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3 August 2012 Watch live streaming video from eurospaceagency at livestream.com
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NASA Mars Rover ‘Curiosity’ Lapel Pin
Tag Archives: european space operations centre
Solar flares over, Venus Express restarts science investigations
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| Venus Express |
16 March 2012
ESA’s Venus Express spacecraft has returned to routine operation after its startracker cameras were temporarily blinded last week by radiation from a pair of large solar flares.
Science observations by ESA’s Venus Express were temporarily suspended on 7 March after the two startrackers – used to help navigate and orient the spacecraft – were overwhelmed by excessive proton radiation.
The proton storm stemmed from the Coronal Mass Ejections (CMEs) emitted by the Sun, which were associated with a pair of massive solar flares that occurred early in the morning on 7 March.
With the startrackers unable to function properly, mission controllers at ESOC, ESA’s European Space Operations Centre, Darmstadt, had to place the spacecraft into a special mode to ride out the storm.
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| Source of Venus Express trouble: Active sun spot group AR1429 |
This meant that all instruments were switched off and routine scientific observations and data gathering were stopped.
“As the radiation faded, the startrackers began functioning normally again on 9 March,” said Octavio Camino, ESA’s Spacecraft Operations Manager.
“After taking some time to conduct a series of thorough spacecraft health checks, Venus Express returned to regular science operations on 12 March at 20:20 GMT.”
Waiting out the storm
This month, Venus Express is going through ‘quadrature’: a period of about five weeks during which the Sun-spacecraft-Earth angle is between 75° and 95°. They occur twice every 19 months.
During quadrature, the spacecraft must maintain a special orientation so that certain instruments are not over-exposed to sunlight and the radio antenna can still be pointed to Earth.
“At any time, if a problem is autonomously detected onboard, the spacecraft might place itself into ‘safe mode’,” says Octavio.
However, if a safe mode were to happen during quadrature operations, and the startrackers were not operating, it would be much more difficult to return the spacecraft to normal operations.
“To be very cautious, we simply stopped science activities to wait out the proton storm,” says Octavio.
The mission operations team used the gyroscopes to maintain a safe attitude while waiting for the startrackers to return to normal.
Venus Express: a very robust mission
“There were no permanent effects; Venus Express is in excellent condition and the operations team performed very well,” said Paolo Ferri, responsible for interplanetary mission operations at ESOC.
“Yes, orbiting Venus means we’re closer to the Sun – and in a potentially hazardous environment.”
“But we have a very robust mission that is once again returning a large amount of valuable scientific data.”
ESA coordinates international satellite reentry campaign
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| Phobos-Grunt orbiter and lander |
An international campaign to assess the imminent atmospheric reentry of Russia’s Phobos–Grunt Mars craft has been put in place by the 12-member Inter-Agency Space Debris Coordination Committee. The participants include NASA and Roscosmos, and the campaign is being coordinated by experts in ESA’s Space Debris Office.
ESA experts are working with international partners in a coordinated prediction campaign focused on Phobos–Grunt, a Russian Mars mission that is expected to largely burn up in Earth’s atmosphere in the next few days.
Phobos–Grunt was launched on 8 November 2011 into an initial Earth orbit of 206 x 341 km. The injection into an Earth-escape trajectory to Mars failed, and the spacecraft was declared lost by the Russian space agency, Roscosmos, on 13 December.
On 2 January, a comprehensive reentry prediction campaign for Phobos–Grunt was begun by the Inter-Agency Space Debris Coordination Committee (IADC), a technical forum for the worldwide coordination of activities related to human-made and natural debris in space.
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| ESA/ESOC – Main Control Room |
ESOC in Darmstadt hosts reentry database
ESA’s Space Debris Office, located at ESOC, the European Space Operations Centre, Darmstadt, Germany, hosts the IADC reentry event database that is used to exchange orbit data and reentry predictions among IADC members.
Orbit data for Phobos–Grunt are provided mainly by the US Space Surveillance Network and the Russian Space Surveillance System. In addition, European radars based in Germany and France are also providing orbit calculations. Based on this, ESA is issuing reentry prediction bulletins to its Members States.
According to its Russian owners, Phobos–Grunt has a mass of 13.5 tonnes, including about 11 tonnes of propellant, and a body size of 3.76 x 3.76 x 6.38 m, with solar wings spanning 7.97 m.
Large number of uncertainties affect reentry
“Right now, due to the large number of uncertainties in the orbit and space environment affecting the satellite, the indications are that Phobos-Grunt could reenter between 13 and 17 January, between 51.4°N and 51.4°S,” says Prof. Heiner Klinkrad, Head of ESA’s Space Debris Office.
