Luna 9 – The First Lunar Soft-Landing

The Soviets claimed many firsts in their space race with the United States. First person in space (and orbit), first woman in space, first satellite in orbit. Most would agree, however, that the United States accomplished the biggest first by being the first (and to this day, only) to land humans on the Moon. But the Soviet space program did claim a important lunar firsts of their own: the first lunar fly-by, the first pictures of the far side of the Moon, and the first soft-landing of a probe on the Moon’s surface.

Luna 9 model

Luna 9 model – Source:

On February 3, 1966, the Soviet spacecraft, Luna 9, completed its 3-day journey to the Moon and landed safely on the lunar surface. This ‘soft-landing’ (as in: not a crash-landing) marked the first time a human-made craft survived a landing on any body other than Earth. The successful landing was accomplished by a number of systems that all had to work flawlessly: inflation of an airbag system to cushion the impact, the retrorocket burn to slow the craft, and the deployment of a contact sensor to determine the precise altitude above the Moon. At an altitude of 5 meters, the contact sensor was triggered: engines were shut off and the landing capsule was ejected. Though the craft’s speed was reduced significantly, it still impacted the Moon at a velocity of 22 km/hr (13.7 miles per hour). The airbags allowed the capsule to safely bounce several times before it came to rest.

Following landing and an approximately four-minute pause, four petals that served as the craft’s shell unfolded and stabilized the probe the ground. Antennas were deployed and the craft’s television camera began recording the lunar landscape, capturing the first views ever seen from the surface of the Moon. In addition to the images and radiation readings, the landing also disproved models that suggested that the Moon was covered in a thick layer of dust that would cause any craft (and eventually, persons) who landed there to sink.

One of the first images taken from the Moon's surface

One of the first images taken from the Moon’s surface – Source: Smithsonian National Air and Space Museum

Luna 9’s batteries lasted for three days after landing, during which the craft was able to record a number of panoramic images and beam them back to Earth.

Joddrell Bank, the British observatory located at the University of Manchester, had been paying close attention to the race between the Soviets and the United States. Scientists there not only tracked Luna 9’s progress, but they also recognized the type of signal that the craft was beaming back. They deployed the correct receiving equipment and were able to acquire the lunar images and publish them before the Soviets even managed to see them. There’s still debate as to whether the Soviet scientists let this happen on purpose or not.

While the Soviets soft-landed their craft first, the United States wasn’t far behind. Three months after Luna 9, the US landed Surveyor 1 on the Moon’s surface. Various robots continued to explore the Moon, paving the way for the humans that followed them. After the United States stopped sending astronauts to the Moon in 1972, the next soft-landing wouldn’t occur until 2013, when the Chinese lander Chang’e-3 brought the rover Yutu to explore our celestial neighbor.

Yuri Gagarin – Hero of the Soviet Union and First Ambassador to the Cosmos

Today marks the anniversary of one of the most historic moments in human history. It was on this day in 1961, that Soviet cosmonaut Yuri Gagarin became the first human to take a journey into outer space. Aboard his Vostok spacecraft, not only did Gagarin become the first person in space, he also was the first to orbit the Earth — something NASA didn’t accomplish until its third manned Mercury mission, some nine months later.

Gagarin - 1964

Yuri Gagarin - 1964

While strapped to the top of a Soviet Vostok-K rocket, Gagarin hummed and whistled “Lilies of the Valley”, cracked jokes, and found plenty of time to laugh, all the while waiting for the ignition below to send him where no man had gone before.

“Poyekhali! (Off we go!)”

Gagarin : Thank you. Goodbye. See you soon, dear friends. Goodbye, see you soon.

Gagarin spent 108 minutes from launch to landing, completing a single orbit of the Earth. It took 25 minutes for ground controllers to be sure he had successfully reached orbit. Gagarin remained calm through the whole ordeal 1 and seemed to rather enjoy himself. He described weightlessness as an unusual, yet enjoyable, experience and radioed back the things he could see out of the windows in his capsule.

