NASA file

Astronaut Rex Walheim mugs for the camera during a flight on the shuttle Atlantis in 2008, with a dried rose floating in zero gravity inside a case.

One of the last astronauts to ride on a space shuttle will be riding a totally different vehicle on Monday: a flower-bedecked float in the 2012 Rose Parade.

Say what?

The 5.5-mile journey down the parade route in Pasadena, Calif., doesn't hold a candle in distance or danger to the 5.3 million-mile journey that NASA astronaut Rex Walheim made in July during STS-135, Atlantis' program-ending mission. But it's a perfect follow-up for several reasons:

• Walheim will be riding on the "Garden of Imagination" float with his brother, Lance, a horticulturist who wrote the book "Roses for Dummies." Lance is the go-to garden guy for Bayer Advanced, an arm of the chemical conglomerate that makes lawn and garden prducts.
• With Lance's encouragement, Rex carried up a dried rose as one of his personal items during a 2008 mission on Atlantis. That rose was featured on Bayer Advanced's trophy-winning Rose Parade float in 2009.
• This Rose Parade appearance gives Rex a chance to smell the roses, literally, after a high-pressure spaceflight. It also gives him an opportunity to reflect on how a little gardening could come in handy for future generations of space explorers.

"If you think about it, that's one of the things we need to develop on our long-term vehicles," he told me this week. "We need to have a self-supporting ecosystem, environmental control systems for recycling air and water, and you have to grow your own food. We're doing that in space. ... These skills that any astronaut has as a young child when they work in the garden and help their parents, well, those turn out to be important on the most advanced vehicles ever made, and on the most complex exploration missions."

It's not clear whether Walheim will have a chance to do some of that space gardening himself. The 49-year-old already has three shuttle flights under his belt, and he's not currently on the schedule for a future spaceflight. With the shuttle program finished, journeys to the International Space Station are the only game in town for NASA astronauts. By the time NASA is ready for trips beyond Earth orbit, Walheim could well be pushing 60.

"I'm not giving up on ever flying again, but it's a litt more difficult to do at this point," Walheim acknowledged.

My interview with Rex and his brother Lance touched on life after the shuttle, the story behind the Rose Parade ride and the future of spaceflight. Here's an edited transcript of the Q&A:

Cosmic Log: So, Rex, what have you been up to since the last shuttle mission?

Rex Walheim: Well, immediately after the mission we did a number of debriefs ... the training folks and the flight controllers. We told them how the mission went, and then we started doing debriefs at the different NASA centers. Then we took our post-flight presentation out farther around, to different organizations and places. We had a chance to go overseas to Italy and Turkey, and talked to some of the military people and their families. That was very rewarding.

Then I went by myself to Australia, to Melbourne, to a museum down there that was doing a space exhibit, and that was my chance to see Australia for the first time. We topped it off with a trip to the White House on Nov. 1. We got to meet President Obama in the Oval Office, and that was exciting. The next day we had a picture taken with John Young and Bob Crippen of STS-1.

Pete Souza / White House

President Barack Obama checks out his astronaut flight jacket in the Oval Office on Nov. 1 as Janet Kavandi, director of flight crew operations at NASA's Johnson Space Center, stands alongside. In the background are STS-135 shuttle crew members Doug Hurley, Sandy Magnus, Chris Ferguson and Rex Walheim.

NASA / Houston Chronicle

The astronauts who formed the crews of STS-1, the first space shuttle mission, and STS-135, the final shuttle mission, pose for a group photo at the Johnson Space Center on Nov. 2 in Houston. They are, from left, STS-135 pilot Doug Hurley, STS-1 pilot Robert Crippen, STS-1 commander John Young, STS-135 commander Chris Ferguson and his crewmates Sandy Magnus and Rex Walheim.

Now it's time to transition to a ground job. I'll be working in the exploration branch, on some of the Orion systems, mostly the launch abort system, and also some of the ground launch systems. And I'll keep my hand in the EVA [spacewalk] business. I'll be working on the early flight suit — kind of a modified ACES [Advanced Crew Escape Suit, popularly known as "the pumpkin suit"], and then work on the next-generation suit for going to an asteroid or to Mars.

Q: Are you interested in a rotation on the space station?

