, the highest award given to a non-government employee. He is a certified flight instructor with instrument and multiengine ratings

He received a bachelor's degree in Physics from Johns Hopkins University; a master's degree in Aerospace Science from Catholic University of America; a Ph.D. in Aerospace Engineering from the University of Maryland; a master's degree in Electrical Engineering from the University of Southern California; a master's degree in Applied Physics from Johns Hopkins University; a master's degree in Business Administration from Loyola College; and a master's degree in Civil Engineering from George Washington University.

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Boeing, Lockheed to form launch joint venture

JOINT NEWS RELEASE
Posted: May 2, 2005

The Boeing Company and Lockheed Martin Corporation have entered into an agreement to create a joint venture that will combine the production, engineering, test and launch operations associated with U.S. government launches of Boeing Delta and Lockheed Martin Atlas rockets. The joint venture, named United Launch Alliance, will reduce the cost of meeting the critical national security and NASA expendable launch vehicle needs of the United States.

"It has become increasingly clear that an alliance of launch capabilities is essential to meet the space communications, surveillance and reconnaissance needs of the 21st century, and to assure access to space," said Lockheed Martin Chairman, President and Chief Executive Officer Robert J. Stevens. "This combination will permit our national customers to achieve their mission objectives while reflecting current budget pressures and providing the government with full cost visibility."

"Both of our companies have developed versions of the Evolved Expendable Launch Vehicle (EELV) in collaboration with the Air Force and have flown them successfully," said Boeing President, Chief Executive Officer and Chief Financial Officer James A. Bell. "By joining together we are convinced that we can provide the customer with assured access to space at the lowest possible cost while ensuring enhanced reliability by eliminating duplicate infrastructure and bringing experts from both companies to focus on mission assurance."

United Launch Alliance will be structured as a 50-50 joint venture between Boeing and Lockheed Martin -- combining services currently provided separately by Boeing Integrated Defense Systems' Expendable Launch Systems division and by Lockheed Martin's Space Systems Company -- for launches of each company's respective rockets. Based upon initial estimates, annual savings to the government resulting from the combination are expected to be approximately $100 - $150 million.

Michael C. Gass, vice president and general manager of Lockheed Martin Space Transportation, has been appointed United Launch Alliance president and chief executive officer and Daniel J. Collins, vice president Boeing Expendable Launch Systems will serve as chief operating officer. In addition, a Boeing executive will be appointed chief financial officer and a Lockheed Martin executive will be named controller at a later date. These leaders will report to a six-member board of directors, with each company appointing three directors.

"The Lockheed Martin and Boeing employees who will be part of this new launch provider understand the enduring needs of our Air Force and NASA customers for mission success," said Gass. "They bring together a remarkable record of accomplishment in launching national-security and scientific space payloads."

"The continued performance of Boeing and Lockheed Martin employees as a new team going forward -- from the engineering center to the factory floor to the launch pad -- will offer even greater reliability and mission assurance to the customer," said Collins.

The agreement, which is subject to government and regulatory approval in the United States and internationally, also stipulates that the companies will immediately request an order from the U.S. District Court suspending all activity in the pending civil litigation related to a previous competition for launches under the Air Force EELV program. Simultaneous with the closing of the transaction, the parties will dismiss all claims against each other.

"The mission of this joint venture is to reliably meet critical launch needs, so it is imperative that the two teams come together as one with all lingering issues resolved," said Stevens. "When agreement was reached to form this alliance, both parties agreed that they were ready to move forward with a clean slate and an undistracted focus on mission success."

Under the terms of the joint venture, Boeing's Delta and Lockheed Martin's Atlas rockets will continue to be available as alternatives on individual launch missions. This will ensure that government customers are able to make decisions that meet the goal of assured access to space with two families of launch vehicles. Upon vehicle selection, the United Launch Alliance team will carry out the mission, including vehicle integration and payload processing.

Lockheed Martin's International Launch Services (including Proton) and Boeing Launch Services (including Sea Launch) are not included in the joint venture. These entities will continue to sell launch services to non-U.S. government customers. Additionally, work the companies are performing independently in support of NASA-sponsored Space Shuttle-Derived Launch Vehicle concepts for future space exploration initiatives will be excluded from this joint venture.

