Hal Clement's "Star Light" (novel): Exploring a high gravity world with weird atmosphere & hydrosphere

This is often listed as one of the two sequels to "Mission of Gravity". Other book, "Close to Critical", didn't really read like a sequel to me, but this one has a much better claim to being the sequel to the legendary original (& a very worthy sequel). The story is generally independent of "Mission of Gravity"; so should be comprehensible even to readers who haven't read the better known book.

Caution: Hal Clement is not for everyone (with the exception of "Needle", which should be quite accessible to anyone used to sf). His stories often require a science background at least to the level of 10+2 school, & then some taste for a certain kind of story - in this case, essentially a description of the weird world.

Story summary.

Dhrawn has a weird hydrosphere - rather than mostly water on earth, it's a mixture of water & ammonia. And phase transitions of the mixture are apparently very weird - like when ambient temperature is nearly fixed or is slightly rising, a flowing river can freeze based on evaporation or condensation of ammonia! We see a lot of weird behavior like this.

Action happens primarily in 3 theaters:

1. Main & the most interesting thread is aboard Kwembly, a huge land based research vehicle with a 100 staff of Mesklinites (from "Mission of Gravity"). Dondragmer, #2 aboard the local ship in "Mission of Gravity", is the captain. Another key character here is Beetchermarlf, a young apprentice.
   
   Why Mesklinites? This is a huge 40g world & very cold; so they're recruited for surface investigation.
   
   This vehicle keeps getting in trouble because of the weird atmosphere: frozen ground suddenly turns into liquid after some precipitation, vehicle gets deposited by a flood at a large angle in a flowing river that promises to become far nastier, river suddenly freezes trapping vehicle & maintenance crew underneath, ...
2. Aboard a space station in geosynchronous orbit is the human team. They operate a bunch of low-orbit remote sensing satellites, & remotely guide Mesklinites on ground.
   
   Communications with Mesklenites get somewhat complicated because the geosynchronous orbit for this very slow rotation world is 6 million miles from surface - means 64 seconds round trip signal travel time.
   
   Key characters from among the large staff are: Alan Aucoin, the administrator of project; Elise Hoffman (aka Easy), main non-technical communications contact with Mesklenites on ground & an expert in Stennish, the Mesklinite language; Benj, Easy's teenage son doing apprenticeship who gets deeply involved in some disaster rescues; & Ib, Easy's super smart husband who speaks little & understands a lot.
   
   We are told two alien species - Drommian & Paneshk - have joined hands with humans in these investigations, but we never meet them. Drommian also appeared in "Close to Critical", but I don't recall Paneshk mentioned in another Clement story.
3. In Mesklinite "Settlement" on ground - the main local research facility headed by Barlennan, the captain of the ship in "Mission of Gravity". He has an agenda of his own, but as a reader, I found his hidden agenda here as uninteresting as similar one was in "Mission of Gravity".
   
   50 years have passed since "Mission of Gravity". No humans from the period survive, but we're told Mesklinite have much longer life expectancy. Hence two Mesklinites from old story, but all humans are new.

Fact sheet.

First published: Analog, June/July/August/September 1970 as a 4-part serial.
Rating: A.
Listed among the stories from John Campbell's Astounding/Analog.
Related: Stories of Hal Clement.