Non-ballistic atmospheric entry
The range-extension is used as a way to allow flights at lower altitudes, helping avoid radar detection for a longer time compared to a higher ballistic path.
The conceptual basis was first noticed by German artillery officers, who found that their Peenemünder Pfeilgeschosse arrow shells traveled much further when fired from higher altitudes.
Investigations at Peenemünde led them to discover that the longer trajectories in the thinner high-altitude air resulted in the shell having an angle of attack that produced aerodynamic lift at supersonic speeds.
[3] In June 1939, Kurt Patt of Klaus Riedel's design office at Peenemünde proposed wings for converting rocket speed and altitude into aerodynamic lift and range.
[8] A-4b used swept wings in order to extend the range of the V2 enough to allow attacks on UK cities in the Midlands or to reach London from areas deeper within Germany.
This design was adapted as a crewed upper stage for the A-9/A-10 intercontinental missile, which would glide from a point over the Atlantic with just enough range to bomb New York before the pilot bailed out.
[8][a] In the immediate post-war era, Soviet rocket engineer Aleksei Isaev found a copy of an updated August 1944 report on the Silbervogel concept.
In 1946, he sent his son Vasily Stalin and scientist Grigori Tokaty, who had also worked on winged rockets before the war, to visit Sänger and Irene Bredt in Paris and attempt to convince them to join a new effort in the Soviet Union.
[10][b] In the United States, the skip-glide concept was advocated by many of the German scientists who moved there, primarily Walter Dornberger and Krafft Ehricke at Bell Aircraft.
The X-20 space fighter saw continued interest through the 1960s, but was ultimately the victim of budget cuts; after another review in March 1963, Robert McNamara canceled the program in December, noting that after $400 million had been spent they still had no mission for it to fulfill.
The primary goal was to have the RV change its path during reentry so that anti-ballistic missiles (ABMs) would not be able to track their movements rapidly enough for a successful interception.
This is used late in the reentry process, combining data from a Singer Kearfott inertial navigation system with a Goodyear Aerospace active radar.
[19] The system was revealed publicly on 1 March 2018 as the hypersonic glide vehicle (HGV) Avangard (Russian: Авангард; English: Vanguard), which officially entered active service as an ICBM payload on 27 December 2019.
[20] Vladimir Putin announced that Avangard had entered serial production, claiming that its maneuverability makes it invulnerable to all current missile defences.
[22] In contrast to the US and Russian MARV designs, the DF-ZF's primary goal is to use boost-glide to extend range while flying at lower altitudes than would be used to reach the same target using a purely ballistic path.
[23][24] Boost-glide became the topic of some interest as a possible solution to the US Prompt Global Strike (PGS) requirement, which seeks a weapon that can hit a target anywhere on the Earth within one hour of launch from the United States.
The Apollo Command Module used a skip-like concept to lower the heating loads on the vehicle by extending the re-entry time, but the spacecraft did not leave the atmosphere again and there has been considerable debate whether this makes it a true skip profile.
[29] The concept continues to appear on more modern vehicles like the Orion spacecraft, which made the first American skip entry in the Artemis 1 mission, using onboard computers.
