The James Webb Space Telescope is generally considered to be in an unserviceable location at SEL2.
If servicing becomes necessary, is it possible for the JWST to use a low energy heteroclinic transfer to reposition itself at a more accessible repair location? Say the EML1 point? This location would make it accessible for diagnostic and repair missions from Gateway/Artemis resources. Once serviced and refueled, it could be returned to SEL2 using a separate booster attached to the launch mount ring.
JWST was deliberately placed in an unstable halo orbit which requires no reorientation for orbital maintenance burns. If these burns are discontinued, JWST will follow the unstable manifold (red in the diagram below) and could be guided into position for a stable manifold (blue in the diagram) transfer to EML1
This NASA paper: https://ntrs.nasa.gov/api/citations/20190028906/downloads/20190028906.pdf studies the energy budget of transfers from Sun-Earth Halo orbits to Earth-Moon orbits (including Near Rectilinear Halo Orbit).
In the paper, several transfers were considered. See table on page 9 for delta-v estimates. The transfers required from 38.5 m/sec (SEL2 to EML2) to 128.5 m/sec (SEL2 to NRHO).
The total delta v budget for the JWST mission is widely stated (but unreferenced) as 150 m/sec. https://ntrs.nasa.gov/api/citations/20160001318/downloads/20160001318.pdf Mid Course Corrections were budgeted at 66.5 m/sec, but this was underused in the actual launch. https://ntrs.nasa.gov/api/citations/20140007519/downloads/20140007519.pdf mentions a station keeping budget of 25.5 m/sec for a planned 10 year mission. From these numbers, it looks like JWST’s remaining delta v is in the ball park for a low energy transfer
Question: Is the fuel supply on JWST adequate for a heteroclinic transfer to an EM libration point? And if so, at what point in JWST’s mission will the remaining fuel be inadequate for the transfer?
ET, come home.