Space Shuttle Main Engines Take Center Stage at Kennedy Space Center


CAPE CANAVERAL, Fla – The space shuttle era is over and the program’s elements are either being dismantled or repurposed for other uses. Such is the case with the Space Shuttle Main Engines or SSMEs. NASA’s fleet of orbiters each used three of these highly-powerful Pratt & Whitney Rocketdyne engines during the shuttle program’s 30 year history. They are now being considered for use in NASA’s Space Launch System (SLS). 

Known within the aerospace industry as the RS-25, these engines are fueled by liquid hydrogen and liquid oxygen and were removed from the orbiters after each flight for refurbishment and maintenance.

In a facility located near Kennedy Space Center’s Orbiter Processing Facility 3, rows of space shuttle main engines or SSMEs await transportation to Stennis Space Center. Photo Credit: Alan Walters/

Next to Orbiter Processing Facility-3 (OPF-3) is the Space Shuttle Main Engine Processing Facility or SSMEPF. There are currently 14 main engines in this facility, each of which has been prepared for storage at NASA’s Stennis Space Center located in Mississippi.

Like some bizarre farm, rows of shuttle engines lay stacked nozzle down or on their sides with large supporting mounts holding them in place. On the second floor of the building are work stations where the SSME’s engine components are easily accessible. This facility is kept immaculate and posters and signage indicate the pride that these workers have for these engines.

It is planned to utilize these engines on the lower stage of NASA’s new Space Launch System or SLS. Photo Credit: Alan Walters/

“There are fourteen post-shuttle engines in this facility,” said Rocketdyne’s Technician Lead Bob Petrie. “Right now all of these engines are being processed for storage to support the SLS program, where they will be used in the lower stage of the new heavy-lift vehicle.”

Space Shuttle Discovery was the first orbiter to receive Replica Shuttle Main Engines or RSMEs. Photo Credit: Alan Walters/

Nine SSMEs have been heavily modified and will serve as mock versions of their former selves when the space shuttles are placed on display in Washington D.C. (Discovery) Los Angeles (Endeavour) and at the Kennedy Space Center Visitor Complex in Florida (Atlantis).


The modified engines are referred to as Replica Shuttle Main Engines or RSMEs. Engineers at Kennedy Space Center in Florida have finished installing RSMEs into space shuttle Discovery. The mock engines were installed this week; with the first being put into place Dec. 5 and the last on Wednesday, Dec. 7 (it takes approximately one day to install one engine). The nozzles on the RSMEs are actual flight nozzles that have flown into space.

It takes about a day to install just one of the engines. The nozzles on these engines come from SSMEs that have flown in space before. Photo Credit: Alan Walters/

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