User:Jadebenn/Mobile Launcher



A mobile launcher (ML), sometimes referred to as a mobile launch platform (MLP), is a type of launch infrastructure used by some vertically-integrated rockets.

The use of Mobile Launchers dates back to the "Integrate-Transfer-Launch" (ITL) concept originally developed for the Titan III launch infrastructure, and adopted by the Apollo program for launch processing at Launch Complex 39. The concept was applied to LC-39, 40, and 41 as originally constructed. LC-39B and SLC-41 continue to use derivatives of this concept in the present.

Apollo


The first three MLs were constructed for transporting and launching the Saturn V rocket for the Apollo program lunar landing missions of the 1960s and 1970s. Each ML originally had a single exhaust vent for the Saturn V's engines. The MLs also featured a 380 ft Launch Umbilical Tower (LUT) with nine arms that permitted servicing of the vehicle on the launch pad, and swung away from it at launch. After the Apollo test program, Cape Canaveral Launch Complex 37 was decommissioned and launches of the Saturn IB rocket were moved to Kennedy Space Center Launch Complex 39B for the Skylab and Apollo-Soyuz programs. ML No. 1 was therefore modified to add a 140 ft four-legged pedestal (nicknamed "the milkstool" because of its resemblance to the stool used by farmers when milking cows by hand) for the shorter Saturn IB to stand on. This allowed use of the Saturn V tower and service arms for the Saturn IB, and Saturn V Ground Support Equipment (GSE) was removed or de-activated and Saturn IB GSE equipment was installed. Upon completion of the Apollo-Soyuz Test Project, this final ML was converted into an MLP to support the Space Shuttle program.

Shuttle
After the Apollo program, the bases of the Mobile Launchers were modified for the Space Shuttle (Space Transportation System) and renamed Mobile Launch Platforms (MLP). The umbilical towers from Mobile Launchers 2 and 3 were removed. Portions of these tower structures were erected at the two launch pads 39A and 39B. These permanent structures are now known as the Fixed Service Structures (FSS).

Titan
Titan III and Titan IV rockets launched from LC-40 and LC-41 utilized mobile launch platforms to decouple assembly of the launch vehicle from launch. This was meant to enable simultaneous assembly of multiple launch vehicles as part of the Titan's Integrate-Transfer-Launch (ITL) concept, allowing a high flight rate from a small number of launchpads.

Constellation
With the retirement of the Shuttle in 2011 and its planned replacement Orion spacecraft and launcher in the design and test phase, NASA converted LC-39B from Shuttle operations to support Orion launches. The Ares I-X suborbital mission utilized MLP-1, to support the stacking and launch operations. The cancelled Ares I-Y would have used the same MLP.

Atlas V
The Atlas V utilizes a MLP when launching from SLC-41. For those launches the rocket stacked on its MLP in the 85.4 m Vertical Integration Facility (VIF), and is then rolled-out over the 550 m distance to the launchpad. The design of this MLP is derived from the MLPs used by the Titan III and IV rockets.

OmegA
Northropp Grumman Innovation System's OmegA will launch from LC-39B using a modified MLP-3. The rocket will be stacked in High Bay 2 of the Vehicle Assembly Building.

Vulcan
United Launch Alliance's Vulcan will use an MLP similar in design to the one used by the Atlas V when launching from SLC-41, altered to support the former's larger design. The Vulcan MLP stands 183 ft tall, and when complete will weigh 1.3 e6lb. It will be equipped with various electronics, power-lines, and cables to support and control the rocket. For the initial Vulcan-Centaur configuration, the MLP will supply liquefied natural gas and liquid oxygen to the first stage, and liquid hydrogen and liquid oxygen to the Centaur upper stage. the basic structure has been completed, but the umbilicals and equipment have yet to be installed.

Space Launch System
The ML that was built to launch the Ares I rocket was modified to support the Space Launch System. The mobile launcher was significantly altered to support the heavier weight and additional thrust of the heavy lift rocket. The biggest modifications to the ML were on the platform's base, where engineers increased the size of a 22 ft2 exhaust duct to a rectangle stretching 60 by and strengthened the surrounding structure.

The SLS will weigh more than twice as much as the planned Ares I rocket. The Ares I rocket would have featured a single solid-fueled first stage, while the Space Launch System will include two large solid rocket boosters and a powerful core with four Space Shuttle main engines. Modifications began on 1 October 2013 and were completed in October 2018.

Due to the increased weight of an unloaded SLS stack compared to the Saturn V, NASA has upgraded CT-2 to a "Super Crawler" capable of carrying the ML and rocket stack to the launchpad.