ENVISAT NEWS

Toutes les informations sur http://envisat.esa.int/

• 12 mars 2002
• 7 mars 2002
• 6 mars 2002
• 4 mars 2002 (ENVISAT)
• 4 mars 2002 (Ariane)
• 1 mars 2002
• 28 février 2002
• 5 février 2002
• 19 décembre 2001
• 28 novembre 2001
• 27 septembre 2001
• 8 août 2001
• 7 août 2001
• 12 juillet 2001
• 5 juin 2001

ENVISAT NEWS - 12 mars 2002

On board payload data recording ( use of the Solid State Recorders) and data dump via the X band channels. (7 March 2002)
ASAR testing of the 320 transmit receive modules, one by one, via the so called module stepping test. (7 March 2002)
Switch On of the GOMOS Instrument Control Unit. (7 March 2002)
ASAR wave mode activated successfully for 30 mn. (11 March 2002)
ASAR module stepping mode test repeated, after tuning of parameters; the 320 receive modules are operating correctly. (11 March 2002)
RA-2 calibration mode activated successfully; data were acquired on ground and analyzed, preliminary results are nominal. (11 March 2002)
Most instrument control units are now ON (except DORIS and MWR). (11 March 2002)

ENVISAT NEWS - 7 mars 2002

Ka-band antenna for communication link with Artemis successfully deployed at 12.10 UTC

ENVISAT NEWS - 6 mars 2002

The Launch and Early Operations Phase (LEOP) has been concluded yesterday, and all Envisat instruments have entered the Switch On and Data Aquisition Phase (SODAP).
LEOP performance has been excellent, with orbit injection by the launcher almost to perfection. This has allowed us to save one year's worth of orbit manoeuvring fuel.
Envisat has now been placed in a drift orbit slightly above the nominal one, so that it will drift slowly in the direction of the orbital plane of ERS2. Once it reaches that plane, it will be lowered into exactly the same orbit as ERS2, with a phase difference resulting in half an hour difference in overpass time.
During LEOP, the solar panel, ASAR antenna and Ka-band antenna unfolded nominally. Some interference in transmission has been noticed over the equator, but this is without consequences to the mission. In short, all systems nominal.

• - GOMOS SODAP ends at L+16days;
• - MIPAS SODAP at L+25days;
• - SCIAMACHY SODAP at L+77days.

ENVISAT NEWS - 4 mars 2002

Solar Panel: Solar Panel delivers 8 kW, which is more then expected before launch.

Saturday 2 March 2002: Envisat altitude raised by 3.5 km, to let it drift until it reaches its planned position 30 minutes ahead of ERS-2. The drift phase will take 33 days to complete, after which Envisat altitude will be lowered again (expected on 3 April). The manoeuvres planned in this first month will consume less fuel than budgeted for. The savings in fuel are equivalent to one additional year of operation in orbit.

Monday 4 March 2002: ASAR Antenna fully deployed at 14.05 UTC The Attitude On board Control System, the batteries and the spacecraft thermal control are all nominal.

Next event: Artemis antenna will be deployed in a couple of days from now. The Artemis satellite is expected to reach its final geostationary orbit in August 2002.

Current location: The current location of ENVISAT can be found at http://envisat.esa.int/ Follow the link "Where is Envisat?" at the bottom of the page.

ENVISAT NEWS - 4 mars 2002

Arianespace's heavy-lift Ariane 5 delivered another perfect performance tonight, placing the massive Envisat environmental satellite into a highly accurate orbit Sun-synchronous orbit.

Ariane 5 lifted off from the Spaceport on the power of its Vulcain cryogenic main engine and two solid boosters. The vehicle's EPS upper stage was used for the final propulsion phase, climbing to the exact target altitude of 7,152.4 km. for release of the Envisat payload.

Today's flight was the 11th launch of an Ariane 5 and its eighth commercial mission under Arianespace management. The success kicks off a busy year for Ariane 5, with four other missions of the new-generation heavy-lift launcher targeted by Arianespace for 2002.

"With the deployment of Envisat tonight, Ariane 5 is once again fully operational, and this capable launcher gives us a lead over our competitors," declared Arianespace Chairman and CEO Jean-Marie Luton. "Tonight's accomplishment is the result of the hard and dedicated work of a team that includes our industrial partners Astrium and EADS; the French CNES and German DLR space agencies; the European Space Agency, and Arianespace."

Envisat is the largest environmental platform ever built by Europe, and will provide an unprecedented look at the environment and the impact of human activity on our planet. The satellite was developed in a European Space Agency program, and it will be operated from ESA's European Space Operations Center (ESOC) in Darmstadt, Germany.

An industry consortium of 50 companies led by Europe's Astrium produced the Envisat spacecraft.

