Now that ASTRO-H has been successfully assembled, the next step is the Thermal Vacuum Test. For these tests, ASTRO-H will be placed into a very large vacuum tank. Inside this tank, the full space environment that the satellite will experience will be simulated, even including simulated sunlight. In this way, how well the satellite operates under the expected conditions of the space environment will be verified. While the satellite itself is 8 meters long, the vacuum tank is even larger, with a diameter of 13 meters. This is as tall as a four-storey building! The satellite will be placed inside this tank where it will be maintained in a thermal vacuum.