Re: "from the GPS system work out the wind speed on the surface." How?
Following the PDF link to http://clasp-research.engin.umich.edu/missions/cygnss/docs/CYGNSS_FactSheet_October2014.pdf and googling over to https://www.esrl.noaa.gov/psd/psd3/multi/remote/using_reflections.html (section 4), it looks a bit like the sort of thing you'd laugh your arse off if it were used in a film as a plot device.
Semi-plausibly, you can use the reflections of GPS signals off the ocean surface like a radar to figure out large wave profiles and (from that) broadly infer ocean surface conditions. I say broadly because the height that is inferred in this way will depend on the wave's direction of travel and you have to know that from some other way, and the height of a wave will in any case also depend on how many miles it has been building up, which again you have to know by other means.
Much less plausibly, if you have a black belt in boffinry, you can also use the GPS signals that are *scattered* from *surface ripples*, producing an interference pattern. The spectra of these waves apparently depend very sensitively on the actual local wind conditions so you can skip all that "other means" crap and proceed directly to omniscience.
So they are watching the slight fuzziness of a ripple, from a hundred miles up, through a hurricane, using someone else's transmitter. (And, as various folk have remarked upon in these forums over the years, the other guys transmitter is already compensating for both Special and General Relativity to be even vaguely useful in the first place.)
Launching the satellite on-the-wing looks positively pedestrian in comparison.