Fifty years ago, on this week, human beings walked on the surface of the moon. I have always considered this to be one of the greatest technological achievements of mankind. The ancients could have only imagined what it would be like to leave our terrestrial home. But that changed in July 1969 when men left the Earth and walked on another world. This feat was made possible by the combined efforts of our finest minds, strong determination, and of course, the Christian worldview.
The Celestial Realm
For roughly six thousand years, humanity was confined to this terrestrial sphere. Many ancient pagan religions considered outer space to be the realm of the gods. The Greeks and Romans thought that the planets actually were gods, and we still refer to the planets by their Roman names. For human beings to penetrate the divine realm was virtually unthinkable. However, Christian thinking eventually permeated and forever changed the science of astronomy.
In the 1500’s, Nicholaus Copernicus suggested that the heavens were not fundamentally different from Earth; he suggested that the Earth was a planet that orbited the sun, just like the others. In 1610, Galileo Galilee became the first person to systematically view the heavens through a telescope and to document what he saw. The heavens were not divine, the planets were not the whimsical gods of ancient mythology. Rather, they were mere creations of the Living God. As such, they exhibited the same kind of orderliness that God has instilled in his earthly creations.
Johannes Kepler expected to find patterns in the movements of the planets because he knew that they were ultimately controlled by the Lord. And through careful analysis of data collected by Tycho Brahe, he successfully found such patterns. He discovered the three laws of planetary motion which describe and predict the orbits of all planets and moons. However, the proximate cause of these motions remained undiscovered.
Then along came Isaac Newton. In the mid to late 1600s, he discovered the mathematical formula that described the force of gravity, along with the laws of nature that govern the motion of all matter. Using mathematics, he found that these laws naturally explained why Kepler’s laws are as they are. He realized that the moon’s orbit was the result of gravity and momentum.
The Advancement of Science
And what do all these scholars have in common? They were all men who believed in the biblical God. As such, they expected to find patterns in nature because God had imposed such patterns on nature. It was common at the time for scientists to be Bible scholars as well. Indeed, Kepler was a devout Christian and had been training to go into full time ministry. However, he recognized that his work in science and mathematics could also be very glorifying to the Lord.
The discoveries of these men would pave the way for manned space exploration. The astrophysicists and mathematicians involved in the space program have used Newton’s laws of gravity and motion to make the calculations necessary for any kind of space travel. The director of NASA responsible for the moon program, Wernher von Braun, was a faithful Christian. He opposed Darwinian evolution and said, “There are those who argue that the universe evolved out of a random process, but what random process could produce the brain of man or the system of the human eye?” Von Braun was largely responsible for the Saturn V rocket used in the Apollo missions. The Saturn V was the largest and most powerful rocket ever created.
Since God is faithful and has promised to uphold His universe in a consistent way (Genesis 8:22, Jeremiah 33:25), we can use experiments and observations performed on Earth to predict what will happen in outer space. After all, the same God upholds both the heaven and the Earth; they obey the same laws because they have the same law-giver. This biblical principle allowed Newton to discover the laws of gravity and motion, and to recognize that such laws are universal. Hence, this biblical principle justified our confidence in the early space program. Using the laws of gravity and motion, physicists were able to design and build rockets that can enter Earth orbit, or even escape Earth orbit.
For example, a rocket requires a force in order to move at all. This is Newton’s first law. Without a net force, an object will not change its velocity. But how much force is required? This is derived from Newton’s second law, which states that the net force applied to an object will equal the object’s mass multiplied by its acceleration. The force is caused by combustion within the rocket which pushes expelled gas downward. Since the rocket pushes downward on the gas, the gas pushes upward on the rocket with equal force. This is Newton’s third law.