United Launch Alliance headquarters will be established in Denver with most engineering and administrative activities consolidated at that location's existing Lockheed Martin Space Systems Company facilities. Major assembly and integration operations will be located primarily at Boeing's manufacturing and assembly facility in Decatur, Ala. As part of the joint venture, Boeing's and Lockheed Martin's launch facilities at Cape Canaveral Air Force Station in Florida and Vandenberg Air Force Base in California will provide flexibility for meeting the requirements for East and West Coast launches.

United Launch Alliance is expected to have about 3,800 total employees at sites in Colorado, Alabama, Florida, California and Texas. It is anticipated that consolidation of the two organizations eventually will result in the elimination of some undetermined number of positions. A range of services will be made available to support those employees transferring to new locations to work with United Launch Alliance.

Completion of the transaction is expected in late 2005 at which time United Launch Alliance operations would begin.

Morgan Stanley served as financial advisor to Boeing and JP Morgan served as financial advisor to Lockheed Martin.

[GioFX]

Has orbiter found NASA's lost Mars Polar Lander?

NASA/JPL/MSSS PHOTO RELEASE
Posted: May 5, 2005

The loss of Mars Polar Lander in December 1999 was a traumatic experience not only for those of us intimately involved in the mission, but also for the U. S. Mars Exploration Program. Following the failure, exhaustive reviews of what happened and why led to major shifts in the way planetary exploration was implemented. Without telemetry, the cause of the failure could only be surmised. It would be extremely important if, through some observation, it were possible to confirm the failure mode.


Credit: NASA/JPL/Malin Space Science Systems
High res image: http://www.msss.com/mars_images/moc/...didate_mpl.jpg


Shortly after the loss of Mars Polar Lander (MPL), the Mars Global Surveyor Mars Orbiter Camera (MOC) was employed to acquire dozens of 1.5 m/pixel images of the landing uncertainty ellipses, looking for any evidence of the lander and its fate. The criteria we used in searching for MPL required a bright feature of irregular or elongated shape (the parachute) within about 1 kilometer (0.62 miles) of a location that included a dark area (rocket-disturbed martian dirt) and a small, bright spot near its center (the lander). In 2000, we found one example (see figure) that met these criteria, but in the absence of any substantive, corroborating evidence, the interpretation that this was MPL and its parachute were considered to be extremely speculative.

Observations by MGS MOC in 2004 of the Mars Exploration Rover (MER) landing sites provided guidance for a re-examination of the previously identified MPL candidate. For example, the material from which the MPL and MER parachutes are made is similar, and its brightness in MOC images can be calculated, at least in a relative sense, as a function of sun angle. The brightness of the candidate "parachute" in the MPL candidate location image turns out to be consistent with it being the same material. The brightness difference of the ground disturbed by rocket blast at the MER sites is similar to the brightness difference seen in the MPL candidate image, again adjusted for the difference in illumination and viewing angles. These consistencies lend credibility to this tentative identification.

If these features really are related to the MPL landing, what can we surmise about that landing from the image? First, we can tell that MPL's descent proceeded more-or-less successfully through parachute jettison and terminal rocket firing. The relative location of the candidate parachute and lander is consistent with the slight west-to-east wind seen in dust cloud motion in the area around the date of landing. The blast-disturbed area is consistent with the engines continuing to fire until the vehicle was close to the ground. How close is not known. The larger MER retrorockets fired at about 100 m altitude and continued firing until the engines were about 20-25 m above the surface; the candidate MPL disturbance is roughly the same size, but whether this means the engines were firing as close to the ground as the MER rockets cannot be determined. These interpretations are consistent with the proposed MPL mode of failure: the engines fired at the correct time and altitude and continued firing until the flight software checked to see if an electronic message indicated that the landing leg contact switch had been set. Since the initial leg deployment several kilometers above the surface apparently induced sufficient motion to trigger this message, the software stopped the engines as soon as the check was made, about 28-30 seconds into the 36-40 second burn. MPL was probably at an altitude of about 40 m, from which it freely fell. This is equivalent to a fall on Earth from a height of about 40 feet. The observation of a single, small "dot" at the center of the disturbed location would indicate that the vehicle remained more-or-less intact after its fall.

