NASA's Space Probes

Explorer Program

1958 - 2011

The Explorer program is a space exploration program that enables investigations from space. It started in 1958 and is still active today. Over 90 space missions have been launched to various destinations. A series of mostly small and medium sized satellites have been launched and form the backbone of the space science program exploring sciences such as astronomy, atmospherics and heliophysics. The most recent launch was in 2009 with the launch of WISE for infrared astronomy.

Explorer I (NASA Public Domain)Explorer 10 Inspection (NASA Public Domain)Explorer IV (NASA Public Domain)Explorer 61 (NASA Public Domain)Explorer 92 (NASA Public Domain)Explorer 30 (NASA Public Domain)

Pioneer Program

1958 - 1960

The Pioneer program was a series of unmanned space missions that was designed for planetary exploration. The Pioneer space probes have been the trailblazers of the space age, truly going where no man has gone before exploring the secrets of the Sun, Jupiter, Saturn, and the void beyond Pluto.

Pioneer 4 Launch Control (NASA Public Domain)Pioneer 3 (NASA Public Domain)Pioneer 2 (NASA Public Domain)Pioneer Schumatic (NASA Public Domain)Pioneer 1 on Launch Pad (NASA Public Domain)Pioneer 6 Artists Impression (NASA Public Domain)

Ranger Program


The Ranger program (1961 -1965) was a series of unmanned missions to the moon, which used vehicles called "crasher spacecraft". These spacecraft were designed to crash into the lunar surface and transmit data until the final impact. The mission was too much for the technology of the period and suffered a high failure rate and was labeled "shoot and hope". The last three missions of the spacecraft were simplified and all returned useful images of the lunar surface.

Ranger 9 (NASA Public Domain)Ranger Program First images of the Moon (NASA Public Domain)Ranger 5 Launch Control (NASA Public Domain)Ranger 4 (NASA Public Domain)Ranger 3 (NASA Public Domain)Ranger 9 First Image (NASA Public Domain)

Mariner Program

1962 - 1973

The Mariner Program (1962-1973) mission's was the USA's first attempt at interplanetary travel... The Marine spacecraft visited Mercury, Venus, and Mars, and laid the groundwork for the US missions to the outer planets. There were ten (10) Mariner vehicles in the series, seven were successful and three were lost. In 1962 Mariner 2 became the first probe to fly past the planet (Venus). In 1964 Mariner 4 flew by Mars and returned the first close-up images of the Red Planet, followed by Mariner 9 which later took detailed photographs of Mars from orbit in 1971. Mariner 10 launched in 1973 became the first spacecraft to visit Mercury.

Mariner 10 (NASA Public Domain)Mariner 4 Parade Float (NASA Public Domain)Mariner 2 Model Given to President Kennedy (NASA Public Domain)Mariner 1 Launch (NASA Public Domain)Mariner Schumatic (NASA Public Domain)Mariner 4 First Image (NASA Public Domain)

Lunar Orbiter Program

1966 - 1967

Between the years of 1966 through 1967 five (5) Lunar Orbiter Missions were launched. The missions would be mapping the lunar surface before the Apollo landings. The first three (3) were focused on taking pictures of those landing sites. Each of the following missions was to map the Moon to ninety-nine percent (99%) completion. All this was done to a resolution of twenty meters (20) by two meters (2) or 12 feet x 6.5 feet.

Lunar Orbiter Spacecraft (NASA Public Domain)Lunar Orbiter  (NASA Public Domain)Lunar Orbiter Camera (NASA Public Domain)Lunar Orbiter image of the Moon (NASA Public Domain)Lunar Orbiter 1 First image of Earth (NASA Public Domain)Lunar Orbiter 1 Diagram (NASA Public Domain)

Surveyor Program

1966 - 1967

The Surveyor probes marked another first for the USA safely landing a probe on the Moon. The first mission (Surveyor I) lifted off on May 30, 1966 and the last (Surveyor 7) landing on the surface of the moon January 7, 1968. The mission of the Surveyor probes were to: obtain close-up images of the lunar surface and help determine if the terrain was safe for manned landings. Each Surveyor was equipped with a television camera able to send singles back to the earth. Surveyors 3 and 7 carried tools to collect soil samples of the surface.

