telescope to be placed at L2 FORCE, small-scale hard x-ray observation with high sensitivity DIOS, small-scale x-ray observation mission to survey warm–hot intergalactic medium APPROACH, small-scale lunar penetrator mission HiZ-GUNDAM, small-scale gamma ray burst observation mission EUVST, solar observation B-DECIGO, gravity wave observation test mission SELENE-R, a Moon-landing mission Hayabusa Mk2/Marco Polo Space Solar Power System (SSPS), space-based solar power prototype launch in 2020, aiming for a full-power system in 2030 Human spaceflight program Japan has ten astronauts but has not yet developed its own crewed spacecraft and is not currently developing one officially. A potentially crewed spaceplane HOPE-X project launched by the conventional space launcher H-II was developed for several years (including test flights of HYFLEX/OREX prototypes) but was postponed. The simpler crewed capsule Fuji was proposed but not adopted. Projects for single-stage-to-orbit, horizontal takeoff reusable launch vehicle and landing ASSTS and the vertical takeoff and landing Kankoh-maru also exist but have not been adopted. The first Japanese citizen to fly in space was Toyohiro Akiyama, a journalist sponsored by TBS, who flew on the Soviet Soyuz TM-11 in December 1990. He spent more than seven days in space on the Mir space station, in what the Soviets called their first commercial spaceflight which allowed them to earn $14 million. Japan participates in US and international crewed space programs including flights of Japanese astronauts on Russian Soyuz spacecraft to the ISS. One Space Shuttle mission (STS-47) in September 1992 was partially funded by Japan. This flight included JAXA's first astronaut in space, Mamoru Mohri, as the Payload Specialist for the Spacelab-J, one of the European built Spacelab modules. This mission was also designated Japan. Three other NASA Space Shuttle missions (STS-123, STS-124, STS-127) in 2008–2009 delivered parts of the Japanese built spacelab-module Kibō to ISS. Japanese plans for a crewed lunar landing were in development but were shelved in early 2010 due to budget constraints. In June 2014, Japan's science and technology ministry said it was considering a space mission to Mars. In a ministry paper it indicated uncrewed exploration, crewed missions to Mars and long-term settlement on the Moon were objectives, for which international cooperation and support was going to be sought. On 18 October 2017, JAXA discovered a "tunnel"-like lava tube under the surface of the Moon . The tunnel appears to be suitable as a location for a base of operations for peaceful crewed space missions,