Bill Ingalls / NASA

The prototype space shuttle Enterprise is seen mated on top of NASA's modified Boeing 747 Shuttle Carrier Aircraft at Dulles International Airport in Virginia on Friday. Enterprise was the first orbiter built for the space shuttle program, but never went into orbit. It was used primarily for ground and flight tests within the atmosphere. Enterprise had been on display at the Smithsonian National Air and Space Museum's Udvar-Hazy Center in Virginia, but is now being prepared for its new home at the Intrepid Sea Air and Space Museum in New York.

A day after the space shuttle Discovery took its place at the Smithsonian, the prototype shuttle Enterprise is perched on a modified 747 jet for its journey to New York. Now the timing of the trip depends on East Coast weather.

Overnight, Enterprise was towed out to Dulles International Airport and hoisted up into the air with two giant cranes. The jet, known as the Shuttle Carrier Aircraft or SCA, was brought underneath the 75-ton artifact. Then Enterprise was lowered down and "soft-mated" onto the plane at three attach points. The bolts will be tightened down for hard-mating on Saturday, in preparation for the big flight to New York.

This is the same process that Discovery went through in Florida leading up to Tuesday's flight to Dulles for its installation at the Smithsonian National Air and Space Museum's Steven F. Udvar-Hazy Center, next to the airport. On Thursday, Enterprise was moved out of the space it held since the center's opening in 2003, and Discovery was moved in.

NASA had been planning for Enterprise and the SCA to take off from Dulles as early as Monday morning, but this afternoon the space agency said the flight would be delayed due to a forecast of inclement weather in Washington as well as New York. "Managers will continue to review weather forecasts and announce a new flight date as soon as practical," NASA said in its advisory.

When forecasters give the go-ahead, the shuttle-jet combo will head up the East Coast and do a series of New York flyovers. You can expect to see the double-decker behemoth sailing over the Statue of Liberty as well as the Intrepid Sea, Air and Space Museum, the retooled ship where Enterprise will be put on display. After the flyovers, the Enterprise will be set down at New York's John F. Kennedy International Airport.

The shuttle-jet flight is old hat for Enterprise: The craft was the first vehicle built for the space shuttle program, and got its name in part thanks to a write-in campaign by "Star Trek" fans. Unlike the fictional starship, NASA's Enterprise never flew in space. Instead, it was used for ground tests as well as aerodynamic test flights atop the 747 carrier plane. Once the shuttle launches ramped up, Enterprise was deemed no longer needed for testing. It was handed over to the Smithsonian in 1985. The Udvar-Hazy Center's James S. McDonnell Space Hangar was specifically designed to show off the Enterprise.

After the 2003 Columbia tragedy, some sections of the Enterprise's wing panels were removed for impact tests, and those tests made a huge contribution to the accident investigation. That demonstrated that the shuttles can continue to benefit the space program long after their retirement.

It will take a few weeks for Enterprise to settle into its retirement home: The cranes will have to be set up for the shuttle's "demating" at JFK. Then Enterprise will have to be lifted onto a barge and brought up the Hudson River by a tugboat. The schedule calls for Enterprise to be hoisted aboard the Intrepid's flight deck sometime in June. It'll be put on display in a temporary climate-controlled pavilion this summer, and eventually housed in a permanent exhibit facility.

After Enterprise, there's one more shuttle-jet flight on tap: the transfer of Endeavour from NASA's Kennedy Space Center to the California Science Center in Los Angeles. That cross-country trip, due to take place in the latter part of this year, is likely to spark a nationwide frenzy of "Spot the Shuttle" sightings.

The last shuttle that flew in space, Atlantis, is going just down the road to Kennedy Space Center's visitor center, so there'll be no need to bring out the plane for that trip.

For more pictures of the Enterprise-747 mating, check out NASA Headquarters' Flickr gallery. And to get updates on the timing of Enterprise's flight and the flyovers, keep tabs on NASA's website as well as msnbc.com's space news section.

More about the shuttle shuffle:

• Astronauts revisit the shuttle's pros and cons
• How NASA selected the shuttles' future homes
• Seattle gets first pieces of shuttle trainer

Updated 5:20 p.m. ET.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

Mark Wilson / Getty Images

Retired senator-astronaut John Glenn is surrounded by other space veterans in front of the space shuttle Discovery during its handover to the Smithsonian at the Udvar-Hazy Center in Chantilly, Va., on Thursday. Glenn says the shuttles were "prematurely grounded" but accepts the shuttle program's end.

