I've just had an email through from Science Alive at The Leisurezone in Harlow that they are about to release details of their home ed science days.
During my year of home ed'ing, my son went to these - one day every half term during school time. They are very good - particularly for SEN children - as they are very hands on. You can either stay all day with your child or leave them there. My son loved the sessions (my LA actually getting something right for him for once!)
They get booked up very very quickly, so if you are interested, contact Science Alive and get your name on their mailing list
Science Alive Home Education