Rex: It's a possibility, but I wouldn't do that for a few years. I'm not sure if I'll get a chance to do that or not, since I've flown three times already. But we'll see. I'm not giving up on ever flying again, but it's a little bit more difficult to do at this point.

Q: If it turns out that you're not in the space station rotation, how do you see the next few years working out? Would astronauts be involved in flight tests?

Rex: Yeah, we'll be involved in the flight tests and in the development of the vehicle, just like we were with the space station. When I first came here in '96, I was involved in the project even before the early assembly flights, developing the procedures, monitoring systems development, things like that.

We already are involved in the same way with Orion, with the crew displays and development of the flight systems. I love working down here at Johnson Space Center. I want to stay here for a while, and be in the Astronaut Office and provide our experience from having flown on the shuttle and having been on the space station to design the next generation of vehicles — whether they be commercial crew or the Space Launch System / Orion exploration system.

Q: Some of your colleagues have gone over to the commercial side. Do you feel as if there are some significant losses in expertise, or is it good to spread that expertise around?

Rex: I think it's really good to spread that expertise around. We'd love to have a lot of these folks stay with NASA, but I think it's great that they're going to the commercial providers and the other contractors, because we need to keep that experience around. The hard part would be to see people going to different industries, and I know that's a possibility for some people. It's hard-won experience, and it's nice to retain that.

The people we've had working on the shuttle program and the space station program are some of the best people I've come in contact with. I enjoy working with them and hate to see them go. But the fact that some are working with the commercial providers will give those companies a realistic appreciation for the difficulties and dangers of spaceflight. That experience will help those companies come along and develop the vehicles they're working on.

Q: I suppose it's a challenge for anyone who's involved in exploration to go through a transition like this. Are there things that you've found are helpful? How do you keep your focus on what's ahead?

Rex: Two ways. One is getting these commercial providers to give us American launches from American soil as soon as possible. Obviously I have a special connection with that, since I was one of the last ones launched. I really have a visceral desire to see people launched from the United States again, so to be able to help out with that ... that hopefully will be a short-term goal, three to five years. There's a lot of work being done on that.

And then there's the chance to dream a little bit, too. Let's get out of Earth orbit. Let's go to these places we've never been to before. That's always exciting to think about, and it's need to be a part of that. That's more long-term, but if you concentrate a little bit on both, the short term and the long term, that gives you a good balance.

You've got to keep in mind that we've been through this kind of transition before, between the Apollo program and the shuttle program. It's not easy, there's no question about that. A lot of people lost their jobs, and they're great people, but we'll gear up again and do some new and exciting programs.

Q: Do you and the other astronauts think about those future trips? What will it take for trips to a near-Earth asteroid, or to Mars?

Rex: I think it'll take the kind of people who left Europe and headed for America and didn't know what they were going to find. They left their old life completely behind. That's what it's going to take for the early explorers of Mars. They'll have a chance to come back, but it's going to be a three-year voyage. When they leave Earth, Earth becomes not this beautiful planet underneath them, like it is with the space station, but it's going to become like any other star. They're going to find themselves in a void of blackness with stars all around them. I've heard people say it's going to rewrite the definition of loneliness. But we have those people. We've had them in the past, and we'll have them in the future: people who will leave their homes and their families for three years on a very risky mission to be the first people to go live on Mars.

That' the kind of person it's going to be. It's going to be the younger folks, because it's going to take some time to get there, but we have those brave explorers coming up. I hope the kids in school now are studying math and science, so they can be among those first explorers who really reach out into the solar system.

Q: How does it feel to be a member of the last crew to fly on a shuttle?

Rex: You know, it's interesting. You don't really think about that a whole lot during the mission. During the preparation for the mission, you never know whether you're going to be the last one, or whether you're going to get to fly. Remember, there was a funding question about our mission. But it's neat to be a part of the last mission and see the tributes that people have done for the shuttle program.

It does start to hit you a little bit later than other folks. A lot of folks felt it at the launch, or when their part of the mission was done. For us, we were so busy over the last four or five months that it took a while to sink in. But when you see people leaving — for example, when Fergy [STS-135 commander Chris Ferguson] left NASA to go work at Boeing — it does sink in. The band is breaking up, and we're going on to different things.

Q: So how did this whole idea of being with your brother on the Rose Parade float come up?

Rex: I'll let Lance take that one.

