Since its formation in 1958 NASA has explored our solar system and peered beyond into the vastness of space, stretching the abilities and frontiers of mankind.
Our understanding not just of the planets and moons of our solar system but of the universe in general is now greater than ever thanks in no small part to the achievements of this fine organization.
At a time of budget cuts and the end of the Space Shuttle era hopefully NASA’s influence will not diminish over the coming years, and it will continue to spark the imagination and inspire future generations.
Below we have listed our Top 10 NASA Missions.
10. Friendship 7 - 1962
John Glenn, the first American to orbit Earth
The Friendship 7 mission, also known as Mercury-Atlas 6 or MA-6, launched from Cape Canaveral in February 1962. On board was a 40 year old astronaut by the name of John H. Glenn, Jr, the objective of the mission was to put the first American in orbit around the Earth.
A year earlier NASA had managed to send the first American into space, Alan Shephard, but not into orbit. The Soviets had achieved this a month before Shephard, in April 1961, so the organization knew that they had some catching up to do.
The mission was successful with Glenn making three orbits of Earth before re-entering the atmosphere. Glenn was picked up by the US Navy after his capsule splashed down in the Atlantic Ocean and instantly became a household name.
Friendship 7 confirmed that just four years after its formation NASA had caught up with the Soviets and the US was now firmly in the space race. The mission also blazed a trail for future astronauts which ultimately led to the moon landings just seven years later.
9. Deep Impact - 2005
Deep Impact strikes Comet Tempel 1
Deep Impact was launched in January 2005 sending it on a trajectory towards a comet more than 400 million kilometers away called Tempel 1. On board the main spacecraft was an 816 pounds (370 kg) impactor, which would be released on a collision course with the comet during its approach.
As the craft neared the comet in July 2005 it released its small but heavy payload. With its own battery and navigation system the projectile was now completely independent of its host craft as it plotted a course towards the comet. On board the impactor a camera would document its journey right up to the last second.
The host spacecraft now maneuvered itself to just 300 miles (500 km) from the comet giving it a grandstand view of the collision. The explosion caused by the impact was viewed by spacecraft millions of miles away and ejected a huge amount of material from the comet, it also left a 100 meter wide crater on its surface.
The analysis of the ejected material using instruments on board the main craft provided scientists around the world with valuable new data and a greater understanding of the composition, density and origin of comets.
8. Viking 1 and 2 - 1975
The hugely successful Viking 1 and 2 missions dramatically changed the way we view the planet Mars. Both missions were launched in 1975 arriving just a couple of months apart in the summer of 1976.
Each mission consisted of an orbiter and a lander. Between them the orbiters mapped the entire planet, revealing huge canyons, volcanoes and evidence of past flowing water.
The landers sent back astonishing images of the Martian landscape which even by today’s standards are highly impressive. They also analyzed soil samples giving us a greater understanding of the composition of the Martian surface.
Viking 1 and 2 reinvigorated our interest in the red planet providing a platform for further missions.
7. Pioneer 10 - 1972
Launched in March 1972 the aptly named Pioneer led the way and provided valuable data for future missions. It was the first spacecraft to pass through the asteroid belt and reach the outer solar system. It passed within 124,000 miles (200,000 km) of Jupiter taking the first ever close up images of the planet. It also captured fuzzy images of the Galilean moons, Io, Europa, Ganymede and Callisto.
Scientists at NASA were surprised at the incredibly high radiation levels the spacecraft detected around Jupiter and feared that it may not survive. Luckily it did but now they knew that any future missions would need much better protection.
Pioneer 10 may have been primitive by today’s standards but that makes its achievements all the more remarkable, without the information it provided the more advanced missions by the Voyager, Galileo and Cassini spacecraft wouldn’t have happened.
Contact with the craft was finally lost in April 2002, it is now thought to be drifting towards the red dwarf star Aldebaran which it will reach in around 2 million years.
6. Mars Exploration Rovers - 2003
Rover Spirit image of a Martian sunset
The twin rovers Spirit and Opportunity were launched separately in the summer of 2003, both landing on Mars in January 2004, opening a new chapter in our exploration of the red planet.
As the rovers plummeted towards the planet they were engulfed in a bubble of air bags, bouncing along the surface until they came to a rest and could begin their mission. Each landed on opposite sides of the planet and set about finding clues to Mars’s past, looking out for indications of previous liquid water activity.
What they found did indeed suggest that Mars was a very different planet a few billion years ago. Soil and rock samples analyzed by the rovers indicated that Mars used to be a wet planet, not the dry desert we know today.
The rovers also sent back many astonishing high resolution images of the planet and the mission lasted far longer than was planned. Initially it was thought the rovers would function for around 90 days, but incredibly the Opportunity Rover is still exploring and sending back data to this day, contact was lost with Spirit in March 2010, more than six years after it landed.
5. Galileo - 1989
Galileo launched from the Space Shuttle
In October of 1989 the Galileo spacecraft was launched from Earth orbit by the Space Shuttle Atlantis, its target was the gas giant Jupiter with a planned arrival date of December 1995.