For some veteran astronauts, today’s transformation of the shuttle Discovery into a museum exhibit is a cause for celebration. For others, it’s a reminder of their regrets. But for John Grunsfeld, the one-time “Hubble Hugger” who is now NASA’s science chief, the dominant feeling is a sense of relief.

Discovery's handover to the Smithsonian's National Air and Space Museum has re-ignited questions about the end of the 30-year space shuttle program. Why did they have to be retired? The short answer is that in the wake of the 2003 Columbia tragedy, policymakers decided that once the job of building the International Space Station was finished, it would just be too risky and expensive to keep the shuttles flying.

Instead, President George W. Bush decided to re-target the space program on destinations beyond Earth orbit. For Bush, the first focus was going to be the moon. President Barack Obama shifted that initial focus to near-Earth asteroids, but the endpoint is the same: eventually getting to Mars. And the shuttles could never do that. They weren't built to go beyond Earth orbit.

Nevertheless, some of America's best-known astronauts think the shuttles should have been kept around a while longer — particularly because NASA will be dependent on the Russians for rides to the space station for the next three to five years.

'Unfortunate decision'
"The unfortunate decision eight and a half years ago to terminate the shuttle program, in my opinion, prematurely grounded Discovery and delayed our research," retired senator-astronaut John Glenn said during today's handover ceremony at the museum's Steven F. Udvar-Hazy Center in Virginia.

Another retired astronaut who rode on Discovery, Tom Jones, voiced similar frustration during an interview conducted before today's ceremony. "I'm reliving the disappointment that the shuttles are retiring without a rapid successor," he told me.

Jones wishes that the White House and Congress had revved up NASA's plan for new spaceships capable of going to the space station and beyond: the Constellation Program, which initially aimed to put U.S. astronauts back on the moon by 2020. Instead, Constellation was so cash-starved and technically challenged that the Obama White House scrubbed the program and reworked elements of it into the current plan to visit an asteroid by 2025.

"We dropped the ball on this," Jones said. "If we just went from 0.5 percent of the federal budget to 0.6 percent, this would all be a non-issue."

The benefit of retaining an American system for resupplying the space station is what motivated Glenn's call to keep the shuttles flying. Glenn made his pitch to the White House in 2010 — but Obama didn't go for it, and the former Democratic senator told me today that he accepts the verdict.

"No need crying over what happened in the past," Glenn said. "Let's get on with the future."

The 'Hubble Hugger' and his pin
Grunsfeld thinks the White House made the right call, at least on the question of grounding the shuttles. He's best-known for his role as a spacewalker on Hubble servicing missions in 1999, 2002 and 2009. During that last mission, Grunsfeld was the one who bade the Hubble Space Telescope goodbye forever. Now he's NASA's associate administrator for science. The way Grunsfeld sees it, keeping the shuttles flying might have led to another disaster like the 1986 Challenger explosion — or the loss of Columbia and its seven STS-107 crew members in 2003.

"There's a possibility we could have flown them for a little bit longer, or extended them at some cost," Grunsfeld told me. "I'm actually extremely thankful that we are rolling Discovery into the Air and Space Museum, and not burying its parts. We flew out the space shuttle program gracefully. We didn't lose another one. It would have been tragic. The fact is that the space shuttle program was ended with dignity — it was an amazing accomplishment, and I'm just thankful for that."

Then he shared what he called a "small, personal story."

"Just this morning, on my flight suit for the first time since the loss of Columbia, I took my STS-107 pin off. I felt like this was an apt celebration, that we flew out the program safely after Columbia, and that affected me very deeply," Grunsfeld said. "Now that we are where we are, I'm looking forward to getting the next space vehicle going."

The end ... and the beginning
Retired astronaut Eileen Collins, who became NASA's first woman shuttle pilot during a 1995 mission on Discovery and went on to command shuttle missions in 1999 and 2005, has some firsthand knowledge about the risks associated with flying the shuttles.

The 2005 mission on Discovery marked NASA's "return to flight" after the Columbia tragedy. She and most other people at NASA had thought they had solved the foam-loss problem that led to the Columbia's doom — but mission managers were shocked to see that the fuel tank shed a substantial piece of foam insulation during Discovery's ascent. No significant harm was done, but it took another year for NASA engineers to rework the problem to their satisfaction.

This week, retired NASA shuttle manager Wayne Hale recounted the episode in a blog item headlined "How We Nearly Lost Discovery."

