During preparations for NASA's LADEE observatory, engineers checked the spacecraft's alignment after it was shipped across the country from the preparation facility at NASA Ames Reseach Center in Mountain View, Calif.
The propulsion system was checked for leaks, solar power panels repaired, and final electrical tests were done before launch.
Engineers then mounted the spacecraft onto a spin table and rotated it at high speeds of approximately one revolution per second, ensuring the spacecraft is perfectly balanced for flight. Even the tiniest offset can damage the delicate instruments.
The team measured any offsets during the spinning, and then added small weights to the spacecraft to make sure it was perfectly balanced. Once balanced, the team loaded the propulsion tanks with fuel, oxidizer, and pressurant, and the spin tests were performed again.