NASA's Artemis II Orion One-Way Doppler Measurements Tracking

I. Introduction: Building on the success of the 2022 Artemis I One Way Doppler Tracking Demonstration (RFI-GSFC-CIS-2022), and in the support of the Space Communication and Navigation (SCaN) Program’s commercial services strategy, this Request for Information (RFI) presents an opportunity for organizations with ground station capabilities to inform NASA on how they may be able to execute tracking of the upcoming Artemis II mission, expected to launch no later than April 2026. All participation will be passive, with no impact on, risk to, or RF radiation emitted towards, the Orion spacecraft. II. Description: This RFI seeks to facilitate NASA SCaN’s increasing use of industry assets and services by demonstrating the potential of non-NASA ground stations to collect one-way Doppler tracking measurements of the Orion spacecraft in Earth orbital and cislunar space. NASA anticipates the activity would encompass multiple phases of NASA’s Artemis II Orion mission, with ground station owners/operators engaging in pre-mission coordination, real-time mission tracking, and sharing their Doppler measurement performance with SCaN during and after the Artemis II Orion mission. This is solely an RFI potentially leading to mutual, voluntary collaboration; nothing in this document should be interpreted to suggest that NASA, nor any part of the United States Government, will pay any expenses a party might encounter while responding to this RFI or conducting any subsequent collaborative activity. III. Technical Overview and Details Radio Frequency (RF) One-way Doppler Measurements: The methodology involves observing the Doppler shift on the Orion S-band return link carrier signal when it is received at a partner ground station. This is a passive operation; no transmissions or uplink signals from the ground station will occur. The objective is to achieve and maintain carrier lock on the signal for tracking purposes; collecting or tracking telemetry data is not part of this activity. Orion is configured to transmit S-band signals within the frequency spectrum of 2200 to 2290 MHz, a range earmarked for Space Operations. For one-way Doppler measurements, Orion’s transmission power specifications are anticipated to be in sync with antenna apertures having a diameter of 9-meters or more (or equivalent gain for a non-parabolic dish antenna). Smaller apertures may be suitable depending on their capabilities. NASA Centers across the nation may be among the recipients of this service data. Additional Technical Insights: Upon submission, organizations having access to operational assets capable of delivering S-band Doppler measurements will be provided with the technical details required to track the Artemis II mission. IV. NASA’s Ambition with Artemis II Mission Overview: The Artemis II mission will send four astronauts in the first crewed Orion Multi-Purpose Crewed Vehicle (MPCV) spacecraft into a lunar flyby using the Block 1 variant of the Space Launch System (SLS). The 10-day mission profile consists of several phases: launch, spacecraft system checkout, trajectory maneuvers, lunar flyby, and Earth return. The Orion spacecraft will be launched from NASA’s Kennedy Space Center and enter Earth orbit. After conducting 24 hours of spacecraft system verification, a series of main engine burns will establish a 4-day outbound transit to the moon. After a lunar flyby at an altitude of approximately 4000 miles, the Orion spacecraft will return to Earth and splashdown in the Pacific Ocean. V. Objectives Behind this RFI The objective of this RFI is to help NASA identify organizations with the capability to support one-way Doppler measurements in cislunar space while also offering a unique opportunity for industry and academia to refine their capabilities while contributing to the historic Artemis II mission. Following the success of the Artemis I One Way Doppler Tracking Demonstration RFI, SCaN aims to utilize this as another opportunity to accelerate industry participation in a mutually beneficial relationship to meet Agency needs and goals. VI. Information to Include in Your Response NASA is seeking potential collaborators who can provide Artemis II one-way Doppler data at no financial burden to the agency or United States Government. Submission Criteria for Organizations: Specifications regarding the functional performance metrics of the proposed ground station(s). RF Tracking: Ground station(s) gain-to-noise temperature ratio (G/T) and aperture dimensions. Time and Frequency Reference (TFR): Ground station TFR system and/or part name/number and performance characteristics (phase noise, Allan deviation over observation times [ τ ] from 1 up to 10.5 seconds, etc.). Any additional relevant ground station performance characteristics. Expertise in the capture and consistent monitoring of the Orion signal and/or similar S-band signals. Ability to generate and document one-way Doppler tracking data. Proficiency to deactivate ground station transmission functionalities, ensuring zero radiation towards Orion. Tracking data format compatibility and the proficiency to send this information to NASA. Tracking data to be compliant with CCSDS Tracking Data Message (TDM) standard. Geodetic Information for each proposed tracking antenna to include “Station Name”, “East Longitude”, “Geodetic Latitude”, and “Height (km)”, as defined in the WGS 84 coordinate frame. Additional Required Supplemental Information: A historical record of one-way Doppler tracking during past launch and/or trajectory sequences. Experiences in conducting spacecraft RF signal tracking and furnishing Doppler tracking for celestial assets positioned beyond GEO. Procedures in place to preempt Uplink radiation. VII. Information Submittals: Organizations interested in providing the above information should submit the information in 5 pages or less, (excluding brochures) to the e-mail address shown below. Use single space, 12 –point, Times New Roman format. The following file naming convention should be used: Artemis II Tracking_RFI_company name.doc. For example, Ford would name its file Artemis II Tracking _RFI_Ford.doc. Authorized file formats include: Microsoft Word, PowerPoint, Excel, or PDF format. Although all submissions received will be carefully reviewed and considered for inclusion in any possible later action, NASA does not commit to adopt or include any particular recommendations in a subsequent document (e.g., a solicitation). Respondents will not be notified of the results of the review. No solicitation exists; therefore, do not request a copy of the solicitation. If a solicitation is released it will be synopsized in Sam.gov. It is the responsibility of potential offerors/bidders to regularly monitor these sites for the release of any solicitation or synopsis. VIII. Response Submission Deadline: Interested parties that currently possess assets that can provide S-band telemetry Doppler measurements should respond to Marta Shelton at [email protected] for more technical details concerning this activity. Responses to this RFI must be submitted no later than 5:00 PM Eastern Daylight Time, on October 27, 2025, to the points of contact identified below. RFI submissions will be accepted as email attachments only. IX. Points of Contact: Antwan Reid, Program Support Procurement Office [email protected] Marta Shelton, CIS Office [email protected]