Why did Apollo mission numbering skip 2,3,4,5 and 6?

Question

Apollo 1 was a ground test that ended in a fire. The next Apollo mission I have any reference to is Apollo 7. What happened to Apollo 2,3,4,5 and 6?

Answer 1

According to Aviation Week & Space Technology, 1967 August 28:

NASA has retroactively assigned the labels of Apollo 1, 2 and 3 to the first three unmanned missions flown.

The magazine also refers to AS-501 as Apollo 4.

By my calculation:

• Apollo 1 = suborbital 1966 Feb 26 as AS-201
• Apollo 2 = suborbital 1966 Aug 25 as AS-202
• Apollo 3 = orbital 1966 059A as AS-203
• Apollo 4 = orbital 1967 113A as AS-501
• Apollo 5 = orbital 1968 007A and 1968 007B as AS-204
• Apollo 6 = orbital 1968 025A as AS-502
• Apollo 7 = manned orbital 1968 089A as AS-205

However, NASA History SP-4009, for the period 1967 March 25 to April 24, tells a different story. After some discussion (in which George Low offered the above as an option), it was eventually decided to keep the burnt mission as Apollo 1, to not number AS 201, 202 and 203, and the next would be Apollo 4 (AS-501) and thereafter number the missions in flight order:

March 25 - April 24

NASA Hq. Office of Manned Space Flight informed KSC, MSFC, and MSC of approved designations for Apollo and Apollo Applications missions:

1. all Apollo missions would be numbered sequentially in the order flown, with the next mission to be designated Apollo 4, the following one Apollo 5, etc., and
2. the Apollo Applications missions would be designated sequentially as AAP-1, AAP-2, etc. The number designations would not differentiate between manned and unmanned or uprated Saturn I and Saturn V missions.

In a letter to George E. Mueller, OMSF, on March 30, MSC Deputy Director George M. Low offered two suggestions, in keeping with the intent of the NASA instruction yet keeping the designation Apollo 1 for spacecraft 012. NASA Hq. had approved that designation before the January 27 fire claimed the lives of Astronauts Virgil I. Grissom, Edward H. White II, and Roger B. Chaffee; and their widows requested that the designation be retained. The suggestions were:

1. Consider the AS-201, 202, and 203 missions part of the Saturn I (as opposed to uprated Saturn I) series; reserve the designation Apollo 1 for spacecraft 012; and number the following flights Apollo 2, etc., or
2. Designate the next flight Apollo 4, as indicated by Headquarters, but apply the scheme somewhat differently for missions already flown. Specifically, put the Apollo 1 designation on spacecraft 012 and then, for historic purposes, designate 201 as mission 1-a, 202 as mission 2 and 203 as mission 3.

A memorandum to the NASA space flight Centers, North American Aviation, and certain Headquarters personnel from the NASA Assistant Administrator for Public Affairs on April 3 stated that the Project Designation Committee had approved the Office of Manned Space Flight's recommendations and that Mueller had begun implementation of the designations.

On April 24, OMSF further instructed the Centers that AS-204 would be officially recorded as Apollo 1, "first manned Apollo Saturn flight - failed on ground test." AS-201, AS-202, and AS-203 would not be renumbered in the "Apollo" series, and the next mission would be Apollo 4.

TWX, Mueller, NASA OMSF, to KSC, MSFC, MSC, "Apollo and AAP Mission Designation," March 25 and April 24, 1967; ltr., Low to Mueller, March 30, 1967; memo, Julian Scheer, NASA Assistant Administrator for Public Affairs, to distr., April 3, 1967.

So there is no official Apollo 2 or Apollo 3.

Hope this helps, Andrew Rennie President Space Association of Australia, Inc.

Answer 2

They were either unmanned test-flights, manned test-flights (Apollo 7), or not-quite-numbered as Apollo missions (AS-201 - AS-203)

http://en.wikipedia.org/wiki/List_of_Apollo_missions

Answer 3

This site writes to say

Apollo 2 and 3: There were no craft named Apollo 2 or 3.

Apparently after the Apollo-1 craft was destroyed during a pre-flight test at Cape Canaveral, the first few mission (through Apollo-6) were unmanned missions to test various aspects of the Apollo program - Launch vehicle, CSM, LM, and their inter-play.

Apollo-7 was the first manned mission after the Apollo 1 disaster; which seems to dovetail with the data you have.

A brief summary of the Apollo program is also listed here

Answer 4

There were no manned flights of Apollo hardware prior to 7. The unmanned flights (of which there were several) apparently didn't earn much historical prominence as the manned flights from 7 onward. Apollo 1, sadly, earned its place in the history books due to the tragic fire.

Each of the flights from 7 to about 15 was notable in some way, mostly for some manned space flight "first":

• Apollo 7: first manned flight of the Apollo crew vehicle
• Apollo 8: first time a crewed vehicle traveled beyond LEO... furthest any human had been from the Earth to that time, first time a human had circumnavigated the Moon.
• Apollo 9: first crewed, in-space operation of the LEM.
• Apollo 10: first flight of the LEM to the Moon, first descent (but not landing)
• Apollo 11: first landing on the Moon
• Apollo 12: first colour TV images from the Moon. Perhaps more significant was that it proved the accomplishment of Apollo 11 was repeatable.
• Apollo 13: first disaster in space. Lunar mission aborted, but crew returned safely.
• Apollo 14: successful mission following Apollo 13
• Apollo 15: first use of the lunar rover

The last two missions (Apollo 16 and 17) accomplished a lot of science, and from a science perspective did new and different things, but from a press point of view, began to look like "more of the same".

Against that backdrop, the early unmanned flights, important as they were to the Apollo program, and confusion in numbering aside, are not on quite the same level in terms of press and public perception.

For what it's worth: footage from Apollo 4 and Apollo 6 turns up all over the place - especially one clip from a camera mounted on the bottom of the second stage in which the first stage is seen falling away, followed by the inter-stage ring.