Памятливый45> Вот её то я никак не могу прочитаь в Ваших источниках.
Потому что читаете невнимательно. Фаза зависания и посадки (пилотируемая P66, которую использовал Армстронг, но есть ещё автоматическая опция - P65 или velocity nulling guidance) в общем описана тут:
3. The
terminal-descent phase (P66) begins automatically at typically
30-m
altitude and ll-m ground range from the landing site, or it may be initiated by the
commander any time during P64. The P66 guidance algorithm controls velocity
only; there is no position control.
P66 nulls the forward and lateral velocity
components to produce a vertical approach to the lunar surface, an objective which
cannot be achieved from visual cues when the surface is obscured by a sheet of
radially moving dust. P66 controls altitude rate to a reference value that is
incremented or decremented by 0.3-m/sec each time the commander raises or lowers
a three-position rate-of-descent (ROD) control switch located near his left hand.
Вот действия Армстронга во время этой фазы:
At MET 102:43:20 (430 feet) Armstrong flicked a spring loaded toggle switch with his left hand, entering the rate-of-descent mode (
P66). Now the computer controlled the spacecraft's thrust to maintain a rate-of-descent commanded by the ROD switch. A flick upward slowed the descent by one foot per second; a flick downward increased the descent rate by the same amount. Using the joystick, Armstrong tilted the LM to null out horizontal velocity and bring the LM to a safe area for touchdown. After some "possibly spastic" control motions because dust kicked up by the exhaust plume distorted his perception of translational velocity, at MET 102:45:40, Armstrong landed the spacecraft safely in the Sea of Tranquility.
Заранее предвидя вопрос "а как же он видел куда он садится, до начала зависания на P66?", отвечаю - на точку посадки он наводился визуально и во время предыдущей фазы, т.н "захода на посадку" или P64. Астронавт видит точку прилунения до начала P66, т.е. до того, как он зависает на высоте (типичной) 30м и в 10 метрах по горизонтали от точки. Во вермя этой фазы можно без проблем выбрать безопасную точку посадки - она длится 146 секунд и горизонтальная скорость всё время снижается (LM продолжает тормозиться). Потом, во время P66 ему остаётся только контролировать горизонтальную скорость относительно поверхности (наклонами LM) и скорость снижения (с помощью ROD). Кроме того, и во время P66 точка посадки ему видна достаточное время, разве что летящая пыль мешает. Вот её общее описание:
2. Approach-phase (P64) guidance begins with initial conditions consisting of,
typically a) 2.2-km altitude and 7.5-km ground range and b) -44-m/sec vertical
velocity and 129-m/sec forward velocity.
In typically 146 seconds, P64 transfers
the LM to a point almost directly above the landing site. P64 provides continuous
visibility of the lunar surface and, specifically, of the landing site until around 5
seconds before terminus. During P64 the commander can direct the LGC to
land
at any visually chosen point on the lunar surface by a landing-site redesignation
procedure which can be continued until initiation of the terminal-descent phase.
Вот действия Армстронга во время этой фазы:
At MET 102:41:32, as the spacecraft passed through 7400 feet, sinking at 125 ft/sec, high gate was achieved. Guidance began using a new set of targets.
The LM pitched forward so that the lunar surface was visible ahead. On the DSKY the mode register changed to 64 indicating the Visibility Phase, and Noun 64 replaced Noun 63. Two two-digit numbers replaced velocity in the top register. One was a "landing point designator" (LPD) angle that indicated
where Armstrong should look along a reticle attached to his window to see where the LM would touch down if it were allowed to land automatically. The guidance system controlled yaw to keep the landing site along the line of the reticle.
The crew could move a hand controller to shift the site. The second number gave the time remaining during which a redesignation could be input.
Armstrong had time to notice that the LPD indicated "we were landing just short of a large rocky crater with very large rocks covering a high percentage of the surface"[15]. So at MET 102:43:08 (650 feet), after deciding that he could not stop short of the crater, Armstrong flipped the autopilot mode switch from AUTO to ATT HOLD to take manual control of the LM's attitude.
He maneuvered to zero pitch to maintain horizontal velocity and skim over the rocky area.
(ATT HOLD meant the digital autopilot's Rate-Command Attitude-Hold mode,
in which the astronaut could command an attitude rate by deflecting a joystick. After the stick was released the autopilot nulled rates to maintain the present attitude.)
ЕМНИП, в том документе (или в последнем) и график дросселирования DPS есть.
http://www.klabs.org/history/ech/memos_misc/r-695.pdf
TALES FROM THE LUNAR MODULE GUIDANCE COMPUTER
Остальное дочитаете сами. Более подробно фазы посадки описаны на страницах 9 по 12
Apollo Lunar Descent and Ascent Trajectories, Planning and post-flight analysis for Apollo 11.
Памятливый45> Всё как у шунейко априори известна траектория снижающегося Орла.
Читайте внимательно. Известна, только до определённого предела.
Памятливый45> Ну ориентацию-звёзды подскажут , а ГСП запомнит, но как понять как траетория проходит относительно центра луны??
А зачем центр Луны? Во время P64-P66 расстояние до поверхности известно в каждый момент, скорость относительно поверхности и скорость снижения известны, положение в пространстве известно, сажай - не хочу.