Lance Walheim: People always said to me, "Why don't you have your brother take a rose up into space?" They were thinking about a live rose. I kidded him — I said, "Well, Rex can't even keep a rose alive in his backyard, how's he going to keep it alive in outer space?" So we came up with the idea of taking a dried rose up, and Rex did that on his previous flight, before the last one. Then we put it on the Bayer Advanced float in 2009.

NASA file

Astronaut Rex Walheim and his brother, Lance Walheim, collaborated on a mission to take a dried rose into space in 2008.

It just became natural to do something with the theme of the parade this year: "Just Imagine." We thought this'd be the perfect place to pay tribute to Rex and the whole shuttle program. We weren't sure until fairly recently that we were going to be able to do it, but it all worked out. I'm the Bayer Advanced expert, of course, so we're very proud to have him on the float.

Q: How does space tie in with the theme of the parade?

Lance: Well, the title of the float is "Garden of Imagination," and it's the story of two brothers who worked in the gardens when they were young and imagined bigger and better things. Rex was imagining going to space, and I was really into plants and wanted to work with plants. There will be a rocket on the float, and there's a trail going up. We'll be at the base of that trail.

Bayer Advanced via Luckie & Co.

Bayer Advanced's Garden of Imagination 2012 Rose Parade float has a flowery trail leading to a rocket ship.

Rex: The tie-in with the "Garden of Imagination" is that it's a place where you have a chance to dream. When you're gardening, you have a chance to let your mind wander. I think it's a place where you can do a lot of good thinking. When I was in our backyard, in our garden or where we were landscaping, it was in San Carlos, which is near San Francisco. You can see down into the Bay Area, and the neat thing about it was the airplanes that were landing at San Francisco International Airport. I could watch the 747s fly over and dream of flying one day. That's where my dreams of flying really took flight, in my backyard in California.

Q: Do you feel as if you have a little more time to spend in the garden, spend with your family, or are there more things that you have to keep your eye on?

Rex: There's always more to accomplish, and a lot of hard work ahead, but the neat thing is that the pressure is off now. It's always tense when you're preparing for a mission and getting ready to fly. The time you have with your family is somewhat limited, and there's always a little pressure there, realizing that you're going to be doing something dangerous. So when you come back, there's almost a joy of life you get. It turned out well, and everybody's safe. It adds a little bit of freshness to all the things that you do. Unfortunately, it doesn't always last that long, but for me, it's lasted a really long time. I just went skiing with my boys in New Mexico, and we spent some time outside and really enjoyed ourselves.

Q: So, Lance, would you say Rex's gardening has improved?

Lance: It's been a little while since I've been to Rex's garden, but hopefully I'll find out soon. A couple of years ago, I sent him some rose bushes as a Christmas present. So the first thing I'm going to do is look for those roses and see how they're doing.

Rex: Well, to be honest, he sent me three rose bushes. Two of the three still survive, and the first one never made it into the ground. I just didn't get around to planting it. But Lance is my consultant, whenever I find some new disease or pestilence out in my backyard here in Texas, I call Lance and ask "what the heck is that" and send him a picture. And he gives me the advice on what to do about it.

Q: Sounds like you better get that garden spruced up, because the boss is coming.

Rex: That's right.

More on the future of spaceflight:

• Next steps in the new space race
• From July: Meet the last shuttle crew
• Cosmic Log archive on the new space race

NBC and other networks are airing television coverage of the 123rd Annual Tournament of Roses Parade at 11 a.m. ET Monday (check your local TV listings). The "Garden of Imagination" float will be the fifth float and the 10th unit in the parade lineup. Look for it on TV between 11:10 and 11:20 a.m. ET (8:10 to 8:20 a.m. PT) Monday.  

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 and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA

The International Space Station looms above Earth during the unorthodox Atlantis fly-around on July 19. The moon can be seen above and to the right of the station.

It's been standard procedure for the space shuttle to make a fly-around and take pictures of the International Space Station just as it's pulling away for the homeward journey. But the procedure was changed for this month's very last visit by the space shuttle Atlantis. After the shuttle backed 600 feet away, pilot Doug Hurley held it in position while the space station rotated 90 degrees to the right. Then Hurley made a half-loop around the station, to give Atlantis' crew members an opportunity to snap pictures of the station from angles never before photographed during a fly-around.

