Cassini’s Grand Finale

On September 15, one of the most fruitful space missions ever imagined will come to an end. After two decades in space, Cassini’s fuel supplies are close to being depleted. To avoid contaminating one of Saturn’s moons, including a pair that could harbor life–Enceladus and Titan–the decision was made to retire Cassini into Saturn’s atmosphere. Up until contact between the orbiter and Earth is lost, Cassini will continue to study our beloved ringed planet. New insight will be gleaned from this mission that’s only made possible by Cassini’s fatal approach to the gas giant. Among the data to be collected:

  • The spacecraft will make detailed maps of Saturn’s gravity and magnetic fields, revealing how the planet is arranged internally, and possibly helping to solve the irksome mystery of just how fast Saturn is rotating.
  • The final dives will vastly improve our knowledge of how much material is in the rings, bringing us closer to understanding their origins.
  • Cassini’s particle detectors will sample icy ring particles being funneled into the atmosphere by Saturn’s magnetic field.
  • Its cameras will take amazing, ultra-close images of Saturn’s rings and clouds.

Cassini launched on Oct. 15, 1997. After a seven-year journey the orbiter arrived at Saturn, carrying the European Space Agency’s Huygens probe. In 2005, the probe successfully landed on Saturn’s largest moon, Titan.


Quick facts about Titan:

  • Titan is the solar system’s second largest moon.
  • It’s the only moon in our solar system that has cloud systems and a dense, planet-like atmosphere.
  • Titan has liquid hydrocarbon lakes, mountains, and seasonal weather patterns.

For 13 years, Cassini has orbited Saturn and provided us with fascinating information about, not just the planet, but its intricate ring system and many moons.

Cassini mission overview infographic

Cassini mission overview infographic – Click for larger version – Source: NASA/JPL

In addition to the important scientific data that was collected by Cassini, are the breathtaking images that have been collected: storms and aurorae on Saturn, detailed views of the worlds that are Saturn moons, and remarkable visions of Saturn’s sensational rings.

For the next week, we celebrate Cassini’s achievements.

Still from the short film Cassini's Grand Finale, the spacecraft is shown diving between Saturn and the planet's innermost ring.

Still from the short film Cassini’s Grand Finale, the spacecraft is shown diving between Saturn and the planet’s innermost ring. – Credit: NASA/JPL-Caltech

John Glenn’s Orbital Journey

On this day in 1962, 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.

Launch of Friendship 7

Launch of Friendship 7, the first American manned orbital space flight. Astronaut John Glenn aboard, the Mercury-Atlas rocket is launched from Pad 14. / Source: NASA

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!

View of Earth from Friendship 7

View of earth taken by Astronaut John H. Glenn Jr. during his MA-6 spaceflight. / Source: NASA

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.

Sunset from Friendship 7

Orbital sunset photographed by Astronaut John H. Glenn Jr. aboard the \”Friendship 7\” during his Mercury-Atlas 6 (MA-6) flight. / Source: NASA

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. 1

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. 2

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.”

Astronaut John H. Glenn Jr. in his Mercury spacesuit

Astronaut John H. Glenn Jr. in his Mercury spacesuit. / Source: NASA

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.


  1. In fact, it was solved during the next Mercury mission, Aurora 7, by Scott Carpenter. To test his theory, he banged on the side of the capsule and watched as they broke off of the exterior of the craft!
  2. And it provided a nice fireworks show for Glenn during re-entry. “My condition is good, but that was a real fireball, boy. I had great chunks of that retropack breaking off all the way through.”

NASA's State of the Solar System

Here’s an excellent infographic that details NASA’s current Solar System (and beyond!) spacecraft missions. It lists every craft NASA out exploring various bodies and their current status.

Click the image to make it a little bigger.

State of the Solar System infographic

State of the Solar System infographic

(Via)

 


Alien Footprints

Ever wondered about the track’s humanity has left on other worlds? If so, you’ll probably appreciate this infographic from Karl Tate and Space.com.


View the list of extraterrestrial vehicles and distances traveled on other worlds.

Source Space.com: All about our solar system, outer space and exploration

It’s a fairly intuitive image, so there’s not a lot I need to say. I’m jealous of the miles of tracks that were laid down by the Apollo astronauts in their moon buggies. Could you imagine?

I hope to live long enough to see just as many human-driven miles on Mars.


The Corned Beef Sandwich Incident

Today marks the anniversary of one of NASA’s more “corny” moments. It was on this day in 1965 that… well, let me explain:

Project Gemini was the bridge between the Mercury and Apollo NASA space programs. Mercury proved NASA had the capability to put humans into Earth orbit, and Gemini set out with a new set of goals, including: putting multiple astronauts into orbit aboard the same craft, learning how to walk in space, practicing rendezvous and docking between crafts, and testing the influence of long-term spaceflights. All of these were necessary to begin the Apollo program with its goal to put a man on the Moon (and bring him back home safely!) before the end of the decade.

Gemini 3 Mission Patch

Gemini 3 Mission Patch / Source: NASA

Following two unmanned Gemini missions, Gemini III was the first manned mission in the program and carried Command Pilot Virgil I. “Gus” Grissom and Pilot John W. Young. Gus Grissom became the first human to fly into space twice, while John Young took his rookie flight.

The Gemini III capsule1 orbited the Earth three times on March 23, 1965, over the course of just under five hours.

Then, at 1 hour, 52 minutes, and 26 seconds into the mission… it happened.


Grissom: What is it?
Young: Corn beef sandwich.
Grissom: Where did that come from?
Young: I brought it with me. Let’s see how it tastes. Smells, doesn’t it?
Grissom: Yes, it’s breaking up. I’m going to stick it in my pocket.
Young: Is it?
Young: It was a thought, anyway.
Grissom: Yep.
Young: Not a very good one.
Grissom: Pretty good, though, if it would just hold together.


John Young, through the aid of fellow astronaut Wally Schirra, had smuggled aboard a corned beef sandwich. Young and Grissom shared a few bites, but it began to crumble and little bits of it began to float around inside the capsule. It was quickly stowed away to prevent the pieces from shorting out any sensitive electronic equipment.

After Gemini III returned to Earth, Young, Grissom, and Schirra, and NASA caught flack for the incident from members of Congress that were looking for an excuse to cut agency funding.

Young elaborated in his 2012 memoir, Forever Young: “A couple of congressmen became upset, thinking that, by smuggling in the sandwich and eating part of it, Gus and I had ignored the actual space food that we were up there to evaluate, costing the country millions of dollars.”

A Congressional Committee even held a hearing over the ordeal.

According to CollectSpace.com: Congressman George Shipley of Illinois explained his concerns to NASA administrator James Webb, associate administer for manned spaceflight George Mueller and director of the Manned Spacecraft Center (now Johnson Space Center) Robert Gilruth, during the hearings: “My thought is that … to have one of the astronauts slip a sandwich aboard the vehicle, frankly, is just a little bit disgusting.

The reply came from Mueller:

“We have taken steps … to prevent recurrence of corned beef sandwiches in future flights.”

Gemini 3 Crew: John Young (L) and "Gus" Grissom (R)

Gemini 3 Crew: John Young (L) and “Gus” Grissom (R) / Source: NASA



And there you have it: the story of the first corned beef sandwich in space. Sometimes a sandwich is just a sandwich, and other times it threatens humanity’s greatest space program.

(This post was originally published on March 23, 2011. It has been slightly modified from its original version.)


  1. Nicknamed by Grissom, “Molly Brown”, after a popular Broadway musical, “The Unsinkable Molly Brown”. NASA PR was originally not impressed with the nickname, but backed off any attempts to ditch the moniker when they discovered Grissom’s back-up name for the capsule was “Titanic”.

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”

GRAIL: Ebb and Flow

Artist's Rendition of Grail Mission

Image credit: NASA/JPL-Caltech

Earlier this month, I gave a minor overview of NASA’s Gravity Recovery And Interior Laboratory (GRAIL) mission. I had mentioned that the two mirror-twin spacecraft that make up the mission were currently — and temporarily — dubbed GRAIL-A and GRAIL-B, with official names coming later in the month. Beginning last October, NASA appealed to elementary students to come up with replacement names for the spacecraft.

Over 11,000 students, from 45 states and several territories, participated in contest, making for stiff competition.

Ultimately, it was the 4th Grade students from Emily Dickinson Elementary school, in Bozeman, Montana, who were chosen as the nationwide winners of the naming competition, with their names of Ebb and Flow. The students arrived at their name by researching what the GRAIL mission was studying and how it worked. They learned how important the Moon is to our lives on Earth, and how the Moon’s gravity causes our high and low tides. They decided on Ebb and Flow, because the names represent both the Moon’s gravity and its effects on our home.

Congratulations Emily Dickinson 4th-Graders! Not only did you come up with great contest-winning names, you came up with names that will forever exist in the historical pages of the world’s exploration of space!

For more about GRAIL, check out these links:


Neil deGrasse Tyson on The Daily Show

Astrophysicist, and renowned promoter of science, Neil deGrasse Tyson, sat down for an interview on The Daily Show with John Stewart. As always, Neil’s commentary drips of a passion for discovery and exploration. Science and comedy mix well!

The Daily Show with Jon Stewart


The Phobos-Grunt Has (Crash) Landed

Phobos-Grunt Mission Poster
[Phobos-Grunt official mission poster. Click for large size.]
(Image Credit: Credit: Roscosmos ( Russian Federal Space Agency)/IKI)

As expected, the failed Russian spacecraft Phobos-Grunt came screaming back to Earth, breaking apart during its collision with our atmosphere, and landing somewhere near 700 miles West of Chile in the Pacific Ocean yesterday.

While the Russian Federal Space Agency, commonly referred to as Roscosmos, has not yet reported any visual observations of debris impact, they were able to note the point it disappeared from orbit.

The 13+ ton craft, most of its weight owing to the onboard fuel that would have taken it to Mars’ moon, Phobos, was one of the larger to return to Earth after failure.  It isn’t currently known — and it may well never be — how much of it burned up in the atmosphere and how much made it to the Pacific — and then, how large those pieces were and what they were composed of. Tthe best case scenario is that all of the fuel burned up in the atmosphere.

Now, the focus will be on what went wrong, which is turning into a drama of its own with Russian officials suggesting that its failure was the result of Russian “anti-heroes” or a secret US military facility in Alaska (HAARP, I presume) purposely disabling the craft from the ground.


Follow-Up on Phobos-Grunt

Following up on a previous story about the failed Russian space probe, Phobos-Grunt, all hope of reviving the craft has been eliminated. Phobos-Grunt is expected to fall back to Earth by the end of this month. The only real questions remaining are when, where, and what might survive re-entry.

Phobos-Grunt

Phobos-Grunt / Image Credit: ESA

It is not uncommon for spacecraft to re-enter Earth’s atmosphere, even uncontrolled (which to a degree, they all are). Disintegration upon re-entry is one of the space industry’s most popular disposal methods for decommissioned and defunct satellites and spacecraft. However, they generally aren’t carrying the amount of fuel that Phobos-Grunt has on board. Most of its 13 tons of weight is fuel — hydrazine and nitrogen tetroxide stored in aluminium tanks. Since fuel tanks are generally specifically designed to withstand extreme pressure and heat, they often survive re-entry; however, the Phobos-Grunt tanks were constructed out of aluminium, which is not only cheaper, but has a lower melting temperature than other common materials. Aside from the fuel, there is also a small amount — less than 10 micrograms — of radioactive Cobalt-57, but such a small amount does not pose any significant problems.

According to Holger Krag, deputy head of the European Space Agency’s Space Debris Office, at the European Space Operations Center in Darmstadt, Germany, the chances of anyone seeing the re-entry, let alone be impacted by any of the debris from Phobos-Grunt, is very low.  With more than 70% of our planet covered in water,  odds are that any debris surviving re-entry will end up in an ocean.

“Relax,” Krag said. “The likelihood of somebody being hit is enormously low. It is way smaller than to be struck by lightning. If you have a thunderstorm above your city you would also not worry too much.”

To sort of sum it all up, Phobos-Grunt will soon be toast. If you’re very lucky, you might see a spectacular light show. It will probably not land on your head.

Though, there were some positive aspects to come from the failure. For example, the re-entry is a new target for the Inter-Agency Space Debris Coordination Committee, which is “an international governmental forum for the worldwide coordination of activities related to the issues of man-made and natural debris in space”.  The more debris we add to Earth orbit, the more important it is to be able to track and deal with the potentially-devastating material; so any “practice” that Phobos-Grunt will provide would be useful.

Additionally, the failure of Phobos-Grunt provided an opportunity for various nations and agencies, as well as professionals and amateurs, to work together on trying to revive the craft, track its orbit, and now chart its re-entry. Information was shared between all of the interested parties and there was much collaboration and cooperation; all of which is important if we are to have a global recognition of the importance of space exploration and the global initiative to work together to continue exploring.