Initially an experimental programme that drew upon traditional glider designs while integrating various new innovations such as the rocket engine, the development ran into organisational issues until Lippisch and his team were transferred to Messerschmitt in January 1939.

During early July 1944, German test pilot Heini Dittmar reached 1,130 km/h (700 mph), an unofficial flight airspeed record that remained unmatched by turbojet-powered aircraft until 1953.

Efforts to improve the aircraft were made (most notably the development of the Messerschmitt Me 263), but many of these did not see actual combat due to the sustained advancement of the Allied powers into Germany in 1945.

[6] One noteworthy fatality was that of Josef Pöhs, a German fighter ace and Oberleutnant in the Luftwaffe, who was killed in 1943 through exposure to T-Stoff in combination with injuries sustained during a failed takeoff that ruptured a fuel line.

[9] After a failed first attempt, one rocket finally ignited as intended and the Ente lifted off, test pilot Fritz Stamer flying it for 4,900 feet (1,500 m) before making a controlled landing.

The airframe was completed in Augsburg and in early 1940 was shipped to receive its engine at Peenemünde-West, one of the quartet of Erprobungsstelle-designated military aviation test facilities of the Reich.

[23] Such apparatus included the radio, reflector gunsight (either Revi16B, -C, or -D), direction finder, compass, firing circuits for the twin cannons, as well as some of the lighting for the cockpit instrumentation.

[citation needed] The resistance group around the Austrian priest Heinrich Maier (later executed) had contacts with the Heinkelwerke in Jenbach in Tyrol, where important components for the Me 163 were also produced.

By 2 October 1941, Me 163A V4, bearing the radio call sign letters, or Stammkennzeichen, "KE+SW", set a new world speed record of 1,004.5 km/h (624.2 mph), piloted by Heini Dittmar, with no apparent damage to the aircraft during the attempt.

[32][33] Once on the ground, the aircraft had to be retrieved by a Scheuch-Schlepper, a converted small agricultural vehicle,[34] originally based on the concept of the two-wheel tractor, carrying a detachable third swiveling wheel at the extreme rear of its design for stability in normal use—this swiveling third wheel was replaced with a pivoting, special retrieval trailer that rolled on a pair of short, triple-wheeled continuous track setups (one per side) for military service wherever the Komet was based.

Both fuel and oxidizer were toxic and required extreme care when loading in the aircraft, yet there were occasions when Komets exploded on the tarmac from the propellants' hypergolic nature.

Then, the other tanker truck carrying the very reactive T-Stoff hydrogen peroxide oxidizer would deliver its load through a different filling point on the Komet's dorsal fuselage surface, located not far behind the rear edge of the canopy.

The aircraft would be kept at level flight at low altitude until the best climbing speed of around 676 km/h (420 mph) was reached, at which point it would jettison the dolly, retract its extendable skid using a knob-topped release lever just forward of the throttle[48] (as both levers were located atop the cockpit's portside 120-litre T-Stoff oxidizer tank) that engaged the aforementioned pneumatic cylinder,[31] and then pull up into a 70° angle of climb, to a bomber's altitude.

The usable Mach number was similar to that of the Me 262, but because of the high thrust-to-drag ratio, it was much easier for the pilot to lose track of the onset of severe compressibility and risk loss of control.

The Komet was equipped with two 30 mm (1.18 inch) MK 108 cannons that had a relatively low muzzle velocity of 540 meters per second (1,772 feet/sec), and were accurate only at short range, making it almost impossible to hit a slow moving bomber.

To improve this, the Walter firm began developing two more advanced versions of the 509A rocket engine, the 509B and C, each with two separate combustion chambers of differing sizes, one above the other, for greater efficiency.

[55] The B-version possessed a main combustion chamber—usually termed in German as a Hauptofen on these dual-chamber subtypes—with an exterior shape much like that on the single chamber 509A version, with the C-version having a forward chamber shape of a more cylindrical nature, designed for a higher top thrust level of some 2,000 kg (4,410 lb) of thrust, while simultaneously dropping the use of the cubic-shape frame for the forward engine propellant flow/turbopump mechanisms as used by the earlier -A and -B versions.

Two 163 Bs, models V6 and V18, were experimentally fitted with the lower-thrust B-version of the new twin-chamber engine (mandating twin combustion chamber pressure gauges on the instrument panel[58] of any Komet equipped with them), a retractable tailwheel, and tested in spring 1944.

On 6 July 1944, the Me 163B V18 (VA+SP), like the B V6 basically a standard production Me 163B airframe outfitted with the new, twin-chamber "cruiser" rocket motor with the aforementioned airframe modifications beneath the original rocket motor orifice to accept the extra combustion chamber, set a new unofficial world speed record of 1,130 km/h (702 mph), piloted by Heini Dittmar, and landed with almost all of the vertical rudder surface broken away from flutter.

Neville Duke exceeded Heini Dittmar's record mark roughly 5+1⁄2 years after Yeager's achievement (and some 263 km/h short of it) on 31 August 1953 with the Hawker Hunter F Mk3 at a speed of 1,171 km/h (728 mph), after a normal ground start.

Waldemar Voigt of Messerschmitt's Oberammergau project and development offices started a redesign of the 163 to incorporate the new twin-chamber Walter rocket engine, as well as fix other problems.

Hertel investigated the Me 163 and found it was not well suited for mass production and not optimized as a fighter aircraft, with the most glaring deficiency being the lack of retractable landing gear.

[71] According to the historian Mano Ziegler, German officials were allegedly considering using the Me 163 to directly ram into enemy aircraft in suicide attacks; this desperate tactic was never actually used.

[76] Following the initial combat trial missions of the Me 163B with EK 16, during the winter and spring of 1944 Major Späte formed the Luftwaffe's first dedicated Me 163 fighter wing, Jagdgeschwader 400 (JG 400), in Brandis, near Leipzig.

[78] The first actions involving the Me 163B in regular Luftwaffe active service occurred on 28 July 1944, from I./JG 400's base at Brandis, when two USAAF B-17 Flying Fortress were attacked without confirmed kills.

When the flight was over Brown had no problems on the approach to the airfield; apart from the rather restricted view from the cockpit due to the flat angle of glide, the aircraft touching down at 200 km/h (120 mph).

[89] Eventually an elderly German woman came forward with Me 163 instruments that her late husband had collected after the war, and the engine was reproduced by a machine shop owned by Me 163 enthusiast Reinhold Opitz.

In 1997 "Yellow 25" was moved to the official Luftwaffe Museum located at the former RAF base at Berlin-Gatow, where it is displayed today alongside a restored Walter HWK 109–509 rocket engine.

The prototype J8M crashed on its first powered flight and was completely destroyed,[100] but several variants were built and flown, including: trainers, fighters, and interceptors, with only minor differences between the versions.

It would have been partially constructed with composite materials, powered by one of XCOR's own simpler and safer, pressure fed, liquid oxygen/alcohol engines, and retractable undercarriage would have been used instead of a takeoff dolly and landing skid.