Today, Collins noted that each shuttles was originally designed to fly for 100 missions or 10 years, whichever came first. Discovery, the most traveled of the shuttles, flew 39 missions ... over the course of 28 years. She recalled that she agreed with the shuttle retirement plan that was announced in 2004, but was disappointed when the Constellation Program was canceled in 2010.

"At that time, I would say yes, we should keep the shuttles flying — with one major exception. Back in 2006, we at NASA made major decisions to start shutting down the pipeline for parts. In 2010, to reverse the decision and continue flying the shuttles was going to be very expensive and take a very long time. So it wasn't realistic to fly them again," she told me.

"The worst thing we can do to our people is to constantly change things ... so in the end, the right thing to do was to fly out shuttle. I am personally very sad to see it go. But the big problem is, we don't have anything to follow on right now. We're going to get there. It's just that right now, we don't have it."

It's not the end of the shuttle program that bothers Collins. Rather, it's the possibility that NASA won't be able to follow through on the beginning of the next program.

"I don't want to see any more canceled programs," she told a school group after today's ceremony. "If we have problems, we need to fix those problems and press on. We can't just cancel and walk away from them. I go to schools, and I talk to kids, and I say, 'If you have problems, stick with it, fix it, don't give up.' We don't want to continue to give up on programs that are going to be taking us out into space, whether it's with robots or with people. We need to keep working on those programs."

What do you think? Here's your chance to weigh in on the end of the shuttle program and the beginning of the next chapter in exploration. Just leave a comment below.

More about what's next for NASA:

• NASA gives all-clear for commercial launch to space station
• NASA's chief says end of shuttle era could usher in new age
• NASA unveils giant rocket design for future space odysseys
• NASA retools spaceship design for missions beyond Earth orbit
• Next steps in a commercial space race

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

Courtesy of Robert Z. Pearlman

A collection of shuttle mission patches, including patches representing STS-1 (the first mission) and STS-135 (the last), can be an inexpensive way to keep spaceflight memories alive.

Space shuttle memorabilia may never be as highly prized as a spacesuit patch sprinkled with moondust — or a lock of Neil Armstrong's hair — but items from the 30-year space program are likely to rise in value as the shuttle era fades into the history books.

Moon-mission memorabilia will always get the top rating on the space souvenir scale, said Robert Pearlman, editor of CollectSpace.com, a website that tracks space history and artifacts as well as modern-day missions. "The peak item among all space history is something that's been to the moon, and in the process of that, picked up moondust," he told me.

Most of the material from the moon — ranging from rocks to dust-laden spacesuits and gloves — is held by NASA for research or by museums for display. Such objects are closely watched, and lunar larceny always makes for a good story: The recently published book "Sex on the Moon" tells the tale of a NASA intern who stole 17 pounds of Apollo moon rocks from Johnson Space Center to impress his girlfriend, and then there's the brouhaha over moon rocks that were given to the state of Alaska but ended up in the possession of a vessel captain who says he fished them out of the trash.

Items that come up for legitimate sale — the occasional spacesuit patch, or wrist-worn checklist, or even a strip of cloth that was torn from a flag before it flew to the moon — can go for tens of thousands or hundreds of thousands of dollars. Even a well-placed autograph by an Apollo astronaut fetches big bucks  — particularly if that astronaut is Neil Armstrong, who set down on the moon exactly 42 years ago today. Among the top sellers: a page from an Apollo 11 flight plan inscribed by Armstrong ($152,000), and one of Armstrong's signed checks from 1969 ($27,350).

In contrast, autographs from space shuttle astronauts generally go for $10 to $20 on the secondary market, Pearlman said. "Or you can get them for free, if they're still with the program," he said. Just send a request to your favorite astronaut in care of NASA Johnson Space Center, CB/Astronaut Office, Houston, TX 77058, and you'll get an autographed photo in reply.

Here are a few other categories of items that Pearlman recommends for a shuttle-era collection:

Mission patches: It's relatively easy to come by the same types of patches that the astronauts wear. A-B Emblem makes the patches used by NASA as well as the "official" shuttle mission patches offered by many hobby shops and mail-order websites. They generally run $5 per patch. Collecting all 135 isn't out of the question (um, that would be $675 or so). Patches that were actually flown in space (or better yet, worn by the astronauts) are harder to come by and more expensive.

