A collection of tools (DNS lookup, ping, traceroute) which can be used from a web browser.
On 2021-03-23, I could not find the tools. Note that this site is related to SolarWinds, who were attacked recently.
New orbit trajectory calculations by Russian scientists contradict NASA's original projections that the golf ball will orbit the earth for approximately 3 days, and suggest a 3 1/2 year orbit is more likely, as the ball will descend by a few yards a day.
The home page of the SoftGPS receiver which accompanies the book A Software-Defined GPS and Galileo Receiver A Single-Frequency Approach by K. Borre et al. (used to be on http://gps.aau.dk/softgps/ )