Newton also discovered the principles of calculus that allow us to solve mathematics problems in which certain variables change with time. For example, the mass of a rocket changes drastically as it expels its spent fuel in the form of gas. This changes the force required to achieve a given acceleration. Furthermore, the principles of calculus allow us to compute the trajectory the rocket must take in order to achieve orbit under the law of gravity. Such computations presuppose that God will continue to uphold His creation in a consistent fashion – otherwise there would be no basis for trusting that the laws of physics will continue to apply in the future as they have in the past, or in space as they do on Earth.
The National Aeronautics and Space Administration (NASA) was created in 1958 to fulfill the spaceflight operations of the United States that were formerly handled by the military. The first human spaceflight project of the United States was the Mercury program. After several unmanned test flights, the Mercury program succeeded in launching the first astronaut, Alan Shepard, into space on May 5, 1961. Shepard’s flight was suborbital; the capsule’s trajectory took Shepard above the atmosphere and then safely back to Earth. This was less than a month after the Soviet Union had achieved the first manned spaceflight with cosmonaut Yuri Gagarin.
In 1962, the Mercury program succeeded in its first orbital flight. John Glenn became the first American to orbit the Earth. Isaac Newton had first realized that orbits are caused by gravity. An object in orbit is falling, but rather than falling toward the Earth, it is falling around the Earth. Newton realized that if an object had sufficient speed, the Earth’s surface would curve away from it at the same rate the object fell. Therefore, the object would remain the same distance from the Earth’s surface. To achieve low earth orbit, an object must travel at a speed of about 17,000 miles per hour.
John Glenn’s flight was a technological triumph. But again, the Soviet Union had accomplished a manned multiple-orbit flight months prior. Decades later, Glenn would return to space aboard the space shuttle. Looking at the Earth from space reinvigorated his faith in God. On his flight in the space shuttle Discovery, Glenn said, “To look out at this kind of creation out here and not believe in God is to me impossible.”
Both the United States and the Soviet Union had demonstrated that people could be launched into space and safely returned to the Earth. But landing on the moon would be a much greater challenge. The Mercury program put human beings into an orbit less than 200 miles above Earth’s surface. But the moon is 240,000 miles from Earth. And to get there would require many other challenges. To prepare for these challenges, NASA initiated the Gemini program.
The Gemini capsule was slightly larger than the Mercury capsule, and held two people. In fact, the program is named after the constellation Gemini – the “twins.” The Gemini program (1965-1966) accomplished a number of challenges that would be necessary for an eventual moon landing. The Gemini spacecraft could maneuver, adjusting its orbit. It was the first to dock two spacecraft both in orbit. The first spacewalk was part of the Gemini program. It allowed NASA to learn what happens medically when people spend many days in space. These were all essential steps for the moon program.
Next came the $25.4 billion Apollo program. The program took place in stages, each one designed to test equipment that would eventually be used to land on the moon. The program would be made possible by the development of the Saturn V rocket – a 36-story behemoth capable of propelling the command module and lunar excursion module (LEM or LM) into lunar orbit. The Saturn V was a three-stage rocket – essentially a rocket on top of a rocket on top of a rocket. When the first stage exhausted its fuel, it fell away and the second stage ignited, and so forth. Only the top portion of this monster actually reaches space; the lower larger portions are what it takes to accomplish this.
But getting there is only part of the problem. Scientists and engineers also had to develop a command module significantly larger than Gemini so that it could hold three astronauts. Concurrently, NASA also commenced development on the lunar excursion module which would allow two of the three astronauts to land on the moon while the third remained in lunar orbit in the command module. This of course required the two spacecraft to be able to undock and redock in orbit, a feat that had already been achieved by the Gemini program.
The Apollo 1 mission was to be the first crewed flight of the program. But tragedy struck during a routine test of the command capsule. The rocket was unfueled during this test and therefore considered safe. But a series of unforeseen events led to the deaths of the three crew members: Gus Grissom, Ed White, and Roger Chaffee. An electrical spark started a fire in the cabin which spread quickly due to combustible nylon material, and the pure oxygen environment of the cabin. The hatch was designed to open inward. But the heat increased the already-high air pressure in the cabin, making it impossible to open the hatch. The disaster led to the suspension of all manned Apollo flights for 20 months, until the cause could be thoroughly ascertained and eliminated in the redesigned capsule.
