The requirement for providing a simple, reliable, and flexible alternative source of light to astronauts in their spacecraft was met by providing each crew member with a flashlight. The best-known model - used by astronauts on the Apollo flights, and all Shuttle flights through to the late '80s - is the iconic brass ACR FA-5 penlight, but another less well-known model was used before this as noted below.
ACR Model FA-3 Penlight - Gemini missions
Gemini 9 penlight (image courtesy RRAuction)
Gemini 12 EVA flown penlight (image courtesy Heritage Auctions)
The first type of penlight used by the astronauts, flown on the Gemini VI to XII missions, was an ACR model FA-3 flashlight. Two of these flashlights were nominally carried per Gemini mission.
During his Gemini 12 EVA Buzz Aldrin carried two of these flashlights with him. The example shown above had the barrel well wrapped with velcro to allow to be easily attached outside the spacecraft. The lense of this penlight apparently became distorted due to the extreme temperature and pressure differentials it was exposed to.
According to the stowage lists this model of flashlight was also to be used on the Apollo 1 mission. Although it's not clear what material was used for the casing of this flashlight, the switch to the all-brass FA-5 model for Apollo 7 may have been related to the potential flammability of the original unit.
FLOWN availability - Only two flown ACR-FA-3 flashlights have been sold at auction.
Unflown availability - I've not seen an unflown example of this kind of flashlight sold at auction.
ACR Model FA-5 Penlight - Apollo and early Shuttle missions
Neil Armstrong's Apollo 11 penlight, part of the NASM collection
The distinctive brass flashlights used on the Apollo missions (from Apollo 7 onwards) were developed under contract with the Langley Research Center by ACR Electronics Co., a subsidiary of Chromalloy American Corp. and supplier of military and civilian survival equipment. The actual manufacture of the flashlights was sub-contracted out to flashlight specialists Fulton Industries of Wauseon, OH.
The magnesium flashlight was powered by two AA batteries and was turned on and off by rotating the bulb end of the brass casing.
These flashlights proved to be vital on the Apollo 13 mission as the crew were forced to rely on them heavily after powering down their stricken spacecraft. In a post-flight letter of thanks sent by the Apollo 13 crew to ACR Electronics they mentioned that even though the penlights were the main source of light after the power-down they never wore out a single set of batteries.
Still frame from Apollo 16 16mm onboard film showing an ACR penlight floating in zero-g in front of a grinning Charlie Duke
[Extract from letter dated Apr 19, 1971 from the Apollo 13 crew to ACR Electronics]
The penlight which you have supplied for the Apollo missions has been very useful and dependable in all missions to date. However, you deserve special praise for the role it played on our mission - Apollo 13.
As you know, due to the explosion, we were forced to ration our
electrical power and water. With regard to the former, we never
turned on the lights in the spacecraft after the accident. As a
result your penlights served as our means of "seeing" to do the
Indeed, Lovell notes in a later letter that when he found his Apollo 13 penlight in a drawer in 1981 it still lit up even though the batteries were the original set installed and used 11 years previously.
The stowage lists for Apollos 10 through 17 show that 6 or 8 penlights were carried aboard each mission.
Composite penlight entries from the Apollo 10-17 Stowage Lists
The first entry shows a number of penlights stowed in the Command Module at launch. On Apollo 7, 8, 10 and 11 there are 5 penlights shown, then 3 on Apollos 12 through 14, and finally 5 again for Apollos 15 through 17. The second entry shows that in addition one penlight was carried by each crewmember at launch. These were stowed in a special pocket on the left upper arm of the Apollo space suits.
Note that whilst the Commander and Lunar Module Pilot carried their individual penlights down to the surface and back, none of the CM-stowed penlights are noted as being transferred to the Lunar Module.
The Serial Numbers of the NASA-issue ACR-FA-5 flashlights reflect three distinct manufacturing batches, with numbers 10xx being manufactured in June and July of 1968, numbers 20xx in February 1970, and numbers 30xx in August 1972. Note that mixtures from different batches were carried on later flights.
FLOWN availability - These penlights were sometimes kept as momentos by the astronauts after the flights and some have found their way to market over the years. It's worth noting that the brass casings of some examples have become heavily corroded, most likely as a result of the original batteries having been left in place over the last few decades. NASA continued to used these flashlights on flights through to at least the late 80s, so numerous flown examples must exist.
Unflown availability - Unflown examples used in training or prototype examples may also find their way to market, but remain extremely scarce and highly sought-after. Supposedly this model of flashlight was also used by the military, but I've yet to see any surplus example appear on the secondary market so my impression is that it was likely only supplied to NASA.
A commercial flashlight (model no. ACR101) using some of the technology developed for NASA was marketed by ACR's parent company Chromalloy Electronics as the "Five Year Light". The name was based on the idea that the flashlight could be left unused for five years without any battery drain. These flashlights were sold from mid 1972 to at least 1978, with a NASA spinoff report mentioning that 2 million units had been sold as of 1975. Vintage examples of this flashlight can be found from time to time on eBay.
Annex: NASA-issue Penlights sold at auction or identified in private or museum collections
|Footnotes : |
 Apollo Experience Report - Crew Provisions and Equipment Subsystem [PDF document]
 Letter from the crew of Apollo 13 to ACR Electronics, dated Apr 19, 1971.
 Letter from Jim Lovell, dated Dec 8, 1981.
 Letter listing items kept by the crew of Apollo 17 after the flight.
 CSD/GFE Allocations and Schedules by Vehicle for Apollo 17.
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