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Post by Chicago Astronomer Joe on Aug 9, 2005 23:39:53 GMT -6
Venus Express Launch Campaign Starts
Toulouse, France (ESA) Aug 09, 2005 ESA's Venus Express spacecraft recently completed its last phase of testing in Europe and is ready to be shipped to its launch site at the Baikonur Cosmodrome in Kazakhstan. One and a half years after its sister spacecraft Mars Express arrived at Mars, Europe's newest planetary probe is ready to depart on the first leg of its journey to Earth's own sister planet, the mysterious Venus.
Venus Express was proposed in 2001, as a mission concept to take as much as possible of the Mars Express design and use it for another planetary mission.
The mission will provide the most comprehensive study ever of the Venusian atmosphere. It will dig into mysteries such as the unexplained fast atmospheric rotation in four days around the planet and the polar vortices.
It will study the global thermal balance and the role of the strongest 'greenhouse effect' found in the Solar System, as well as the structure and dynamics of the clouds and the mysterious ultraviolet markings detected above the cloud cover.
Venetian atmosphere is 90 times as dense as Earth's. Hard to break a gap in that.
I'm only guessing here, but maybe the oxygen and carbon that would be sequestered in rock on Earth is combined by heat as carbnon dioxide on Venus.
The citizens of Venice might be surprised by that first statement. ;D
The guess is basically correct, although the sequence of events is a little different. Earth is cool enough to have liquid water; Venus is not. Carbon dioxide dissolves in water. On Earth the dissolved material is reformed into rock at the bottom of bodies of water.
Last Edit: Aug 11, 2005 17:45:57 GMT -6 by Centaur
Post by Chicago Astronomer Joe on Nov 5, 2005 5:20:17 GMT -6
Venus Express Ready for Lift-off
The European Space Agency's upcoming Venus Express mission to our planet's "evil twin" should reveal a planet of extremes, and more than a few surprises. One question revolves around the identity of a mysterious "unknown ultraviolet absorber", which seems to limit the amount of sunlight that reaches the planet's surface. Scientists are also hoping to find out if the planet still has active volcanoes. Venus Express is due to lift off from the Baikonur Cosmodrome on November 9th and arrive at Venus in April 2006.
Post by Chicago Astronomer Joe on Nov 9, 2005 19:55:50 GMT -6
Europe's First Mission To Venus Makes Successful Launch
Baikonur, Kazakhstan (AFP) Nov 09, 2005 Europe's first mission to Venus was successfully launched Wednesday from the Baikonur cosmodrome in Kazakhstan and emitted a first signal at the start of its 163-day journey to the turbulent planet. The Venus Express probe separated from the Soyuz Fregat carrier around 90 minutes after the 0333 GMT blast-off on the first expedition to Earth's closest neighbour in over 10 years.
"A perfect mission," said Jean-Yves Le Gall, head of Starsem, which was in charge of the launch, after the take-off.
The probe soon emitted its first signal. "The baby cried. Venus Express has begun its operational mission," said Jean-Pierre Cau of EADS Astrium, which built the spacecraft's propulsion system.
Post by Chicago Astronomer Joe on Dec 13, 2005 3:52:58 GMT -6
Messenger Engine Burn Puts Spacecraft On Track For Venus
At 6:30 a.m. (EST) Monday NASA's Mercury-bound Messenger spacecraft successfully fired its large bipropellant thruster for the first time since launch, completing the first of several critical deep space maneuvers that will help the spacecraft reach Mercury orbit. The 524-second burn changed Messenger's velocity by about 316 meters per second (706 miles per hour), putting the solar-powered spacecraft on track for a 3,140-kilometer (1,951-mile) altitude flyby of Venus on October 24, 2006.
"This is a major accomplishment for the mission," said Messenger Mission Operations Manager Mark Holdridge, of the Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Md. "That bi-prop engine is the last major component of the spacecraft that we haven't used in space and one we'll need at least five more times to orbit Mercury. The successful performance of this main engine proves that the spacecraft is up to the task."
Until today, only 16 of the Messenger spacecraft's 17 thrusters had been used in five small trajectory correction maneuvers. This latest maneuver, known as Deep Space Maneuver 1 (DSM 1), is the first to rely solely on the largest, most efficient thruster.
Post by Chicago Astronomer Joe on Mar 8, 2006 6:26:35 GMT -6
Venus Express Closing In On Destination
Paris, France (SPX) March 7, 2006 ESA's Venus Express spacecraft is closing the distance to its destination and remains on course for its rendezvous with the veiled planet on April 11, mission controllers said.
The Venus Express team said the spacecraft's systems are ready for the orbit insertion around Venus and for the first in-orbit operations. Controllers based their assessment of the spacecraft's readiness for the approach to Venus on the "excellent" performance of the main engine during its Feb. 17 test.
After the engine burn, the team needed to make only a minor trajectory correction. That operation, involving the spacecraft's four thrusters, took place successfully on Feb. 24 and lasted 14 seconds.
Venus Express has now traveled more than 250 million kilometers (160 million miles) - more than half of its way to Venus via its spiraling trajectory. The spacecraft has just crossed the path of the planet and will move inside the orbit of Venus to anticipate the celestial motion of the planet and catch up with it on April 11.
