Subject: Re: CAPSTONE Status
From: Daniel Adamo <[email-masked]>
To: "ATIG (L-Z)" <[email-masked]>
Date: Sat, 31 Dec 2022 11:46:18 -0800

ATIG Members-

Enough as-flown data on this Gateway pathfinder CubeSat mission have accumulated to warrant a look at CAPSTONE’s trajectory history since launch, its stability in NRHO, and other properties.  Be in touch if you have any comments, questions, or further insights to share regarding the attached PDF.

Happy 2023!

-Dan

From: Daniel Adamo <[email-masked]>
Date: Monday, September 12, 2022 at 12:25
Subject: CAPSTONE Status

ATIG Members-

CAPSTONE, NASA’s cubesat mission to practice flying in a lunar nearly rectilinear halo orbit (NRHO, the initial orbit selected for NASA’s lunar Gateway space station), has hit an anomaly during an 8 September 2022 trajectory correction maneuver (ref. https://spacenews.com/capstone-enters-safe-mode-during-trajectory-correction-maneuver/).

Since July 2022, I’ve been meaning to share the circuitous path CAPSTONE is taking from Earth’s vicinity via the SEL1 Lagrange point to lunar NRHO.  Unfortunately, trajectory data available to the public via JPL’s Horizons ephemeris server have been a mash-up of as-flown and roughly planned data, including positional jumps across the Moon’s orbit, provided by the Advanced Space, LLC navigation team.

The attached plot is to some degree typical of that history.  No data are available from launch on 28 June 2022 until CAPSTONE’s separation from its upper stage on 4 July.  As-flown data extend from 4 July until 5 September.  Therefore, the plot will not reflect steering errors or an early/late termination of the 8 September maneuver.  Neither does the plot appear to reflect extended NRHO stationkeeping after arrival at the Moon vicinity in late October 2022.  Consequently, regard the attachment as a very tentative/approximate situation awareness source for CAPSTONE positions in the coming weeks/months.

-Dan