Postal mementos: "For the price of a stamp you can get a memento of the last landing, or still the last launch," Pearlman said. Actually, make that two stamps. You can send a self-addressed, stamped envelope to Postmaster, NASA Kennedy Space Center, FL 32899, and ask to have the envelope, also known as a cover, hand-canceled and sent back to you with the date of launch or landing. Pearlman said U.S. Postal Service rules allow the postmaster to back-date such cancellations up to 30 days, so you're still in the clear for Atlantis' July 8 launch. To make the memento more special, some folks decorate the envelopes with space-themed artwork, and use spacey stamps like the Mercury stamps issued this year. (But make sure the stamps provide the proper postage.)

Flown items: Bucketfuls of mementos have been flown up on shuttle missions and brought back down to Earth. After the missions, they're kept by the astronauts as souvenirs, or given away to VIPs, museums and schools. Some historically significant items have been flown on behalf of institutions: For the last Hubble servicing mission, the crew brought up a basketball that was used by astronomer Edwin Hubble when he was on the University of Chicago's championship team. Atlantis' mission is no different. "This flight has 22,000 American flags on board," Pearlman said. Such flags do turn up for sale, and "in theory it'd be possible to put together a collection of American flags from each of the 135 missions," he said. An alternative would be to snag one of the 10,000 flags that was flown on the first shuttle mission in 1981, and pair it with one of the thousands being flown on Atlantis to mark the shuttle era's beginning and end.

Mission 'mistakes': Just as flawed stamps and coins go for a premium, "mistaken" mission memorabilia will sometimes be more collectible than your run-of-the-mill shuttle stuff, depending on the rarity of such items. For example, an authentic mission patch for STS-61E, a flight that was canceled due to the 1986 Challenger explosion, can go for hundreds of dollars. Something similar could conceivably happen with memorabilia related to last year's flight of Atlantis, STS-132, which was touted at the time as Atlantis' final flight. Later, NASA decided to add one more flight of Atlantis, meaning that STS-132 is no longer the last. "That's now viewed as a mistake," Pearlman said.

Shuttle parts: Space shuttle tiles have been popular collectibles through the years, Pearlman said, but with the shuttle era winding down, "NASA has made them more and less available at the same time." The space agency has clamped down on distribution of the discarded tiles through surplus sales. The tiles that have been removed from the shuttles during processing are buried in disposal sites — and in fact, a former shuttle worker was arrested in February for rescuing tiles from the trash and selling them. Over the past few months, NASA has been getting rid of thousands of unused tiles and other castoffs by distributing them to museums and educational institutions. If you qualify, you pay a nominal amount for shipping and handling — less than $25 for a tile. But if you're just a collector, you'll have to turn to the secondary market. Just make sure it's legit.

Will shuttle memorabilia ever rank as high as Apollo memorabilia? Not likely. Two of the prime factors behind collectibility are rarity and an artifact's ability to fire the imagination — and it's hard to beat the Apollo moon missions on that score. Less than 40 men went into space during the Mercury, Gemini and Apollo programs, including 12 who walked on the moon. In comparison, 355 astronauts flew on 135 shuttle missions to low Earth orbit.

"One hundred and thirty-five missions may scare away collectors, because it was such a large program," Pearlman said.

But when you look beyond the trinkets, it's hard to escape the sense that appreciation of the space shuttle program will grow in time, as Americans reflect on its accomplishments (building the International Space Station and fixing Hubble) rather than its failings (high cost and high risk, including the loss of 14 astronauts).

"There is a shuttle generation that hasn't yet grown old enough to pine for their youth," Pearlman said, "but that will come in; the next 20 or 30 years. The space shuttle will be part of those childhood memories. The program is ending a bit prematurely for that generation. To be honest, it's ending prematurely for any generation. But they say that you should go out at the top ... well, the shuttle certainly seems to be going out at its peak."

How will the shuttle era be remembered? As that era heads into its final day, feel free to reminisce and reflect in the comment space below. 

More tales of space souvenirs:

• Ex-astronaut tries to sell camera from moon trip
• Buzz Aldrin sues trading-card company
• Confederate flags on space station draw ire
• Missing moondust returned to NASA
• Apollo 12 'Playboy' stowaway auctioned
• Vintage Soviet space capsule sold for $2.9 million

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also add me to your Google+ circle, and check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Brendan Smialowski / Getty Images

SpaceX CEO Elon Musk stands alongside rocket models at the National Press Club as he announces plans to build the Falcon Heavy rocket. Observers say the heavy-lift launch system could send an 11-ton payload to Mars.

