National Geographic

VOICES Voices Icon Ideas and Insight From Explorers

Menu

NASA PART II. MANNED SPACE FLIGHT — “A breath taking success…”

“That’s one small step for [a] man, one giant leap for mankind.” — Neil Armstrong

With the retirement of the Shuttle Discovery, the manned space program of NASA — just one of half-a-dozen components of NASA’s mission — effectively went into dormancy, at least in as far as the use of American booster rockets in placing astronauts into space. Please, see the previous installment in this series, “THE PASSING OF AN ERA: THE RETIREMENT OF THE SPACE SHUTTLE.”

And to experience vicariously a “mind-blowing” sub orbital flight, I recommend watching the 400-second video of a space shuttle below, with your speakers turned up. For best result: after the video begins, click on “Watch it in Youtube,” then click on “full screen”:  http://io9.com/5893615/absolutely-mindblowing-video-shot-from-the-space-shuttle-during-launch 

The Space Age had started with the Soviets placing the Sputnik, a grapefruit sized satellite into orbit in 1957; then shortly thereafter they sent a dog into orbit, with no intentions of recovering it. Finally, in April 1961 Cosmonaut, Yuri Gagarin, became the first man to orbit the earth. The United States was caught by surprise, and with a certain degree of fear. Not only was its science and technology appearing to fall behind, there were after all military implications. In a mobilization akin to the Manhattan Project that built the Atom Bomb two decades earlier, the United States created the National Air and Space Administration, and commissioned the Apollo Project. The German-American rocket engineer, Werner von Braun, was appointed the Director of NASA’s Marshall Redstone Arsenal in Huntsville, ALA, to design and test the boosters. In those early days, rocket after rocket ignited on its launch pad, and toppled over, or began to lift off before plunging back down.

A biting joke revealed the frustration of NASA engineers about the Soviet’s clear lead in the space-race, “Their German scientists are better than our German scientist.”

Initially, seven astronauts were selected, and, a month after Gagarin’s historic flight, Alan Shepherd was chosen as the first American to be launched into space, albeit in a suborbital flight that lasted 15 minutes. John Glenn became the first American astronaut to orbit the earth, and indeed on Feb 22, 1962 he made three orbits before returning to earth. I remember well, just two months earlier around Christmas 1961, seeing Col. Glen and his wife and children in a Sears Roebuck Store in Arlington, Virginia, shortly before he left for Cape Canaveral, Florida to make preparations for his flight.

Group portrait of the Apollo 11 crew (left to right) Commander, Neil Armstrong; command module pilot, Michael Collins; and lunar module pilot, Edwin Aldrin, Jr.

Many of us were eye witnesses to the televised broadcast of the mission to the moon, certainly unrivaled as the most dramatic success of NASA. Fulfilling President’s Kennedy’s 1961-vow to put men on the moon by the end of the decade of the 60s, Armstrong, Aldrin and Collins journeyed to the moon in July 1969, and settled into a lunar orbit.

Neil Armstrong is reflected in the visor of Edwin Aldrin's space suit.

Then on July 20, 1969, Armstrong and Aldrin, boarded the Lunar Lander, descended to the surface of the moon, made observations, collected samples, and blasted off from the moon to rejoin Collins in the Lunar Orbiter, before beginning the long trek back to the earth. Thanks to the television cameras, we were all there, experiencing first hand space travel, while wincing at the extraordinary dangers. It was not just two men walking around on the dusty surface of the moon, it was our entire species traipsing around.

The basic physics of space flight — orbital, sub-orbital flight and escape velocity — is actually well understood, with its roots in Isaac Newton’s  Principia of 1687. Indeed, it is Newton’s Third Law, “For every action (force) there is an equal and opposite reaction (force),” that explains propulsion in interstellar space. Of course, it is essential to know Newton’s Second Law; the inverse square-nature of gravitational attraction; the expression for centripetal acceleration; as well as the conservation law for mechanical energy. To travel to the moon and return, classical Newtonian physics is all that is needed. To make it a gentle landing on the surface, Einstein’s General Relativity must also be brought in.

But the practical aspect of space travel began with the pioneering studies by the American physicist, Robert Goddard (1882-1945). Goddard, whose career spanned Clark University in Worcester, MA and Princeton University,  designed and tested the first fully functioning liquid fuel rocket — replete with a gyro system and a precisely designed nozzle to expel the burning gases — in 1926. But it was the Germans who applied and improved upon Goddard’s discoveries in creating the dreaded V-2 rockets that struck terror in England in WWII. Evidently, Buzz Aldrin’s father had studied physics under Professor Hubbard at Clark University, an interesting tidbit supplied in the comment by Ms. Hoffmann.

