Only 12 men have had the honor of walking on the moon, but six astronauts were in charge of getting them there and bringing them home safely. These were the command service module pilots, whose job it was to circle the moon and return to Earth - without setting a foot on the lunar surface.

These six people are often overshadowed by the moonwalkers. Their stories are worth telling, though, especially in honor of the upcoming 40th anniversary of the first lunar landing.

The first CSM pilot is the most famous. Michael Collins flew on the Apollo 11 mission, carrying Neil Armstrong and Buzz Aldrin to the moon for the first lunar landing. He circled the orb for nearly a day in solitude. For 48 minutes out of each orbit he was out of radio contact with Earth.

In his autobiography, Collins wrote "this venture has been structured for three men, and I consider my third to be as necessary as either of the other two." He also said he never felt lonely, but "awareness, anticipation, satisfaction, confidence, almost exultation."

Richard Gordon, commander of the Yankee Clipper – the Apollo 12 CSM, was the second to orbit the moon while others walked on the surface. While he circled, he mapped out potential landing sites for future missions. He was slated to walk on the moon in the Apollo 18 mission, but that mission was canceled.

Stuart Roosa spent 33 hours in orbit during Apollo 14. His skill as the CSM pilot was needed after initial attempts to dock with the lunar module failed.

Alfred Worden was listed in the Guinness Book of World Records as the “most isolated human being” while he was orbiting the moon during the Apollo 15 mission. When the Endeavour was at its greatest distance from the lunar crew, Worden was 2,235 miles away from any other human being.

Ken Mattingly is probably well known for his actions on the ground of the ill-fated Apollo 13 mission, but he finally did get to go to the moon for the Apollo 16 launch. Mattingly used instruments aboard Casper to map a stretch of the lunar surface all around its equator.

The final mission, Apollo 17, put Ronald Evans in control of the command module, America. Evans holds the record of more lunar time in orbit than anyone else: 147 hours, 48 minutes.

Each of these men spent countless days training next to their more-heralded moonwalker colleagues. Yet, while their capsule brethren actually touched another heavenly body, these brave astronauts could only stare out their window and marvel at the view.

– Larry Frum

Okay, that headline is the only joke in this post about turning astronaut waste into drinking water.

So please get the "yuck" factor out of your system and read on.

Among tons of equipment that the space shuttle Endeavour hauled to the International Space Station (ISS) is a new water-purification system that recycles everything - humidity, condensation, sweat and yes, even urine - into purified drinking water.

(CNN's intrepid space correspondent Miles O'Brien sampled an earth version of the H20 during his coverage of Endeavour's launch on Friday. Other than a hint of an iodine aftertaste.... he pronounced it OK.  Miles did several live shots on CNN TV, and eventually finished the bottle.)

The WRS, or water recovery system, includes two refrigerator-sized racks packed with a distiller and filters.

"We use some traditional technology, such as filtration systems, but some of the technology is unique to our operation, like working without gravity," said Bob Bagdigian of the Marshall Space Flight Center in Huntsville, Alabama. He's the project manager for NASA's Environmental Control Life Support System (ECLSS).

Each crew member on the ISS uses just under a gallon of water a day. Water is needed for drinking, brushing teeth, flushing toilets, showering, and washing hands, clothes and dishes. About two thirds of that water now comes from Russian Progress resupply vehicles, the European Space Agency's Jules Verne automatic transfer vehicle, and NASA space shuttles. The remaining third comes from a small water processor on the Russian side of the station. That system captures sweat, and other water vapor in the air as it passes through the air-conditioning system, filtering it and turning it into drinkable water.

With the planned doubling of the station crew from three to six, there's a need to look for more efficiency in handling supplies - especially water, that is plenty heavy and therefore plenty expensive to bring up from the ground.

Any long-term outpost on the moon or Mars will have no choice but to recycle liquids. So it made sense that an early version of such a system be tested on the space station. If this system works as planned, it should cut the need for water delivery by 65 percent, producing 6,000 pounds of potable water each year.

The environmental team at Marshall in Huntsville, Alabama, does more than just water purification. These microbiologists, chemists, materials, chemical, mechanical, and software engineers are part plumbers, part HVAC workers and part environmental police for the space station crew. Their systems do everything from providing oxygen and potable water to removing carbon dioxide from the cabin air and maintaining cabin temperature and humidity levels.

So how sure will the station residents be that the water is fit for human consumption?

They won't drink a drop until several samples have been flown back to Earth and are tested and re-tested.

The purification technology design also has provided assistance on Earth. Similar equipment has been used in aid centers after earthquakes in Iraq and Pakistan, said Bagdigian.

Does Bagdigian, trained as a biologist and chemical engineer, ever get tired of the bathroom humor?

