The crucial series of six major engine burns – needed to get LISA Pathfinder to its final science orbit around L1 – continues to go well. Since the last blog post, the mission control team at ESOC have conducted the 5th burn as well as a smaller ‘test’ burn using the reaction control thrusters. Here’s the latest update from Spacecraft Operations Manager Ian Harrison, sent in at 04:30 CET today:

LISA Pathfinder apogee-raising orbits, prior to departure for SEL1 Credit: ESA

LISA Pathfinder apogee-raising orbits, prior to departure for SEL1. We’re now on the big one! Credit: ESA

The fifth orbit-raising engine burn, ARM#5, has been executed successfully and LISA Pathfinder is now in a highly elliptic orbit with apogee above 120 000 km. We also conducted a functional check of the ‘CTCM’ mode, which uses the reaction control thrusters to generate a push (aka ‘delta-v’) rather than the main engine*; this system will be used for small manoeuvres in the future.

The ARM#5 and CTCM burns both over-performed, and so during this long final orbit, all the burn performances are being analysed to plan the final Earth-escape burn with the best possible accuracy.

During the weekend, LISA Pathfinder will escape the Earth and be guided into a free-drift orbit towards L1.

Note*: The main engine delivers a thrust of around 400N, whereas the smaller thrusters provide around 10N thrust