Post by Chicago Astronomer Joe on Mar 27, 2006 22:11:39 GMT -6
Team readies for Venus arrival
Venus Express mission controllers at ESA's Space Operations Centre (ESOC) are in intensive preparation for an 11 April arrival at the spacecraft's namesake destination. The critical manoeuvre will involve a deft combination of basic physics, expert spacecraft engineering and precise timing. Next month's Venus Orbit Insertion (VOI) will mark the arrival of the first ESA mission at Venus, one of the Solar System's most enigmatic planets.
Orbit insertion comprises a series of telecommands, engine burns and manoeuvres designed to slow the spacecraft from a velocity of 29 000 km per hour relative to Venus just before the first burn to an entry velocity some 15 percent slower, allowing it to be captured into orbit around the planet.
Pointing engine for braking
Controllers will command the spacecraft to 'slew' (rotate) so as to point the engine nozzle in the direction of motion starting at 08:03 (all times CEST on Earth) 11 April. Venus Express will perform an approximately 51-minute main engine burn starting at 09:19.
The spacecraft's solar arrays will also be positioned so as to reduce the possibility of excessive mechanical load during engine ignition.
Over the subsequent days, a series of additional burns will be done to lower the orbit apocentre (point furthest from the planet) and to control the pericentre (point closest to the planet). The aim is to end up in a 24-hour orbit around the 'hothouse' planet early in May.
Critical manoeuvres require precise timing
All steps must take place in the correct sequence and the spacecraft must be brought into the correct configuration in time for the main engine burn, which itself can only happen at a specific moment. The risk is that, if any problems occur, the spacecraft could miss its 'window' for capture, making any recovery extremely challenging.
During the engine burn, the spacecraft will also enter an occultation, which occurs when Venus Express travels behind the planet so that the line of site to Earth is blocked; it will lose radio contact for almost 10 minutes. Controllers will closely watch for reacquisition of radio contact once the occultation ends at 09:56.
"Venus orbit insertion is a complex step. The main challenge is that the manoeuvre must happen at the right time," says Jean-Baptiste Gratadour, Attitude and Orbital Control Systems Engineer for Venus Express at ESOC and one of the dozens of engineers and scientists now readying for arrival at Venus.
During orbit insertion, the spacecraft will be 125 000 000 kilometres from Earth and the round-trip signal time will be 13 minutes and 32 seconds.
Post by Chicago Astronomer Joe on Apr 3, 2006 11:37:21 GMT -6
Venus within ESA probe reach
After its five-month, 400-million-kilometre journey inside our Solar System following its lift-off on 9 November 2005, ESA's Venus Express spacecraft will finally arrive on 11 April at its destination: planet Venus.
Venus Express mission controllers at the ESA Space Operations Centre (ESOC) in Darmstadt, Germany, are making intensive preparations for orbit insertion.
This comprises a series of telecommands, engine burns and manoeuvres designed to slow the spacecraft down from a velocity of 29000 km per hour relative to Venus, just before the first burn, to an entry velocity some 15% slower, allowing the spacecraft to be captured into orbit around the planet.
The spacecraft will have to ignite its main engine for 50 minutes in order to achieve deceleration and place itself into a highly elliptical orbit around the planet. Most of its 570 kg of onboard propellant will be used for this manoeuvre. The spacecraft's solar arrays will be positioned so as to reduce the possibility of excessive mechanical load during engine ignition.
Over the subsequent days, a series of additional burns will be done to lower the orbit apocentre and to control the pericentre. The aim is to end up in a 24-hour orbit around Venus early in May.
The Venus Orbit Injection operations can be followed live at ESA establishments, with ESOC acting as focal point of interest (see attached programme). In all establishments, ESA specialists will be on hand for interviews.
ESA TV will cover this event live from ESOC in Darmstadt. The live transmission will be carried free-to-air. For broadcasters, complete details of the various satellite feeds are listed at television.esa.int.
The event will be covered on the web at venus.esa.int. The website will feature regular updates, including video coverage of the press conference and podcast from the control room at ESA's Space Operations Centre.
Post by Chicago Astronomer Joe on Apr 11, 2006 19:07:44 GMT -6
European probe goes into orbit around Venus
A European space probe went into orbit around Venus on Tuesday, mission controllers said, after a 400-million-kilometre (250-million-mile trip) to peer into its toxic atmosphere and swirling clouds.
The Venus Express probe slowed down and locked into Venus's gravitational field at 10:08 am (0808 GMT), said controllers at the European Space Agency's Space Operations Centre in Darmstadt, Germany.
"A fantastic moment. We are finally around Venus," said the Canadian head of the project, Don McCoy, in a video broadcast from the headquarters of the European Space Agency (ESA) in Paris.
Venus Express -- the first European probe to Venus -- is due to spend 486 Earth days -- or just two Venusian days -- studying its hot, dense atmosphere, which is choked with 96-percent carbon dioxide.
At some 120 million kilometres from Earth, the craft fired its main engine for 51 minutes to help reduce its spped of 29,000 kilometres per hour and slip into Venus's gravitational pull.
It will first spend nine days ranging between 400 and 350,000 kilometres (250 and 217,000 miles) from the planet before going into regular orbit.
Venus Express -- a virtual copy of the Mars Express now orbiting the Red Planet -- carries seven powerful instruments to probe the thick swirl of clouds covering Venus, testing for geological information and evidence of volcanic activity.
It is also due to examine the 400 kilometre-per-hour winds that rage in the skies 60 kilometres above the planet's surface, and whose causes are unknown.
The 220-million-euro (264-million-dollar) Venus Express was built by the European satellite company EADS Astrium and launched on November 9, 2005, by from the Baikonur base in Kazakhstan.