On March 17, 1945, an SS unit fired eleven V2 rockets from a launch site in the Netherlands — to strike what target?

The rockets were aimed at the Ludendorff Bridge in Remagen (Germany), which US troops had seized and were using to cross the Rhine. The attack was ordered by Hitler and Himmler, it was the first attempt to use V2 rockets against a specific tactical target. Because the rockets were highly inaccurate, none struck the bridge itself, but detonations nearby still killed and injured American soldiers and German civilians.

https://en.wikipedia.org/wiki/Battle_of_Remagen#V2_rockets_used

https://www.v2rocket.com/start/deployment/v2s-on-remagen.html

Wellenbrecher is correct. There were 11 V-2 rockets fired at the Ludendorff Bridge in Remagen (Germany), but all of them missed the bridge. The closest one hit at 270 meters (890 feet) from the bridge and killed 3 American troops. The troops there said that the blast felt like an earthquake.The inaccurate missiles landed as far away as Cologne, 64 kilometers (40 mi) to the north. One struck the town of Oedingen, destroying a number of buildings and killing German citizens and American troops. The Germans tried to bomb the bridge from the air but the Allied forces but up heavy antiaircraft fire everytime the Luftwaffe attacked. About a third of the Luftwaffe aircraft would be shot down as they attacked the bridge.The enemy also tried to hit the bridge with artillery shells and hit it with 2 or 3 shells but the weakened bridge still stood.

After weeks of aircraft bombing, direct artillery hits, near misses, and deliberate demolition attempts, the Ludendorff Bridge finally collapsed on 17 March 1945 at about 3:00 pm. From its capture 10 days before, over 25,000 troops and thousands of vehicles had crossed the bridge and the other two newly built tactical bridges and other temporary bridges. This bridge helped to shorten the war by 2 weeks. Soon the news spread that Hitler had 4 Nazi officers executed because they failed to destroy the bridge before the Allies captured it.