One detail missing:
The payload of Ariane flight 501 was the Cluster satellites. This was a group of four satellites which would orbit in formation to measure solar winds in three dimensions. A successful launch would have meant setting a new record for the number of satellites launched simultaneously
After the failure of the launch, these satellites were destroyed. However, the European Space Agency succesfully launched Cluster II (essentially the same mission) in two seperate launches, on the 16th of July and the 9th of August 2000.
But this time, a Russian Soyuz rocket was used.