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| H. Klinkrad |
He adds that this window will shorten as we approach reentry.
“Analyses by Roscosmos and NASA indicate that the fuel tanks, filled with unsymmetrical dimethylhydrazine – referred to as UDMH – will burst above 100 km altitude, release the propellant and largely demise thereafter.”
“This, combined with a relatively low dry mass of just 2.5 tonnes, means that Phobos–Grunt is not considered to be a high-risk reentry object.”
“Roscosmos expects that at most, some 20 to 30 fragments may reach Earth’s surface, with a total mass of less than 200 kg.”
Since the beginning of the space age, there has been no confirmed report of an injury resulting from reentering space objects.
IADC assesses potentially hazardous reentries
In recent years, IADC members have developed a data exchange network specifically supporting the assessment of potentially hazardous reentries, which allows members to enter and extract orbit data in order to refine reentry predictions.
IADC member agencies include ESA, NASA, European national agencies and the Russian, Chinese, Canadian, Japanese, Ukrainian and Indian space agencies.
Results from the Phobos–Grunt reentry campaign will be used by IADC members to improve reentry models and make future predictions more accurate.
Enhancing Europe’s observation capacity
In 2009, ESA launched the Space Situational Awareness Preparatory Programme, which, in part, aims to design a network of surveillance and tracking systems and novel data processing technologies that will enable Europe to build up a complete catalogue of orbiting objects.
This system will provide highly accurate data to reduce the threat from on-orbit collisions and improve predictions of where and when uncontrolled satellite re-entries could occur.
ESA station unable to establish new link with Phobos-Grunt
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| ESA’s 15m tracking station, Perth, Australia |
25 November 2011
UPDATE After establishing contact with Russia’s Phobos-Grunt Mars mission earlier this week, ESA’s tracking station in Australia received no signal from the spacecraft last night. ESA engineers are investigating the cause in close collaboration with Russian mission controllers.
Despite listening intently during four scheduled communication passes during the night of 24–25 November, ESA’s 15 m-diameter dish antenna at Perth, Australia, did not receive any signals .
The slots for communication, timed to coincide when Phobos–Grunt was passing over in direct line-of-sight with the station, began at 20:12 GMT and ran until 04:04 GMT. Each lasted just 6–8 minutes, providing very limited windows for sending commands and receiving a response.
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“The team here at ESOC will do their utmost to assist the Russians in investigating the situation.” |
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“Our Russian colleagues provided a full set of telecommands for us to send up,” said Wolfgang Hell, ESA’s Phobos–Grunt Service Manager, “and Perth station was set to use the same techniques and configurations that worked earlier. But we observed no downlink radio signal from the spacecraft.”
ESA’s contact with the Mars mission on the night of 22 November marked the first receipt of spacecraft data since contact was lost shortly after separation from the launch vehicle was confirmed on 8 November.
One piece of positive news: observations from the ground indicate that the orbit of Phobos–Grunt has become more stable.
“This could mean that the spacecraft’s attitude, or orientation, is also now stable, which could help in regaining contact because we’d be able to predict where its two antennas are pointing,” said Manfred Warhaut, ESA’s Head of Mission Operations at the European Space Operations Centre, Darmstadt, Germany.
“The team here at ESOC will do their utmost to assist the Russians in investigating the situation.”
UPDATE 25.11 14:30 GMT – The next scheduled communication slot for ESA’s Perth station is set for the night of 25 November, when it will again be allocated to support Phobos–Grunt.
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| • | Space Operations & Situational Awareness (http://www.esa.int/SPECIALS/Operations/index.html) |
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| • | ESTRACK ground stations (http://www.esa.int/SPECIALS/Operations/SEM8YCSMTWE_0.html) |
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| • | Phobos-Soil mission (http://sci.esa.int/science-e/www/area/index.cfm?fareaid=122) |
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More news |
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| • | ESA station keeps contact with Russian Mars mission Phobos-Grunt (http://www.esa.int/SPECIALS/Operations/SEM5AJZW5VG_0.html) |
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| • | ESA tracking station establishes contact with Russia’s Mars mission (http://www.esa.int/SPECIALS/Operations/SEM4NEZW5VG_0.html) |
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More information |
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| • | NPO Lavochkin (http://www.laspace.ru/rus/index.php) |
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| • | Roscosmos (http://www.roscosmos.ru/main.php?lang=en) |
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