Here is the video of the ramp deploying and 2 robots (one after one) climbing up on top of it. There will be two of those ramps on the side of our robot.
Thanks to Tim Arnold from MARS from hosting this video. Since there were complains about not being able to access youtube videos from schools, Tim was gracious enough to let me upload it on their site.
we thought about useing a pnenumatic system like yours and letting gravity do the rest but decided it might not be safe acording to F.I.R.S.T. plus we were worried the drop might cause the ramp to tear itself apart
even so, that looks like a really simple and strong design