Surveyor 3 Photo of Tycho Crater (NASA Public Domain)Surveyor 5 Footpad (NASA Public Domain)Surveyor 3 Camera (NASA Public Domain)Surveyor 1 Launch (NASA Public Domain)Surveyor 3 View (NASA Public Domain)Surveyor Program Shadow on the Moon (NASA Public Domain)

Pioneer 10 and Pioneer 11

1972 - 1974

Pioneer 10 and Pioneer 11 were robotic space probes. Pioneer 10 was launched in 1972 and its mission was to send back data and images of Jupiter. It was the first spacecraft to reach escape velocity from our Solar System. Escape velocity is not generated from the constant use of a rocket but just providing an initial boost. You can think of this similar to kicking a football once you apply the initial force it's on its way under its own power. Pioneer 11 was launched in 1973 and mission was to study the asteroid belt around Jupiter and Saturn. Communications with both probes has long since been lost due to power constraints on the spacecraft.

Pioneer 10 Contruction (NASA Public Domain)Pioneer 10 Launch (NASA Public Domain)Pioneer 11 Disgram (NASA Public Domain)Pioneer 10 Trajectory (NASA Public Domain)Pioneer 10 Plaque (NASA Public Domain)Pioneer Concept Art (NASA Public Domain)

Helios Probes

1974 - 1976

The Helios I and Helios II space probes program was a joint venture between NASA and the Federal Republic of Germany. The probes were launched into heliocentric (orbit around the sun) for the purpose of studying solar processes. Helios 1 was launched on December 10, 1974 and Helios 2 was launched on January 15, 1976. The probes had a maximum speed record among spacecraft at 157,078 mi/h. The probes completed their primary missions by the early 1980s, with Helios 2 sending data up to 1985. The probes are still remaining in their elliptical orbit around the Sun but no longer send data.

Helios Tracking Control Center (NASA Public Domain)Helios (NASA Public Domain)Helios Spacecraft Launch Configuration (NASA Public Domain)Helios Prototype (NASA Public Domain)Helios Assembly (NASA Public Domain)Helios on Launch Pad (NASA Public Domain)

Viking 1 and Viking 2


The Viking Mars missions were done by the Viking 1 and Viking 2 spacecraft. The two probes were launched within weeks of each other, with Viking 1 launching on August 20, 1975 and Viking 2 launching September 9, 1975. The Viking spacecraft consisted of an orbiter and a lander, which remained connected, for nearly a year until it reached Mars orbit. As the orbiters circled the surface of Mars they began taking pictures of the Martian surface. Analysis of these images by engineers on Earth enabled them to select a landing site.

Viking Trenches for Soil Samples (NASA Public Domain)Viking Images of Mars (NASA Public Domain)Viking Atrists Impression of the Orbiter releasing the Lander (NASA Public Domain)Viking Lander (NASA Public Domain)Viking 1 (NASA Public Domain)

Voyager 1 and Voyager 2


The Voyager probes, launched in 1977 are carrying a greeting to any form of life. Taking advantage of a favorable planetary alignment the probes were launched to explore beyond our solar system. By the year 2020 both probes will be out of our solar system 10.5 to 12.5 billion miles away. Each carries, a 12-inch gold-plated copper disk containing sounds and images that portray the diversity of life and culture on Earth. As of December 2011 on Voyager 1 and Voyager 2 are still sending signals back and are on course to exit the solar system.

Voyager 2 Payload Assembly (NASA Public Domain)Voyager 2 Gold Plated Record attached to Spacecraft (NASA Public Domain)Voyager Diagram (NASA Public Domain)Voyager 1 in Simulation Chamber (NASA Public Domain)Voyager 1 (NASA Public Domain)Voyager 2 Launch (NASA Public Domain)

Pioneer Venus Multiprobe and Pioneer Venus Orbiter


The Pioneer Venus Project involved the use of various spacecraft. The Venus Pioneer Venus 1 was launched in 1978 and was inserted into Venus Orbit to study the planet. The main objective was to investigate the solar wind in the Venusian environment, map the planet's surface through a radar imaging and study the upper atmosphere and ionosphere. The Orbiter remained in orbit as the Multirole spacecraft would be sent to probe the surface. The Multirole spacecraft carried one large and three small atmospheric probes. It was predicted that it would not survive the descent through the Venusian atmosphere. One of the Pioneer probes continued to function for forty-five (45) minutes after reaching the surface. It carried seventeen (17) experiments and operated until it ran out of fuel and was destroyed by the Venusian atmosphere in August 1992.

