ESA Document - Emits - ESA

s
Z (m)
x 10
-1
4
0
1
2
3
4
Impulsive Hohmann Transfer
Applied Delta V
Station Keeping
Forced Motion
Station Keeping
Forced Motion
Free Drift
Trajectory in CRF (height vs. X)
-16 -14 -12 -10 -8 -6 -4 -2 0 2
x 10 4
5
X (m)
Figure 4-110: Intermediate rendezvous
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 374 of 422
4.5.2.4.2 Terminal rendezvous
Next, the crew commands a forced approach to the next hold point located at 100 meters in front
of the target and also in V-bar. This new hold point will be the base of a station keeping
manoeuvre that will allow the crew to check again the status of the subsystem and the
availability of the docking port, etc.
Finally, a new forced approach is commanded and the MAV reaches the docking port of the
Orbiter that establishes the structural latching of all required elements.
4.5.2.4.3 Transfer of crew and dedocking
Finally the structural latching occurs. The crew is transferred from the MAV to the orbiter. After
that the MAV is ejected. Then there is a check out of all orbiter subsystems. Once this is done,
the departure to Earth can begin.
4.5.2.5 Baseline design
The MAV final stage is a three-axis stabilised spacecraft.
The attitude determination main sensors are the star tracker (STR) and the inertial measurement
unit (IMU). During Sun acquisition and safe modes, Sun acquisitions sensor and Earth infrared
sensors are principally used. The two STRs that will be operated in parallel for some phases of
the mission.