He laughed. Non-scientists, especially kids, can identify with such a basic human function, he said.

"Everybody is interested in living in space and how that is going to become a reality."

–Marsha Walton, Producer, CNN Science and Technology

Dozens of bloggers kept their thoughts flowing during the countdown to the launch of Endeavour on Friday. Only one person did it from Firing Room 3 of the Launch Control Center at the Kennedy Space Center.

Steve Siceloff in the Firing Room the day before the launch of STS-126. His Endeavour launch blog Friday was the first written from this nerve center of the countdown. NASA photo

“It’s a great environment. The only better seat would be on the shuttle itself,” said Steve Siceloff, public affairs web writer at KSC.

Bloggers around the world got much of their countdown information from Launch Commentator Candrea Thomas on NASA TV.

Siceloff had a lot more raw information to process.

“I’m listening to eight different audio loops. That takes some training of its own,” he said.

The rocket scientists talking on all those other channels are monitoring the orbiter, three main engines, an external fuel tank, two solid rocket boosters, and oh, a couple million other parts.

So what’s the atmosphere in the firing room?

“It’s actually very calm. Everybody’s into their books and into their own world. They’ve all got headsets on so they don’t talk loudly,” he said.

Siceloff, who says he’s been a space geek since he was a kid, used to cover NASA for the Fort Pierce Tribune and Florida Today.

He’s been blogging, writing and producing for the NASA web pages for a year and a half.

Endeavour’s launch blog got underway at 2:30pm. For the most part, it was a very quiet countdown.

“The launch team is working no technical issues” was a very common refrain on NASA TV.

But about 15 minutes before the scheduled 7:55pm eastern launch, we “civilians” in the NASA press room suddenly displayed the loud, rough, somewhat chaotic personality of most newsrooms.

There were a few words on NASA TV about a technical issue. Something about a door not being latched.

After miles of checklists and a near flawless countdown, could an open door stop this launch?

Here’s how Siceloff handled that first flare of a problem on the launch blog:

7:40 p.m. – Launch controllers are discussing a potential issue with a door in the White Room. There is concern whether the door has been pinned back. The door in question is not on Endeavour.

(The White Room is an environmental chamber that mates with the orbiter, where the Closeout Crew assists the astronauts in boarding and getting strapped into their seats on the shuttle.)

While scores of us in the press room were on the phone with our editors with a “Danger Will Robinson… this COULD be a showstopper” tone in our voices, Siceloff said the scene was far more serene in the Firing Room.

“It was very calm, very confident, very thorough. I never heard anyone on a loop sound excited,” said Siceloff. His next entry:

7:46 p.m. – T-9 minutes and counting . . . Launch controllers have cleared the door issue, saying it does not pose a hazard to Endeavour as it climbs away from the launch pad. All launch teams are go for launch.

So do rocket scientists ever get excited?

“When the shuttle clears the tower, there’s a whole lot of clapping,” said Siceloff.

And yes, said Siceloff, the stuff they say about rocket scientists is true.

“They really are the smartest people in the world,” he said.

By Marsha Walton, CNN Science and Technology Producer

As the shuttle Endeavour pursues its expansion and re-supply mission to the International Space Station, the political world still turns nearly 200 miles below. Will a President Barack Obama and a fractured economy spell change for NASA and space exploration?

The space shuttle Endeavour blasts off successfully Friday night.

The agency's $17 billion annual budget - about a third of which goes to fund the shuttle and other space missions  – may be under scrutiny, along with everything else, in our new financial climate.

On the campaign trail this year, Obama said, "We cannot cede our leadership in space.  That's why I'm going to close the gap, ensure our space program doesn't suffer when the shuttle goes out of service."

But skeptics raise multiple questions, starting with the fact that the president-elect made that statement in the heat of a tight campaign and in NASA's Florida backyard. It wouldn't be the first time that a president abandoned a lofty promise to reach for the stars.  In his 2004 State of the Union speech, President Bush announced an ambitious effort for manned missions to the Moon and Mars.   But the money never came through, and it's rarely been mentioned since.

With the shuttle slated for retirement in 2010, how long will it take to get the replacement vehicle ready?  Many think the 2015 deadline for the Orion craft and its Ares rocket is too rosy.

Can we afford it?  NASA's budget is only about two-thirds of one percent of the Federal budget, but is it high enough on our national priority list?

And just what are we getting back for our dollars?  Is the science we're getting from the Shuttle and the ISS going to pay for itself?

Proponents say it would be shortsighted to ditch our science and exploration efforts because America can't afford to fall farther behind in tech and science literacy.

