--- title: "World’s Most Secretive 737 Is Supporting NASA’s Historic Artemis II Launch" description: "It is rare to see the unique NT-43A aircraft at all, let alone flying over Florida ahead of the first crewed lunar space mission in decades." date: "2026-04-01" modified: "2026-04-01" authors: - name: "Thomas Newdick" job_title: "Staff Writer" link: "https://www.twz.com/authors/thomas-newdick" - name: "Joseph Trevithick" job_title: "Deputy Editor" link: "https://www.twz.com/authors/joseph-trevithick" url: "https://www.twz.com/space/worlds-most-secretive-737-is-supporting-nasas-historic-artemis-ii-launch" categories: - "Air" - "Air Forces" - "Airborne Radar" - "Airborne Sensors" - "NASA" - "Space" - "U.S. Air Force" --- # World’s Most Secretive 737 Is Supporting NASA’s Historic Artemis II Launch ![The U.S. Air Force Materiel Command’s highly secretive NT-43A has been spotted in Florida, apparently taking part in the preparations for the launch of NASA's long-delayed Artemis II lunar space mission.]() *A stock picture of the NT-43A aircraft, also commonly known by the callsign RAT55. Phodocu* The U.S. Air Force Materiel Command’s secretive [NT-43A]() has been spotted in Florida, taking part in the preparations for the launch of [NASA's long-delayed Artemis II lunar space mission](). This highly unique and notoriously shy plane, a converted militarized Boeing 737-200 variant (T-43) also commonly known by the callsign RAT55, has long been used as an airborne [signature measurement]() platform to support [work related to stealthy military aircraft](). However, during a high-stakes space launch, its two huge radar arrays, modular electro-optical and infrared sensors, and other capabilities would likely be well-suited to gathering telemetry and other valuable data, as you can read more about [here](). RAT55 was spotted yesterday flying over Melbourne, on Florida's eastern coastline, which was already highly unusual. The jet is very easy to identify, even in the distance, due to its heavily modified nose and massive aft radome protruding from the rear of the fuselage. The NT-43A seems to live at the [Tonopah Test Range Airport (TTR)](), a high-security facility in Nevada long associated with [shadowy]() aircraft [programs](). It is often spotted flying around Area 51 in Nevada and Edwards Air Force Base in neighboring California, both of which are major U.S. military flight test hubs. [It is rare]() to [see it anywhere else](). https://twitter.com/Brevardjetphoto/status/2039088495260512562 The sighting of RAT55 in the skies above Melbourne aligned with online tracking data for a flight using the callsign NASA522. That track showed the aircraft – apparently miscoded as a C-130 Hercules transport plane – taking off from MacDill Air Force Base, situated to the southwest, and then flying an oval-shaped orbit in restricted airspace around the Kennedy Space Center's [Launch Complex 39B](). The aircraft then returned to MacDill. ![]() **ADS-B Exchange** https://twitter.com/norb420/status/2039103689126985847 The Artemis II mission is currently scheduled to launch from Launch Complex 39B today at 6:24 PM EDT. A [Space Launch System]() (SLS) rocket will take four astronauts in an [Orion capsule]() into space on what is [expected to be a nine-and-a-half-day-long trip](). This will be the first crewed lunar mission of any kind since Apollo 17 in 1972, but [the Artemis II crew]() will not actually set foot on the Moon. They will instead pass by, hopefully setting a new record for the longest distance that people have traveled away from Earth. The target distance is 252,000 miles, some 4,000 miles [beyond the current record](), set by the crew of [the ill-fated Apollo 13 lunar mission]() in 1970. The Artemis II mission's main goal is to help lay the groundwork for future missions to the lunar surface, the first of which is now expected to come in 2028. https://twitter.com/NASAArtemis/status/2039331072547184868 NASA regularly uses fixed-wing aircraft to gather imagery and other important data during space launches. One of its [high-flying WB-57F research planes](), which are routinely used to provide optical tracking, was also flying around Launch Complex 39B yesterday at the same time as the NASA522 flight. The WB-57F conducted that flight from the Kennedy Space Center’s [Shuttle Landing Facility]() (SLF). https://twitter.com/Dillonshrop06/status/2039190784025440643 ![]() *A stock image of one of NASA’s WB-57Fs. *NASA* One of NASA's WB-57Fs, which carries the U.S. civil registration number N926NA. *NASA** It is unclear why RAT55 has been called in to help, especially given that the U.S. military, and [the U.S. Navy in