NASA file

The spacefliers on the International Space Station show off their Yuri's Night T-shirts during 2011's celebration. Yuri's Night commemorates the anniversary of Soviet cosmonaut Yuri Gagarin's history-making spaceflight as well as NASA's first shuttle flight — but for the first time since Yuri's Night was established in 2001, there are no space shuttles in service.

Yuri's Night has been celebrating space odysseys since 2001, on the 40th anniversary of Soviet cosmonaut Yuri Gagarin's history-making launch into orbit — but it's much more challenging to find cause for celebration this year.

First of all, it's been just a year since the huge golden anniversary of the first human spaceflight, in 2011. To mark the occasion, Yuri's Night put on more than 600 events in 75 countries, and that's a hard act for anyone to follow. Perhaps more importantly, this year marks the first Yuri's Night since NASA retired the space shuttle fleet. For the next few years, there's no way to launch astronauts from U.S. soil.

"With the shuttle era coming to an end, there's going to be a lot of nostalgia this year," Veronica Ann Zabala-Aliberto, director of marketing for Yuri's Night 2012, told me this week. "It's going to be an interesting time to see how people bridge the gap."

The past, present and future of spaceflight — and of Yuri's Night — will be up for discussion on Wednesday when Zabala-Aliberto and I get together for "Virtually Speaking Science," an hourlong talk show that takes place in the Second Life virtual world and on BlogTalkRadio. The show gets under way at 9 p.m. ET (6 p.m. PT/SLT). Feel free to drop in or tune in, and if you can't listen to the stream in real time, you can always download the podcast via BlogTalkRadio or iTunes.

Yuri's Night traditionally focuses on April 12, which is the anniversary of Gagarin's launch as well as the first shuttle flight in 1981. But not all of this year's more than 150 events take place on that date. The Romanians get the party started with a school event titled "Dancing With the Stars" on Thursday, and the Peruvians close it out at an aerospace conference on April 26. In between, there's a series of parties, lectures, workshops and other events on all seven continents (yes, including the South Pole on Antarctica).

There'll be two parties in Second Life and one in Star Trek Online (just head for Quarks Bar at Deep Space Nine). And even as he's counting down to the big day, executive director Ryan Kobrick is working to get more venues on board, across the planet and off-planet as well.

"It's never too late to register," Kobrick told me. "It's for all ages and all demographics. Having a handful of friends over for dinner counts for Yuri's Night, if you go with that theme. Every Yuri's Night party is unique. The point is to bring people together and celebrate the past, present and future of spaceflight."

This year, the celebration may be accompanied by a sense that the future of spaceflight is not assured. NASA's plan calls for commercial ventures to start launching astronauts to the space station in 2017 or so, setting the stage for trips beyond Earth orbit in the 2020s. The first targets for those voyages of exploration include near-Earth asteroids, with Mars as the eventual goal. But that vision is still in flux, and the budget that's been proposed for NASA is more suited for an era of retrenchment rather than expansion.

This isn't the first time NASA has gone through a painful transition. "We are currently experiencing the same timeline as when the Apollo program ended," Zabala-Aliberto pointed out. But the current situation does pose an extra challenge for U.S. human spaceflight.

"This gives us a catalyst to fight more, to let the general public know, 'No bucks, no Buck Rogers," Zabala-Aliberto said.

The tools being used to get the word out include events like the ones organized through Yuri's Night, as well as online venues such as Facebook and Twitter, YouTube and Ustream, LinkedIn and Flickr. This year, Kobrick is aiming to have live updates posted to Live.Yurisnight.net, which is powered by Posterous. There's also a video series with the theme "I Celebrate Yuri's Night Because..."

"We've always had a foot in the door with all the different channels that have come out," he said.

But the key is to keep the spirit of Yuri's Night going for the rest of the year as well, and that's what Zabala-Aliberto and her colleagues are aiming to do — by working with other space-minded organizations, taking advantage of the technological tools at their disposal, and letting people know "that they do have a say in the space program, and they can make a difference."

"Yuri's Night gives everybody that sense that you can still be a part of it," Zabala-Aliberto said. "You're around like-minded people. ... It's not going to be a wake, that's for sure."