To be sure, NASA's had its triumphs and tribulations in recent years.  On the down side, there's been uncertainty over the shuttle, the Columbia disaster, a couple of failed Mars missions, the earth-bound controversy over political censorship of the agency's climate scientists and NASA's first successful launch into the tabloid world with last year's bizarre astronaut love-triangle story.  

NASA's victories, however, are unmistakable:  The Hubble Space Telescope has led what's now routinely called "The Golden Age of Astronomy;" the Mars Rovers' unexpected five years of service; and groundbreaking research in space, on land, and in the oceans.

So let's hear from you:  What should the Obama Administration do?  Has NASA earned our continued support?  Does the mission need to be corrected?  Or should we put the money elsewhere?

Watch CNN's Situation Room Monday at 5 p.m. ET for a report from Miles O'Brien on Obama and the future of space policy.

And you can read the Obama campaign's space policy here.

– Peter Dykstra, Executive Producer, CNN Science, Technology, and Weather

Workers at the Kennedy Space Center will roll the space shuttle Endeavour from launch pad 39B to 39A Thursday in advance of a mission to the International Space Station targeted for November 14.

Space shuttles Atlantis, left, and Endeavour on their launch pads last month.

Endeavour has been undergoing preparations for launch on pad 39B for the past month. For a time, it was second in line for launch behind Atlantis on pad 39A, which had been scheduled to fly the fifth and final Hubble Servicing Mission this month.

A Hubble mission carries additional risk because astronauts cannot take refuge in the space station in the event of Columbia-style catastrophic damage to the orbiter on lift-off. So before the final Hubble mission was approved, NASA managers decided it would only be safe to fly if a rescue vehicle was prepared and ready to launch on very short notice. Endeavour was to have been that rescue vehicle.

The Hubble launch was postponed in late September due to a computer failure on the telescope. Mission managers now want to replace that computer - but the spare needs to be prepared for flight, and the astronauts need time to train on how to do the replacement. The Hubble mission is now scheduled to fly no earlier than February. Workers rolled Atlantis back from pad 39A to the vehicle-assembly building on Monday.

Launch pad 39B, where Endeavour is currently located, it being modified to launch NASA’s next generation of manned spacecraft called Orion. While it is still technically possible to launch a space shuttle off 39B, NASA would prefer to keep the modification work underway – which is not possible when there is a shuttle parked there. So the launch team has opted to move Endeavour from 39B to the now empty 39A, and allow the construction work on 39B to resume.

Endeavour’s crew, led by Commander Chris Ferguson, will carry up additional equipment and supplies to the space station that will make it possible to expand the station crew from three to six people next year.

Spacewalkers will also work on a malfunctioning rotator joint on the left side of the station that is designed to rotate and track the sun. It has been out of commission for the last year, and complete repairs will continue into 2010. But station engineers hope the Endeavour astronauts can make it functional again.

–Kate Tobin, Sr. Producer, CNN Science & Technology

A Soviet space shuttle has finally landed in a museum.  After a long history and a virtual world tour, a Shuttle Buran was put on permanent display to the public on Friday at the "Technik Museum Speyer" near Manheim, Germany.

Photo: Aaron Cooper, CNN

When you first walk into the Buran building you could easily mistake the shuttle for its American counterpart.  It looks almost identical to NASA's fleet, but the museum points out it's not just a Soviet copy.  They explain the similarities saying both design teams were governed by the same laws of physics, had similar goals, and Soviet designers drew on NASA's publicized research but the end products were substantially different.

The Technik Museum already had a large collection (everything from a Boeing 747 mounted high in the air, to a Cold War U boat, fire trucks, typewriters and model trains) but museum director Hermann Layher dreamed of adding a space shuttle.

The U.S. shuttles are still in use, but the Soviet Union's Buran shuttles were mothballed when funding was cut shortly after the collapse of communism.  Only one had ever been launched (unmanned in 1988), but that was destroyed in 2002 when its hangar collapsed.

One of the test models was available.  Buran OK-GLI, like the U.S. Space Shuttle Enterprise, was built to test aerodynamics for landings.  Unlike it's American counterpart the OK-GLI had 4 jet engines attached to its tail so it could take off for its test flights (the Enterprise had to be carried aloft by a Boeing 747.)

The Buran OK-GLI had been displayed at the 2000 Olympics in Sydney, then was taken to Bahrain to be exhibited, but got mired in a legal battle between its owners and the exhibitors.  The Technik Museum was able to buy it and after a long legal battle brought it to Germany.  It was first shipped by sea, then pushed on barges up the Rhine River to the city of Speyer.

In all the museum spent about 10 million Euros (about 15 million dollars) to buy the shuttle, bring it to Germany, and put it on display in it specially built hangar.  Friday a steady stream of museum visitors, including me, flooded into that hanger to see exactly what a Soviet space shuttle looks like.