What is important about having a candidate for the Mars Polar Lander site? It gives the MOC team a place to target for a closer look, using the compensated pitch and roll technique known as "cPROTO." Examples of cPROTO images and a description of this capability, developed by the MGS team in 2003 and 2004, were discussed in a MOC release on 27 September 2004. Without a candidate for targeting a cPROTO image, it would take more than 60 Earth years to cover the entire Mars Polar Lander landing ellipse with cPROTO images, because the region spends the better part of each Mars year covered with carbon dioxide frost, part of each winter is spent in darkness, and, because of several uncertainties involved with the technique, it often takes two, three, or more tries before a cPROTO image hits a specific target. Now that a candidate site for Mars Polar Lander has been identified, we have a cPROTO target, which may permit us to obtain an image of about 0.5 meters per pixel (allowing objects approximately 1.5-2.5 meters in size to be resolved) during southern summer this year. At the present time (May 2005), the landing site is just beginning to lose its cover of seasonal carbon dioxide frost.

[GioFX]

NASA Chief Pushes for Shuttle's Replacement

By Marcia Dunn
AP Aerospace Writer
posted: 13 May 2005
1:08 a.m. ET

CAPE CANAVERAL, Fla. (AP) -- NASA's new boss made an impassioned case Thursday for speeding up development of a new spacecraft so that the United States will not lose access to space when the shuttle is retired, but warned something else will have to be sacrificed.

Administrator Michael Griffin told a Senate subcommittee in Washington that to cover the cost of the shuttle replacement's accelerated debut, he may be forced to delay some space station and exploration research.

“We can't do everything on our plate, and we have to have priorities and first things first,'' he said.

Griffin wants to fly the proposed new spacecraft as soon as possible once the space shuttle fleet is retired in 2010 - avoiding a four-year gap in which the United States would have no way to launch astronauts.

The current plan, which he inherited when he took over NASA last month, calls for the new vehicle to carry a crew into orbit by 2014 and be capable of traveling to the moon and Mars, with modifications, in the years beyond.

Griffin said he finds that four-year launch gap unacceptable and hopes to have a plan for closing it by mid-July. The new crew exploration vehicle, or CEV, is a key part of President Bush's plan for returning astronauts to the moon by 2020.

“CEV needs to be safe, it needs to be simple, it needs to be soon,'' Griffin told reporters later in the afternoon.

The six-year gap between the 1975 Apollo-Soyuz mission and the 1981 debut of the shuttle damaged both the U.S. space program and the nation, Griffin said. “I don't want to do it again.''

“The United States of America should always have its own access to space,'' said Sen. Barbara Mikulski, D-Md.

Griffin told the Senate subcommittee on commerce, justice and science that he does not know how much it will cost to accelerate development of the crew exploration vehicle, still in the early design phase. But he said by choosing a single contractor in 2006, rather than having two contractors competing in flight in 2008 as envisioned by the former NASA administrator, $1 billion or more could be saved for use in the near term.

Additional money could be saved by putting off research at the international space station - such as experiments geared toward long-term moon stays or Mars habitation _ and possibly eliminating the handful of shuttle flights needed to fly that equipment, Griffin said. Eighteen shuttle missions are currently on the books to finish building the space station, along with 10 supply runs for a grand total of 28.

Right now, NASA's three remaining shuttles are grounded as the agency struggles to remedy all the safety concerns arising from the 2003 Columbia tragedy. Managers hope to launch Discovery on the first mission since the disaster in mid-July; repair work is going slow, though, and the schedule is tight.

Griffin assured the senators he would use a scalpel rather than a meat ax in cutting the research budget for the space station and other exploration systems, and would look at delaying projects not yet begun.

“Now the research ... is very valuable and it must be done,'' he said. “But if it is delayed a very few years in order to allow us to complete and affect a suitable transition between systems, then I believe that that delay would be worth it. And that would be where I would look for the money.''

Griffin pledged that NASA will complete the space station, currently just half built. But if the station still isn't finished when the shuttles are retired, the space agency may turn to unmanned rockets to haul up the remaining gear.