Join us for a Yuri's Night kickoff on "Virtually Speaking Science," and check out the Yuri's Night website for a party near you. While you're clicking,

"Virtually Speaking Science" takes place at 9 p.m. ET Wednesday at the MICA Small Auditorium at Stella Nova in Second Life and is broadcast on BlogTalkRadio. Many thanks to the Meta Institute for Computational Astrophysics for co-sponsoring the Second Life event. The hourlong show will be archived on BlogTalkRadio and iTunes. Check out these other podcasts from "#VSScience":

• JPL's Dave Beaty on the search for life on Mars
• Shawn Lawrence Otto on science and politics
• Ig Nobel impresario Marc Abrahams on silly science
• Rocket scientist Robert Zubrin on Mars exploration
• Propulsion expert Marc Millis on interstellar spaceflight
• Sean Carroll on the puzzling frontiers of physics
• Rand Simberg on the private-enterprise vision for spaceflight
• Martin Hoffert on the future of energy policy
• George Djorgovski on science in virtual worlds
• Alan Stern on suborbital research and NASA's mission to Pluto
• Col. 'Coyote' Smith on the outlook for space solar power
• Tim Pickens on rocket ventures and the Google Lunar X Prize

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.

Nikolay Korchekov / Reuters

Spectators watch a fireworks display presented to celebrate the 50th anniversary of Yuri Gagarin's historic spaceflight, in Moscow's Victory Park on April 12.

More than 500 parties are going on to celebrate the 50th anniversary of the first human spaceflight and the 30th anniversary of the shuttle program. Among the highlights: the debut of the trippy space documentary “First Orbit,” greetings from the International Space Station and the Mars500 simulation of a Red Planet mission, contests, giveaways — and the Google doodle of the day.

All these events tie into Yuri's Night, a global celebration of spaceflight that originated in Los Angeles 10 years ago. The annual event commemorates Soviet cosmonaut Yuri Gagarin's blastoff on April 12, 1961, plus Columbia's first-ever space shuttle flight on April 12, 1981. Today's anniversary is bittersweet because this may be the last year of the shuttle fleet's service.

Tonight's L.A. party is a star-studded affair at the Griffith Observatory, during which Yuri's Night co-founders Loretta Hidalgo-Whitesides and George Whitesides (who is now Virgin Galactic's president) will reflect on the past and look forward to the future. They're not the only ones. This year the parties are proceeding on all seven continents.

Google

The logo on the Google homepage was set up to launch Yuri Gagarin's rocket when moused over.

"Everyone from Google to the Los Angeles Times is making note of this historical landmark, and I'm thrilled to see how excited people around the world are to celebrate the spirit of exploration and discovery that Yuri Gagarin embodied," Yuri's Night assistant director Brice Russ said in today's overview. "Whether your nearest Yuri's Night event is down the street or 100 miles away, there's something you can do to participate."

To find out about that something, check the event list at the Yuri's Night website. Some events take place after April 12, so if you have to stay in tonight, there's still a chance that you can party down.

Also, there's still a couple of days before the deadline for the Yuri's Night video and print ad contests, as well as a space-tour sweepstakes. You could win an expenses-paid trip to Russia for a zero-G flight, or even to Baikonur to watch a Soyuz liftoff.

A whole constellation's worth of websites are celebrating spaceflight today, including Scientific American, Wired, Smithsonian Air & Space and of course our partners at Space.com.

Over at Spacevidcast, meanwhile, you could watch a global Yuri's Night webcast and snag one of a million e-book copies of Andrew Kessler's "Martian Summer." Yuri's Night has also teamed up with Posterous to set up a "Yuri's Night Live" sharing site for photos and videos. Don't forget to check in with Yuri's Night via Twitter, Facebook, Flickr and YouTube.

And speaking of YouTube, here's a selection of videos to get you in the holiday mood:

More about Yuri Gagarin and space history:

• Why the world remembers its first spaceman
• Fifty years later, relive the first space odyssey
• The sky's the limit for outer-space records
• Look for Yuri Gagarin on msnbc.com

Join the Cosmic Log community by clicking the "like" button on our Facebook page or by following msnbc.com science editor Alan Boyle as b0yle on Twitter. To learn more about my book on Pluto and the search for planets, check out the website for "The Case for Pluto."  

The whole world is gearing up for the 50th anniversary of humanity's first flight in space, made by Soviet cosmonaut Yuri Gagarin on April 12, 1961.

For Russians, the date is observed as Cosmonautics Day, an annual holiday going back to Soviet times. And for the past 10 years, the rest of the world has been celebrating the occasion as "Yuri's Night," which has replaced the Communist Party theme with a dance-party theme.