Meeting the launch time to the second

The Envisat mission profile set a very specific launch time for tonight's flight: 10:07.59 p.m. at Kourou, and the countdown proceeded without interruption to allow ignition to occur at the exact moment desired.

Launch teams demonstrated the maturity of Ariane 5 by smoothly handling a problem that occurred the night before liftoff. The vehicle was transferred from its final assembly building during the morning of February 27, but was rolled back that night after an umbilical tube was became detached in the launch zone during the windy evening hours.

The umbilical was reinstalled during Ariane 5's rapid visit to the final assembly facility. The vehicle rolled out once again this morning - moving along the 3.5-kilometer-long rail track leading to the launch zone. This activity occurred without interruption to the countdown.

Arianespace managers said this operation validated the capability of launch teams to handle such issues quickly, underscoring the Ariane 5 launch system's high operational level.

The heavy-lift launcher of reference

Flight 145 also demonstrated Ariane 5's ability to handle large, heavyweight satellites. The mission's 8,000-kg. Envisat polar platform - which is 10 meters tall - was easily accommodated under the launcher's 17-meter long payload fairing.

One of Ariane 5's primary missions will be carrying telecommunications satellites to geostationary transfer orbit (GTO), and the heavy-lift vehicle is the only operational commercial launcher with a proven payload capacity of more than 6,500 kg. to GTO.

Arianespace is targeting the service entry later this year of an even more powerful, more competitive Ariane 5 capable of carrying 10 metric tons to GTO. The increased performance, combined with Ariane 5's standard 5-meter-wide payload fairing, will enable Arianespace to pair up many of the industry's satellites for cost-efficient dual launches.

A further growth is planned for 2006, when Ariane 5's GTO payload lift capability is boosted to 12 metric tons.

Ariane 5 operations at the Spaceport are backed by the commercial launch services industry's most modern infrastructure. The Spaceport's new S5 payload processing complex allows satellites to be checked out, prepared and fueled within a single facility under the most stringent clean room conditions. Envisat was the first satellite to use the S5 complex for its complete preparation, fueling and pre-launch checkout procedure.

Arianespace's next mission is set for the second half of March, using one of Arianespace's last remaining Ariane 4s. This flight will carry the dual satellite payload of JCSAT-8 for Japanese operator JSAT Corporation, and the Astra 3A spacecraft for Luxembourg-based operator SES.

After tonight's Envisat launch, the Arianespace backlog stands at 39 satellites to be launched, plus 9 ATV (Automated Transfer Vehicle) servicing spacecraft for the International Space Station.

pour plus d'informations, le site Arianespace [news & information]

ENVISAT NEWS - 1 mars 2002

ESA PR-10. The eagerly awaited launch of ESA's Envisat environmental monitoring satellite took place in Kourou, French Guiana, today at 22:07:59 hrs Kourou time (02:07:59 hrs CET). Envisat's spectacular night-time launch also marked the return to business for Europe's Ariane 5 launcher.

Lift-off was witnessed by dozens of cheering engineers, scientists and project members at the launch site and at ESA centres across Europe. Rising into a clear sky, the Ariane 5 propelled the Envisat towards a lofty vantage point some 800 km above the Earth's surface.

Envisat - the most ambitious Earth observation satellite - follows in the footsteps of ESA's successful ERS-1 and ERS-2 missions launched in the 1990s. It will boost Europe's capacity to take part in the study of the Earth and its environment by supporting critical research programmes on global warming and climate change issues, as well as performing crucial tasks such as pollution and disaster monitoring .

After a flawless lift-off, the Ariane 5 placed Envisat into sun-synchronous orbit, allowing ESA ground controllers at the space operations centre in Darmstadt, Germany, to take full control for the first time of the most complex satellite ever built in Europe.

"This has been a particularly exciting day for ESA and the European space community as a whole," said José Achache, ESA's Director of Earth Observation. "Europe is taking an important lead in global observations for worldwide environmental needs and Envisat is going to make a significant impact on the future of remote sensing of the Earth."

The ten instruments on board Envisat, more than on any other satellite, cover a wide spectrum of phenomena, delivering evidence of the interactions between the atmosphere, the ocean, the polar ice caps, the vegetation as well as human activity at the surface of the Earth. We will be able to trace the smallest changes to the Earth's surface anywhere on the globe. The importance of this mission has triggered great interest in the Earth-science community, both at a European level and worldwide.

Commenting from Europe's spaceport in French Guiana, Jacques Louet, ESA's Envisat Programme Manager, admitted that there was a certain risk to pack so much know-how into just one satellite. "However, if we want to have a comprehensive understanding, we must follow this path", he said.

