W. Jody Mandeville, InTrack Radar Technologies; Gim Der, InTrack Radar Technologies; Tim McLaughlin, InTrack Radar Technologies; Roger L. Mansfield, InTrack Radar Technologies; Vincent Vella, InTrack Radar Technologies
Keywords: cislunar, small telescope, orbital determination
Abstract:
This paper reports real-world end-to-end tracking of a cislunar object using a small aperture telescope. The goal of this research is to assess the ability of using a modest, commercially available telescope and camera to monitor and maintain custody of a cislunar object during a variety of orbital regimes. We show the quality of our observations in all orbital regimes, combined with a custom three-body propagation algorithm, result in orbital determination accurate enough to maintain custody and cue a two-degree field-of-view telescope days later.
The motivation of this research performed by InTrack Radar Technologies (IRT) was to explore the potential of using a low-cost, small-aperture telescopes to acquire and track an object in a non-traditional, cislunar orbit. NASA’s Artemis I mission afforded the perfect opportunity to test our cislunar satellite acquisition and tracking capabilities and to use the data to assess the performance of a new three-body orbital determination algorithm developed by DerAstrodynamics.
The observation data for this research was collected by Pine Park Observatory located near Colorado Springs, Colorado. The telescope used was Celestron 8” f/2.0 Rowe-Ackermann Schmidt Astrograph (RASA) coupled with a QHY 174M-GPS camera. Both the telescope and the camera are consumer grade and commercially available. The telescope combined with the QHY 174M-GPS camera’s 11.25 x 7.03 mm CMOS focal plane provides a 1.6 x 1.0 degree field-of-view. Pine Park Observatory uses custom developed telescope control and satellite tracking software.
To acquire and track the Orion crew capsule shortly after launch, the research team used JPL Horizons ephemeris data. However, since the launch was later than planned, the ephemeris data was not correct. The research team searched around the location where Artimis was supposed to be and eventually located the rocket body and crew capsule approximately 45 minutes head of the projected location. The research team repeated the process nine more times using the JPL Horizons ephemerides for initial pointing followed by an area search, if necessary, to find and track the crew capsule throughout the 25-day mission. The images were processed photometrically using aperture photometry and the astrometric using custom software that utilizes Astrometry.net and a local GAIA star catalog. The accuracy of the observations was compared to the JPL Horizons special perturbations ephemeris showing our observations to be accurate to within a few arcseconds.
After the data collection phase, all of the observations were processed using DerAstrodynamics’ orbit determination algorithms with three-body propagation. This processing resulted in orbit determination with differential correction that is accurate to within two-degrees days later.
In this paper we present data and graphs showing the accuracy of our observations as well as the accuracy and durability of the orbital determination and propagation using three-body orbital algorithms. Our conclusion is that a modest telescope with capable command and control techniques coupled with cutting-edge three-body orbital algorithms can do a commendable job acquiring, tracking, and maintaining custody of cislunar objects like the Orion crew capsule.
Date of Conference: September 19-22, 2023
Track: Cislunar SDA