One of his Future History stories, it was first published in Astounding Science Fiction (July 1941, as by Anson MacDonald) and collected in The Green Hills of Earth (and subsequently The Past Through Tomorrow).
The company is asked to do the impossible: enable an interplanetary conference to be held on Earth, whose strong gravity is inhospitable to many of the native races of other planets and moons in the solar system.
In a side plot, the team also have to deal with a rich woman who wants to visit her son recuperating from a skiing injury over a thousand miles away while simultaneously conducting a fashionable party at her home.
Much of the action of the story is not, as one might expect, about the science or engineering of creating an antigravity device to allow the conference to take place, but about how to persuade the world's leading physicist, a Dr. O'Neill, to undertake the job.
[1] O'Neill is too wealthy to be tempted by money, but longs to possess a museum piece, a Chinese porcelain bowl called "The Flower of Forgetfulness".