Apollo missions 2 and 3 were planned, but canceled because they were considered unnecessary. The Apollo 4 mission was unmanned, and was the first full-scale launch of the Saturn V rocket. Apollo 5 and 6 were also unmanned. Apollo 7 was the first manned flight of the program. The astronauts were launched into Earth orbit using the (smaller) Saturn Ib rocket.
The launch of Apollo 8 occurred on December 21, 1968. Apollo 8 was a particularly significant step in the program because it was the first time that the Saturn V rocket would propel human beings into space. It must have been intimidating for the three astronauts as they listened to the countdown while sitting on top of the 947,000 pounds of explosive fuel necessary to produce the 7.5 million pounds of force needed to lift the mighty Saturn V off the launch platform. Will every part of that complex machine work properly?
This mission would be the first in which human beings would leave Earth orbit, and transfer into an orbit around the moon. The three astronauts, Frank Borman, Jim Lovell, and Bill Anders would be the first human beings to see the moon up close as they orbited around it at a distance of only 100 miles from its surface. To achieve lunar orbit, the astronauts had to ignite the propulsion system at just the right time, for just the right length of time, and the ship had to be pointed in the right direction. All this had to be done when the spacecraft was on the far side of the moon, and therefore out of radio contact with the Earth. A small error in any one of these numbers could potentially cause the craft to crash into the moon, or escape into deep space unable to return to Earth. You can imagine the relief at Mission Control when the Apollo 8 capsule re-appeared from behind the moon in its proper trajectory.
On Christmas Eve, 1968, the Apollo 8 crew became the first human beings to orbit the moon.
They orbited the moon 10 times. The astronauts were treated to spectacular views of the barren, cratered surface of the moon. On the fourth pass, they happened to be looking in the right direction at the right time to see the Earth rise above the lunar horizon. They took a picture of the event, which has now become one of the most famous photographs in history: “Earthrise.”
During their ninth orbit, the astronauts began one of their planned television transmissions in which they described what it was like to see the moon from so close. Then, Bill Anders said that they had a special message for the people of Earth. Each of the three astronauts took turns reading from Genesis chapter 1, recounting the creation of the universe by God. Nice touch! Borman closed with the following words, “And from the crew of Apollo 8, we close with good night, good luck, a Merry Christmas and God bless all of you—all of you on the good Earth.” After the tenth orbit, and another engine burn, the crew returned safely to Earth.
Apollo 9 was a crewed mission testing the lunar model and its ability to dock with the command module. This mission took place in Earth orbit. Apollo 10 was the practice run for the moon landing. Again, three astronauts would orbit the moon, but this time the lunar module was also included, allowing the crew to practice separation and docking in lunar orbit. The lunar module was lowered to a distance of just 9.7 miles above the lunar surface before returning to dock with the command module.
Thanks to the dedication and hard work of thousands of people, and the successes of previous missions, the Apollo 11 mission would be the first to place people on the surface of the moon. Two of the astronauts, Neil Armstrong and Edwin “Buzz” Aldrin would descend to the moon in the lunar module named “Eagle” to a dark region on the right side of the moon called “The Sea of Tranquility.” Mike Collins would remain in orbit in the command module “Columbia.” During the descent, the Eagle’s computer crashed (and rebooted) five times, but the astronauts and mission control were able to deal with each instance.
As they neared the surface, Armstrong could see that the exact location of the planned landing site had too many large boulders for a safe landing. So he took control and manually maneuvered the LEM past the boulders, and past a small crater. But time was limited. The Eagle had only a small amount of fuel on board – just enough to land on the moon and return to orbit to dock with Columbia. If Armstrong took too long, it would trigger an automatic abort, lest the two astronauts be stranded on the moon to die. Fortunately, Armstrong was able to find a level location to land, and shut down the engines, with less than 30 seconds of auxiliary fuel remaining. Armstrong then radioed mission control with the historic words: “Houston, Tranquility Base here. The Eagle has landed.”
