You do not need an access card to enter the building. More information
on the Science park can be found "here
Take the train from the airport to Centraal Station. Once at the Centraal station get a 'Sprinter Train' to Amsterdam Science Park. There are many trains from the airport. From Centraal station there is a train at 18 and 48 mins past the hour (normally platform 13b - but check) and the journey takes 8 mins to the stop (Science Park) followed by a short minute walk under the bridge to NIKEF. At the automatic ticket machines at the airport select the 'other station' button and type 'AM' which will bring up a short list of stations including the 'Science Park'. Its €4.10 one way.
Another way is to take the train form the airport railway station to the station Amsterdam Zuid WTC From Amsterdam Zuid WTC take metro 51 (direction Centraal Station) and get out at Amstel Railway Station From Amstel Station take the city bus number 40 in the direction Muiderpoort Station. Get off at the gate at Sciencepark 105.
The top fields are the address of departure. In this example I've used the address for the Bridge Hotel (Amstel 107, Amsterdam); the NH Tropen Hotel address is Linnaeusstraat 2 in Amsterdam. The middle fields are for the arrival address, in this case the address of NIKHEF (Kruislaan 409, Amsterdam). The last fields are for when you want to make the trip; here i've filled in Tuesday 24 january, arrival time 8:45; the "aankomst" (arrival) button specifies that the time you give is when you want to show up at the destination; select "vertrek" (departure) if you want the time you give to be the time you start your trip.
Once you've filled in the fields, click "geef reisadvies" (give trip advice). If you do so you get the following screen.
Near the top you see a number of various departure times, the light grey one is the one being shown in detail. Read it as follows:
You read the detailed information as follows (line by line).
For general map information, Mappy has very good maps. One hitch about Mappy, it does not yet show the new road along the southwest border of the Science Park; the bus stop "Science Park Amsterdam" is located on this road.