As for the Hubble Space Telescope, Griffin has ordered work to begin on one last shuttle servicing mission, with $291 million set aside in next year's budget. Whether that mission takes place will depend on the success of the next two shuttle missions.

Griffin's predecessor, Sean O'Keefe, ruled out Hubble visits by astronauts because of post-Columbia safety concerns.

_____________________________________________

Prometheus, ISS Research Cuts Help Pay for Shuttle and Hubble Repair Bills

By Brian Berger
Space News Staff Writer
posted: 12 May 2005
11:02 a.m. ET

WASHINGTON -- NASA sent Congress a revised spending plan for 2005 that would significantly cut the Project Prometheus nuclear power and propulsion program, cancel a host of international space station-based biological and physical research activities, and postpone some space science missions, including two advanced space telescopes and a Mars science lander slated to launch in 2009.

The cuts were necessary, according to NASA, to pay the remaining $287 million tab for preparing the space shuttle for its return to flight, to make a substantial down payment on a potential Hubble Space Telescope servicing mission, to accommodate $400 million worth of special projects that lawmakers added to NASA’s budget last year, and to cover larger than predicted bills for a variety satellite projects being prepared for launch.

NASA informed Congress of these intended changes in an updated 2005 Operating Plan sent to Congress May 11. A copy of the operating plan, obtained by Space News, details changes both big and small that NASA says it needs to make to its $16.2 billion budget 2005 to get through the end of the fiscal year.

NASA’s latest operating plan includes the full $291 million Congress directed it to spend this year preparing for a possible Hubble servicing mission. NASA’s last spending plan, sent to Congress in December for review, allocated only $175 million of that amount to a Hubble mission. In February, NASA announced, to the chagrin of Hubble-supporters in Congress, that it would abandon any effort to save Hubble.

Since taking over as NASA administrator last month Mike Griffin has reversed that decision and ordered engineers at Goddard Space Flight Center to start preparing a Hubble servicing mission on the assumption that one will ultimately go forward. A formal decision is expected after the shuttle makes its return to flight.

Griffin explained his rationale in a May 10 letter accompanying the operating plan, saying that funding return to flight, Hubble servicing, programmatic overruns and releasing the $400 million in congressional earmarks “has created some difficult choices” for NASA.

“Given a choice, my preference as Administrator is to eliminate lower-priority programs rather than reducing all programs in the face of budget difficulties, to maintain efficient execution of the programs which remain,” Griffin wrote lawmakers. “Delays and deferrals inevitably lead to increased life cycle costs and erode the overall performance of the Agency's programs. Thus, NASA must set clear priorities to remain within the budget which has been allocated.”

Cut from NASA’s latest operating plan are about $160 million worth of space station-based biological and physical research efforts that a recently completed, although unreleased, NASA review concluded were unnecessary in light of NASA’s new focus using the space station for research that directly serves the needs of its space exploration goals.

While that is bad news for fundamental biological and physical research, some newly identified high priority areas of investigation will receive more money in the months and years ahead, according to Griffin.

“These high- priority areas include space radiation health and shielding, advanced environmental control and monitoring, advanced extra-vehicular activities, human health and countermeasures, advanced life support, exploration medical care, and space human factors,” Griffin wrote. “The highest priorities for research on ISS have been identified as medical research with human subjects and microgravity validation of environmental control and life support technologies. Lower-priority tasks, which are now subject to reduced funding, include basic research using model organisms (such as cells or rodents), and fundamental research in physics, material science, or basic combustion - with no direct link to exploration requirements.”

NASA also plans to refocus Project Prometheus on the development of “space-qualified nuclear systems to support human and robotic missions” especially those needed to support NASA’s near term exploration goals. NASA started the program known as Prometheus in 2002 to develop nuclear power and propulsion systems for deep space probes like the Jupiter Icy Moons Orbiter, a flagship-class mission that NASA deferred indefinitely earlier this year once it became clear that the undertaking would cost tens of billions of dollars and not necessarily help NASA accomplish its goal of returning to the Moon and sending humans to Mars.

The operating plan sent to Congress would cut $171 million from the Prometheus budget, leaving the program with $260 million for the time being.