The spacecraft was named after the 17th century Italian astronomer Galileo Galilei, who discovered the four largest moons of Jupiter in 1610. On arrival the craft would study these moons as well as dispatching a small atmospheric probe into the depths of Jupiter.
Even before its arrival Galileo would witness an astonishing event, in 1994 fragments of the comet Shoemaker-Levy 9 were hurtling towards Jupiter. Galileo was in a prime position to capture amazing images of the enormous impacts as the comet struck the atmosphere of the gas giant.
Five months before arriving at Jupiter, Galileo released the atmospheric probe, travelling at over 100,000 miles per hour the probe reached the planet five months later. The heat shields it had been equipped with protected it as it crashed through the upper atmosphere and it began to slowly descend with the aid of a parachute. The probe transmitted data for almost 1 and a half hours before it succumb to the intense pressures and high temperatures.
Galileo itself reached Jupiter in December 1995, becoming the first spacecraft to enter into orbit around the gas giant. Over the next 8 years the spacecraft would study the Jovian system in detail.
The mission revealed that Io was undergoing extensive re-surfacing due to constant volcanic activity, provided more evidence that Europa contained a warm interior ocean, and discovered that Ganymede was producing its own magnetic field, the only moon in the solar system known to do so.
New data was also revealed about Jupiter’s enormous magnetosphere, its ring system and the planet's interactions with it moons. The mission was a resounding success, giving us a greater understanding of the largest planet in the solar system and its intriguing moons.
Galileo was deliberately crashed into Jupiter to avoid contaminating the possible salt water ocean of Europa, disappearing into Jupiter’s atmosphere in September 2003.
4. Cassini-Huygens - 1997
The Cassini-Huygens spacecraft
Cassini-Huygens was a joint NASA and European Space Agency (ESA) mission named after the French-Italian astronomer Giovanni Domenico Cassini and the Dutch astronomer Christiaan Huygens.
The Cassini spacecraft was launched in October of 1997 on a seven year journey to Saturn, it eventually placed itself in orbit around the planet in July 2004. On board the spacecraft was the ESA built Huygens probe, which was released by Cassini in December 2004 to begin its journey towards Saturn’s moon Titan. Huygens successfully navigated its way through the moon’s thick atmosphere and landed on Titan in January 2005. The probe provided valuable data and sent back the first ever pictures from the moon’s surface. Combined with data and images compiled by Cassini, Titan was revealed as a kind of primordial Earth in deep freeze, with lakes and rivers of liquid methane and many of the organic materials required for life.
Cassini also provided insight into another of Saturn’s intriguing moons, Enceladus. Images provided by the spacecraft showed that the moon was geologically active, with water ice being ejected from fissures on its icy surface, rather like a geyser on Earth. During an extremely close fly-by in 2008 Cassini managed to analyze some of the material being thrown into space by the moon, which showed the presence of organic materials. The new data indicated that the interior of the small moon could be warm, and combined with the presence of organic materials Enceladus is now considered as one of the prime candidates for life in the entire solar system.
Of course Cassini also studied Saturn and in particular its ring system. The rings are often compared to the dust and gas discs that form around young stars, these discs go on to form planetary systems and studying Saturn gives scientists an insight into how this happens.
The Cassini spacecraft is still going strong with its mission extended to at least 2017. The images and data it has sent back have been crucial in furthering our understanding of the Saturnian system and the solar system.
3. STS-61 - 1993
The Hubble Telescope being repaired
STS-61 was originally planned as a routine mission to be conducted by the crew of the Space Shuttle Endeavour to service the Hubble Telescope. But due to major issues with the space based telescope the mission had now become one of the most complex and technically challenging missions NASA would ever undertake.
In April of 1990 the Space Shuttle Discovery launched the Hubble Telescope into orbit. The telescope was designed to capture ground breaking images of distant objects in our universe, but as the first images were relayed back to Earth NASA instantly knew there was a problem. The images were nowhere near as sharp or detailed as expected, after an investigation it was discovered that the telescope’s primary mirror had been incorrectly ground, which produced a fuzzy image.
It was a major embarrassment for NASA as they frantically searched for a solution. They knew that the first service of the telescope would be in December of 1993, and they decided to use this mission to repair it. Space Shuttle astronauts would have to add a new optical component to the telescope which would act as a pair of eyeglasses, countering the error with the mirror.
It was an audacious plan, this incredibly intricate task would have to be done in Earth orbit, in zero gravity, by astronauts wearing cumbersome space suits. The mission would involve several extremely dangerous space walks in a very hostile environment. Despite these risks seven crew members on board the Space Shuttle Endeavour set off to repair the faulty telescope In December of 1993 .
On day 3 of the mission Endeavour approached the telescope and performed the delicate task of grasping it with the shuttle’s robot arm, allowing it to be pulled into the cargo bay. Over the next six days the astronauts would perform a series a five spacewalks, totaling a record breaking 35 and a half hours, adding the new eyeglass, a new camera and changing the solar panels.