particular](), has an array of dedicated range support aircraft specially configured to support missile test activities, and a history of [using them to support NASA launches]() in the past. *TWZ* has reached out to the Air Force and NASA for more information. Still, as already noted, the NT-43A does have a sensor suite that would likely be very relevant to the space launch support mission. Beyond helping to collect more general telemetry information, the unique capabilities the aircraft has to offer might be used to gain more detailed insights into various aspects of the SLS rocket and the Orion capsule at launch. One of the tasks RAT55 is more typically understood to perform is helping to verify surface coatings on low-observable (stealthy) aircraft. Specialized coatings and other materials, [especially to provide critical thermal protection](), are a key aspect of space launch rocket and spacecraft design. Though the WB-57F has numerous [modular payload bays, as well as space]() for sensor and other equipment in underwing pods, the NT-43A offers a more capacious airframe, overall, along with optional dorsal fairings. NASA could fill this space with additional systems to meet other mission requirements. In addition, it is worth mentioning here that NASA only has three WB-57Fs, and [one made a fiery belly landing in Houston](), Texas, back in January. The current status of that aircraft is unclear. Whether or not this was a factor in the decision to utilize the NT-43A is unknown. The Air Force does have its own previous history of supporting NASA Moon missions, specifically, with specialized fixed-wing aircraft, which [*The Aviationist* has noted](). During the 1960s and 1970s, the U.S Air Force supported the Apollo program with a fleet of [EC-135N Apollo/Range Instrumentation Aircraft (ARIA) planes](), which were also used to track missile tests. The ARIA jets carried very large radars in their bulbous noses. Those aircraft were later redesignated as EC-135Es and continued to be used for various flight test activities until the last example was retired in 2000. ![]() *An EC-135N/E ARIA aircraft. *USAF** Choosing the NT-43A for this task at all is still somewhat curious, given the U.S. military's array of other missile tracking and range support telemetry aircraft, especially [within the U.S. Navy](). Those fleets continue to evolve, including with the Navy's addition of its [Gulfstream G550 business jet-based NC-37B](). Repurposed [RQ-4 Global Hawk drones]() are even now in the mix. There is a history of similar U.S. military planes supporting NASA launches in the past. It isn't clear if additional roles for the NT-43A are going to be a common thing, but it certainly appears that its mission set is expanding. This is a very interesting development for an aging aircraft that has lived in the shadows for so long. Regardless, the Artemis II launch is especially important for NASA, in general. There has only been one all-up launch of an SLS before now, in 2022, and no astronauts were on board at that time. The Artemis program has been dogged by setbacks and delays, with the [hope originally that the Artemis III mission]() would bring Americans back to the lunar surface in 2024. ***The video below shows the first SLS launch as part of the uncrewed Artemis I mission in 2022.*** https://www.youtube.com/watch?v=VUiEdqcLg-k NASA is now in line to finally reach the next Artemis milestone with today's planned launch, and is doing so with help from the Air Force's unique and rarely seen RAT55. ***UPDATE: 7:42 PM EDT –*** We have now received additional information from the U.S. Air Force about RAT55, which you can find in a follow-up story [here](). *Contact the author: thomas@thewarzone.com* ## Author Thomas Newdick is a staff writer at *TWZ*, where he covers military aviation, defense technology, weapons systems, and international security. Based in Berlin, Germany, he reports on conflicts, military modernization efforts, and emerging aerospace technologies around the world, with a particular interest in airpower and its role in contemporary warfare. His reporting is informed by deep expertise in modern and historical airpower, particularly in Europe, with a focus on military aviation, air campaigns, and aerospace developments across the continent and beyond. Over a journalism career spanning more than 25 years, Thomas has become known for making complex defense and aerospace topics accessible to a broad audience. His reporting combines technical expertise, historical context, and a focus on the real-world operational and strategic implications of military developments. ### Author social links [Twitter]()