What were the chances that Apollo would safely land on the moon?

Question

Becuase theres no doubt that a lot of risk was encountered while going on the moon. I just want to hear an approximate guess as to the percentage chance that everything would work out perfectly while undertaking humankinds most diffucult mission EVER without much experience in space prior to going to the moon?

Answer 1

The accumulated risk for a catastrophic failure was at less than 3% for the whole mission. There was a lot of redundancy in Apollo.

Also, "without much experience" in space is complete nonsense.  At the end of Gemini, the USA had overtaken the USSR in terms of man-hours in space.

Answer 2

Seven missions went, six succeeded.  That's 85%.

Some say that since the Saturn V booster never had a failure, that it's probability of success was 100%.

Between Apollo 16 and Apollo 17, a coronal mass ejection came by the Earth/Moon system.  If there were a mission in progress at that time, the astronauts very likely would have died.  The risk factor has to do with the time from when they leave low Earth orbit to when they get back to low Earth orbit.

If this problem isn't solved when we go back to the Moon for longer durations, then people will die.

I've met an astronaut.  He said that to be an astronaut, you have to be smart enough to do the mission, and dumb enough to actually go.  I'm not sure why there are volunteers. Maybe they don't teach them statistics.

Answer 3

Chances of everything working perfectly was nearly 0%. Chances that the little problems would affect the mission and be irrecoverable from, about 10% (as we have seen in the case of Apollo 13). The important thing is that there was redundancy built into the systems, and that ways around problems were available.

Answer 4

What Vincent Van Gogh said.

Answer 5

Graduated missions led confidently to a landing on the Moon

We designed seven types of missions to test the suitability and safety of all equipment in all mission phases. These were designated by letters A through G:

A.  Unmanned flights of launch vehicles and the CSM, to demonstrate the adequacy of their design and to certify safety for men. Five of these flights were flown between February 1966 and April 1968; Apollo 6 was the last.

B.  Unmanned flight of the LM, to demonstrate the adequacy of its design and to certify its safety for men. The flight of Apollo 5 in January 1968 accomplished this.

C.  Manned flight to demonstrate performance and operability of the CSM. Apollo 7, which flew an eleven-day mission in low Earth orbit in October 1968, was a C mission. Apollo 8, which flew the CSM into lunar orbit in December 1968 was also a C mission, but designated as C-Prime, to distinguish it from the prior flight.

D.  Manned flight of the complete lunar landing mission vehicle in low Earth orbit to demonstrate operability of all the equipment and (insofar as could be done in Earth orbit) to perform the maneuvers involved in the ultimate mission. Apollo 9, which flew in March 1969, satisfied this requirement.

E.  Manned flight of the complete lunar-landing mission vehicle in Earth orbit to great distances from Earth. When the time came to commit this mission to flight, we decided that we had already accomplished its objectives and that it was not required. But because this mission was in the program, we had made detailed plans for it, and in fact pulled much of the planning, preparation, and training forward to use in the Apollo 8 lunar-orbit mission.

F.  This was a complete mission except for the final descent to and landing an the lunar surface. Apollo 10, flown by Stafford, in May 1969, was an F mission. The need for this mission was hotly debated. Here we would be, 50,000 feet above the Moon, having accepted much of the risk inherent in landing. The temptation to go the rest of the way was great; but this mission demonstrated the soundness of the strategy of "biting off chunks". The training and confidence of readiness that the Apollo 10 mission gave the entire organization was of inestimable value.

G.  The initial lunar-landing mission. This, of course, was accomplished by Armstrong, Aldrin, and Collins in July 1969.

During the mid-1960s the Apollo Support Department of the General Electric Company in Florida conducted extensive mission reliability studies for NASA. These studies were based on very elaborate reliability models of all of the systems. A reliability profile over the course of a mission was generated by computer simulation, and a large number of such simulations were carried out for different scenarios. Based on those studies, the probability of landing on the moon and returning safely to earth never dropped below 90%.

Answer 6

Today, we'd never take the risks we took on the Apollo missions.  

To give you an idea how far technology has advanced since (and because of) the Apollo missions, the computer in the LM only had 18k of memory.  A basic cell phone has more computer power than that.  

Your computer probably has more processing power than all of mission control had back then.  

But given the technology we had at the time, NASA did the best they could to minimize risk.

Still, the space program was too risky for astronauts to be able to buy life insurance.  

An actual percentage of risk of death?  Probably below 2% on Apollo 11, and somewhat lower on later missions.  

Whatever it was, it was high enough that astronauts couldn't buy life insurance.