Want to stay on top of all the space news? Follow @universetoday on TwitterApollo 18 was one of three missions that were canceled by NASA due to budgetary constraints. Apollo 19 and Apollo 20 were the other two. Apollo 18 was originally scheduled to be a ”J” mission, meaning that it would include a three day stay on the Moon and the use of the lunar rover and and extended number of scientific experiments.
The Apollo space missions were originally broken down into several types: A thru G with H,I and J added later.
- A – Unmanned Command Service Module (CSM) test
- B – Unmanned Lunar Module (LM) test
- C – Manned CSM in low Earth orbit
- D – Manned CSM and LM in low Earth orbit
- E – Manned CSM and LM in an elliptical Earth orbit with an apogee of 7400 km
- F – Manned CSM and LM in lunar orbit
- G-Manned lunar landing
The H missions were short missions that would have two extra vehicular activities (EVA’s). The J missions were meant to have a longer stay on the lunar surface and three EVA’s. Lunar Orbital Survey Missions were conceived that would have seen a long duration orbital mission of the Moon using a Service Module bay loaded with scientific equipment. These were called the I missions, but all of them were canceled when it became clear that the budget was going to be cut. Instead NASA incorporated the equipment into the J missions and trailed it from the CSM.
The cancellation of Apollo 18 left some surplus equipment laying around. Instead of wasting the money and scraping the rocket and modules NASA used some of the parts on other missions and as historical displays at various locations around the United States.
There is a nice article about the Apollo 18 mission here. Here on Universe Today we have a great article about all of the Apollo missions in general. One of the greatest challenges to the Apollo program was to overcome the atmospheric conditions of the Moon. Astronomy Cast offers a great episode about the different atmospheres around the galaxy.