Here are some of the high-resolution pictures. Scores of additional images focus in on details that NASA engineers wanted to check. "The images will be evaluated by experts on the ground to get additional information on the condition of the station's exterior," NASA said.

NASA

The International Space Station's solar panels are nearly edge-on in this view. Two Russian Soyuz lifeboats and two Progress cargo ships are docked on the left side.

NASA

Earth spreads out nearly 250 miles (400 kilometers) below in the background of this unusual view of the International Space Station.

NASA

The sun shines brightly on the International Space Station in this parting shot, captured by Atlantis' crew.

More views from the last shuttle mission:

• Last looks at the shuttle in orbit
• Space station crew watches Atlantis descend
• Photographers capture Atlantis' last landing
• Southern lights are sweeter in space
• Aircraft captures unique view of launch 
• Shuttle Atlantis' last trek to liftoff 
• Atlantis' flight on PhotoBlog

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.

Thierry Legault / Astrophoto.fr

A three-image composite tracks the International Space Station and the shuttle Atlantis as they move across the sun's disk on July 15.

They look like alien bugs hopping across the sun, but these specks may represent the very last pictures of a space shuttle in orbit as seen from Earth.

French astrophotographer Thierry Legault, an expert in the technique of tracking spacecraft silhouettes, captured these views of the International Space Station and the shuttle Atlantis during their final rendezvous. Atlantis landed today, bringing the 30-year space shuttle program to an end.

The picture above is a composite, showing three views of the station-shuttle complex as it passed over the sun's disk on July 15. Legault had to travel to just the right location to get the shot. This one was taken from Caen in France. The entire transit took just seven-tenths of a second. Legault has labeled the shuttle and elements of the space station in this higher-resolution view:

Thierry Legault / Astrophoto.fr

The labels on this image point out the position of Atlantis and components of the International Space Station during a July 15 transit.

In an email, Legault told me that he traveled through the Czech Republic, Germany and the Netherlands to capture the silhouettes. One picture, snapped north of Prague and posted to Legault's website, shows the space station and the shuttle side by side, 50 minutes after Atlantis' undocking earlier this week.

Legault produced the piece de resistance today during a stopover near Emden, in northern Germany. It may not look quite as impressive as the others, but it could well be more historic. Legault wrote that the picture was taken "just 21 minutes before the deorbit burn, therefore there are chances that it is the very last image of a space shuttle in orbit."

Here's a composite of four images, taken during the 0.9-second-long transit. The silhouettes of Atlantis are highlighted within white circles:

Thierry Legault / Astrophoto.fr

A four-image composite tracks Atlantis' transit across the sun's disk, just 21 minutes before today's deorbit burn. The white circles highlight Atlantis.

For the telescope and camera buffs out there, Legault says the images were produced using a Takahashi TOA-150 6-inch apochromatic refractor (focal length 3600mm) on an EM-400 mount, with a Baader Herschel wedge. The camera is a Canon 5D Mark II, set for an exposure of 1/8000s, 100 ISO, working in continuous shooting at four frames per second. Transit forecasts were calculated by www.calsky.com.

Merci beaucoup to Thierry for sharing his pictures with us through the years.

More great views of Atlantis:

• Space station crew watches Atlantis descend
• Photographers capture Atlantis' last landing
• Southern lights are sweeter in space
• Aircraft captures unique view of launch 
• Shuttle Atlantis' last trek to liftoff 
• Atlantis' flight on PhotoBlog

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.

NASA

The greenish glow of an auroral display sweeps around Earth's south polar region in this photo, captured from a vantage point on the International Space Station. The shuttle Atlantis and its robotic arm, as well as one of the station's solar arrays, loom up in the foreground.

The pilot for NASA's last space shuttle flight, Doug Hurley, says one of the highlights of Atlantis' trip to the International Space Station was seeing an "incredible" display of southern lights — and after seeing these pictures, I'd have to agree with him.

This photo from the space station shows the greenish auroral glow sweeping around the south pole, following the edge of the atmosphere. Atlantis is in the foreground with its robotic arm extended into the center of the frame, and one of the station's gold-colored solar arrays juts in the right edge. You can even see the stars hanging in the night sky.

 Another picture provides a more detailed view of the shimmering lights, with Atlantis' inspection boom poking through the frame.