As a practicing Christian, Buzz Aldrin then radioed mission control and invited listeners to give thanks with him. He then read a section from the Gospel of John chapter 15, beginning in verse 5: “I am the vine, you are the branches…” He then privately brought out a small container with wine and bread that had been given to him by his church, and he took communion. Nice touch!
The two astronauts suited up and depressurized the cabin. Armstrong opened the hatch and proceeded down the LEM ladder. The event was broadcast on live television, with 650 million people watching. Upon reaching the base, Armstrong set foot on the surface of the moon. It was one small step for a man, one giant leap for mankind. Aldrin followed about 20 minutes later, and commented on the strange beauty of the lunar surface as a “magnificent desolation.”
The gravity on the moon’s surface is only one sixth that of Earth. The astronauts had prepared for this as best they could under Earth conditions, but no one really knew what it would be like to experience such slow gravity. Armstrong commented that it was surprisingly easy to walk around. But the way we walk on Earth doesn’t work well under such weak gravity. Instead, the astronauts used either a kangaroo hop, or a loping gait to move around. The fine soil of the moon was slippery, and Armstrong and Aldrin found that they had to plan their movements several steps ahead.
The astronauts collected samples of the lunar soil along with a number of rocks for analysis back on Earth. They also planted an American Flag into the lunar soil. This turned out to be more difficult than expected. Below the inch or so of lunar topsoil, the surface is quite hard. Nonetheless, they eventually succeeded. Mission control then radioed them with a phone call from President Nixon, who congratulated the astronauts on their brave success.
The lunar astronauts took many pictures of the desolate environment. They also deployed some scientific instruments on the lunar surface, including a seismometer to measure moonquakes, and a mirror array designed to reflect laser beams back to their source. The latter instrument would later be used to measure the distance to the moon with unprecedented precision. After an hour and a half of walking on the moon, Aldrin returned to the LEM. Armstrong followed about 40 minutes later.
The Eagle was on the moon’s surface for a total of 21 hours, 36 minutes. It was designed in two sections – a lower descent stage and an upper ascent stage. These stages separate upon completion of the lunar mission, and only the ascent stage leaves the moon, carrying the two astronauts back to the command module. The descent stage of the Eagle is still on the surface of the moon, and we now have the technology to directly image it. As the ascent stage launched, Aldrin saw the blast of the exhaust knock over the American flag. Later Apollo missions would place the flag at a greater distance from the LEM to prevent this.
The Eagle successfully re-docked with the Columbia, much to the relief of Mike Collins, who shook Armstrong’s hand as the two moonwalkers returned to the command module. The Eagle was then discarded, and the Columbia burned its engines to return to Earth. It splashed down in the Pacific Ocean right on schedule. The crew, capsule, and cargo were successfully recovered by the aircraft carrier USS Hornet. The astronauts were held in quarantine for several weeks just in case they had been infected by some lunar microbes. Of course, that was not the case.
Six additional Apollo moon missions followed Apollo 11, each designed to study a particular area of the moon. The Apollo 12 lunar module landed in the “Ocean of Storms” region of the moon in November, 1969. Pete Conrad and Alan Bean explored this region, while Richard Gordon piloted the command module. Conrad and Bean did two separate moonwalks lasting a total of nearly eight hours – far longer than the Apollo 11 excursions.
