Top Qs
Timeline
Chat
Perspective
HTV-X
Uncrewed cargo spacecraft developed by JAXA From Wikipedia, the free encyclopedia
Remove ads
HTV-X, also known as the New Space Station Resupply Vehicle (Japanese: 新型宇宙ステーション補給機, Hepburn: Shingata Uchū Sutēshon Hokyūki), is a Japanese cargo spacecraft under development by the Japan Aerospace Exploration Agency (JAXA). It is designed as the successor to the H-II Transfer Vehicle (HTV) for International Space Station (ISS) resupply missions. The first launch is scheduled for 21 October 2025.[3]
.svg){kind=logo}
Remove ads
Background
The HTV-X is manfacturered by Mitsubishi Heavy Industries with contributions from Mitsubishi Electric.[4] IHI Aerospace provides the propulsion system[5] and American company Sierra Nevada Corporation provides the Common Berthing Mechanism and hatch kit.[6]
Design
Summarize
Perspective
HTV-X consists of three main modules, arranged from top to bottom on the launch pad:
- A 3.8-metre-long (12 ft) unpressurised cargo module, which is a hollow cylinder with internal shelving. This module significantly increases the volume available for unpressurised cargo.
- A 2.7-metre-long (8.9 ft) central service module, capable of independent operation. It features two solar panel arrays generating 1 kW of power (compared to 200 W on the original HTV) and batteries with a peak output of 3 kW (up from 2 kW). Communications are also upgraded, with a 1 Mbit/s link in addition to the previous 8 kbit/s link. The HTV-X lacks a main engine and instead uses a ring of reaction control system (RCS) thrusters for propulsion. Some components are mounted externally for easier astronaut access.[7]
- A 3.5-metre-long (11 ft) pressurised logistics module, similar in design to that of the HTV but extended by 0.2 metres (7.9 in). This module is now located at the bottom of the stack rather than at the top. An initial design proposed a side access hatch for late cargo loading while the spacecraft was mated to the launch vehicle. However, the final 2021 design eliminated the side hatch. Instead, late access is provided through the same hatch used while docked to the ISS. This required the development of a special Payload Adapter Fitting (PAF) on top of the H3 rocket’s upper stage.[1]
The HTV-X has a length of 6.2 metres (20 ft), or 10 metres (33 ft) with the unpressurised cargo module fitted. Atop the H3 rocket, the payload fairing and payload dispenser have been widened from 1.7 to 4.4 metres (5 ft 7 in to 14 ft 5 in), allowing the pressurised logistics module to be swapped out for alternate modules, to add increased structural strength, and to accommodate the originally planned side hatch.[8]
Re-using the pressurised logistics module design of HTV allows for minimizing the development cost and risk. Concentrating the RCS and the solar panels on the service module will simplify the wiring and piping, reducing weight and manufacturing cost. Loading the unpressurised cargo outside the spacecraft allows larger cargo, only limited by the launch vehicle fairing. The aim is to cut the cost in half, while keeping or extending the capability of the existing HTV.[9] By the simplification of the overall structure it was expected the launch mass of HTV-X to be dropped to 15,500 kilograms (34,200 lb) from HTV's 16,500 kilograms (36,400 lb), while the maximum weight of cargo will be increased to 5,850 kilograms (12,900 lb) (net weight, excluding support structures) from HTV's 4,000 kilograms (8,800 lb).[8]
Other payloads being considered to replace the unpressurised cargo module while carrying out ISS resupply missions are an external sensor package, a technology trial of an IDSS airlock with automated station docking as used by the Progress and ATV craft, a trial of rendezvous and docking with a simulated satellite module, a smaller satellite piggybacking the launch to reach ISS orbit, a station return capsule, assembling a beyond Earth orbit mission such as lunar lander from smaller modules and acting as a space tug shuttling orbiting unpressurised cargo modules to the ISS allowing for resources such as recyclable materials, excess propellant and spare parts to be stored in orbit for future use rather than discarded.[8]
Remove ads
History
Summarize
Perspective
In May 2015, Japan's Ministry of Education, Culture, Sports, Science and Technology announced a proposal to replace the HTV with an improved, cost-reduced version preliminarily called HTV-X.[10][11] The proposal of HTV-X in 2015 was as follows:[9]
- To re-use the design of HTV's Pressurised Logistics Carrier (PLC) as much as possible, except for adding a side hatch for late cargo access after the spacecraft-launch vehicle integration.
- To replace the Unpressurised Logistics Carrier (ULC), Avionics Module, and Propulsion Module with a new Service Module.
- To load the unpressurised cargo on top of the Service Module rather than inside the spacecraft.
In December 2015, the plan to develop HTV-X was approved by the Strategic Headquarters for Space Policy of the Cabinet Office, targeting launch in fiscal year 2021 for the flight of HTV-X1 (Technical Demonstration Vehicle) by the H3 Launch Vehicle.[12][8] As of June 2019[update], NASA's Flight Planning Integration Panel had set the launch of HTV-X1 for February 2022.[13]
With the Japan-US Open Platform Partnership Program (JP-US OP3) agreement in December 2015 to extend cooperation on ISS operations through 2024, Japan will provide its share of ISS operation costs with the form of transportation by HTV-X, and also be given an opportunity to develop a possible small return capsule.[14]
A design change in 2021 removed the side hatch of the pressurised module.[1]
As of 2021[update], an evolved version of HTV-X called HTV-XG is being considered for transporting cargo to the Lunar Gateway as part of the Artemis program.[15]
Flights
As of April 2025[update], three flights are planned to resupply the ISS.[1]
As of December 2024[update], HTV-X4 and HTV-X5 are tentatively planned for launch in JFY2027–JFY2029.[18]
Remove ads
See also
References
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads