Posts Tagged ‘ NASA ’
51 years ago today, the Atlas rocket boosters that John Glenn, inside his Friendship 7 capsule, was strapped to the top of ignited. Millions of Americans watched as the resulting 350,000 pounds of thrust vibrated the vehicle that was about to take the first American into orbit around the Earth.
CAPCOM (Capsule Communicator): 3… 2… 1… 0.
John Glenn: Roger. The clock is operating. We’re underway.
Minutes later, John Glenn became the fifth human in space and the first American to enter Earth orbit. Previously, Alan Shepard and Gus Grissom became the first and second, respectively, Americans in space; however, John Glenn was the first American to reach the important milestone of completing orbits of the Earth.
For the next 4 hours and 55 minutes, John Glenn completed three orbits of the Earth, reaching speeds greater than 17,000 miles per hour. NASA was still concerned about the effects of spaceflight on humans and this was the longest one an American astronaut had been subjected to yet. John Glenn remarked a number of times during the mission that he felt just fine, and was rather enjoying himself.
Five minutes into the mission:
John Glenn: Oh, that view is tremendous!
John Glenn witnessed three sunsets from space during the flight.
John Glenn: The sky above is absolutely black, completely black. I can see stars though up above.
John Glenn: This is Friendship Seven. At this, MARK, at this present time, I still have some clouds visible below me, the sunset was beautiful. It went down very rapidly. I still have a brilliant blue band clear across the horizon almost covering my whole window. The redness of the sunset I can still see through some of the clouds way over to the left of my course. Over.
From his fantastic vantage point, he observed dust storms and fires in Africa and the lights of Perth, Australia.
And then there was his “fireflies”, which he first noticed at about 1 hour and 15 minutes into the flight:
John Glenn: This is Friendship Seven. I’ll try to describe what I’m in here. I am in a big mass of some very small particles, that are brilliantly lit up like they’re luminescent. I never saw anything like it. They round a little: they’re coming by the capsule, and they look like little stars. A whole shower of them coming by.
They swirl around the capsule and go in front of the window and they’re all brilliantly lighted. They probably average maybe 7 or 8 feet apart., but I can see them all down below me, also.
CAPCOM: Roger, Friendship Seven. Can you hear any impact with the capsule? Over.
John Glenn: Negative, negative. They’re very slow; they’re not going away from me more than maybe 3 or 4 miles per hour. They’re going at the same speed I am approximately. They’re only very slightly under my speed. Over.
They do, they do have a different motion, though, from me because they swirl around the capsule and then depart back the way I am looking.
Are you receiving? Over.
There are literally thousands of them.
These “fireflies”, as Glenn called them after the mission, were later determined to be ice crystals that would accumulate on the craft on the dark side of the Earth and then begin to break off of the capsule when the Sun’s heat returned.
Back on the ground, serious considerations were being made. A flight controller received a warning from a sensor on Friendship, indicating a loose heat shield. If the sensor was correct in its reading, the only thing holding the heat shield in place was the straps from the retrorocket package. After debate, a decision was made; Glenn was instructed to refrain from jettisoning the retropack — a normal procedure for re-entry — in hopes that it would hold the heat shield in place during re-entry; the alternative was the craft and Glenn disintegrating in the Earth’s atmosphere. Control offered no explanation for the procedure until after successful re-entry. Glenn suspected a problem with the heat shield, but remained focused on the parts of the craft he could control.
CAPCOM: This is Texas Cap Com, Friendship Seven. We are recommending that you leave the retropackage on through the entire reentry.
John Glenn: This is Friendship Seven. What is the reason for this? Do you have any reason? Over.
CAPCOM: Not at this time; this is the judgment of Cape Flight.
The sensor ultimately proved to be faulty and the heat shield remained securely attached to Friendship.
Aside from using more fuel than expected for attitude corrections, a hot spacesuit that had to be regularly adjusted for cooling, and excess cabin humidity, the rest of the flight was essentially flawless.
Glenn fired his retrorockets and descended back to Earth. He splashed down in the Atlantic, 40 miles downrange from the expected landing site. The USS Noa reached Friendship seventeen minutes later and hoisted it onto the ship. Glenn was supposed to exit the capsule from the top hatch, but instead decided to blow the side hatch instead. With a loud bang, the hatch blew open and Glenn emerged and jumped to the deck of the Noa. With a smile, his first words were: “It was hot in there.”
