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<\/p>\nNASA has released a Request For Information for a new engine the agency will use on the Orion European Service Module beginning with EM-6 (Exploration Mission 6). The Request For Information states that the engine is needed by mid-2024 in order to support the EM-6 flight of the Space Launch System, which under the currently in effect budget and operational timeline for NASA will be No Earlier Than 2027.<\/p>\n
Orion Service Module engine RFI:<\/b><\/p>\n
As part of NASA\u2019s plan to utilize as much hardware that remained at the end of the Space Shuttle program as possible for the SLS (Space Launch System) rocket and Orion capsule, the agency mandated that Orion\u2019s European Service Module (ESM) utilize the leftover Space Shuttle Orbital Maneuvering System (OMS) engines for the first five Orion\/ESM flights. <\/p>\n
The supply of available Shuttle OMS engines will run out after EM-5, currently slated for No Earlier Than 2026, as the European Service Module is expended at the end of each flight and not reused. As such, NASA requires a replacement engine beginning with EM-6, and the agency took the first step toward that replacement yesterday in releasing a Request For Information (RFI) to the aerospace industry.<\/p>\n
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The Orion and European Service Module (with left-over Space Shuttle OMS engine) docked with the under construction Deep Space Gateway on the EM-3 mission. Credit: Nathan Koga for NSF\/L2<\/p>\n
\u201cNASA invites industry to submit a response to this Request For Information to assist NASA in planning for the development of a new Service Module Main Engine for the Orion Multi-Purpose Crew Vehicle.\u201d<\/p>\n
All RFI responses are due by 16 March 2018 to the Johnson Space Center in Houston, Texas, and according to the RFI document, \u201care intended to provide input for an assessment of a new engine for the ESM with respect to the constraining performance and interface requirements.<\/p>\n
\u201cNASA desires a low cost replacement engine to minimize program cost and schedule impacts to the Orion vehicle. The replacement engine shall minimize development time for an engine and reduce manufacturing\/production costs while still meeting NASA programmatic, technical, design, construction, and workmanship approaches and standards for human rating.\u201d<\/p>\n
However, because the Orion ESM has been designed to use the leftover Shuttle OMS engines, the needed replacement engine must meet strict and already determined operational constraints and a host of other already-determined requirements.<\/p>\n
SpaceX (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n Thus, NASA\u2019s RFI is a way to ensure the agency is following the best practices possible to keep the cost of the new engine down while still meeting all safety and timeline requirements.<\/p>\n Constraining parameters:<\/b><\/p>\n Based on the current Shuttle OMS engine parameters, NASA\u2019s RFI for the new service module engine states that the engine must have a minimum specific impulse (ISP) of 310 seconds using already established Standard Inlet Conditions.<\/p>\n The Orion Multi-Purpose Crew Vehicle and European Service Module. Credit: NASA<\/p>\n According to the RFI, those Standard Inlet Conditions include a fuel inlet pressure of 244 psia, an oxidizer inlet pressure of 240 psia, and a propellant temperature of 70\u2109.<\/p>\n The engine must also be able to produce roughly 6,000 lbf of steady-state thrust in a vacuum with an engine thrust roughness \u201cless than +5% of average steady state thrust.\u201d<\/p>\n Moreover, the engine must reach 90% of steady-state thrust within 0.45 seconds (+\/- 0.1 seconds) of receiving the \u201con\u201d command while also not exceeding a peek overthrust of 150% of the mean steady-state thrust upon engine start.<\/p>\n The new engine must also use an oxidizer to fuel mixture ratio of 1.65 (+\/- 0.03), carry a maximum weight of \u201c~284 lbf\u201d and a length of roughly 79 inches (with a max \u201chead end to gimbal\u201d length of 23 inches).<\/p>\n Drawing of the current OMS engine for the European Service Module, showing length and height requirements\/recommendations. Credit: NASA<\/p>\n The current Shuttle OMS engine \u201cgimbal to nozzle exit\u201d length of 56 inches can be varied on the new engine, and the RFI specifically notes that if such a variance is suggested that the RFI answering company provide insight as to why.<\/p>\n Additionally, the engine must be able to gimbal greater than +\/- 6 degrees in pitch and yaw during operation, must not exceed a maximum power consumption of 309 W, must be able to restart as soon as 240 seconds after its previous shutdown, and must be capable of supporting a mission duration of a minimum of 21 days for lunar missions and 210 days of \u201cquiescent duration in cislunar or transit conditions.\u201d<\/p>\n But the engine\u2019s space-base and operational requirements aren\u2019t the only points of information requested by NASA. The agency also released a set of requirements for the engine\u2019s ground support, control of catastrophic hazards requirements, failure detection for crew safety requirements, independent confirmation of failure assessments, and reliability.<\/p>\n Specifically, NASA requested information on the ground handling elements for the engine, including installation, checkout, loading, cleaning, installation in Europe, testing in Europe and the United States, testing at various NASA centers\/facilities, as well as launch preparations.<\/p>\n<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2018\/02\/Screen-Shot-2018-02-15-at-12.03.42.png\")
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