NASA

Thursday night's southern lights shimmer in a picture taken from the International Space Station, with Atlantis' inspection boom angling through the picture.

The southern lights, like the northern lights, are sparked when electrically charged particles from the sun interact with Earth's magnetic field. For more amazing views of Atlantis' auroras, check out NASA's photo gallery for the shuttle mission, as well as Space.com's report about the pictures.

More marvelous views from Atlantis' mission:

• Father and son see shuttle's start and end
• Space station takes center stage
• Aircraft captures unique view of launch
• Students reach high for amazing launch photos
• Last shuttle launch marks the end of an era
• Crowds flock to Atlantis' last countdown
• Shuttle Atlantis' last trek to liftoff
• NASA's last shuttle seen from space

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 file

A fish-eye view of the International Space Station, captured by NASA spacewalker Ron Garan, features the recently delivered Alpha Magnetic Spectrometer in the foreground. A Russian Progress cargo ship and a Soyuz crew capsule are docked on the left end of the station. The structure to the left of the AMS is a radiator. One of the station's gold-colored solar arrays is visible in the background. And off to the right, the shuttle Atlantis is docked to the station's Harmony node.

After the space shuttle Atlantis lands, the focus of the U.S. space program shifts to the International Space Station — so it’s fitting that NASA spacewalker Ron Garan took a moment to capture this eye-filling wide-angle view of the station at the end of this week’s final outing of the space shuttle era.

This wasn't the last spacewalk by any means. The 500-ton space station is as big as a football field and as roomy as a five-bedroom house, and it's going to need plenty of exterior upkeep over the next decade of operation. But it was the last opportunity for astronauts to take pictures of a space shuttle in outer space ... from outer space.

"Only one problem with this image — the tendency to make you stop whatever you're doing, stare at it, lose your concentration and drool uncontrollably," NBC News space analyst Jim Oberg says in an email. "At least that's how it affects me."

'Big deal' for space station science
It's also fitting that NASA has finally revealed how scientific experiments will be managed aboard the space station in the years ahead. Today the space agency announced it has selected a Florida-based nonprofit group known as the Center for the Advancement of Science in Space, or CASIS, to take charge of research operations that use the U.S. portion of the space station as a national laboratory. The center will be located at the Space Life Sciences Laboratory, near NASA's Kennedy Space Center.

The U.S. segment of the space station was given national-lab status in 2005, and over the past few months, NASA has been evaluating potential partners for managing the lab operations. CASIS will be in charge of maximizing the station's research return for non-NASA applications — based on scientific peer review, analyses of the economic and technological value of potential projects, and the availability of funding. NASA said CASIS will also raise the station's profile as an educational platform.

The cooperative agreement initially will have a value of up to $15 million per year, NASA said in its news release.

"The space station is the centerpiece of NASA's human spaceflight activities, and it is truly an national asset," NASA Administrator Charles Bolden was quoted as saying. "This agreement helps us ensure the station will be available for broad, meaningful and sustained use."

CASIS is a consortium of organizations spearheaded by Space Florida. "CASIS is a perfect fit with the state's strategy to support the space, science and technology industries through strategic collaboration and partnerships," Florida Lt. Gov. Jennifer Carroll, the chair of Space Florida's board of directors, said in a statement. "By making the space environment more widely accessible to industrial and academic research, the ISS National Lab will help strengthen and diversify the U.S. economy and inspire the next generation."

U.S. Sen. Bill Nelson, a Florida Democrat who flew on the shuttle Columbia in 1986, said today's announcement was "a big deal."

"It's going to bring money, jobs and industry to diversify an area hard-hit by retirement of the shuttle program," Nelson said in a news release.

Breakthrough or multibillion-dollar bust?
The space station has long been criticized for providing less research value than scientists had hoped. We'll have to see if that criticism fades now that the station is out of its construction phase.

During a briefing conducted before Atlantis' launch, Mike Suffredini, NASA's space station program manager, said the initial goal was to devote 35 hours of the astronauts' time to research on a weekly basis, plus whatever they wanted to do during their off time. "We find that crews give quite a bit of their weekends to research," he said.

One of the space station's marquee science projects is a long-running investigation of how microgravity affects the virulence of pathogens such as the microbes that cause salmonella poisoning or MRSA. Scientists involved in the project, which could result in new vaccines, have an experiment aboard Atlantis for the last shuttle mission.