Glenn returned to a hero’s welcome and a ecstatic ticker-tape parade in New York City. Americans were energized with the progress in the race with the Soviets. And with John Glenn’s help, America — and mankind itself — took another step forward into the uncharted heavens above.
*This post was originally published February 20, 2011. Small updates have been made since then.
27 years ago today, seven explorers gave their lives in the pursuit of scientific understanding. 73 seconds after lift-off, Challenger broke apart and disintegrated over the Atlantic Ocean.
We remember Michael J. Smith, Dick Scobee, Ronald McNair; (back row) Ellison Onizuka, Christa McAuliffe, Gregory Jarvis, Judith Resnik.
We thank them for assisting in this planet’s quest to reach for the stars.
*This post originally published on January 28, 2011.
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Pioneer 10 and 11 launched in 1972 and 1973, respectively, and were Earthkind’s first explorers of the outer planets and emissaries to deep space. Pioneer 10 became the first spacecraft to pass through the asteroid belt and observe Jupiter up-close, providing us with details of the gas giant’s interior, atmosphere, magnetic fields, and some of the most breath-taking images of Jupiter we had ever seen. Pioneer 11 wasn’t far behind, and after making its own observations of Jupiter, it went on to Saturn to open our eyes to the mighty ringed planet in the same way Pioneer 10 had done for Jupiter. (But this isn’t a story about the accomplishments of the Pioneer program; I’ll save that for another day.)
In addition to all of the data and images sent back, however, those two Pioneers also sent back a mystery. As early as 1980, it was noticed that the spacecrafts were experiencing an acceleration force toward the sun of .000000000874 m/s2 (meters per second, per second). To be clear, this does not mean the Pioneers are heading back towards the Sun. Pioneer 10 and 11 are cruising away from the Sun at a speed of around 132,000 kilometers per hour (82,000 miles per hour) and 175,000 kilometers (110,000 miles per hour), respectively, and this force is 10 billion times smaller than the acceleration we feel from the Earth’s gravitational pull. Nonetheless, the force is real and our instruments and techniques are precise enough to notice.
Many plausible causes were considered to explain the anomaly, including:
perturbations from the gravitational attraction of planets and smaller bodies in the solar system; radiation pressure, the tiny transfer of momentum when photons impact the spacecraft; general relativity; interactions between the solar wind and the spacecraft; possible corruption to the radio Doppler data; wobbles and other changes in Earth’s rotation; outgassing or thermal radiation from the spacecraft; and the possible influence of non-ordinary or dark matter.
In 1994, a thorough, long-term, collaborative study was undertaken to try and solve the anomaly. Initial results from that study were released in 1998, with a detailed analysis following in 2002. All known systematics were tested and calculated, yet that 8.74±1.33×10−10 m/s2 deceleration force remained. The origin of the anomaly was still unaccounted for, though the leading theory was that it was the result of anisotropic thermal radiation (don’t let the big words intimidate you, this just means heat was being radiated from the Pioneers in a certain direction). In 2004, another paper was published, proposing a deep space mission to solve the anomaly once-and-for-all.
But now, that expensive deep-space mission won’t be necessary, according to a paper just submitted by astrophysicist Slava Turyshev and his team of scientists and engineers, with thanks, in no small part, to The Planetary Society and its members.
With funds provided by The Planetary Society, Turyshev and his team were able to collect and compile great volumes of data from the two Pioneer missions. The data had to come from a variety of different sources and came in any number of formats, media, and condition. According to Bruce Betts, Director of Projects at The Planetary Society:
“This was not an easy (or quick) task. These missions lasted for more than 30 years. Imagine all the people, computing formats, and hardcopy and electronic storage devices involved over that period, and you’ll start to get an idea of the problem.”
Think of what you would have to go through if I handed you a 5.25″ floppy disk that contained… well, it couldn’t contain much compared to the amount of data we exchange today, but whatever it was, it was something you needed. Imagine trying to find the hardware to read the disk, and then the intermediary hardware and software that would be required to get the data from the disk onto one of today’s modern machines so you could even utilize it. If you consider how much technology has changed between now and floppy disks, you can only begin to imagine how much it has changed since the 1970s and how cumbersome compiling all of this data, let alone securing it, must have been. I digress.
