If your inbox has an e-mail from a nasa.gov address with the subject line “STS-135 Tweetup CONFIRMATION”–congratulations! You won one of 150 invitations to see the last space shuttle launch from the Kennedy Space Center’s press site, about 3 miles from pad 39A.

Tweetup badges

You’re in for an amazing experience, as I found when I attended NASA’s Tweetup for the final launch of Endeavour in May. But it can also be intimidating to prepare for. Here are some tips I picked up that may help you get ready for your Tweetup.

(If you didn’t get that e-mail, don’t lose heart. People do get called up off the waitlist.)

Travel: As you may have read here before, the shuttle is not the most reliable vehicle ever, making the odds of an on-time launch for Atlantis on July 8 rather poor. Paying change fees or buying a refundable fare gets expensive quickly. Instead, fly Southwest or check fares between your city and Orlando a week from now; if they’re not much cheaper than tickets a month out, wait to book until NASA sets the official launch date at the Flight Readiness Review June 28.

Check alternate airports too. Melbourne is closer than Orlando; Tampa may be on the other coast of Florida, but the generous speed limits allow you to clock that distance in about two hours if you don’t hit traffic.

Hotels can be trickier. At the STS-134 Tweetup, many of us wound up staying together in rented houses or apartments for the first launch attempt–yes, despite the fact that most of had not met each other face to face until then. On the second attempt, with fewer people around, hotels weren’t a problem.

I usually Priceline rental cars but did not in this case: I wanted to be able to return them early or extend the rental if necessary.

Tweetup, day one: This is when NASA gives you a tour around the Kennedy Space Center–the highlight being the chance to walk into the Vehicle Assembly Building and gawk at a roof more than 500 feet overhead. As it gets damn hot in Florida, bring water and wear sunscreen. We were told to bring food as well, but that proved unnecessary when they invited us to hit the employee cafeteria. (The food is nothing special, but how many other cafeterias are across the street from a building tall enough to stack a Saturn V?)

The Tweetup will also feature talks and demonstrations by various NASA types. My favorites were astronauts recounting their experiences going up, staying there and coming back. The day should conclude with a ride out to the pad to see the Rotating Service Structure (the large structure on the pad that covers the shuttle until a day before launch) roll back to reveal Atlantis. But it may not: weather prevented our viewing RSS retraction on the first try, and I couldn’t get back to KSC in time to see it on the second launch attempt.

Tweetup, day two: This involves long stretches of waiting, punctuated by stabs of adrenaline when the countdown comes out of a hold, you look at the shuttle on the pad or you hear somebody speak the words “shuttle,” “liftoff” or “launch.” Aside from further talks by NASA folks, the only major event we had on the schedule before the launch was the chance to wave to the astronauts on their ride to the pad in NASA’s “Astrovan”–which, on the first try, came to an untimely halt when a wiring problem emerged and the Astrovan made a U-turn away from the pad.

It will be tempting to freak out over the weather. But although NASA’s Launch Commit Criteria look absurdly strict, they only apply to conditions at launch, not four hours before.

The press site–basically, an open lawn–affords a ridiculous amount of space to roam around. The closest possible view will put you on the other side of the countdown clock, but that was the only place I could park my tripod for an unobstructed view.

Many people don’t recommend trying to photograph a shuttle launch at all–you don’t want to watch it through a viewfinder. To avoid that issue, lock the camera on a tripod, oriented vertically, so it has the shuttle no higher than the lower third of the frame. (Don’t worry too much about getting the enormous zoom lenses you’ll see recommended for more distant spots; I took my photos with maybe a 20x zoom, using automatic focus and exposure.) When you get to a few seconds before liftoff, mash the shutter button repeatedly; 5 seconds after liftoff, zoom all the way out and keep pressing the shutter.

For the love of all that’s holy, don’t try to live-tweet the launch. But after the shuttle has departed from view, jot down your impressions while they’re still fresh.

Don’t plan on going anywhere for at least two hours after launch–it will take a while for the roads to clear.

With STS-135 currently set to launch in the late morning, I suggest getting a pre-launch breakfast at Baker’s Bagels, on State Route 3 a few miles south of the south entrance to KSC. When I stopped there in April, I was amused to a) see a kegerator with a “free beer” sign taped to its side and b) have missed Foursquare founder Dennis Crowley checking in there 20 minutes earlier. For a late lunch or dinner, Shuttle’s Dugout Sports Bar & Grill, a bit farther south on 3, could be any other sports bar–except for the shuttle and Saturn V models out front, the NASA photos inside and the KSC employees who show up.

What if it scrubs? Don’t panic, and don’t make plans based on initial estimates of the new launch time–especially if it’s a mechanical issue at fault. Use your extra free time to tour the KSC visitors’ center (we got free admission), and make time in particular for the hokey but enjoyable Shuttle Launch Experience ride. There are also non-space attractions nearby, such as beaches or the Merritt Island National Wildlife Refuge. And take time to hang out with your fellow Tweetup attendees–having a beer with them while discussing when the launch might happen is all part of this weird bonding experience.