As of today, the Yuri's Night website has registered 321 parties in 61 countries, from Afghanistan to Vietnam. (And I still have hope for Zimbabwe.) The event's associate director and director of media relations, Brice Russ, emphasized that the event doesn't focus on Mother Russia or the Cold War.

"We call it Yuri's Night and celebrate Yuri Gagarin's flight, but it's not just a celebration of a single person doing a single thing," he told me. "It's celebrating what Yuri's flight stood for: exploration, adventure, scientific discovery. It's nice to see how far we've come in 50 years, and with Yuri's Night we'll be doing our best to go as far as we can in the next 50 years."

Russ pointed out that there's a strong U.S. angle to the April 12 festivities. "It's not just the 50th anniversary of Gagarin's flight, but it's also the 30th anniversary of the shuttle program," he said. 

10 years of Yuri's night
The first Yuri's Night festivities were organized in 2001 by two space enthusiasts named George Whitesides Jr. and Loretta Hidalgo. From the beginning, Whitesides and Hidalgo (who are now married) tailored the event for the next space generation rather than the Apollo era. Rock music, dancing, glamour and glitter are an accepted part of the Yuri's Night scene, but the pocket-protector crowd is welcome as well.

"It's pretty funny seeing space geeks mixing it up with the young and the beautiful," Hidalgo Whitesides said in a news release. "In Los Angeles, we see our share of space-inspired fashion. There are a lot of silver bikinis."

The highlights include:

• Two contests to get the space-exploration juices flowing. One calls for contestants to create a print ad (poster, magazine advertisement, postcard, etc.) that would inspire readeres to "think about space and support humanity's future among the stars." Grand prize is a four-day trip to Russia for a zero-gravity flight aboard an Ilyushin-76 airplane, valued at $9,000. The other contest offers $500 for the best Yuri's Night tribute video. Deadline for both contests is April 15.
• A sweepstakes that offers an expense-paid trip to Russia's Baikonur Cosmodrome in Kazakhstan, to see a Soyuz liftoff like the one that took place today. Value: $9,000. Entry deadline: April 15. Cost of entry: $0.
• The relaunch of the Yuri's Night app for the iPhone, which gives you the full rundown on hundreds of events, as well as a countdown clock so you don't miss the liftoff. (You can also follow @YurisNight on Twitter or check out the Yuri's Night Facebook page.)
• The world premiere of an experimental documentary film titled "First Orbit," produced by British filmmaker Christopher Riley with music by Philip Sheppard. The 105-minute film will be shown for the first time on YouTube on April 12, and at hundreds of Yuri's Night venues around the globe.

First night for 'First Orbit'
"First Orbit" deserves special notice: The movie re-creates 1961's one-orbit flight, using exclusive imagery from the International Space Station. Riley worked things out with the European Space Agency to have Italian astronaut Paolo Nespoli shoot footage from the station's Cupola observation deck as the station flew along the same orbital path that Gagarin followed 50 years earlier.

Riley told me that the station follows Gagarin's route every couple of days. "The tricky part was that I needed to film at exactly the same time of day that Gagarin flew," he said. That happens only every six weeks or so. Fortunately, Nespoli was able to get most of the imagery during an orbital pass in early January.

The soundtrack blends the original audio from Gagarin's mission with Sheppard's score, plus reports about the flight that aired on Radio Moscow, TASS and the BBC 50 years ago.

Riley said the "First Orbit" project served as a "sort of overture" for a film he's planning to make about the decades-long international drive to explore outer space. "I'd really like to do a film in 30 languages, where everybody talks about their own experience in Earth orbit," he told me.

So what will happen to "First Orbit" when Yuri's Night is over? "It's a bit like a dead lottery ticket," Riley joked. "I suspect no one's going to be interested in the film for a few months after April 12. But I think this film will be like a good Christmas movie. It'll come back every year, around April 12."

What will you be doing for Yuri's Night? Do you remember what it was like 50 years ago, when Gagarin flew? Or 30 years ago, when a space shuttle blasted off for the first time? Or even 10 years ago, when Yuri's Night got its start? Take this opportunity to share your spaceflight memories in a comment below.

More about space history:

• Why the world remembers its first spaceman
• Where were you when Apollo flew?
• Audio slideshow: Voyage of the millennium
• Timeline: Glory days on the final frontier
• Timeline: Trace the space shuttle era