Hong Kong aims to adjust listing rules to grab a share of initial public offerings (IPOs) by mainland China’s space companies as activity in the sector increases in line with Beijing’s priorities and heightened activity in the sector following the blockbuster June listing by Elon Musk’s SpaceX.That could lead to more head-to-head competition between the Hong Kong stock exchange and the Shanghai Stock Exchange, which is now drawing a majority of such listing applications, including commercial...