3.9 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Boost-glide | 3/3 | https://en.wikipedia.org/wiki/Boost-glide | reference | science, encyclopedia | 2026-05-05T12:33:15.179305+00:00 | kb-cron |
=== Reentry vehicle use === The technique was used by the Soviet Zond series of circumlunar spacecraft, which used one skip before landing. In this case a true skip was required in order to allow the spacecraft to reach the higher-latitude landing areas. Zond 6, Zond 7 and Zond 8 made successful skip entries, although Zond 5 did not. The Chang'e 5-T1, which flew mission profiles similar to Zond, also used this technique. 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. NASA referred to it simply as "lifting entry". A true multi-skip profile was considered as part of the Apollo Skip Guidance concept, but this was not used on any crewed flights. 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.
== Flight mechanics == Using simplified equations of motion and assuming that during the atmospheric flight both drag and lift forces will be much larger than the gravity force acting on the vehicle, the following analytical relations for a skip reentry flight can be derived:
γ
F
=
−
γ
E
,
{\displaystyle \gamma _{\mathrm {F} }=-\gamma _{\mathrm {E} },}
where
γ
{\displaystyle \gamma }
is the flightpath angle relative to the local horizontal, the subscript E indicates the conditions at the start of the entry and the subscript F indicates the conditions at the end of the entry flight. The velocity
V
{\displaystyle V}
before and after the entry can be derived to relate as follows:
V
F
V
E
=
exp
2
γ
E
L
/
D
,
{\displaystyle {\frac {V_{\mathrm {F} }}{V_{\mathrm {E} }}}=\exp {\frac {2\gamma _{\mathrm {E} }}{L/D}},}
where
L
/
D
{\displaystyle L/D}
is the lift-to-drag ratio of the vehicle.
== See also == High Speed Strike Weapon (HSSW) (USA) DF-ZX (China) DF-17 (China) Prompt Global Strike (PGS) (USA) Alpha Draco (USA) ArcLight (missile) (USA) DARPA Falcon Project (USA) Boeing X-51 Waverider (USA) North American X-15 (USA) Tupolev Tu-130 (Russia) BrahMos-II (India / Russia) Hypersonic Technology Demonstrator Vehicle (India) Multiple independently targetable reentry vehicle Planar reentry equations
== Notes ==
== References ==
=== Citations ===
=== Bibliography === Neufeld, Michael (1995). The Rocket and the Reich: Peenemünde and the Coming of the Ballistic Missile Era. Simon and Schuster. ISBN 9780029228951. Yengst, William (April 2010). Lightning Bolts: First Maneuvering Reentry Vehicles. Tate Publishing. ISBN 9781615665471.