Crossbow included strategic operations against research and development of the weapons, their manufacture, transportation and attacks on their launch site, and fighter intercepts against missiles in flight.

[3][15] In May 1943 Allied surveillance observed the construction of the first of eleven large sites in northern France for secret German weapons, including six for the V-2 rocket.

Officials debated the extent of the German weapons' danger; some viewed the sites as decoys to divert Allied bombers, while others feared chemical or biological warheads.

[16] The Allies received detailed information about V-1, V-2 and Peenemünde research site from the Austrian resistance group around the priest Heinrich Maier.

[16] Carl Spaatz, commander of U.S. Strategic Air Forces in Europe (USSTAF), responded on 28 June[31] to "complain that Crossbow was a 'diversion' from the main task of wearing down the Luftwaffe and bombing German industry" for the Combined Bomber Offensive, and to recommend instead that Crossbow be a secondary priority since "days of bad weather over Germany's industrial targets would still allow enough weight of attack for the rocket sites and the lesser tactical crises.

"[32] By 10 July, Tedder had published a list of Crossbow targets which assigned 30 to RAF Bomber Command, six to the tactical Allied Expeditionary Air Force, and 68 to Spaatz's USSTAF; after which Spaatz again complained,[3]: 239  so Eisenhower allowed "spare" bombing of non-Crossbow targets: "Instructions for continuing to make Crossbow targets our first priority must stand, but ... when ... the entire strategic forces cannot be used against Crossbow, we should attack – (a) Aircraft industry, (b) Oil, (c) ball bearing (German): Kugellagerwerke, (d) Vehicular production" (Eisenhower, 18 July).

Spaatz unsuccessfully proposed that attacks concentrate on the Calais electrical grid, and on gyrocompass factories in Germany and V-weapon storage depots in France.

[35] Crossbow bombing resumed after the first V-2 attack and included a large 17 September raid on Dutch targets suspected as bases for Heinkel He 111s, which were air-launching V-1s.

[43] Despite the defences, by 27 June, "over 100,000 houses had been damaged or destroyed by the V-1 ... and shattered sewage systems threatened serious epidemics unless fixed by winter.

"[32] Of the 638 air-launched V-1s that had been observed, guns and fighters brought down 403; 66 fell in the London Civil Defence Region and 169 in other places, including Southampton on 7 July and one as far north as Manchester.

[45] Under the codename Bodyline, investigations by SIS, the Combined Services Detailed Interrogation Centre, and the Photographic Reconnaissance Unit were able to confirm existence of rocketry activities at Peenemunde and Sandys reported his findings to the chiefs of staff that the Germans were developing rockets, were probably well-advanced and countermeasures should be studied[45] The Bodyline Scientific Committee (19 members, including Duncan Sandys, Edward Victor Appleton, John Cockcroft, Robert Watson-Watt) was formed in September 1943 regarding the suspected V-2 rocket.

[46] A British sound-ranging system provided "trajectory [data] from which the general launching area could be determined", and the microphone(s) in East Kent reported the times of the first V-2 strikes on 8 September 1944: 18:40:52 and 18:41:08.

[48] Unlike the V-1, which had a speed similar to the fastest available fighter planes, the velocity and trajectory of a V-2 made aircraft interception an impossibility.

Happenstance instances of Allied aircraft encountering launched V-2 rockets include: 29 October 1944, Lieutenants Donald A. Schultz and Charles M. Crane in a Lockheed P-38 Lightning attempted to photograph a launched V-2 above the trees near the River Rhine,[49] 1 January 1945, a 4th Fighter Group pilot aloft over the northern flightpath for attacking elements of five German fighter wings on Unternehmen Bodenplatte that day, observed a V-2 "act up for firing near Lochem ... the rocket was immediately tilted from 85 deg.

602 Squadron RAF Spitfire Mk XVI pilot, Raymond Baxter's colleague "Cupid" Love, fired at a V-2 just after launch.