Japan's ANA Holdings has joined H.I.S. travel agency in investing in PD Aerospace, a private Japanese firm that specialises in manned spacecraft development.

According to a press release issued last week, H.I.S. has acquired a 10.3% stake in the firm for JPY30 million (USD264,000) with ANA buying a 7% stake for JPY20.4 million (USD180,000).

PD Aerospace is in the process of developing a reusable eight-seater spacecraft propelled by an engine capable of switching between jet- and rocket-power depending on environment.

An unmanned prototype is scheduled to be flown to an altitude of 100 kilometres in 2018, following which a manned attempt will be made by 2020. Should both trials prove successful, the firm hopes to begin commercial space flights by the end of 2023.