In my introductory physics classes I’ve frequently assigned the calculations for a variety processes in celestial mechanics. The earth is approximately 4,000 miles (6,400 km) in radius, the distance between the earth and moon (measured center-to-center) is approximately 240,000 miles (395,000 km). Finally, the mass of the moon is 1/81 that of the earth. These numbers, along with a few universal constants are sufficient to make the calculations. One has to accelerate to almost 18,000 mph (30,000 kph) to achieve a low-earth orbit, and 25,000 mph (40,000 kph) to achieve escape velocity from the earth. In order to make the journey to the moon, Apollo 11’s capsule had to go into an earth orbit, then accelerate to achieve escape velocity in a prescribed direction to rendezvous with the moon — which was in its own orbit approximately 240,000 miles (400,000 km) from the earth. Of course, there were minor mid-course corrections to place the space vehicle — comprised of the 3-man Apollo capsule and the Lunar lander — into precisely the right orbit around the moon. Once the coupled-system had settled into that orbit, the Lunar Lander would be decoupled from the Lunar Orbiter — with Armstrong and Aldrin on board — descend to the lunar surface. After 2 1/2 hours, the two men would board the lunar lander, and be launched into an orbit to rendezvous with the Lunar orbiter. They would have to accelerate and escape from the lunar orbit, return to earth, go into orbit…


Comments

  1. 行動電源
    http://www.powerbankdigital.com
    July 1, 2013, 9:31 pm

    I have been searching on-line more than three hrs today, however I never discovered any fascinating post like yours . It’s pretty really worth sufficient for me. Personally, if all site owners and bloggers produced good content as you did, the web will probably be much more useful than ever before.

  2. Melissa
    Worcester, MA
    May 15, 2012, 11:06 am

    One minor correction of note: Clark University, where Robert Goddard (“the father of modern rocketry”) taught, is located in Worcester, Mass. – not Wooster. Did you know that Goddard taught Buzz Aldrin’s father? The Clark alumni magazine recently interviewed the astronaut and learned some interesting facts: http://youtu.be/-v0jqTCCtdg

  3. [...] honor of the space shuttle retirements, National Geographic recognized the achievements of the Challenger Spaceship program in a two part article [...]

  4. [...] honor of the space shuttle retirements, National Geographic recognized the achievements of the Challenger Spaceship program in a two part article [...]

  5. Future
    Future
    May 9, 2012, 5:06 am

    Finally the US Manned Space Program is restored to its rightful state – permanent sleep.

  6. Matt Cooper
    Dallas, Texas
    May 9, 2012, 12:30 am

    Robert,

    Thank you for piecing together intricate several sections of history together that I never had known before! You would be an interesting person to know.

  7. Bulent Atalay
    May 8, 2012, 10:09 pm

    Thank you very much for the incisive comment. I agree with you that our German scientists were better than any that the Soviets were able to remove from Germany to work for them. It’s just that their scientists had been put to work secretly before ours. (Von Braun, it seems, had been instrumental in our rescue of many of them.) I did not know that NASA was created as a civilian agency to be specifically independent of the military — to President Eisenhower’s credit. Incidentally, he “biting joke” that I cited was a throwaway line by Bob Hope. (I was an undergraduate/rower at Georgetown University, and Mr. Hope’s son, Tony, was the manager of the Crew crew. Mr. Hope had taken us all out for dinner, and we were laughing dutifully at everything he said.) As a sequel to the foregoing blog, I will write personal memories of a mission that failed — the Apollo 13. While still a young assistant professor of physics, I had been invited to the launch of the Apollo 13. Shortly after the launch I boarded an Easter Airlines flight to return to DC, and I heard the pilot announce “a serious mishap” had been detected on the mission. The entire nation held its collective breath for days as the capsule kept on course to the moon, swung around, then returned. I believe, it was Grumman J-5 engine that would have normally lifted the lunar lander off the moon that was used in slowing the capsule’s reentry into atmosphere. Thank you again for the very useful comment. Bulent

  8. Robert Carver
    New Orleans
    May 8, 2012, 8:16 pm

    Just a few points from a historian of the space program. We had the capability to launch a satellite before the Soviets but politics kept Eisenhower from pursuing what seemed like to him to be another expensive military program. Wernher von Braun and his team were kept on ice after they were brought to the US after WWII. They were later moved to the Redstone Arsenal in Huntsville to work on rockets for the Army as the Cold War heated up. They were expressly prevented from building boosters that could achieve orbit. So in reality our Germans were much better than the Soviets’ Germans.

    After the surprise of Sputnik Ike resisted the calls to put the American booster/satellite program under the aegis of the Air Force, CIA or other military agency. Ike wanted to decouple our space program from the military which is why NASA was created in 1958 to lead our response. Von Braun and his rocket team did not join NASA when it was created because he was still working for the Army Ballistic Missile Agency which had used a modified Redstone booster (Jupiter-C) to successfully launch Explorer I in January of 1958. It wasn’t until 1960 that von Braun and his team were moved over to NASA when von Braun was picked to be the first director of the Marshall Space Flight Center in Huntsville, Alabama.

    The Redstone was used just for the first two Mercury sub-orbital flights. The USAF’s modified Atlas booster was used for the rest of the Mercury Program. The USAF’s Titan booster was modified for use during Gemini. The von Braun team was tasked to work on the Saturn family of boosters to get Americans to the moon via the Apollo Program. It was the mighty Saturn V rocket that took our astronauts to the moon and later launched Skylab.