The High-Gain Antenna System is on the Orbiter! The HGAS provides communication coverage with the Earth in both the S-band and Ka-band radio frequencies. Also, the HGAS points a laser ranging telescope that we use to measure the distance between the earth and the Orbiter to a precision of 10 cm. The HGAS team has put in long hours integrating and testing this subsystem in preparation for its final installation on the Orbiter today.

Also this week, we re-integrated our command and data handling box (C&DH). This box was removed last week for a modification to the Coarse Sun Sensor circuit. The box is back on the Orbiter and fully checked out. Today, we re-installed the solar array interface panel, closing out the avionics deck.

Here is the Orbiter with the HGAS installed. It is on the -Z face, with the avionics radiator on each side of it. Right now, the radiator is covered with an aluminum panel which protects the delicate mirrors from impact and contamination. You can see the close-out panel on the -Y face (left) where the solar array will attach. The solar array gimbal is at the bottom of the panel in the middle. The four array attach points are visible at the top corners and just below the middle of the panel. One of our two omni-directional antennas is mounted on the boom at the top.