Video

Video was first used at CSG in 1985 for Flight 15.

Loyal sidekick to the still photo, both are frequently used together in news stories.

In practical terms, video coverage enables all the major campaign activities to be captured, with regard to both the satellite and the launcher.  A carefully-shot video can also become a practical working document.  For example, in the ATV campaign, a three-minute film is shot each week to record the most important operations.  This footage is coupled with a speeded-up video of all the movements of the ATV occurring over the same period.  The result gives an optimal view of the operations undertaken, in less than three minutes.  

In addition, a technical film of the launch is produced for Arianespace and the CNES/DLA, which brings together all the images taken in the Launch zone, as well as any other suitable locations, depending on the time and the weather.  It is broadcast the day after launch at the CRAL (post-launch review board), then joins the campaign film on a DVD containing coverage of all the dynamic phases.  A slightly-modified version, destined for space agencies and the media, is also shown by guides during visits to the Base.

Whereas a photo records a single moment in an event, video can chronicle an entire process. Certain crucial stages, like closing the hatches on the launch table, must be analysed by an optical/video technician to ensure that there has been no malfunction or failure.  If there is a problem during the course of any operation, the first-level customers can come and watch footage at the reading tables installed in the Saturn facility, where the original silver halide film is archived.

Image, video… impossible to ignore video-surveillance:

Although this is not the place to talk about the series of surveillance cameras guarding the perimeter of the Space Base, the Optical/video service does manage the images from the internal surveillance cameras in the operational buildings.  This network is the sole raison d'être of the Image Production and Dissemination Centre, which is the main authority responsible for the viewing of all satellite and launcher operations at any time during the campaign.

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Using launch videos to nurse Ariane

Located right up close to the launch table and the flame trenches, the high-speed cameras in the Launch Zone record the formidable spectacle of Ariane's lift-off.  In the event of an anomaly, their images are scrutinised to diagnose and resolve the problem.

Use of technical images by the DLA/SDS

In its capacity as design authority for the ELA ground facilities, the CNES DLA/SDS (the Ground Facilities Sub-directorate of the Launcher Directorate) assists Arianespace in resolving certain problems that may arise during a campaign.  As the Ariane 5 ground facilities have been fully qualified, this involves checking that the facilities remain within their accepted qualification range.  In 2005 for example, while watching the films it was revealed that wear and tear on certain parts - which have since been replaced - was slowing down the closure of the LBS chambers (containing the onboard/ground links) on the launch table.  These images are used to try and understand any anomalies.  The main difficulty is in finding and confirming any scenario, in order to be able to propose a reliable solution to Arianespace.

Practical use of images

Arianespace systematically analyses the images from the high-speed cameras in the Launch Zone: a level zero analysis.  It contacts the DLA if it detects anything suspicious; they then review and analyse the images together.  The films essentially reveal mechanical problems, mainly relating to the release of umbilical connectors, separation of the cryogenic arms, nozzle exits on the launch table and disconnection of the LBS links beneath the launcher.  The anomalies identified are often sudden, violent events.  As a typical example, during flight 171 last year, a hose was detected which had come loose and was flapping dangerously in the launcher environment, due to the blast at lift-off.  However, after the launch no trace of this incident was found in the Launch Zone.  It was only when the camera images were studied that the hose responsible was identified, which led to its attachment system being modified.

Silver halide or digital format?

Considering that the Optical/Video team only examines these images in detail two or three times a year, their production is expensive in relation to the service they provide.  But although the Ariane 5-ELA system works well, when a problem does arise these images are crucial.  There is, therefore, no question of scaling-down the service (currently based on the use of silver halide film).  Nevertheless there is a plan to switch to high-speed digital cameras, both for their lower operating costs and because of the increasing obsolescence of the traditional cameras.  Although their performance is not as good in terms of speed and image quality, they will be sufficient for the intended purpose.  In addition, their operating costs will be lower and the photos will be ready for analysis more quickly.