–CNN Producer Aaron Cooper in Speyer, Germany

7PM UPDATE:  NASA just held a teleconference for reporters to discuss the Hubble mission delay.  The basic facts we gave you earlier in the day still hold up.  The part that has failed is called the Control Unit/Science Data Formatter.  There is a replacement part housed at the Goddard Space Flight Center, where Hubble operations are based.  The Hubble team will be putting that part through a series of tests to make sure it is operational and ready to fly, and they say they are confident it will pass.   If all goes as planned, Atlantis could be ready to fly by mid-February.

The Hubble Space Telescope. Source: NASA

In the mean time, the Space Shuttle Program will be making forward plans over the next couple of weeks.  Most likely, they will decide to remove the Hubble payload from Atlantis and eventually roll that shuttle back to the Vehicle Assembly Building.  Endeavour would then move to launch pad 39A and could be ready to launch as soon as November 14.

4PM UPDATE:    NASA has confirmed the launch will be delayed.   A new launch date has not been announced, but it will likely slip to January or February 2009.

Regarding the malfunctioning computer on the telescope: for an unknown reason, the principal channel on the on-board scientific data download system stopped working over the weekend.  Efforts to troubleshoot the problem have failed.  Later this week, telescope operators will try to activate a redundant downlink channel.  That "B-side" channel has never been switched on in orbit - it was last activated during ground tests in the late 1980's or early 1990.  Even it it works, the computer system will be left without redundancy.  Scientists and engineers will need time to study the problem, and determine whether that system can be replaced during the upcoming mission.  It would also take time for engineers to configure replacement hardware for flight, and for astronauts to train for a removal and replacement task.

Sources tell CNN the space shuttle Atlantis mission to conduct the fifth and final servicing mission for the Hubble Space Telescope will very likely  be delayed until early next year.

An additional technical problem has cropped up with the telescope's on-board scientific data downlink computer. Scientists and engineers will need time to study the problem, and determine whether additional repair tasks will be added to the mission.

Atlantis has been targeted for launch October 14. The next shuttle mission in the queue is a shuttle Endeavour mission to the International Space Station. It is currently targeted for launch on November 16.

–Kate Tobin, Sr. Producer, CNN Science & Technology

Discovery glided to a perfect landing under blue skies at the Kennedy Space Center in Florida today.    Commander Mark Kelly put her down right on the center line of Runway 15 at the Shuttle Landing Facility, wrapping up a 5,332,723 million mile journey that began on May 31.  During their two week visit to space, they installed the main component of the Japanese Kibo Laboratory onto the orbiting outpost.

This was:

-the 123rd shuttle flight

-the 35th flight of Discovery

-the 26th shuttle mission to the International Space Station

-the 10th post post-Columbia mission

-The 98th post-Challenger mission

-There will be 10 more missions before the fleet is retired in 2010

Mark your calendars for the next shuttle mission, currently targeted to launch October 8.  Astronauts will pay a final visit to the Hubble Space Telescope to switch out stabiizing gyroscopes and install  some new instruments that will hopefully keep the Hubble operational into the next decade.

–Kate Tobin, Sr. Producer, CNN Science & Tech

Discovery will be coming home to the Kennedy Space Center in Florida at 11:15am Eastern time this morning.

Entry Flight Director Richard Jones has just given the "go for deorbit burn" call...meaning the Discovery astronauts will fire the engines at 10:10am Eastern this morning to slow the the spacecraft for atmospheric re-entry.  The approach path will bring it over the Pacific Ocean, the Yucatan Penninsula, the Gulf of Mexico, Naples, Florida, Lake Okechobee, and then into the KSC region.  The plan is for Commander Kelly to land on Runway 15 at the Shuttle Landing Facility.  Miles O'Brien talked to Kelly about it, and, all things being equal, Kelly prefers that runway.   That approach involves a series of left turns, which provide the pilot with better visibility coming in.

Miles will be covering the landing live on CNN starting about 11:10am - tune in and join us!

–Kate Tobin, Sr. Producer, CNN Science & Tech

Let's say you see a star where there wasn't one five minutes ago.  And it's moving.   And it's definitely not a plane.  

You may be looking at the International Space Station, or, after its docking today (Monday), the Space Shuttle and ISS together.

NASA operates a site that can show you the location of the two  - and when you might be able to catch a fleeting glimpse of them from your own yard:  Just add clear skies, darkness, and a relative absence of bright city lights

The ISS Viewing Schedule comes with an applet where you can enter your location or ZIP code, and you'll get the time and date of when to look, along with the location in the sky of where to look.    The next one for my home outside Atlanta is June 3 at 10:51pm.

Peter Dykstra   Executive Producer   CNN Science and Tech