We started about seven centimetres above the surface on Sol 458 (11 March) and we are now at the surface with the scoop on Sol 536 (30 May 30), after six cycles of hammering over 11 weeks.
If you click on the image on the right you can see a movie assembled from images taken since February as they pushed down. The mole has clearly descended into the Martian soil about seven centimeters, or about three inches. The issue now, as shown in the movie, is that the mole is now deep enough that the scoop is pressed against the ground. It can’t really push down anymore on the mole, at least in this configuration.
They have the option of using the scoop’s tip to push farther into the ground, but that involves some risk. First they plan to let the mole continue to dig, without the scoop’s help, in the hope that it is now finally deep enough into the ground that the ground is finally able to provide the friction required to hold the mole in place. If this doesn’t work, they will then try using the scoop to fill the hole up to provide more friction.
If that doesn’t work, they will then try using the scoop tip to provide the added pressure.
All in all, it does appear there is now hope that the mole will eventually get the heat sensor for measuring the internal temperatue on Mars deep enough to do its primary mission. Stay tuned!