Observation de la terre

Follow ESA's Earth observation missions as they are prepared for liftoff
  1. When preparing a satellite for launch, the engineers use big red tags to mark components that must be removed before the satellite is encapsulated in the rocket fairing and launched. The idea is to remove these components as late as possible in the launch campaign, and the red tags serve as an important reminder do so. These items are usually covers that protect things like optics, connectors and so on. Very careful attention is paid to removing these items because if one is forgotten, the satellite will not work properly and there’s a good chance that the mission will be lost. ESA’s Gilles Labruyère, who is currently working on the Aeolus campaign in Kourou, said, “There are stories of satellites being lost because an antenna or a solar array couldn’t deploy. “To make sure nothing is forgotten, all of the items are listed and get checked off on removal. We also have cases with holes that are the same shape of every red tag. If a hole remains unfilled, liftoff is prohibited.” While the engineers have spent the last couple of days making sure that this painstaking task is done, they were also able to witness something pretty exciting, albeit from afar – an important milestone in the development of Europe’s new generation of launchers. On 16 July, there was the hot firing of the P120C solid-propellant motor to prove its flight-worthiness for use on the Vega-C rocket next year and on Ariane 6 from 2020. Read more: Hot firing proves solid rocket motor for Ariane 6 and Vega-C. The photo above shows the cloud of smoke from the test site several kilometres away. The yellow and white building on the right is the cleanroom where Aeolus is being prepared for launch on 21 August. The campaign to launch ESA’s […]
  2. The Aeolus launch campaign team at Europe’s spaceport in Kourou, French Guiana, reports that the ‘functional tests’ has been done and that Aeolus is working well. The satellite is held in a vertical position, allowing engineers to access the different components. They have tested the pressure of the propulsion tanks, piping, valves, filters and thrusters. The most recent tests included working on the radiator. The photo shows one of the ‘quality engineers’ taking a very careful look here. He looks a bit like a surgeon! Some tests are automated, such as checking the onboard software and making sure that the satellite receives commands. So with everything going well, the next milestone will be the all-important reviews on this first part of the campaign, after which the focus will be mainly on fuelling the satellite. Liftoff set for: 21 August at 21:20 GMT (23:20 CEST). Read more about the Aeolus mission.
  3. With the campaign to launch ESA’s Aeolus wind satellite on 21 August well underway, the satellite’s telescope has been opened and expected to make sure it is perfectly clean and shiny. While Aeolus’ novel laser technology is arguably the sexy part of the instrument, its telescope, which measures around 1.5 m across, it pretty dominant and equally important. It is used to collect backscattered light from the atmosphere and direct it to the receiver. In short, the laser system generates a series of short pulses of ultraviolet light which are beamed down into the atmosphere. The telescope collects the light backscattered from particles of gas and dust in the atmosphere. The time between sending the light pulse and receiving the signal back determines the distance to the ‘scatterers’ and therefore the altitude above Earth. As the scattering particles are moving in the wind, the wavelength of the scattered light is shifted by a small amount as a function of speed. The Doppler wind lidar measures this change so that the velocity of the wind can be determined. It is clearly important to make sure that the instrument is absolutely spotless, so engineers at the launch site in Kourou have first turned to the telescope before its cover is replaced. ESA’s Gilles Labruyere said, “It’s always is an optical puzzle to look into the telescope and try to identify what one sees and in what direction! The surfaces of the two mirrors are almost perfectly reflective. The engineers who do this certainly have to adjust their eyes afterwards.” Following the inspection they concluded that the telescope is ‘very clean and can fly as is’. While the telescope is clean and shiny, some of the wildlife that the team has encountered outside the cleanroom seems to be quite the opposite. A lovely […]
  4. The MetOp-C launch campaign has kicked off with the first of three Antonovs landing at Cayenne Airport, French Guiana on 20 June. The cargo aircraft transported 11 containers of equipment for ground support and IT-infrastructure. The second Antonov carrying the two main modules of the spacecraft, the Service Module and the Payload Module, followed a few days later. And the third flight brought the solar array. This is in preparation for the launch later this year of the third polar-orbiting MetOp satellite, MetOp-C. The first two satellites, MetOp-A and -B were launched in 2006 and 2012 respectively and are improving weather forecasts thanks to their ability, among other features, to measure temperature and humidity profiles from a relatively close 800 km-altitude orbit. Launching a new satellite every 5–6 years guarantees a continuous delivery of high-quality data for medium- and long-term weather forecasting and climate monitoring until at least 2023. The launch of MetOp-C will ensure that these observations will also be available on a daily basis in the future. Read more about the MetOp mission.
  5. Following its arrival at Europe’s spaceport in Kourou, French Guiana, on 29 June, the Aeolus satellite has been taken out from its transport container, placed on its integration trolley for testing and connected to its electrical support equipment. Initial checks indicate that both Aeolus and its instrument have withstood its journey from France in good condition. ESA’s Aeolus project manager, Anders Elfving, said, “We are obviously all extremely pleased that Aeolus has now arrived at the launch site. An awful lot of work and planning went into making sure it arrived safe and sound  – now it’s full steam ahead for preparing the satellite for liftoff on 21 August.” The team has also done the ‘ launch adapter fit check’, which is to make sure that the satellite actually fits the Vega rocket adapter and confirms that everything is aligned. This too went well. Cranes were then used to position Aeolus back on its integration stand. It hasn’t been all work work work for the team though. Some of them managed to get a quick look at the launch site: the Aeolus flag, the Ariane 5 rocket moving on the launch pad and the Soyuz launch pad.     Read more about the Aeolus mission.