Apollo 13 was scheduled to explore the Fra Mauro highlands. But a critical malfunction aboard the command module crippled the craft shortly after translunar injection. A short circuit caused an explosion in one oxygen tank, which damaged another. With the oxygen depleted, the command module would not be usable, and this prevented any moon landing. Instead, the three crew members, Jim Lovell, Jack Swigert, and Fred Haise, transferred to the lunar module “Aquarius,” using it as a lifeboat. Apollo 13 did reach lunar orbit, and used the moon’s gravity to redirect the craft in an Earthward direction. Thanks to some ingenious improvising, the crew survived and returned safely to Earth. This event was very accurately portrayed in the Ron Howard movie Apollo 13 – one of the best movies I have ever seen.
The Apollo 14 crew successfully completed the Apollo 13 mission – placing astronauts Alan Shepard and Edgar Mitchell on the Fra Mauro highlands. This region is near the center of the moon as seen from Earth. Again, a number of scientific instruments were placed on the lunar surface, and various rock samples were collected. In addition to his scientific duties, Shepard decided to have a bit of fun on the moon. He brought with him two golf balls and a six iron. He shanked the first ball. But his second swing was a spectacular success. Golf balls can go very far in one-sixth Earth gravity with no air resistance.
Apollo 15 placed astronauts David Scott and Jim Irwin on the Hadely-Apennine region, a rather mountainous region of the moon, while Alfred Worden piloted the command service module. The lunar module for this mission also carried a lunar rover – a wheeled vehicle designed for driving on the moon. This allowed the astronauts to explore a much greater area in a given time. They spent more time on the moon than any previous mission. After returning from this mission, Jim Irwin became a Christian and defended the literal, historical account of Genesis. Beginning in 1973, he went on several expeditions to find Noah’s Ark. Irwin said that he had felt the power of God while walking on the moon. This motivated him to share the Gospel. He said, “Jesus walking on the earth is more important than man walking on the moon.” Irwin passed into glory on August 8, 1991 at the age of 61.
In April, 1972, the Apollo 16 mission placed astronauts John Young and Charles Duke on the moon, while Ken Mattingly piloted the command service module. As with the previous mission, this Apollo 16 lunar module carried a lunar rover to expediate travel along the moon’s surface. In addition to collecting rock samples, the astronauts deployed a number of scientific instruments on the surface, designed to measure such things as cosmic ray influx, lyman-alpha emissions, and local magnetic fields. After his time on the moon, Charles Duke became a born-again Christian. When he made Jesus Lord of His life, it saved his marriage and gave him peace that he did not have before. Interestingly, Charles Duke has an identical twin brother, Bill, whom I met at a church service several years ago. Apparently, Bill was at Mission Control for part of the time when his brother was on the moon, which may have caused some heads to turn.
December 1972 would see the last Apollo moon mission – Apollo 17. Astronauts Eugene Cernan and Harrison Schmitt landed on the moon and Ronald Evans piloted the command module. The LM again carried a lunar rover for rapid transport along the surface. A number of scientific instruments were placed on the moon, and numerous surface samples were collected. Three additional Apollo missions had been planned. But these were scrubbed due to budget cuts. As of the writing of this article, twelve men have walked on the surface of the moon. Plans to return to the moon are underway.
The End of an Era
An Apollo command service module, unused in the moon program due to budget cuts, would see service in 1975. It would be used to dock with a Soviet Soyuz capsule in Earth orbit. This “handshake in space” symbolized the end of the cold war, and perhaps bolstered further cooperation between Americans and Russians. Today, the USA and Russia routinely work together in space missions, such as joint participation in the International Space Station. This Apollo-Soyuz Test Project is sometimes referred to as Apollo 18, although NASA did not assign that number. It perhaps symbolizes the end of one era, and the beginning of another.
As of today, over 500 people have visited space. But the vast majority of these have been only about 200 miles above Earth’s surface – in low Earth orbit. Only 24 people have left Earth orbit – the astronauts who entered lunar orbit as part of the Apollo program. NASA has planned the Artemis program to send people back to the moon with a possible target date as early as 2024. Can it be done?