Gagarin's Vostok 3KA Capsule

Gagarin's Vostok 3KA Capsule

A 42-second retrofire burn took place over Angola, approximately 5,000 miles from his landing site. When the commands were initiated to separate the service module from the reentry module, a bundle of wires unexpectedly kept them attached. The two components began reentry together, but finally separated following some extreme gyrations. The gyrations continued after separation, but Gagarin radioed that “Everything is OK”, reasoning that the gyrations could be expected from the spherical shape of the craft and didn’t want to “make noise” about it. At 7km above the ground, Gagarin was ejected — as planned 2 — from the Vostok and his parachute immediately deployed. Vostok fell until about 2.5km (8,200 feet) before its main parachute deployed. A couple of schoolgirls witnessed Vostok’s landing and described the situation: “It was a huge ball, about two or three metres high. It fell, then it bounced and then it fell again. There was a huge hole where it hit the first time.”

Gagarin landed on the ground as a world hero. The Soviets were emboldened by their great accomplishment, and you could be certain that the early American space program had to pick their collective jaws off the floor and wonder how they would catch up.

So today, we tip our hats to Yuri Gagarin and the bold first step he took to get us to where we are now — 51 years later.

Yuri Gagarin's Signature

Gagarin's signature

To learn more about Yuri Gagarin and his historic flight, check out:

*This post originally published April 12, 2011. It has been slightly modified from its original version.

  1. Just prior to launch, Gagarin’s pulse was at a mere 64 beats per minute.
  2. It wasn’t until 1971 that the Soviets acknowledged that he didn’t land with his craft. The Fédération Aéronautique Internationale regulations required that a person land with their craft for it to count as a successful spaceflight. The Soviet government forced Gagarin to lie in press conferences to get the FAI to certify his flight, which they did.

Explorer 1: America's First Space Satellite

Explorer 1

Explorer 1 – Source: NASA

You probably know that Russian Sputnik satellite was the first human-made satellite to be placed into orbit. If not, I’m guessing you’ve at least heard of it. While the Russians beat the United States in that first declaration of space dominancy, America wasn’t far behind. Today we learn the story of the United States’s first orbital satellite: Explorer 1 1.

Towards the end of 1957, news of the Russian’s space accomplishments was rocketing around the world. Their successful Sputnik spacecrafts had recorded new entries in world history: Sputnik 1 was the first human-made object put into Earth orbit; and Sputnik 2 carried the first living creature larger than a microbe, a poor dog sacrificed in the name of science, named Laika.

The United States’s credibility was in question. Could the US compare to the Russian’s space prowess?

News of Sputnik’s milestones kickstarted an otherwise stalled United States space satellite program. The United States Army Ballistic Missile Agency (ABMA), directed by Wernher von Braun, teamed up with the federally-funded research facility, JPL (Jet Propulsion Laboratory) under the direction of Dr. William H. Pickering. JPL designed the Explorer 1 craft, while the ABMA modified one of its Jupiter-C rockets (gaining the designation Juno 1) to carry Explorer 1 payload into orbit.

A few months prior, in December of 1957, the United States Navy had attempted to put the first US satellite in orbit. That rocket made it about four feet above the launchpad before failing catastrophically in a magnificent ball of fire. Its failure earned such laughable nicknames as: Flopnik, Stayputnik, Oopsnik, and my favorite, Kaputnik.

Rapid work began on the satellite and launch system, and in only 84 days they had completed the design, construction, and assembly of Explorer 1 and its complementary rocket.

Explorer 1 schematic

Explorer 1 schematic – Source: NASA

Explorer 1 consisted of two major components: the 37.25 inch scientific portion, containing science and communication instruments, mated to a 45.5 inch rocket booster. This package was placed atop the 70-foot-tall Juno 1: a four-stage, Redstone-family booster rocket.

Explorer 1 launched from Cape Canaveral, Florida, at 10:48pm local time on January 31, 1958.

Explorer 1 entered an eccentric orbit around Earth, with the closest point in its orbit at 358 kilometers (222 miles) and its furthest at 2,550 kilometers (1,580 miles). It completed an orbit every 114.8 minutes. Mercury batteries powered the craft’s high-power transmitter for 31 days, with the low-power transmitter operational for 105 days. Explorer 1’s final transmission was received on May 23, 1958. The silent Explorer 1 continued to orbit for more than 12 years, its orbit finally decaying to the point of re-entry and destruction in the atmosphere over the Pacific on March 31, 1970. By then, it had completed more than 58,000 orbits.

Explorer 1 effectively initiated the Cold War space race. But it did more than just prove that the United States could compete with the Russians in putting things in orbit. Explorer 1 conducted real science and made some important discoveries that would be important to understand as the world progressed into a space-faring society.

