Interplanetary spaceflight or interplanetary travel is the crewed or uncrewed travel between stars and planets, usually within a single planetary system. In practice, spaceflights of this type are confined to travel between the planets of the Solar System. Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions. Crewed flights have landed on the Moon and have been planned, from time to time, for Mars, Venus and Mercury. While many scientists appreciate the knowledge value that uncrewed flights provide, the value of crewed missions is more controversial. Science fiction writers propose a number of benefits, including the mining of asteroids, access to solar power, and room for colonization in the event of an Earth catastrophe.
Space exploration is the use of astronomy and space technology to explore outer space. While the exploration of space is currently carried out mainly by astronomers with telescopes, its physical exploration is conducted both by uncrewed robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main sources for space science.
Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. In-space propulsion exclusively deals with propulsion systems used in the vacuum of space and should not be confused with space launch or atmospheric entry.
Space colonization is the use of outer space or celestial bodies other than Earth for permanent habitation or as extraterrestrial territory.
Solar sails are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large surfaces. A number of spaceflight missions to test solar propulsion and navigation have been proposed since the 1980s. The first spacecraft to make use of the technology was IKAROS, launched in 2010.
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit 22,300 miles (35,900 km) above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently.
Spaceflight is an application of astronautics to fly objects, usually spacecraft, into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such as satellites in orbit around Earth, but also includes space probes for flights beyond Earth orbit. Such spaceflight operate either by telerobotic or autonomous control. The more complex human spaceflight has been pursued soon after the first orbital satellites and has reached the Moon and permanent human presence in space around Earth, particularly with the use of space stations. Human spaceflight programs include the Soyuz, Shenzhou, the past Apollo Moon landing and the Space Shuttle programs. Other current spaceflight are conducted to the International Space Station and to China's Tiangong Space Station.
SSL, formerly Space Systems/Loral, LLC (SS/L), of Palo Alto, California, is a wholly owned manufacturing subsidiary of Maxar Technologies.
A CubeSat is a class of miniaturized satellite with a form factor of 10 cm (3.9 in) cubes. CubeSats have a mass of no more than 2 kg (4.4 lb) per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats are put into orbit by deployers on the International Space Station, or launched as secondary payloads on a launch vehicle. As of December 2023, more than 2,300 CubeSats have been launched.
The Japan Aerospace Exploration Agency (JAXA) is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orbit, and is involved in many more advanced missions such as asteroid exploration and possible human exploration of the Moon. Its motto is One JAXA and its corporate slogan is Explore to Realize.
Private spaceflight refers to spaceflight developments that are not conducted by a government agency, such as NASA or ESA.
Space-based solar power is the concept of collecting solar power in outer space with solar power satellites (SPS) and distributing it to Earth. Its advantages include a higher collection of energy due to the lack of reflection and absorption by the atmosphere, the possibility of very little night, and a better ability to orient to face the Sun. Space-based solar power systems convert sunlight to some other form of energy which can be transmitted through the atmosphere to receivers on the Earth's surface.
Spaceflight began in the 20th century following theoretical and practical breakthroughs by Konstantin Tsiolkovsky, Robert H. Goddard, and Hermann Oberth. First successful large-scale rocket programs were initiated in Nazi Germany by Wernher von Braun. The Soviet Union took the lead in the post-war Space Race, launching the first satellite, the first man and the first woman into orbit. The United States caught up with, and then passed, their Soviet rivals during the mid-1960s, landing the first men on the Moon in 1969. In the same period, France, the United Kingdom, Japan and China were concurrently developing more limited launch capabilities.
RazakSAT is a Malaysian Earth observation satellite carrying a high-resolution camera. It was launched into low Earth orbit on 14 July 2009. It was placed in a near-equatorial orbit that presents many imaging opportunities for the equatorial region. It weighs over three times as much as TiungSAT-1 and carries a high-resolution Earth observation camera. Developed in conjunction with the Satrec Initiative, the satellite's low inclination brought it over Malaysia a dozen or more times per day. This was intended to provide greatly increased coverage of Malaysia compared to most other Earth observation satellites. An audit report released in October 2011 revealed that the satellite had failed after one year of operation.
Solaren, Inc. is a Southern California startup corporation created to use solar energy for terrestrial electricity usage. In 2009, the company had a contract under negotiation with Pacific Gas and Electric Company of California to deliver 200 megawatts of power for at least 15 years, starting in 2016. The cost of the contracted activities has been reported as "slightly more" than California's projected energy cost in 2016 of 12.9 cents per kilowatt hour. As of 2014, the planned delivery date has been moved back to the end of the decade.
Liberty was a 2011 launch vehicle concept proposed by Northrop Grumman Space Systems and Airbus Defence and Space for phase 2 of the NASA Commercial Crew Development (CCDev) program intended to stimulate development of privately operated crew vehicles to low Earth orbit.
SpaceWorks Enterprises, Inc. (SEI) is an aerospace engineering company based in Atlanta, Georgia, United States that specializes in the design, assessment, hardware prototyping and flight demonstration of advanced space concepts for both government and commercial customers.
Breakthrough Starshot is a research and engineering project by the Breakthrough Initiatives to develop a proof-of-concept fleet of light sail interstellar probes named Starchip, to be capable of making the journey to the Alpha Centauri star system 4.34 light-years away. It was founded in 2016 by Yuri Milner, Stephen Hawking, and Mark Zuckerberg.
The future of space exploration involves both telescopic exploration and the physical exploration of space by robotic spacecraft and human spaceflight.
Galactic Energy is a Chinese private space launch enterprise flying the Ceres-1 and developing the Pallas-1 and 2 orbital rockets. The company's long-term objective is to mine asteroids for rare metals and minerals.