Given its sheer size, Envisat has involved almost all of Europe's space industries in the development of numerous advanced technologies, particularly for the payload.

Envisat is expected to be declared operational after just a few weeks, once its payload has been checked out and the various data-recovery links set up. Then the satellite's six-month long commissioning phase will begin, ensuring that the ten instruments are operating as specified and that we can start delivering validated products to our users.

"Now Envisat is in orbit, the culmination of many years work really begins and we are looking forward to the environmental benefits the satellite is going to bring to Europe", added Mr Achache.

The successful launch of Envisat also marked a return to service for the Ariane 5 launcher. It's upper stage has undergone over 300 tests since last summer, following the failure of flight Ariane 510 to insert two satellites, including ESA's Artemis, in the correct orbits. However, thanks to ion propulsion, the Artemis mission is turning into a success story, as the satellite is making its way to geostationary orbit, and nominal operations could start this summer.

pour plus d'informations, le site ENVISAT/ESA

ENVISAT NEWS - 28 février 2002

Watch the next Flight 145 launch live on Internet : http://www.arianespace.com

Arianespace Web site's Video Corner to carry live Webcast of upcoming Ariane 5 flight

Arianespace's Web site will carry the live Webcast of Flight 145, scheduled for launch on the night of February 28/March 1.

This important mission will be the first Ariane 5 mission of 2002, and will orbit Europe's massive Envisat payload - the world's most advanced Earth environmental monitoring satellite.

The Webcast, to be carried in the Arianespace Web site's Video Corner, will begin 20 minutes before the scheduled liftoff, and will continue to 50 minutes after the launch. Arianespace has further improved the format of its Webcast for Flight 145, providing additional useful information to follow the mission in real time.

The liftoff of Flight 145 is scheduled at:

• - Local time at the Kourou, French Guiana launch site: 10:07.59 p.m. on February 28, 2002;
• - GMT : 01:07.59 a.m. on March 1, 2002;
• - Paris, France : 02:07.59 a.m. on March 1, 2002;
• - Washington, D.C., U.S.A. : 08:07.59 p.m. on February 28, 2002.

pour plus d'informations, le site Arianespace [news & information | video corner]

ENVISAT NEWS - 5 février 2002

Launcher

The acceptance test firings of the AESTUS L511 engine (10 firing tests in total) have been satisfactory concluded by 13 January, demonstrating a very stable ignition sequence. The new ignition sequence, tested on the flight engine and on the two qualification engines, includes an helium cushion building up via the MMH feed pipe before ignition:

• - Helium is injected 250ms before N2O4 valve opening;
• - The helium valve is closed 150ms after N2O4 valve opening;
• - The MMH valve is opened 60ms after closure of the helium valve;

The qualification of the ARTA 5 engine is well advanced. On 30 January, 31 tests were already successfully performed (out of 33 planned tests) and 10 extra tests are also planned on this engine to further explore its behaviour. These 10 extra tests will not be repeated on ARTA 4. The qualification testing is late by one day with respect to the original planning. With still 33 qualification tests to be performed on the ARTA 4 engine, the end of the qualification testing is predicted for 24 February. The qualification review Board will hold a partial review on 12-13-14 February and plans to have its final review meeting on 25 February, followed by a Comite Directeur meeting on 26 February. The formal approval of the Qualification Board Report by the Comite Directeur is necessary for getting a launch go ahead. There is no time margin.

The next Ariane 4 launch, carrying an INTELSAT satellite, is planned for early morning, 20th February. This date is just compatible with the CSG site reconfiguration constraint to be ready for supporting the Ariane 5 launch on 28 evening, Kourou time.

Satellite

The satellite preparation activities are right on schedule:

• - The solar array has been integrated, a mini deployment was performed, the flight Kevlar cables were tensioned for flight, and the whole solar array is covered by a purging tent on the satellite, to protect against corrosion of the diodes;
• - The SAR antenna is equipped with its flight Kevlar cables, tensioned to flight loads;
• - The flight batteries are installed;
• - The functional tests of the service module have been completed, including verification of the AOCS sensors and actuators.

The next major key point is the Bilan Technique POC (Plan Operation Combinees) planned for 14 February. A this review, the decision to enter into the POC will be taken. Arianespace has been requested at this point to confirm that:

• - the launcher is on schedule;
• - the AESTUS qualification programme is on schedule, compatible with the launch date.

Ground Segment

For the FOS ( Flight Operation Segment) at ESOC, The freeze has been successfully concluded.

For the PDS ( Payload Data Segment) the freeze planned for 31 January was not successful, several tests needs be repeated. The freeze is planned for 11 February. The PDS is not a holding element for the launch, and will be ready in time to support the instrument switch on data monitoring and early commissioning.

