Von Braun and more than 100 core R&D V-2 personnel surrendered to the Americans, and many of the original V-2 team transferred their work to the Redstone Arsenal, where they were relocated as part of Operation Paperclip.

During the late 1920s, a young Wernher von Braun bought a copy of Hermann Oberth's book, Die Rakete zu den Planetenräumen (The Rocket into Interplanetary Spaces).

Von Braun's thesis, Construction, Theoretical, and Experimental Solution to the Problem of the Liquid Propellant Rocket (dated 16 April 1934), was kept classified by the German Army and was not published until 1960.

[20][21][page needed][22] In 1943, the Austrian resistance group including Heinrich Maier managed to send exact drawings of the V-2 rocket to the American Office of Strategic Services.

[30]: 76–78 At launch the A4 propelled itself for up to 65 seconds on its own power, and a program motor held the inclination at the specified angle until engine shutdown, after which the rocket continued on a ballistic free-fall trajectory.

A protective layer of glass wool was also used for the fuel tanks so the A-4 did not have a tendency to form ice, a problem which plagued other early ballistic missiles such as the balloon tank-design SM-65 Atlas which entered US service in 1959.

[36][30]: 81–82 Some later V-2s used "guide beams", radio signals transmitted from the ground, to keep the missile on course, but the first models used a simple analog computer[37] that adjusted the azimuth for the rocket, and the flying distance was controlled by the timing of the engine cut-off, Brennschluss, ground-controlled by a Doppler system or by different types of on-board integrating accelerometers.

[13]: 12  Although Hitler commented on 22 September 1943 that "It is a great load off our minds that we have dispensed with the radio guiding-beam; now no opening remains for the British to interfere technically with the missile in flight",[14]: 138  about 20% of the operational V-2 launches were beam-guided.

[3] Test launches of V-2 rockets were made at Peenemünde, Blizna and Tuchola Forest,[12]: 211  and after the war, at Cuxhaven by the British, White Sands Proving Grounds and Cape Canaveral by the U.S., and Kapustin Yar by the USSR.

Various design issues were identified and solved during V-2 development and testing: Through mid-March 1944, only four of the 26 successful Blizna launches had satisfactorily reached the Sarnaki target area[39]: 112, 221–222, 282  due to in-flight breakup (Luftzerleger) on re-entry into the atmosphere.

[14]: 281  Testing confirmed that the so-called 'tin trousers' – a tube designed to strengthen the forward end of the rocket cladding – reduced the likelihood of air bursts.

Speer stated, "As head of the Todt organisation I will take it on myself to start at once with the building of the launching site on the Channel coast," and established an A-4 production committee under Degenkolb.

The raid resulted in 735 lives lost, with heavy losses at Trassenheide, while 178 were killed in the settlement, including Dr. Thiel, his family, and Chief Engineer Walther.

[14]: 285  – the first landed at Staveley Road, Chiswick, killing 63-year-old Mrs. Ada Harrison, three-year-old Rosemary Clarke, and Sapper Bernard Browning on leave from the Royal Engineers,[15]: 11  and one that hit Epping with no casualties.

The British government, concerned about spreading panic or giving away vital intelligence to German forces, initially attempted to conceal the cause of the explosions by making no official announcement, and euphemistically blaming them on defective gas mains.

That same date, a transport carrying a missile took a wrong turn and ended up in Serooskerke itself, giving a villager the opportunity to surreptitiously take some photographs of the weapon; these were smuggled to London by the Dutch Resistance.

The largest loss of life by a single rocket attack during the war came on 16 December 1944, when the roof of the crowded Cine Rex was struck, leaving 567 dead and 291 injured.

The death toll in London did not meet the Nazis' full expectations, during early usage, as they had not yet perfected the accuracy of the V-2, with many rockets being misdirected and exploding harmlessly.

[65] Missile strikes that did hit targets could cause large numbers of deaths; 160 were killed and 108 seriously injured in one explosion at 12:26 pm on 25 November 1944, at a Woolworth's department store in New Cross, south-east London.

[66] British intelligence also helped impede the effectiveness of the Nazi weapon, sending false reports via their Double-Cross System implying that the rockets were over-shooting their London target by 10 to 20 miles (16 to 32 km).

Work on this basic concept continued and developed into a plan to deploy a large number of guns in Hyde Park that were provided with pre-configured firing data for 2.5-mile (4.0-kilometre) grids of the London area.

Plans for an operational test began, but as Pile later put it, "Monty beat us to it", as the attacks ended with the Allied capture of their launching areas.

This was done by sending deceptive reports on the sites hit and damage caused via the German espionage network in Britain, which was secretly controlled by the British (the Double-Cross System).

An example of the impression it made is in the reaction of American pilot and future nuclear strategist and Congressional aide William Liscum Borden, who in November 1944 while returning from a nighttime air mission over Holland saw a V-2 in flight on its way to strike London:[83][84] "It resembled a meteor, streaming red sparks and whizzing past us as though the aircraft were motionless.

[citation needed] While interned after the war by the British at CSDIC camp 11, Dornberger was recorded saying that he had begged the Führer to stop the V-weapon propaganda, because nothing more could be expected from one ton of explosive.

[90] Three hundred rail-car loads of V-2s and parts were captured and shipped to the United States and 126 of the principal designers, including Wernher von Braun and Walter Dornberger, were captives of the Americans.

In addition to V-2 hardware, the U.S. Government delivered German mechanization equations for the V-2 guidance, navigation, and control systems, as well as for advanced development concept vehicles, to U.S. defence contractors for analysis.

During October 1946 (as part of Operation Osoaviakhim) they were obliged to relocate to Branch 1 of NII-88 on Gorodomlya Island in Lake Seliger where Helmut Gröttrup directed a group of 150 engineers.

[102][page needed] Between May and September of 1946, CEPA, the forerunner to today's French space agency CNES, undertook the recruitment of approximately thirty German engineers, who had previous experience working on rocket programs for Nazi Germany at the Peenemünde Army Research Center.

The Backfire report, published in January 1946, contains extensive technical documentation of the rocket, including all support procedures, tailored vehicles and fuel composition.