Spacecraft Assembly

Solar Array and High-Gain Antenna

June 5, 2008

The LRO team has been busy finishing all the details. We are checking out every heater and temperature sensor connection, shielding cables, tying harnesses down for flight, and installing blankets. We have run through tests of all of the electronics on the spacecraft, but we plan to do one more run for the record before we start environmental testing. The flight operations team executed several simulations over the last few weeks.

The Solar Array System was assembled as a stand-alone subsystem two weeks ago. We successfully executed a full deployment on the test stand on May 20th (the same day the flight operations team simulated a deployment). We integrated the interface panel and solar array gimbal on the Orbiter and ran the gimbal through its paces. We also hooked the array up with extension cables and verified that light on the array properly sends current into the Orbiter.

The High-Gain Antenna System completed its thermal vacuum testing, and we are getting ready for installation on the Orbiter.

We found a serious problem with our sun sensor input circuit. During integration of the coarse sun sensors, the engineers discovered that the input resistance in our flight computer system was too high, so we have removed the box from the Orbiter. We have already made the resistor change and will re-integrate the box on the Orbiter after vibrating it to verify that is was reassembled properly.

Here's the avionics panel almost ready for final close-out. On the right, a technician measures the position and alignment of our instruments.

Craig Tooley, the LRO project manager, describes the LRO mission to actor George Takei who played Mr. Sulu on the television show Star Trek. In the background, the LRO mechanical team prepares for some work on the Orbiter and the harness team takes a break..

June 12, 2008

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.

  Completing Integration Phase | Environmental Testing