Don't expect to hear any nostalgia about the soon-to-end space shuttle era from Elon Musk, the millionaire founder of Space Exploration Technologies. Musk isn't prone to look to the past, but rather to the future — to a "new era of spaceflight" that eventually leads to Mars.

SpaceX may be on the Red Planet sooner than you think: When I talked with him in advance of the shuttle Atlantis' last liftoff, the 40-year-old engineer-entrepreneur told me the company's Dragon capsule could take on a robotic mission to Mars as early as 2016. And he's already said it'd be theoretically possible to send humans to Mars in the next 10 to 20 years —  bettering NASA's target timeframe of the mid-2030s.

You can't always take Musk's timelines at face value. This is rocket science, after all, and Musk himself acknowledges that his company's projects don't always finish on time. But if he commits himself to a task, he tends to see it through. "It may take more time than I expected, but I'll always come through," he told me a year ago.

Since that interview, a lot of things have come through for SpaceX. The company has conducted successful tests of its Falcon 9 rocket and Dragon capsule. Before the end of the year, another test flight is expected to send a Dragon craft all the way to the space station for the first time. If that test is successful, SpaceX can start launching cargo to the International Space Station under the terms of a $1.6 billion NASA contract.

The company is also in line to receive $75 million more from NASA to start turning the Dragon into a crew-worthy space taxi for astronauts by 2015 or so. And just today, the company broke ground on a California launch pad that could be used by the next-generation Falcon Heavy rocket starting in 2013.

Once the Dragon and the Falcon Heavy are in service, the main pieces would be in place for a Mars mission, Musk said.

"One of the ideas we're talking to NASA about is ... using Dragon as a science delivery platform for Mars and a few other locations," he told me. "This would be possibly be several tons of payload — actually, a single Dragon mission could land with more payload than has been delivered to Mars cumulatively in history."

SpaceX is working with NASA's Ames Research Center in California on an interplanetary mission concept that could theoretically be put into effect for a launch "five or six years from now," Musk said.

By that time, astronauts will once again be riding on U.S.-made spaceships to the space station, including the Dragon — that is, if the current schedules hold true. But there's a lot of doubt surrounding those schedules. As you'd expect, the end of the space shuttle program and the shape of spaceships to come were major themes in my conversation with Musk. Here's an edited version of the Q&A on those subjects:

Cosmic Log: A lot of people are saying that when the space shuttle stops flying, that might be the end of the American space program. The idea is that commercial spaceflight providers are not going to be able to do the job, and there won't be sustainable interest in building the beyond-Earth-orbit rocket that NASA has on the drawing board. What's your response to the claim that this is really the end?

Elon Musk: It flies in the face of the facts. Six months ago, we had the second launch of the Falcon 9 and the first launch of the Dragon. The Dragon orbited Earth twice, it performed orbital maneuvers, it made a precision re-entry under the control of thrusters, and it landed within a mile of our target. We brought the Dragon back, and it was actually in good enough condition that we could fly it again if we wanted to.

SpaceX

SpaceX's Dragon capsule sits on the deck of its recovery ship after its successful orbital flight in December.

So as far as I'm concerned, it's not the death of anything. What we're really facing is quite the opposite. I think we're at the dawn of a new era of spaceflight, one which is going to advance much faster than it ever has in the past.

The space shuttle was designed in the '70s, and it really didn't improve after almost 40 years. They've upgraded the electronics here and there, but that's about it. That's incredibly static when you consider how other fields of technology have improved.

Now, with the public-private partnership that NASA has established with SpaceX, and the efforts made by other companies, we're actually going to see dramatic improvements in spaceflight technology for the first time since the '60s. The Dragon is taking technology to a whole new level beyond the shuttle.

The shuttle is fairly constrained because it's a winged vehicle with a landing gear. It can't land anywhere except Earth, and even on Earth, it can land only on certain runways. It doesn't have any ability to go beyond Earth orbit. But because the Dragon has a propulsion-based landing system and a much more capable heatshield than the shuttle's, it can land anywhere in the solar system with a solid surface — as long as you can throw it there. The Falcon Heavy can throw it pretty much anywhere in the solar system.

Q: The Dragon certainly looks different from the shuttle, and some people might get the impression that it's a step backward, back to the days of Apollo.

A: I've heard that. But I hope we can make it clear that this is actually a big step forward from the shuttle. It can do all sorts of things that the shuttle can't do. People look at something like wings and say, yeah, that's how a spaceship should look. But let's say you had a boat, and you put wheels on it and drove it down the road. It'd look pretty silly, right? Well, why do you have wings in a vacuum?