Once Turyshev and his team were able to assemble the more-complete data picture, they were able to isolate the source of acceleration: that anisotropic thermal radiation. Again, Bruce Betts:
Why was the thermal emission from the spacecraft anisotropic and slowing the spacecraft down? First of all, because the Pioneer spacecraft were spin-stabilized and almost always pointed their big dishes towards Earth. Second of all, because two sources of thermal radiation (heat) were then on the leading side of the spacecraft. The nuclear power sources, more formally Radioisotope Thermoelectric Generators (RTG), emitted heat towards the back side of the dishes. When the dishes reflected or re-radiated this heat, it went in the direction of travel of the spacecraft. Also, the warm electronics box for the spacecraft was on the leading side of the spacecraft, causing more heat to spill that direction. Photon pressure, the same type of thing used in solar sailing, then preferentially pushed against the direction of travel, causing a tiny, but measurable, deceleration of the spacecraft – the Pioneer Anomaly.
At the end of the day, there are a few take-home lessons to be learned. First, Occam’s Razor proved itself once again (some of the suggestions to account for the Pioneer Anomaly were the need to invoke a new type of exotic physics). The second is that you can’t just apply Occam’s Razor and say that anisotropic thermal radiation is the simplest theory and therefore correct, you have to painstakingly collect all of the data needed to prove it — and more importantly, you have to have the experts that are willing to put forth the
years decades of research to solve the mystery. Finally, you take in the account that this was made possible with the help of citizen scientists and those of us that contribute to furthering our understanding of the Universe, through means such as The Planetary Society.
This new paper will undoubtedly generate more discussion about the Pioneer Anomaly and others will work to verify or disprove its results, but at this point it seems pretty safe to say that one of space physic’s mysteries is no more.
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They took rocket-grade kerosene and liquid oxygen, and turned it into 1.5 million pounds of thrust, 32 million horsepower, and made it possible to take the Apollo astronauts to the Moon. I’m talking about the Rocketdyne F-1 rocket engines used in the first stage of Saturn V — the only vehicle to take humans outside of low-Earth orbit.
Following launch, five F-1 engines would burn for about 2-and-one-half minutes, boosting the Saturn V and its payload to an altitude of nearly forty miles, and 55 miles downrange from Cape Kennedy. At that point, the first stage (S-1C) containing the F1 engines would separate from the rest of the Saturn V and fall back to Earth, crashing into the Atlantic Ocean where they would rest forever.
(Image Credit: NASA)
At least, forever was how long we thought they would sit there….
Amazon.com founder, Jeff Bezos, recently announced that a “team of undersea pros” that he funded had found the most famous F-1 engines of all; the ones from Apollo 11 that launched humanity to the Moon, where the first humans would walk on another world. But finding them is just the start, Bezos Expeditions is planning on actually recovering one or more of the F-1s.
“We don’t know yet what condition these engines might be in – they hit the ocean at high velocity and have been in salt water for more than 40 years. On the other hand, they’re made of tough stuff, so we’ll see”, Bezos said in the announcement. He also pointed out that regardless of how long the engines have spent 14,000 feet below the surface of the Atlantic, they are still the sole property of NASA. He also stated that he had requested that NASA make available for display at the Museum of Flight in Seattle, Washington, the second F-1 his group manages to salvage (the first presumably would go to the Smithsonian).
NASA followed the announcement with a press release of their own, in which NASA Administrator Charles Bolden expressed his support for the project, and acknowledged the request to house a second (or the first, if the Smithsonian declines it) F-1 at Bezos’ requested facility.
“NASA does retain ownership of any artifacts recovered and would likely offer one of the Saturn V F-1 engines to the Smithsonian Institution’s National Air and Space Museum in Washington under long-standing arrangements with the institution as the holder of the national collection of aerospace artifacts.
“If the Smithsonian declines or if a second engine is recovered, we will work to ensure an engine or other artifacts are available for display at the Museum of Flight in Seattle, as Jeff requested in his correspondence with my office.”
As of yet, there hasn’t been an announced timeline, cost, or specific details released about the project; however, I personally suspect Bezos will have no problem pulling together the resources needed to tackle the feat.
Bezos ended the announcement with a quote that echoes my own heart when it comes to NASA’s ability to inspire:
NASA is one of the few institutions I know that can inspire five-year-olds. It sure inspired me, and with this endeavor, maybe we can inspire a few more youth to invent and explore.
Good luck, Bezos Industries. Thanks for taking the public treasure that NASA is and multiplying its inspiration for generations to come.
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