At a time of writing, a Rosetta orbiter has perceived no new signals from a Philae lander on a aspect of Comet 67P/C-G given a last, really brief, vigilance receipt on a dusk of 14 June.
This was expected, however, as a booster was behaving pre-planned scholarship observations – involving possibly a booster slew or off-pointing from a comet iota – via a dual probable Philae-Rosetta daily communication slots.
On Monday 15 June, teams during ESA, DLR and CNES concluded to a new orbiter arena that will optimise a opportunities for lander-to-orbiter communication. This includes a change to underside indicating (that is, indicating directly during a comet nucleus) during a daily communication slots, that will come into outcome Wednesday morning, in line with a new arena change.
Rosetta’s scholarship investigations will also be practiced to adjust to a new trajectory.
Commands to adjust a arena were successfully uploaded Monday evening; serve commands will be uplinked on Thursday evening. The booster will perform dual manoeuvres, one on Wednesday morning and a second on Saturday morning. The outcome of a dual ‘dog-leg’ browns will be to move a orbiter to a stretch of 180 km from a comet and to imitate a orbiter-comet geometry of a initial contact.
This circuit obscure had been designed formerly with a design of drifting as low as safely possible, given no star tracker problems have been rescued while drifting in a terminator craft during 200 km altitude. But now it also has a advantage of improving communication possibilities with Philae.
This morning, 16 June, a booster was during about 224 km and relocating out to about 235 km from a comet on a pre-planned trajectory. When Philae’s vigilance was initial perceived on 13 Jun a spacecraft-comet subdivision was 200 km; by 14 Jun this was 206 km and a vigilance was weaker.
It is usually once a orbiter is on a new trajectory, drifting closer to a comet with underside indicating in a latitudes of a lander that a communication possibilities will be improved.
Source: Rosetta blog