S-IVB. The telescope would be docked to a CSM with a three-person crew. Solar panels on the telescope would provide additional power, allowing an extended mission of 21–28 days. The telescope module would include a pressurized compartment providing additional living and workspace for the crew. The Apollo Manned Survey Mission proposed an Earth-observation science module also based on the LM ascent stage, and would also have been launched using a S-IVB vehicle into a high-inclination orbit. It was also proposed that a surplus Saturn V would launch a crewed lunar survey mission to establish suitable sites for later crewed landings. The wet workshop space station concept provided for a low-budget Earth orbiting station. The original plan, as proposed by Wernher von Braun, used the S-II stage as the primary structure of the station, with the area normally filled by the S-IVB stage replaced with an equipment carrier. These plans were modified to use the S-IVB when Saturn V production ended with just enough boosters for the lunar missions alone. In the meantime several of the Earth-orbit "checkout" missions for Apollo had been canceled, leaving a number of Saturn IBs unused. The plans were changed to use the S-IVB stage, used on both rockets, as the primary station structure. A modified S-IVB would be launched into orbit, the second stage carrying a docking module and large solar panels in the area normally carrying the LM. A CSM would then be able to dock with the second stage and enter the now-empty fuel tanks. It was also suggested that the Apollo Telescope and Survey Mission modules might be docked to the Wet Workshop to create a modular space station. The "Planetary Grand Tour" was moved to the Mariner program as "Mariner Jupiter-Saturn", which was later calved off into the Voyager program. Two probes were launched in 1977 on Titan IIIE rockets, with Voyager 2 completing the full Grand Tour in 1989. Skylab Originally, AAP missions would alternate with Apollo lunar missions, starting in 1969. However, when NASA's 1969 budget was cut, focus was shifted to the Skylab space station proposal, which managed to accommodate the equipment already specified for some of the AAP missions. Specifically, Skylab included the Apollo Telescope Mission (renamed the Apollo Telescope Mount) attached to the docking station used by the CSMs. Since the first two stages of the Saturn V had enough payload capability by themselves to place