The mission was a resounding success and Hubble began producing the clear and crisp images that had been expected. The astronauts had pulled of the near impossible in extremely difficult circumstances. Since then the Hubble Space Telescope has captured many remarkable images of distant galaxies, nebulae and stars, which have furthered our understanding of the universe, and it’s thanks to the heroic crew members of Endeavour’s repair team.
2. Apollo 11 - 1969
Neil Armstrong on the lunar surface
On the morning of July 16th 1969 three men were about to embark on a journey that would make history. Michael Collins, Buzz Aldrin and Neil Armstrong sat in the command module of Apollo 11 and waited for the countdown, their mission would be to land the on the moon. At 9.32 am local time the enormous Saturn V rocket roared into action and began propelling the astronauts from the Kennedy Space Center into Earth orbit.
Around three hours after take off the last stage of the Saturn V rocket fired the astronauts towards the moon and separated from the craft. The Apollo 11 spacecraft consisted of three parts, the Command Module which would act as the living quarters and control center for the three astronauts, the Service Module which contained fuel, water and oxygen, and the Lunar Module which would be used to land on the moon.
It would take a further three days before they reached the moon, some 250,000 miles away (400,000 km). During this time the three astronauts would spend most of their time in the cramped conditions of the 13 foot long command module, performing checks and relaying messages to the Mission Control Center in Houston. The technology was primitive, the only computer on board had the equivalent processing power of a digital watch.
On July 19th Apollo 11 entered lunar orbit and began preparations for its descent to the moon. The next day the lunar module containing Buzz Aldrin and Neil Armstrong, separated from the command module with Michael Collins left inside. Two hours later Houston Control received the historic message from Armstrong, “The Eagle has landed”, confirming that the module had successfully landed on the surface of the moon with only a few seconds of fuel remaining.
More than 6 and a half hours later Neil Armstrong began his descent from the lunar module and at 9.56 pm (EST) July 20th 1969 became the first man to step foot on the moon. As millions of viewers around the world held their breath Armstrong said “That's one small step for man, one giant leap for mankind”. Aldrin soon joined him and they both spent a couple of hours collecting samples and laying down scientific equipment.
The following day they successfully blasted off from the lunar surface and docked with the command module in lunar orbit. Three days later on July 24th the three astronauts re-entered Earth’s atmosphere and splashed down in the Pacific Ocean. What they had achieved was something extraordinary for the time and considered by many as mankind’s greatest ever achievement. The US had won the space race and NASA had not only invigorated an interest in space exploration but had become a source of American national pride.
1. Voyager 1 and 2 - 1977
In the summer of 1977 the twin Voyager spacecraft would embark on a remarkable ‘Grand Tour' of the Solar System, visiting the outer planets and capturing images of worlds that had never been seen in such detail before, but the journey was only possible thanks to a scenario that occurs every 175 years. NASA knew that rocket power could only get a spacecraft to Jupiter and no further, but in the mid 1960’s they discovered that in just over a decade later the outer planets would be aligned in such a way that the spacecraft would receive a gravitational slingshot from each one allowing them to get as far as Neptune, some 4.5 billion km from Earth.
In August and September of 1977 Voyager 1 and 2 were launched, reaching their first destination of Jupiter in the spring and summer of 1979. They sent back spectacular images of Jupiter’s turbulent atmosphere and confirmed that the great red spot was indeed an enormous storm.
The craft then turned their attention to Jupiter’s moons, discovering that Io was volcanically active, that Europa had a frozen surface of water ice possibly covering an ocean of warm water, and that Ganymede was larger than the planet Mercury.
Voyager 1 and 2 arrived at Saturn a year apart, in June of 1980 and August of 1981. Scientists at NASA were bombarded with incredible images of Saturn’s rings sent by the twin spacecraft. They were discovered to be more complex than previously thought, with strange spokes of dust emanating from them that came and went, some rings were held in place by tiny shepherd moons while others were intertwined.
Saturn’s other moons were also surprising, some are scarred with huge craters more than a quarter of their size, it was evident that enormous collisions had taken place in the past and maybe some moons had been shattered completely. This led to some speculation that Saturn’s rings were made of debris from destroyed moons.
Most surprising of all was Titan, the Voyagers discovered that the moon was shrouded in a thick, orange, nitrogen based atmosphere, but unfortunately they didn’t possess the necessary equipment to peer through the clouds.
Saturn signaled the end of planetary exploration for Voyager 1 as its trajectory sent it out of the solar system, but Voyager 2 continued on to Uranus and Neptune, and is still the only spacecraft to have ever visited those planets.
Voyager 2 made one last amazing discovery before it too sped into the vastness of interstellar space. The images it sent back of Neptune’s largest moon Triton showed that it was geologically active, with plumes of nitrogen gas erupting from its surface, it was the last thing NASA scientists had expected at around 4.5 billion km from the sun.
After Voyager’s incredible discoveries our understanding of the solar system had to be re-written. Their achievements stretched the capabilities of mankind to the absolute limit and radically changed our perception of what was possible in the solar system. Incredibly both spacecraft still function and send back data to this day.