Pioneer Venus Orbit (NASA Public Domain)Pioneer Venus Multiprobe (NASA Public Domain)Pioneer Venus Probe (NASA Public Domain)Pioneer Venus (NASA Public Domain)Pioneer Venus Assembly (NASA Public Domain)Pioneer Venus with Probes Attached (NASA Public Domain)

Galileo Probe


The Space Shuttle Atlantis carried the Galileo space probe into its mission in 1989. Galileo would fly-by the Earth, Venus and the asteroid belt. Galileo approached its final destination in 1994 and returned images of the comet Shoemaker-Levy 9 crashing into Jupiter. When it reached Jupiter (in 1995) a parachute probe, separated from the orbiter and, gathered data on the planet's atmosphere as it descended to the surface. Galileo continued to orbit Jupiter and make close flybys of its main moons until it was intentionally destroyed in 2003. Galileo was able to discover that Jupiter's faint ring system consists of dust from impacts on the four small inner moons.

Galileo Launch (NASA Public Domain)Galileo Deployment (NASA Public Domain)Galileo Orbiter Assembly (NASA Public Domain)Galileo in Space (NASA Public Domain)Galileo Diagram (NASA Public Domain)Galileo image of Venus (NASA Public Domain)

Hubble Space Telescope


The Hubble Space Telescope was taken into space on the Space Shuttle Discovery in 1990. The Hubble Space Telescope has four main observation instruments that observe in the near ultraviolet, ultraviolet, visible, and near infrared, light. The images collected are assigned colors to make the colorful images the Hubble is famous for. The Hubble's orbit outside of the Earth's atmosphere allows it to take extremely sharp images with almost no background light. Its observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.

Hubble Nebula 3 (NASA Public Domain)Hubble Deployed from Discovery (NASA Public Domain)Hubble Nebula 2 (NASA Public Domain)Hubble Image of Nebula (NASA Public Domain)Hubble Space Telescope Launch (NASA Public Domain)

Mars Global Surveyor


The Mars Global Surveyor launched in November 1996 and reached Mars on September 11, 1997. It was the USA's return to the planet after the Viking missions of the 1970's. With limited fuel onboard it was to run out of fuel April of 2003. In August of 2001 engineers found a way to steer the ship so it would use eight hundred percent (800%) less fuel extending its life. It completed its primary mission in January 2001 and finally failed to respond to commands on November 2, 2006. In January 2007 NASA officially ended the mission. The Surveyor spacecraft orbited the Mars planet twelve (12) times a day and used high-resolution cameras to explore the surface returning more than 240,000 images.

Mars Global Surveyor Image of Mars Gullies (NASA Public Domain)Mars Global Surveyor Image of Mars Craters (NASA Public Domain)Mars Global Surveyor Assembly (NASA Public Domain)Mars Global Surveyor Image of Mars Gullies in full color (NASA Public Domain)Mars Global Surveyor (NASA Public Domain)Mars Global Surveyor Camera (NASA Public Domain)

Mars Phoenix Lander


The Phoenix lander was launched from the Kennedy Space Center in Florida on August 4, 2007 and landed on the surface of Mars on May 25, 2008. During its mission scientists used instruments to: 1. to explore the Martian arctic soils for possible indicators of life, past or present 2. to examine potential habitats for water ice, 3. to enhance our understanding of Martian atmospheric processes, 4. to measure volatiles, such as water and organic molecules in the northern polar region of Mars. The multi-agency program was headed by the Lunar and Planetary Laboratory at the University of Arizona, under the direction of NASA's Jet Propulsion Laboratory. The lander completed its mission in August 2008. In 2010 a flyby image of the Phoenix on Mars was taken. The image indicated that the probe had not survived the harsh Martian winter. One of the solar panels appears to be broken off. The mission was declared concluded on November 10, 2008, after engineers were unable to re-contact the craft.

Mars Phoenix Lander Launch (NASA Public Domain)Mars Phoenix Lander Assembly 2 (NASA Public Domain)Mars Phoenix Lander Assembly with Solar Arrays Open (NASA Public Domain)Mars Phoenix Footpad on Mars Surface (NASA Public Domain)Mars Phoenix Lander Assembly (NASA Public Domain)Mars Phoenix Lander Artists Impression (NASA Public Domain)


The temperature of the earth's interior increases by 1 degree every 60 feet down.