Money for the Crew Exploration Vehicle, meanwhile, would remain untouched at $421.9 million for the year, even though NASA has said it intends to accelerate the program in order to minimize any gap between retiring the shuttle in 2010 and fielding the new system. NASA is still evaluating its options for accelerating the program, but has already announced that it intends to pick the contractor it wants to build the system in early 2006 instead of late 2008.

In addition to the cuts and increases, the operating plan also indicates that NASA intends to take planning for a Hubble servicing mission away from its Exploration Systems Mission Directorate and give it back to the Science Mission Directorate. Exploration Systems, however, picks up full responsibility for NASA’s nascent Lunar Robotic Exploration Program and the ISS Crew and Cargo Services effort to find alternatives to the space shuttle for delivering cargo and potentially people to the space station. That effort, initiated in 2004, had been under the management of the Space Operations Mission Directorate, which is in charge of the shuttle and station programs.

NASA would also delay the Space Interferometry Mission and Terrestrial Planet Finder, two advanced space telescope projects slated to launch some time after the James Webb Space Telescope. Griffin’s letter also says that NASA is considering delaying the Mars Science Laboratory mission from 2009 to 2011. NASA’s operating plan cuts nearly $72 million from the program.

[GioFX]

New Photos are First of Spacecraft Orbiting Mars

By Tariq Malik
Staff Writer
posted: 19 May 2005
2:45 p.m. ET

A NASA spacecraft circling Mars has spied, for the first time, two of its fellow probes orbiting the red planet.

Red planet veteran Mars Global Surveyor (MGS) successfully photographed NASA’s Mars Odyssey probe and the European-built Mars Express spacecraft during a series of observations released Thursday.

From its polar orbit around Mars, the MGS probe found Mars Express first as the two spacecraft flew over the red planet on April 20. Separated from its orbital target by a distance of 155 miles (249 kilometers), the MGS probed turned its Mars Orbiter Camera lens toward the passing spacecraft to snap the first two images of a red planet orbiter.

Because of the distance between MGS and Mars Express, the European orbiter appears as little more than a narrow blur in the final composite image. But astronomers analyzing the image said the Express probe appeared to be about 1.5 meters by 15 meters in dimensions, which is consistent with what they would expect from the MGS spacecraft’s vantage point.

Just one day after its Mars Express encounter, MGS found NASA's Mars Odyssey probe.

Odyssey and the MGS spacecraft share similar near-polar orbits, sometimes passing within 9 miles (15 kilometers) of each other. Odyssey orbits higher than MGS to prevent collision.

During the recent pass, MGS compiled two views of the Odyssey orbiter – in which a distinct spacecraft profile can be seen – in images taken 7.5 seconds apart. In the first view, MGS was just 56 miles away (90 kilometers) away from its NASA-built relative, but a few seconds later the two spacecraft were separated by about 84 miles (135 kilometers). Because of the additional distance, Odyssey appeared to move more slowly.

Built by San Diego-based Malin Space Science Systems, the Mars Orbiter Camera has been a key tool for the for the MGS spacecraft, which entered orbit around the red planet in 1997. Mars Odyssey arrived at the planet in 2001, with Mars Express following suite in late 2003.

From a distance of 62 miles, MGS’ camera has a field of view 830 yards (758 meters) across, so any mismatch in timing during its orbiter photography would have yielded only blank space. But the orbiter managed to photograph its fellow red planet probes while all three circled Mars at 7,000 miles an hour (11,265 kilometers an hour).

The images of both Mars Express and Mars Odyssey from the MGS probe were obtained by the Mars Global Surveyor operations teams at Denver’s Lockheed Martin Space System, as well as NASA’s Jet Propulsion Laboratory and Malin Space Science Systems.


The Mars Odyssey spacecraft appears twice in the same frame in this view taken by NASA's Mars Global Surveyor (MGS). On the right, Odyssey is some 56 miles away from MGS, while on the left - just 7.5 seconds later - it has moved to sit some 84 miles away. Credit: NASA/JPL/MSSS. Click to enlarge.

