The OSTM/Jason-2's launch

In the framework of a cooperation between Cnes, Eumetsat, Nasa and Noaa, the OSTM/Jason-2 altimetry satellite was launched the 20^th of June, 2008. The qualification review and the operational readiness was finished in March 2008, the satellite will be flown during April to the Vandenberg Air Force Base, in California (United States). The spacecraft will be integrated on a Delta II launch vehicle and the fairing will be installed, covering the payload, just before the Flight Readiness Review takes place.

: Photo of the Delta II launcher on its launch pad and detailed views with the spacecraft under the fairing

Vandenberg, on the SLC2 West launch pad

Before the OSTM/Jason-2 reaches its final orbit at 1,336 km with a 66° inclination, on the Topex/Poseidon and Jason-1 tracks, another exciting step will occur at the time of the launch. On the SLC2 West launch pad, OSTM/Jason-2 will wait for a right launch window to meet Jason-1 and to allow a continuous ocean observation from space.

Boosted and ballistic phases

The launch phase consists of a set of delicate operations for both the launcher and the spacecraft bolted under the last stage fairing. Starting at H0-10 h, this phase lastsuntil the spacecraft/launcher separation, after about a 55 minutes flight.

An onboard camera will try to film this separation phase and then the solar panels deployment.

: Launch schedule with duration in seconds (click to enhance).

: Click on each image to visualise the videos : "stone" mode (top), solar panels deployment, "barbecue" mode and instruments pointed to geodetic nadir (bottom).

Separation

The spacecraft/launcher separation releases an automatic sequence of the attitude control ignition to allow the satellite to locate on its orbital coordinate system. At this moment, the satellite is appearing in a "stone" mode (vidéo .mpg, 8s, 5,3 Mo).

Instruments deployments

The instruments, folded to be protected from vibrations during the boosted phase, are released and deployed automatically. The solar arrays are starting to deploy 140 seconds after separation and are completely deployed 260 seconds after separation (video .mpg, 21 s, 5,3 Mo).

This new satellite dimension (a 9.7 m-wingspan) has the effect of reducing the satellite rotational speed on its axis. The satellite is appearing in a "barbecue" mode, while its different sides are alternately subjected to the sunlight (video .mpg, 16 s, 4,2 Mo).

But it's not yet finished : the Proteus plateform elements are activating and the payload instruments are powered-up by the ground project team. All these delicate operations are performed while the satellite is within visibility of a ground station. In particular, the satellite control center monitors the instruments to point to geodetic nadir (video .mpg, 30 s, 7,5 Mo).

Orbital maneuvers and in-orbit checkout

The OSTM/Jason-2 will enter orbit below the Jason-1's altitude and after about two weeks, will maneuver to be placed on its operational orbit in order to be behind Jason-1 by about 60 seconds. The formation flight of the two satellites will last approximately nine months which will enable a rigorous comparison and correlation of the OSTM/Jason-2 and Jason-1 altimetry results.

Further information:

View videos footage of the liftoff and the separation
Why Vandenberg? Video produced by Cnes.

For the record:

Jason-1 launch and press kit (p. 7) in 2001.