Pre-Phase A Report - Lisa - Nasa

7.1 System configuration 145
2220 mm
480 mm
Thermal
Shield Baffle
1800 mm
210
mm
Figure 7.2 Top and side cross sections of the LISA spacecraft.
Star
Trackers
With the single Delta II 7925 H launch and the assumed excess energy of the initial orbit,
the spacecraft will slowly drift behind the earth and a continuous low thrust will take the
spacecraft to their final operations configuration in 400 days, using 19.1 kg, 13.9 kg, and
17.7 kg of xenon propellant, respectively (20 kg corresponding to a δV of 1305 m/s). The
ion engine assumed is the Hughes XIPS thruster, which generates 18 mN of thrust and
needs 500 W of electrical power. Two solar arrays are deployed after launch separation
to generate the power needed (see Figure 7.3). The extended solar panels are mounted
on one-axis gimbals to track the sun as the direction between the thrust axis and the
direction to the sun change throughout the 13 months cruise phase. Two ion engines will
be carried on each propulsion module, but only one will be used at a time. The second
Corrected version 2.08 3-3-1999 9:33