4 ms·
Pressure from solar wind will constantly put some torque onto telescope as its center of pressure is offset from center of mass. This torque will be counteracte
by terramex 5y ago
Pressure from solar wind will constantly put some torque onto telescope as its center of pressure is offset from center of mass. This torque will be counteracted by reaction wheels but they have maximum rotation speed and need to be unloaded using thrusters periodically.
- WalterBright 5y agoA rudder would work to counter any torque from the solar wind, and can be used to orient it.
- michaelwilson 5y agoThus, the "Aft Momentum flap": https://www.jwst.nasa.gov/content/webbLaunch/deploymentExplorer.html#1 https://www.jwst.nasa.gov/content/webbLaunch/deploymentExplo...
- terramex 5y agoMomentum flap will bring average CoP closer to CoM but CoP will shift as JWST is rotated to point at different targets. Unwanted torque can be minimised by carefully choosing observations targets so it mostly cancels out but it cannot be done perfectly.
- dev_tty01 5y agoI wonder if the target scheduling will take that into account to minimize average drift? Interesting set of calculations...
- terramex 5y ago> As an additional challenge, the JWST observation schedule in the next 21-day period will not be known at the time of SK [station keeping] maneuver planning. A planned observation schedule one week ahead will be available, but the actual observation schedule will be event-driven. If a ‘target of opportunity’ arises then the schedule can be changed within 48 hours to point at the new target. https://ntrs.nasa.gov/api/citations/20140007519/downloads/20140007519.pdf https://ntrs.nasa.gov/api/citations/20140007519/downloads/20...