The problem with a return trip to the moon is not technology. We have had the technology since the late 1960s, and of course technology today is far superior. The problem is funding. During the Apollo program, Congress dedicated up to 4% of the federal budget to NASA. Today, NASA receives less than half of one percent. Furthermore, there is no motivation to beat the Russians to the moon, and we already have lots of moon rocks from the Apollo missions. But a return moon mission would be an important step of a program to eventually send people to visit Mars. In any case, the future of space exploration is an exciting prospect.
Did it Really Happen?
Sending men to the moon has to be one of the greatest technological achievements of mankind. To think that human beings have travelled 240,000 miles into space and walked on another world boggles the mind. It is so extraordinary that some people have to ask, “did it really happen?” In one sense, I get it. The event is so amazing it is hard to believe. Then again, many of the events of the Bible are extraordinary. Can you believe that the entire Earth was once flooded with water? Can you believe that the entire universe was spoken into existence by God in six days? Can you accept that God Himself became a man, died in our place, and rose from the dead?
Like the moon landing, many of the events recorded in the Bible are so far outside our everyday experience that many people find them difficult to accept. I freely admit that it is extraordinary that God created the universe in six days, and it is extraordinary that men have walked on the moon. But an important consideration when we consider the possibility of extraordinary claims is this: “what is the alternative?” The only thing more unbelievable than these events is if they didn’t happen.
Think about it. If the universe is not the creation of God, then all of the complexity and patterns we see in nature are just accidents. Now that is truly absurd! If the Earth were not flooded with water, then why do we find water-deposited rock layers full of fossils covering the continents, and hundreds of flood legends from cultures all around the world? Are these things just an astonishing coincidence? That would be far more unbelievable than a worldwide flood.
Likewise, if we never landed on the moon, then somehow thousands of people were able to manufacture consistent evidence including perfect photographs and video footage. It is absurd on the face of it because we simply did not have the technology in the 1960s to fake it. We are only now at the point where computer-generated-video is nearly indistinguishable from reality. But that is a very recent development. Even relatively recent fictional movies that show people on the moon or other worlds just don’t look quite right. For one, there is simply no way to fake 1/6 Earth gravity in a sound stage. Playing a video in slow motion doesn’t work, because all the other actions look so obviously slow. You cannot slow the effect of gravity in a video without slowing everything else by the same amount.
And what about all the pictures we have of the Earth from space such as the famous 1968 “Earthrise?” Conspiracy theorists will say these were all photoshopped… two decades before Photoshop was invented. That would be quite a trick! And the rocks we brought back from the moon are available for inspection – I’ve seen them. Their composition is quite different from Earth rocks. Furthermore, recall that the astronauts left a special reflector on the moon’s surface. We can prove this is there by shining a powerful laser at it, and recording the time of the return beam. (It takes about three seconds for the beam to reach the moon and return to the Earth). Even amateurs have performed this experiment confirming that the reflector really is there.
The thing that is perhaps most absurd about such conspiracy theories is the notion that the thousands of people working at NASA, and the hundreds of thousands involved in building the various components that went into the Apollo program were all able to lie with such perfect consistency. Each bore witness to various aspects of a consistent account; how could they do that with a fictional story? When people lie, they must invent details from their own imaginations – and different people naturally invent different details. Hence, liars can be identified by asking them sufficient questions until they contradict each other (Mark 14:55-59). False testimony is always inconsistent.
The Bible tells us that when multiple witnesses give consistent testimony to what they saw – each from their own point of view – this is the mark of truth. Jesus said, “by the mouth of two or three witnesses every fact may be confirmed.” (Matthew 18:16b, see also Deuteronomy 19:15, 17:6, 2 Corinthians 13:1). This is ultimately the reason we know Christ rose from the dead – eye witnesses who gave consistent testimony (Acts 2:32, 3:15). The witnesses to the Apollo program are in the thousands and their testimony is consistent. Therefore, to call them all liars is to say that Jesus was wrong. Truth is not determined by our emotional preferences or intuition. It is determined by the mind of God and revealed to us in any number of ways. There are many truths that are counter-intuitive. But we are morally obligated to accept the truth on the basis of sufficient evidence, such as consistent multiple eye-witness testimony.