"We're close to some groundbreaking news here, so this could be a good one," Joe Delai, payload manager for Atlantis' STS-135 mission, told journalists.

It'd be nice if the post-shuttle era came to be remembered as a golden age for space station science — but what do you think? Is the station suited for science, or will it turn out to be a shiny $100 billion white elephant? Feel free to weigh in with your comments below. And while you're contemplating your comments, feast your eyes on these additional images from Tuesday's spacewalk:

NASA via Reuters

Spacewalker Ron Garan rides on the International Space Station's robotic arm as he transfers a failed pump module to the cargo bay of space shuttle Atlantis.

NASA via Getty Images

NASA spacewalker Mike Fossum takes a picture while attached to the International Space Station's robotic arm on Tuesday. California's Central Valley can be seen far below as a green swath running from left to right, with Mono Lake shining like a tiny blue jewel.

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.

Mark Kirkman / Interspace News

Msnbc.com's Alan Boyle takes the controls in the commander's seat inside the shuttle motion-base simulator at NASA's Johnson Space Center.

After a decade of trying, I finally landed a space shuttle.

Not the real thing, of course. I'm talking about a simulated landing, basically flown on a computer. Every once in a while, I've tried my hand on the arcade-game-style shuttle simulators you might find at science centers and museums, and it hasn't been pretty. I'd come down to hard, or confuse my "up" and "down" on the joystick, or veer off the landing strip. I've gotten pretty used to flashing red lights and low scores over the years.

So when it came time to go up the stairs and climb into the motion-base shuttle simulator at NASA's Johnson Space Center, the first thing that came to mind was the Astronaut's Prayer: "Dear Lord, please don't let me screw up" (or something like that). The pressure got just a bit worse when our trainer for the session, NASA flight controller Corbett Hoenninger, told our crew of journalists that the folks who rode in the simulator just before us were the Atlantis astronauts themselves.

I climbed into the commander's seat for the initial takeoff. The motion-base simulator is a little bit like the ones you might find at high-class amusement rides — a mockup cockpit that's crammed with real-looking hardware, including a heads-up electronic display on the forward window and a 1980s-vintage seatbelt with five clip belts for the shoulders, waist and crotch.

As I gripped the joystick with my right hand, Hoenninger was reassuring.

"I have faith in you," he said.

"I don't," I answered.

First, we experienced launch. There was really nothing I needed to do, except to roll with the rocking simulator, listen to the recorded rumble and watch the solid-rocket boosters fall away on the computer-generated display out the side window. Then we went right to the landing sequence.

There are lots of gauges and rolling balls that the real astronauts can probably make sense out of, but for me, the key thing was to peer into the heads-up display and use the joystick to keep a small glowing diamond inside a bright circle on the heads-up display. The circle shifts around the screen, to reflect how you should be moving the joystick to make a banking turn and level up the gliding shuttle for final approach to the simulated runway.

I went through a little bit of that up-down problem, but Hoenninger was there to remind me of the difference — and alert me about two little triangles that would start rising up from the bottom of the video display. As the start of the runway grew larger on my display, the triangles served as a guide for moving the joystick so that you landed level instead of falling onto the runway like a brick. The latter alternative is something I'm all too familiar with.

Believe it or not, I actually set our virtual runway on the ground without crashing, although there was an inelegant thump and a screech that sounded off-nominal. Then Hoenninger reminded me about the pedals. The shuttle has two hydraulic pedals that control your wheel braking to keep you on the centerline as you slow the craft to a stop. The system couldn't be simpler, but it still took me a few seconds to get the coasting under control — in part because I let my feet slip off the pedals while I was flying.

After my landing, each of the other three journalists took their turn. All of us set the shuttle down successfully. In fact, Hoenninger told me later that not one of the visiting media types had crashed. That made me feel a little less special. But I did get a "Certificate of Accomplishment" for successfully landing the motion-base shuttle mission simulator, which I'll put in a place of honor in my office cubicle.

So now I can finally put my shuttle jinx to rest — and just in time, too. With the end of the shuttle program, the shuttle simulator is due to be disassembled and shipped off to Texas A&M, to be used by a new generation of aerospace engineers and virtual space jockeys. To those Aggies, I say: Godspeed ... and keep your feet on the pedals.

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. 

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.