Q: One of the issues that always comes up when discussing commercial involvement in NASA spaceflight is the safety issue. A lot of the critics of your program have focused on that concern as the sticking point. NASA certainly devotes a lot of attention to safety assurance, and some say that's why it's so expensive to put humans into space. Any attempt to cut corners on that would make the whole enterprise look questionable. How do you respond to that?

A: Well, first of all, I suspect that the people saying that wouldn't have a problem flying on Southwest Airlines or driving a car or taking other types of transport that are not government-operated. The government does have a role in safety oversight, and anything we do for NASA goes through an extremely rigorous safety and liability examination. But I think what actually needs to happen is a dramatic improvement in safety. The current state of affairs with the shuttle is not acceptable at all. The shuttle's accident rate is not OK. Who would get on an airplane if you had a 1.5 percent chance of dying?

Q: Do you see any sign that NASA has different standards for oversight of commercial operations and for the shuttle program? After all, there's a whole army of engineers dealing with shuttle operations and processing.

A: I do think there are different standards. For us, the standards are higher. The shuttle, for example, has no escape system. We would not launch [astronauts on] our vehicle without an escape system, nor would NASA want us to. Also, with our vehicle, there's far less to go wrong on any given flight. With the shuttle, if anything serious goes wrong with this extremely complex vehicle, it's curtains. There's no escape. If the shuttle's level of reliability was acceptable, we could fly astronauts this year.

Q: Do you think NASA has the right vision for spaceflight? The idea is that space station resupply in low Earth orbit would be left to commercial ventures, freeing NASA up to develop the heavy-lift Space Launch System for exploration beyond Earth orbit. Some people have wondered whether the Space Launch System is really going to be necessary.

A: Personally, my view is that space transport overall should be much more of a private-public partnership, and that applies to heavy lift as well. The best use of NASA's resources is to focus on the unique scientific instruments and payloads that are truly one-off items. That's actually how it works right now for Earth-observing and space science missions. They launch the spacecraft primarily on United Launch Alliance rockets, a Delta or an Atlas. If it's a probe to Mars, or to the asteroid belt, or it's a weather satellite, it'll go up on a United Launch Alliance rocket. Obviously, in the future, they'll go up on our vehicles as well. I think that works pretty well, and I think it makes sense to extend that model to all sizes of rockets.

Q: So it sounds as if you see a role for SpaceX in exploration beyond Earth orbit. Do you see any scenario where a mission to the moon or Mars could be completely private-sector?

A: It's not out of the question. I do think missions like that are ideally handled as public-private partnerships. There are questions about how you'd pay for the missions. But the absolute goal of SpaceX is to develop the technologies to make life multiplanetary, which means being able to transport huge volumes of people and cargo to Mars. So we'll do whatever is necessary to achieve that goal.

Previously:

• Is the space effort dying, or evolving?
• After the shuttle lands, layoffs loom
• Shuttle's legacy: Soaring in orbit and costs 
• Gallery: Ten players in the commercial space race

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also add me to your Google+ circle, and check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA / Monica Soler

A researcher demonstrates a pee-recycling technology based on forward osmosis that will be tested on the space shuttle Atlantis.

During the final days of shuttle Atlantis' final flight, an astronaut will inject a urine-like fluid into a special bag designed to convert the fluid into a drinkable, sugary solution. If it works, future astronauts may use it to make their own pee a safe and satisfying liquid refreshment.

Astronauts on the International Space Station already drink recycled urine but the glitch-y system takes energy from the orbital lab's limited supply. The new system doesn't require electricity; rather it relies on a process called "forward osmosis."

NASA describes forward osmosis as "the natural diffusion of water through a semi-permeable membrane from a solution of a lower concentration to a solution with a higher concentration. The semi-permeable membrane acts as a barrier that allows small molecules such as water to pass through while blocking larger molecules like salts, sugars, starches, proteins, viruses, bacteria and parasites."

The semi-permeable membrane (a bag) is filled with a sugary solution that is nested within an outer bag. The dirty fluid — including pee, sweat and dishwater — is injected into the outer bag. As it makes it way to the inner bag, the contaminants are left behind. The result, if all goes well, is a quaffable liquid.

One of the four astronauts will test the textbook-size recycler toward the end of Atlantis' 12-day mission, scheduled for liftoff on Friday. Fortunately, the test will be with a pee-like solution, not the actual bodily fluid.

The system was demonstrated to reporters at the Kennedy Space Center this week. Wired's Dave Mosher, who was on scene, has the details.