[gpc]

News Release: 2005-084 May 24, 2005



Voyager Spacecraft Enters Solar System's Final Frontier



NASA's Voyager 1 spacecraft has entered the solar system's final frontier. It is entering a vast, turbulent expanse where the Sun's influence ends and the solar wind crashes into the thin gas between stars.



"Voyager 1 has entered the final lap on its race to the edge of interstellar space," said Dr. Edward Stone, Voyager project scientist at the California Institute of Technology in Pasadena. Caltech manages NASA's Jet Propulsion Laboratory in Pasadena, which built and operates Voyager 1 and its twin, Voyager 2.



In November 2003, the Voyager team announced it was seeing events unlike any in the mission's then 26-year history. The team believed the unusual events indicated Voyager 1 was approaching a strange region of space, likely the beginning of this new frontier called the termination shock region. There was considerable controversy over whether Voyager 1 had indeed encountered the termination shock or was just getting close.



The termination shock is where the solar wind, a thin stream of electrically charged gas blowing continuously outward from the Sun, is slowed by pressure from gas between the stars. At the termination shock, the solar wind slows abruptly from a speed that ranges from 700,000 to 1.5 million miles per hour and becomes denser and hotter. The consensus of the team is that Voyager 1, at approximately 8.7 billion miles from the Sun, has at last entered the heliosheath, the region beyond the termination shock.



Predicting the location of the termination shock was hard, because the precise conditions in interstellar space are unknown. Also, changes in the speed and pressure of the solar wind cause the termination shock to expand, contract and ripple.



The most persuasive evidence that Voyager 1 crossed the termination shock is its measurement of a sudden increase in the strength of the magnetic field carried by the solar wind, combined with an inferred decrease in its speed. This happens whenever the solar wind slows down.



In December 2004, the Voyager 1 dual magnetometers observed the magnetic field strength suddenly increasing by a factor of approximately 2-1/2, as expected when the solar wind slows down. The magnetic field has remained at these high levels since December. NASA's Goddard Space Flight Center, Greenbelt, Md., built the magnetometers.



Voyager 1 also observed an increase in the number of high-speed electrically charged electrons and ions and a burst of plasma wave noise before the shock. This would be expected if Voyager 1 passed the termination shock. The shock naturally accelerates electrically charged particles that bounce back and forth between the fast and slow winds on opposite sides of the shock, and these particles can generate plasma waves.



"Voyager's observations over the past few years show the termination shock is far more complicated than anyone thought," said Dr. Eric Christian, Discipline Scientist for the Sun-Solar System Connection research program at NASA Headquarters, Washington.



The result is being presented today at a press conference in the Morial Convention Center, New Orleans, during the 2005 Joint Assembly meeting of Earth and space science organizations.



For their original missions to Jupiter and Saturn, Voyager 1 and sister spacecraft Voyager 2 were destined for regions of space far from the Sun where solar panels would not be feasible, so each was equipped with three radioisotope thermoelectric generators to produce electrical power for the spacecraft systems and instruments. Still operating in remote, cold and dark conditions 27 years later, the Voyagers owe their longevity to these Department of Energy-provided generators, which produce electricity from the heat generated by the natural decay of plutonium dioxide.



For more information about Voyager visit: http://www.nasa.gov/vision/universe/...yager_agu.html and http://voyager.jpl.nasa.gov/ .



For information about NASA and agency programs on the Internet, visit: http://www.nasa.gov/home/index.html .

[GioFX]

What's It Like Where Voyager Is?

05.24.05

To envision the Sun's presence in the Milky Way galaxy, think of a ship plowing through the ocean, being tossed by currents. As the ship sails ahead, a bow shock spreads around the vessel.

The area under the Sun's influence, stretching well beyond the planets and forming what's called the heliosphere, is like a ship. The outer edges of the heliosphere are gently buffeted by interstellar wind, the gas and dust between the stars. As the Sun orbits the center of the Milky Way galaxy, the heliosphere moves as well, creating a bow shock ahead of it in interstellar space.

Termination Shock:
Blowing outward billions of kilometers from the Sun is the solar wind, a thin stream of electrically charged gas. This wind travels at an average speed ranging from 300 to 700 kilometers per second (700,000 - 1,500,000 miles per hour) until it reaches the termination shock. At this point, the speed of the solar wind drops abruptly as it begins to feel the effects of interstellar wind.

