Where is the Swedish National Space Board ("Rymdstyrelsen") situated?

Means of reaching the SNSB from Stockholm/Arlanda (ARN) Airport:

1.  A taxi drive from the airport will take about 30 minutes and should not cost more than 500 SEK (ask for a price before entering the vehicle - otherwise it might cost 4 times more).  SNSB is situated on the outskirts of Stockholm facing the airport, so most of the trafic in Stockholm is avoided.

2.  The train Arlanda Express will take you to central Stockholm in less than 20 minutes at a cost of 260 SEK  There are usually four departures per hour, at 5, 20, 35 and 50 minutes past the hour.  The stations are situated under the airport.  You can buy a ticket with manual service in the arrival hall or on the train (costs extra), or from yellow automates on the station platform.  To continue the journey from central Stockholm, see below.

3.  Buses bound for Stockholm depart frequently from the airport and are cheaper than the train, but take more time. 

Means of reaching the SNSB from central Stockholm:

A.  The trip by taxi will take about 10 minutes outside the rush hour.
B.  SNSB is 10 minutes from central Stockholm by underground.  Stations are marked with a blue T on white background.  SNSB is situated along the the blue line going to Hjulsta.  The closest station is Vreten.  When leaving station Vreten follow the street outside to the left until it ends.  Continue in the same direction on the footpath passing the large parabolic antenna and the rocket.  The walk is just 3 minutes or so.