More on peeing and drinking in space:

• Space urine recycler to get fix-it part
• Cheers! Crew drinks up recycled urine in space
• Broken urine recycler may affect space mission
• We won't water it down: That is potable pee
• Space beer headed for zero gravity bar

Scott Andrews / for msnbc.com

In one of 120,000 images shot during the time-lapse, NASA's space shuttle Atlantis is hoisted before being mounted with "the stack" before rollout at Kennedy Space Center in Florida.

As the sun sets on NASA's spaceflight program, three talented people set out to document the preparations for shuttle Atlantis' final launch.

Armed with 15 cameras, Scott Andrews, his son Philip Andrews and Stan Jirman teamed up to shoot and seamlessly combine a whopping 120,000 still images. The finished product is condensed into a 3-minute time-lapse video that makes the four-day process of preparing the shuttle for its trek to the launch pad look like a cakewalk.

The time-lapse is the culmination of 40 years of collaboration. Photographer Scott Andrews, a technical consultant for Canon, has been photographing launches and landings professionally since Apollo 15 in July 1971.

Scott Andrews / for msnbc.com

The morning after rollout, NASA's space shuttle Atlantis rests on the launch pad at Kennedy Space Center in Florida.

Throughout the years he has helped hundreds of photographers from around the world and worked closely with the NASA spaceflight program. Scott said his main mission in creating the time-lapse is to pay tribute to all of the shuttle workers.

Referring to the origins of the time-lapse video, Scott said "Anybody could have done this time lapse — but nobody did."

So Scott sat down and drafted a 47-page proposal and made six trips to the Kennedy Space Center to finally get the "yes" he needed. This all hinged on the trust he had built during his tenure, split between Kennedy and Johnson space centers.

In the end, they produced a tribute to not only the shuttle workers, but also NASA and the spaceflight program as a whole.

Veteran NBC space correspondent Jay Barbree summed it up best: "When historians look back, they will write that the shuttle was a reusable ship that carried astronauts into orbit.  It was an essential brick on the road to distant places beyond our planet."

Related content:

• Slideshow: The life of shuttle Atlantis
• Video: Space shuttle crew: 'We want to make sure we go out in style'
• Slideshow: Month in Space Pictures
• More space news from msnbc.com

Alan Boyle / msnbc.com

Susan Crippen is to be laid off next month from her job as a shuttle crew trainer at Johnson Space Center.

Thirty years ago, Bob Crippen was on the first space shuttle crew. Twenty-four years ago, his daughter Susan became part of the space effort as well, taking a job as a shuttle crew trainer at NASA's Johnson Space Center in Houston. Now the shuttle program is ending, and so is Susan Crippen's job.

I asked her whether her famous father had any advice for her. "No," she replied. "He just worries about me getting laid off."

Crippen, 46, is just one of an estimated 4,500 NASA contract employees due to lose their jobs between now and mid-August, including about 1,000 in the Houston area. She works for United Space Alliance, the shuttle program's prime contractor, as a training instructor for simulated shuttle launches and landings.

NASA file

NASA astronaut Bob Crippen floats in weightlessness during the first shuttle mission, STS-1, in 1981.

The shuttle Atlantis' astronauts went through their final simulations last Friday. After the sim, the crew of four gave Crippen and her colleagues a round of goodbye hugs. Now the shuttle crew is in Florida, getting ready for this Friday's scheduled launch. The motion-base simulator on which they trained will go to Texas A&M's aerospace engineering department.  Other training equipment will be divvied up among museums across the country. And in just a few weeks, the shuttle training team will be disbanded.

For the next few years at least, NASA's astronauts will be trained in Russia to ride in Soyuz spacecraft to and from the International Space Station, under the command of Russian cosmonauts. They'll still get training in Houston for operations aboard the space station, and for the spacewalks that will need to be conducted from the station. Eventually, the astronauts might have to learn their way around the commercial space taxis that are just now in the design and development phase. But from now on, no one will ever need to be trained to fly the space shuttle. 

When I visited the team's control room on Friday, just hours after the final sim, a half-dozen trainers were reflecting on their storied past and their uncertain future. Susan Crippen studied physics at the Unversity of Texas at Austin, and went to work at Johnson Space Center right after graduation. She's not yet sure what she's going to do after she's laid off, but it sounds as if aerospace is in her blood — in part because of the family connection.