Explorer 1 contained two main scientific instruments: one for detecting cosmic rays, and another for studying micrometeorites.

The micrometeorite package consisted of a “wire grid (arrayed around the aft section of the rocket body) and an acoustic detector (placed in contact with the midsection)“. Over the course of the experiment, 145 micrometeorite hits were detected.

The cosmic ray detection equipment made even greater discoveries. This was accomplished by an “Anton 314 omnidirectional Geiger tube detector“, which measured the flux of charged particles hitting the detector. The experiment was overseen by Prof. James A. Van Allen.

A peculiarity was noted in this experiment: the expected radiation count was approximately 30 per second, but the detector would occasionally return a result of zero. It was determined that these zero count intervals coincided with altitudes greater than 2,000 kilometers (1,200 miles). Further research determined that at those altitudes, the detector was actually being over-saturated and overwhelmed by the radiation. This led to the discovery of an energetic belt of charged particles that surround magnetized planets , such as Earth. This belt was named after James Van Allen, and today are known as Van Allen radiation belts. Knowledge of this region would become essential to the survival of humans that would travel through them in later space programs. The discovery was designated as one of the greatest of the International Geophysical Year.

William Hayward Pickering, James Van Allen, and Wernher von Braun at a press conference announcing the orbital insertion of Explorer 1.

William Hayward Pickering, James Van Allen, and Wernher von Braun at a press conference announcing the successful orbit insertion of Explorer 1 – Source: NASA

At around 1:00 am on February 1, 1958, just hours after Explorer 1’s successful orbit insertion was verified, William Hayward Pickering, James Van Allen, and Wernher von Braun were ushered to the National Academy of Sciences building in Washington, D.C.  to conduct a press conference that would make headlines around the globe.

That press conference produced one of the most iconic images of the Space Age. In the image, Pickering, Van Allen, and von Braun stand triumphantly, holding a model of Explorer 1 high above their heads.

A Moment in Time: Explorer 1 – Each of these three men thus represented a component of Explorer 1’s success: the rocket, the satellite and the science payload. Each represented an institutional underpinning crucial to the fledgling American space program: the Army, the Jet Propulsion Laboratory and scientific research as represented by the University of Iowa. Each had converged from his own path to the singular moment depicted in the triumphal image.


The success of Explorer 1 can’t be overstated. It proved the efficiency that could be achieved through collaboration between civilian and military agencies, it was one of the major sparks that ignited the Cold War space race, and it confirmed the United States as a powerful contender to the Russians.

  1. At the time of launch, also designated as Alpha 1958

Today Marks The Anniversary Of Humankind's First Spacewalk

It was on this day in 1965, that cosmonaut Alexey Leonov crawled out of his Voskhod 3KD 1 spacecraft and performed humankind’s first spacewalk.

Stills of Alexey Leonov conducting mankind's first spacewalk.

Stills of Alexey Leonov conducting mankind’s first spacewalk. / Source: NASA Great Images in NASA Collection

Alexey Leonov stepped into uncharted territory on that historic day, marking a milestone in human exploration. While it wasn’t immediately publicized 2, Leonov’s 12-minute-9-second spacewalk skirted on the edge of disaster.

Once Leonov entered the vacuum of space, his spacesuit become inflated and maneuverability suffered. The real trouble began as Leonov tried re-entering the Voskhod 2 craft, and became stuck in the the hatch due to the inflated suit. He was forced to partially depressurize his suit in order to fit through the hatch, putting himself at great risk of suffering decompression sickness, known as ‘the bends’.

While the spacewalk and a number of other elements of the mission lingered on the verge of catastrophe, this was a time when survival equated to success.

American astronauts followed suit soon after, as they crawled out of their Gemini capsules to experience the same joy and danger Leonov experienced (Gene Cernan’s Gemini spacewalk was also a close-call). We’ve come a long way since those baby-steps into space, with now over 200 humans having walked in space.

So, to General Leonov, I offer a belated congratulations and thank you for pushing against the boundaries of the final frontier.

*This post originally published on March 18, 2011.*

  1. The mission was Voskhod 2, the craft was Voskhod 3KD
  2. The Soviets originally claimed the spacewalk went off without a hitch, and that Leonov was “feeling well both during his period outside the cabin and after he re-entered the spacecraft”