Heliosphere:
The solar wind, emanating from the Sun, creates a bubble that extends far past the orbits of the planets. This bubble is the heliosphere, shaped like a long wind sock as it moves with the Sun through interstellar space.

Heliosheath:
The heliosheath is the outer region of the heliosphere. Voyager entered the heliosheath about 14 billion kilometers (approximately 8.7 billion miles) from the Sun. This is about 94 times the distance from the Sun to Earth.

The heliosheath is just beyond the termination shock, the point where the solar wind slows abruptly, becoming denser and hotter. The solar wind piles up as it presses outward against the approaching wind in interstellar space.

Heliopause:
The boundary between solar wind and interstellar wind is the heliopause, where the pressure of the two winds are in balance. This balance in pressure causes the solar wind to turn back and flow down the tail of the heliosphere. Once Voyager passes the heliopause, it will be in interstellar space.

Bow shock:
As the heliosphere plows through interstellar space, a bow shock forms, much as forms in front of a boulder in a stream.

Voyager 2:
Voyager 2 has visited more planets than any other spacecraft, swinging by Jupiter, Saturn, Uranus and Neptune. Voyager 2 was deflected downward by Neptune and is heading southward below the plane of the planets. With a somewhat lower speed than Voyager 1, it is about eighty percent as far from the Sun.

Voyager 1:
Voyager 1 is the most distant human-made object in the universe, At the beginning of 2005, the spacecraft was about 94 times as far from the Sun as is Earth. It was deflected northward above the plane of the planets' orbits when it swung by Saturn in 1980 and is now speeding outward from the Sun at nearly one million miles per day, a rate that would take it from Los Angeles to New York in less than four minutes. Long-lived nuclear batteries are expected to provide electrical power until at least 2020 when Voyager 1 will be more than 13 billion miles from Earth and may have reached interstellar space.

[gpc]

Chi ha progettato quelle sonde doveva avere palle e contropalle... mi meraviglio che riescano ancora a ricevere i segnali, tra l'altro.

[GioFX]

Originariamente inviato da gpc

Chi ha progettato quelle sonde doveva avere palle e contropalle... mi meraviglio che riescano ancora a ricevere i segnali, tra l'altro.

Le migliori missioni in assoluto per me sono Pioneer 10 e 11, Voyager e la sovietica Venera.

Pioneer 10 rimane la più eccezionale: è stata la prima sonda a lasciare il sistema solare, è ed stata "ascoltata" fino a due anni fa, poi il segnale è diventat troppo debole, arrivando a terra solo la portante senza informazioni). La missione è stata chiusa nel 1997.

Detto questo cmq il programma Voyger è senza dubbio il più eccezionale, come è stato studiato soprattutto, sfruttando la ciclicità degli allineamenti dei pianeti esterni, in modo da fare Giove, Saturno, Urano e Nettuno in un singolo colpo!

[duchetto]

che tipo di informazioni si possono raccogliere una volta usciti dal sistema solare?

[GioFX]

Originariamente inviato da duchetto

che tipo di informazioni si possono raccogliere una volta usciti dal sistema solare?

intendi quando si è fuori dell'eliopausa?

[duchetto]

Originariamente inviato da GioFX

intendi quando si è fuori dell'eliopausa?

si

[Luther Blissett]

Penso nessuna, comunque questo topic è stupendo.

[GioFX]

come nessuna?!?

niente affatto!!!!

intanto è tutta da conoscere la realtà su quanto sia estesa l'eliopausa e soprattutto il terminal shock, inoltre anche qualora si avesse conferma dalla telemetria dei magnetometri che si è definitivamente usciti dall'influenza del Sole, cosa che non averra prima di qualche anno, si potranno studiare tutti i misteriosi fenomeni del vento interstellare e delle forze che consentono alle stelle della nostra galassia di avvicinarsi ed allontanarsi come in una fisarmonica!

[gor]

credo che il problema sarà vedere fino a quando ce la farà a trasmettere dati,queste sonde sono state una sorpresa per la loro longevità.