The moon landings are a triumph of Christian thinking. This isn’t to say that everyone involved in the moon program professed a saving faith in Christ. Some did, some did not. But all involved had to think in a Christian way in order to succeed. That is, they had to assume that the universe operated in a lawlike fashion as if upheld by the mind of God. The whimsical gods of pagan religions won’t do; they were inconsistent and would change their mind. And atheism gives no reason to expect any consistency in nature whatsoever. Everyone involved in the Mercury, Gemini, and Apollo programs had to either knowingly or unwittingly rely upon God’s promise to uphold nature in a consistent fashion (Genesis 8:22).
NASA was (and still is) comprised of some brilliant scholars and dedicated craftsmen. Their ingenuity and combined determination have accomplished the seemingly impossible. And yet, it is the living God who gave such intellect to people. The Lord is the one who upholds all nature in a consistent way (Hebrews 1:3) for our benefit. He designed our senses and our mind to be able to probe the universe, to study and understand creation. The biblical worldview and no other can justify our confidence in the science that made the moon landings possible. Hence, the success of such missions is actually a demonstration of the truth of the Bible.
Of course, the Apollo program confirmed some of the specific claims of the Bible as well. While many pagan religions accepted the celestial objects as gods, the Bible teaches that the luminaries are mere objects: inanimate creations of God and not divine (Genesis 1:14-19). This may be why God created them on day 4 rather than day 1. Furthermore, we now have photos of the Earth from space, confirming the biblical teaching that the Earth is round (e.g. Job 26:10, Isaiah 40:22). The famous Earthrise photo also shows that the Earth hangs upon nothing, just as the Bible teaches in Job 26:7. The Apollo program confirms what all science confirms: the Bible is true.
 The exception is the planet Uranus which is named after a Greek god.
 This is not to say that they had perfect doctrine. Galileo was Roman Catholic, and Isaac Newton had an unorthodox and possibly heretical view of the Trinity. However, these men were strongly influenced in a positive way by the Bible and publicly said so. Their belief in God (whether a saving faith or not) fueled their scientific discoveries. Science makes sense in a universe upheld by the mind of the biblical God, but makes no sense in a chance universe.
 Von Braun, in a letter read by Dr John Ford to the California State Board of Education on Thursday September 14, 1972.
 Shepard was the first astronaut, but not the first person in space. The USSR was first, but referred to their space explorers as cosmonauts.
 NASA used pure oxygen for the cabin in the Mercury and Gemini programs to save fuel. Earth’s atmosphere is about 80% nitrogen, and only 20% oxygen. We need oxygen to breath, but we don’t need nitrogen. Since air has weight, it makes little sense to lift the weight of unusable nitrogen into space when the astronauts only need oxygen to breathe. However, Apollo 1 revealed the danger of a pure oxygen environment.
 The orbit was elliptical, taking the astronauts from 69.5 miles from the surface up to 193.3 miles.
 Some estimates are a bit lower, and others up to 50 seconds.
 As he acknowledged later, Armstrong had meant to say “one small step for a man” rather than “one small step for man….” Without the indefinite article, “man” means “mankind,” which makes the statement confusing, e.g. “one small step for mankind, one giant leap for mankind.”
 The Apollo 13 movie immortalized Jim Lovell’s line “Houston, we have a problem.” In fact, Swigert had originally said, “Okay, Houston, we’ve had a problem here.” Lovell then repeated, “Uh, Houston, we’ve had a problem.” The movie producers were concerned that the use of the past-tense “had” made it sound like the problem was over, which reduces the suspense. So for the movie, the line was changed to the present tense: “Houston, we have a problem” in a forgivable bit of artistic license.