Topic: EB: Marquardt R-4D attitude control thruster
eflynn New Member
Posts: 3 From: Clearwater. FL, USA Registered: Jun 2015
posted 06-10-2015 04:37 PM
I currently have a very interesting and rare find. It is a Marquardt R-4D control thruster for the Apollo program. Currently for sale on eBay.
Sixteen engines just like this one were mounted on the exterior of each lunar module. Because both lunar module and service module were jettisoned during the Apollo missions, no flown examples exist. However, these are quite rare with only about 800 of them were made.
I am not sure of the origin of this R-4D, but it does appear to be dated on it with 2067, which I believe would be February of 1967. This one has the wires cut off on it and appears that it may have been used for some type of testing. It originated from an individual that worked for NASA for a number of years.
SpaceAholic Member
Posts: 4437 From: Sierra Vista, Arizona Registered: Nov 1999
posted 06-10-2015 04:53 PM
Not as rare as one may believe given continued Aerojet production proceeds even up through today (the qty of 800 represents only an estimate of what was produced as of 1985). Application of the R-4D was/is much broader the project Apollo.
eflynn New Member
Posts: 3 From: Clearwater. FL, USA Registered: Jun 2015
posted 06-11-2015 02:01 AM
I would agree that the Marquardt R-4D is not very rare in itself as I understand they were used in many different capacities including satellites. In my opinion, they are really only valued based on the contract they were used for and the time frame in which they were used or manufactured.