###Answer the question from the input provided. Please answer from input only.

###Input: Almost all the rocks show evidence of impact process effects. Many samples appear to be pitted with micrometeoroid impact craters, which is never seen on Earth rocks, due to the thick atmosphere. Many show signs of being subjected to high pressure shock waves that are generated during impact events. Some of the returned samples are of impact melt (materials melted near an impact crater.) All samples returned from the Moon are highly brecciated as a result of being subjected to multiple impact events.

In 2009, NASA held a symposium on project costs which presented an estimate of the Apollo program costs in 2005 dollars as roughly $170 billion. This included all research and development costs; the procurement of 15 Saturn V rockets, 16 Command/Service Modules, 12 Lunar Modules, plus program support and management costs; construction expenses for facilities and their upgrading, and costs for flight operations. This was based on a Congressional Budget Office report, A Budgetary Analysis of NASA's New Vision for Space, September 2004. The Space Review estimated in 2010 the cost of Apollo from 1959 to 1973 as $20.4 billion, or $109 billion in 2010 dollars.

Looking beyond the manned lunar landings, NASA investigated several post-lunar applications for Apollo hardware. The Apollo Extension Series (Apollo X,) proposed up to 30 flights to Earth orbit, using the space in the Spacecraft Lunar Module Adapter (SLA) to house a small orbital laboratory (workshop). Astronauts would continue to use the CSM as a ferry to the station. This study was followed by design of a larger orbital workshop to be built in orbit from an empty S-IVB Saturn upper stage, and grew into the Apollo Applications Program (AAP). The workshop was to be supplemented by Apollo Telescope Missions, which would replace the LM's descent stage equipment and engine with a solar telescope observatory. The most ambitious plan called for using an empty S-IVB as an interplanetary spacecraft for a Venus fly-by mission.

The S-IVB orbital workshop was the only one of these plans to make it off the drawing board. Dubbed Skylab, it was constructed complete on the ground rather than in space, and launched in 1973 using the two lower stages of a Saturn V. It was equipped with an Apollo Telescope Mount, the solar telescope that would have been used on the Apollo Telescope Missions. Skylab's last crew departed the station on February 8, 1974, and the station itself re-entered the atmosphere in 1979, by which time it had become the oldest operational Apollo-Saturn component.

In 2008, Japan Aerospace Exploration Agency's SELENE probe observed evidence of the halo surrounding the Apollo 15 Lunar Module blast crater while orbiting above the lunar surface. In 2009, NASA's robotic Lunar Reconnaissance Orbiter, while orbiting 50 kilometers (31 mi) above the Moon, began photographing the remnants of the Apollo program left on the lunar surface, and photographed each site where manned Apollo flights landed. All of the U. S. flags left on the Moon during the Apollo missions were found to still be standing, with the exception of the one left during the Apollo 11 mission, which was blown over during that mission's lift-off from the lunar surface and return to the mission Command Module in lunar orbit; the degree to which these flags retain their original colors remains unknown.



###Question: What did NASA name the series seeking up to 30 more flights to Earth's orbit?

###Answer: {'answer':'Apollo X'}