Conclusion

All ESA activities are on schedule for the set launch date. The launcher is on schedule but any delay in the next Ariane 4 launch or in the ongoing qualification tests of the upper stage engine ( ARTA 4 tests) will impact on the ENVISAT launch date.

pour plus d'informations, le site ENVISAT/ESA [features of the week]

ENVISAT NEWS - 19 décembre 2001

A two weeks satellite maintenance campaign was organised mid October to execute a periodic maintenance on the moving parts of the Service Module, the Payload Module and the Instruments. These activities demonstrated that the satellite is perfectly healthy.

On the launcher failure investigations, following the problem encountered with the AESTUS engine on the upper stage (EPS) during the last Ariane L510 flight 12 July 2002, significant progress has been achieved in the understanding of the AESTUS engine ignition sequence:

More than one hundred tests have been performed on two test engines at the Lampoldshausen test facility, Germany The tests results as well as the detailed modelling of the engine ignition sequence have permitted to identify the most likely causes of the L510 launch failure.

A way forward has been defined to guarantee a safe AESTUS engine ignition and operation on the next ARIANE 5 flights: it includes additional verifications on the ground, in the integration and preparation of the engine, some modifications of the ignition sequence to be validated during firing tests at Lampoldshausen, as well as some additional precautions in the launch preparation at the Guyana Space Centre.

The Ariane Failure Inquiry Board, set right after the flight 142 failure, has been recently reconvened. This Board endorsed, on 13 December 2001, the work-plan leading to resumption of the Ariane 5 flights early 2002. The next Ariane 5 launch, L511, is set to launch and deliver ENVISAT directly on its sun-synchronous orbit.

The foreseen corrective procedural and operational measures will be verified by tests to be conducted on two qualification engines as well as on the L511 engine. The L511 EPS engine has been selected and will arrive in Lampoldshausen 3rd January 2002 for firing tests of the new ignition sequence and for overall validation of the engine.

The launch of ENVISAT has been set to 1st March 2002 at 1:07:59 UT. Based on the above, The ENVISAT phase 2 launch campaign will resume early January 2002.

pour plus d'informations, le site ENVISAT/ESA [news]

ENVISAT NEWS - 28 novembre 2001

Due to further tests required on the Ariane upper stage engine, as part of the failure recovery plan, the ENVISAT launch has been delayed and is now contemplated for 2002, week 8.

pour plus d'informations, le site Arianespace

ENVISAT NEWS - 27 septembre 2001

The action plan designed to return Ariane 5 to service is moving ahead. All recommendations issued by the inquiry board are being applied methodically and rigorously. Planned modifications are now underway on the ground-based test stand used to validate flight conditions during static firings of the Ariane 5 upper stage engine. As a result, the resumption of Ariane 5 flights is expected in January 2002.

pour plus d'informations, le site Arianespace

ENVISAT NEWS - 8 août 2001

The Inquiry Board, set to analyse the anomaly encountered on the Ariane 5 upper stage during the launch of 12 July 2001, has delivered its final conclusions and recommendations 1 August 2001.

On this basis, Arianespace established a workplan with the launcher industrial prime, EADS, and steps have already been taken to prepare immediately for the required tests. Accordingly, Arianespace plans to perform its next Ariane 5 launch end November 2001, with ENVISAT on board.

The ENVISAT launch campaign should therefore resume end September (2 months before launch).

pour plus d'informations, le site ENVISAT/ESA [news]

ENVISAT NEWS - 7 août 2001

The Inquiry Board appointed to investigate the malfunction of Ariane 5's EPS upper stage during Flight 142 submitted its report to Arianespace on August 1. As requested, the board pinpointed the causes for the anomaly and recommended corrective measures. All of the recommendations have been accepted, and they will be applied as quickly as possible.

Arianespace is now targeting the next Ariane 5 launch for late November, a delay of approximately two months compared to the initial schedule for this mission [...]

pour plus d'informations, le site Arianespace

ENVISAT NEWS - 12 juillet 2001

Kourou, July 12 , 2001. The first data analysis from the Ariane 510 launcher (flight 142) indicates that the targeted  orbit for the ARTEMIS and BSAT-2 B satellites was not reached.

Both satellites have been separated on an orbit of 17 528 km apogee, 592 km perigee and 2,9 degrees inclination for a targeted orbit of 35 853 km apogee, 858 km perigee and 2 degrees inclination. The analysis of the flight data have already started. A press conference is scheduled Friday, July 13 at 10:00 am Kourou Time (13:00 U.T, 03:00 pm Paris Time, 09:00 a.m Washington time, and 10:00 p.m Tokyo time).

pour plus d'informations, le site Arianespace

ENVISAT NEWS - 5 juin 2001