Apollo 8 orbited the moon, and obviously Apollo 11 landed. I'm wondering if there were any test missions to get unmanned ships to the moon and safely back to Earth? It seems like a big jump to suddenly send manned ships there.
I'm wondering if there were any test missions to get unmanned ships to the moon and safely back to Earth?
There were no uncrewed round-trip missions to the moon prior to Apollo 11.
Several one-way missions landed safely on the moon without crew before 1969, but did not return, including the American Surveyor series. The first of these, Surveyor 1, landed on the moon on June 2, 1966.
In 1970, the first robotic round-trip mission, the USSR's Luna 16, returned samples from the moon.
There weren't any huge technical obstacles to robotic lunar round-trip missions. The Luna round-trips used a clever return trajectory that required only a single burn from the moon's surface with no course corrections afterwards, but that technique constrained when and where they could land on the moon; a multiple-burn return would have required a little more sophistication in the probe's guidance and navigation system (and thus more mass and cost), but it wouldn't have been impossible to do pre-Apollo-11.
Returning from the moon takes a vehicle several times larger than one that just needs to get there; if you don't do a lunar orbit rendezvous like Apollo did, then you need to carry all the fuel for your return journey all the way to the moon's surface. Luna 16 was more than 5 times as massive as Surveyor 1, for example, requiring a 700-ton Proton booster to go to the moon instead of a 140-ton Atlas-Centaur.
Lunar orbit rendezvous offers a path to a lunar landing mission with a smaller vehicle at the cost of additional mission complexity, and automatic docking had been demonstrated by the USSR in 1967.
The USSR's lunar landing plan would possibly have landed one LK uncrewed as a backup, followed by a second LK with a single crew member, but they never got the necessary N1 booster to work. The LK itself had a backup ascent engine, so this plan provides 8 times as many ascent engines per crew member as Apollo. They clearly didn't want to strand a cosmonaut on the moon.
It seems like a big jump to suddenly send manned ships there.
It would have been technically feasible to land an Apollo LM (with some modifications) uncrewed. However, one of the major lessons of the X-15 program was that the combination of automation and human capabilities in a complex system was far more reliable than either human or automation alone. If, for example, Apollo 10 had flown its LM to the surface without a crew, it would have had substantial risk of crashing (having no way to know if it was coming down in a field of boulders) and the program would have missed out on the first-hand observations of the crew.
No. NASA was focused on manned missions. The unmanned Surveyor series proved that a Moon landing was possible, and launching from the lunar surface wasn't considered risky enough that an unmanned trial run was considered worth doing. The closest any of the Surveyors came to "Earth return" was Surveyor 6, which performed a "hop" reaching an altitude of four meters, landing three meters to the side of the original touchdown point.
The Soviet Union took two shots at it: an unnamed mission that failed on launch in June 1969 and Luna 15 (crashed into the Moon 13 hours after the start of Armstrong's moonwalk), but the first successful unmanned sample-return mission was Luna 16, in September of 1970.