Bob Crippen was a naval aviator who was assigned to the Air Force's military astronaut program in 1966. He became a NASA astronaut in 1969, just after the Apollo 11 moon landing. In 1981, Crippen and Apollo 16 commander John Young flew Columbia on the shuttle program's first space mission — a mission that historians now say was riskier than NASA thought at the time. After STS-1, Bob Crippen flew on the shuttle three more times. He took on a variety of management posts at NASA, left the space agency in 1995, then worked as an aerospace executive until his retirement in 2001.

Susan Crippen, the second of three daughters, still remembers that first shuttle flight.

"I did go to the first launch, but I'm not going to the last launch," she told me.

Instead, she'll be standing by at Mission Control, along with other trainers from the team.

"If anything occurs that's unexpected, our teams will get called for real-time support, and we'll go over here to the simulators, and we'll run through those procedures, kind of like in Apollo 13," shuttle training team lead Juan Garriga told the Houston Chronicle.

During Friday's final simulation run, the trainers were wearing matching green polo shirts, emblazoned with the logo for Atlantis' final mission, which is known as STS-135. Garriga made it sound as if there was a little magic in the number: He told me that when he tallied up his team's requests for the STS-135 shirts, the number of entries came to ... 135.

Maybe it's a good omen for the future. The shuttle team could sure use one.

More from Johnson Space Center:

• Inside NASA's 'Skunk Works' lab
• Last shuttle crew faces a heavy load
• After shuttle lands, layoffs loom
• How Atlantis' top tweeter got that way

The shuttle story in depth:

• Interactive: Final shuttle mission in focus
• Cast of characters: Space crews in the spotlight
• Interactive: Space shuttle timeline
• Slideshow: Atlantis, this is your life

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," Alan's book about the controversial dwarf planet and the search for new worlds. 

Roberto Beltramini / Space 3D

A 3-D view created from NASA imagery shows the space shuttle Endeavour docked to the International Space Station during that shuttle's last mission in May.

How can you possibly improve upon the ultimate pictures of the space shuttle and the International Space Station together in orbit? By turning them into 3-D photos, of course.

That's what Italian amateur astronomer Roberto Beltramini did with the imagery captured in May by his countryman, astronaut Paolo Nespoli. The "ultimate" opportunity presented itself when Nespoli and two other spacefliers were leaving the space station to come back home during the shuttle Endeavour's final orbital tour. Nespoli shot high-definition stills and video from the departing Soyuz spacecraft, and the fruits of his labors were made public last month.

Beltramini took pairs of slightly offset images and tweaked them to produce these stereo views, displayed on his Space 3D gallery and republished with permission.

Roberto Beltramini / Space 3D

In this view, you can make out Endeavour's robotic arm curling around the shuttle. Red-blue glasses are required for the 3-D effect.

Roberto Beltramini / Space 3D

A different perspective shows Endeavour's rear end, head-on.

These are perspectives we'll never see again — not even during Atlantis' program-ending visit to the space station this month. It was a scheduling fluke that a Soyuz craft happened to be leaving the station while Endeavour was docked, and the circumstance is virtually certain not to be repeated.

We just might see Atlantis and the station linked together from a different perspective, however. Photographers such as France's Thierry Legault are getting better and better at snapping amazing pictures of the station-shuttle complex from Earth, and during Atlantis' mission, you'll want to check Legault's website as well as Patrick Vantuyne's 3-D photo gallery.

Update for 9:40 p.m. ET: You'll need red-blue glasses to get the full 3-D effect from the pictures offered by Beltramini and Vantuyne. I'm in the process of sending out 3-D specs to at least a dozen (and probably more) members of the Cosmic Log Facebook community as part of our occasional "3-D Giveaway" program. To join the community, all you have to do is click the "Like" button on the Facebook page. The glasses are being provided courtesy of Microsoft Research. (Msnbc.com is a joint venture of Microsoft and NBC Universal.) If you're one of today's winners, congrats: I'll start sending out the glasses after Atlantis lifts off.

More 3-D views from space:

• Explore the 3-D depths of Mars
• Get a fresh 3-D look at Phobos
• See a Martian crater in 3-D
• See a Martian milestone in 3-D
• See the Martian arctic in 3-D
• See more depths of Mars in 3-D
• 3-D delights from Mars
• Still more from Mars in 3-D
• Go on a space mission in 3-D
• See the moon's marvels in 3-D
• Saturn's moons in 3-D
• More from outer space in 3-D
• Fly through a nebula in 3-D
• Cosmic Log's 3-D-O-Rama

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.