SPECIAL REPORT: Behind the scenes for Pathfinder's landing on Mars

JULY 1:

Inside JPL's Von Karman Auditorium, with the mighty Voyager spacecraft lined up to left, it's the first Pathfinder press conference. The first thing you notice about the Pathfinder mission team is how young so many of them are.

There's a "veteran" here and there, like Project Manager Tony Spear. But Matt Golombek, project scientist, Rob Manning (flight system -- meaning the spacecraft on its way to Mars -- chief engineer) and Richard Cook, mission manager, are a new generation. Their briefing is upbeat: things have gone well to date. And listening to Matt Golombek review the science that can be done, the excitement builds in the audience.

For 21 years after the Viking spacecraft arrived at Mars, humans have not gone back to the Red Planet -- at least successfully. There've been at least two Russian failures and one American. Listening to the engineers, you wonder, how can Pathfinder possibly have its parachute and airbags inflate, its retrorockets fire, on cue -- after seven months in space? Sitting in the audience, watching camera men dance around the full-size model on its painted drop cloth with rust-red rocks, I can't help feeling nervous, more nervous than the Pathfinder team, it seems.

Later that afternoon we are on the last tour of Mission Control before the area is buttoned up for the landing, set for three days hence. It's pretty empty:

JULY 2:

Jennifer Harris, flight director for Sol 1, is busy monitoring spacecraft data. One sign reads: OBJECTS ON THE CALENDAR ARE CLOSER THEN THEY APPEAR. True for Pathfinder, and true also for our upcoming live two-hour special. Like the spacecraft, we also rely on satellite dishes and there are 101 things to go wrong. Also like Pathfinder we rely on a team of hard working people. But hearing that it's only 40-50 people who "fly" Pathfinder, it seems an amazing accomplishment, almost more impressive than the hundreds of people it's taken to fly previous missions.

Out on the mall area, nestled between the buildings at JPL, is evidence of what the spacecraft's really like: a huge cluster of airbags, like a giant bunch of grapes, shows what the spacecraft is going to look like when it bounces down on the surface.

It's an amazing time to be at an amazing place.

JULY 3:

Today the press conference is once more upbeat: but it's followed by one involving NASA Administrator Dan Goldin. "People have to be grown-up enough to understand that bold things, like Pathfinder, run risks. I want my people to try, and if they fail, learn from their mistakes and try again." It's a frank statement, but it matches Matt Golombek's blunt reponse to a press question: "We don't think any dust storm (something talked about in the media in the past few days) will deposit enough dust to impair the mission." He cites Viking data: crisp, even blunt, unlike the polite replies to oddball press questions served up by many others. It's as if the entire team is trimmed down to fitting weight, no time for anything other than facts. But amid the seriousness, there's some time for fun and human feelings. Early on July 3, the Mars Global Surveyor (MGS) team march en masse to the Mars Pathfinder offices. There are red and blue balloons for nearly everyone in sight! Glenn Cunningham, on behalf of MGS, presents large framed posters to Tony Spear and others. MGS's time will come. Now it's Pathfinder that's on the front-burner.

JULY 4:

10:00 a.m., Pacific: The first briefing of what should be landing day. Overnight, the team looked at Pathfinder's position and realized there was no need for a trajectory correction maneuver: they were within 45 kilometers of where they needed to be, close to some higher features which, navigator Pieter Kallemeyn said, made the planetary geologists happy. Rough enough to be interesting, gentle enough not to trouble the spacecraft. Maybe. Probably. Within 3.5 hours the spacecraft should be on the surface. For some of the team, like Pieter, their job is almost done. For others, the excitement's just beginning, with what they hope will be days of rover operations on the surface.

Downtown the Planetary Society's PlanetFest starts off as a huge success, people thronging everywhere. A large-screen projection system brings in NASA-TV, and people sit expectantly, listening to the blow-by-blow coverage of the mission. Upstairs, I try and time my presentation on "Live from Mars" to the actual landing. I run the sequence showing what should happen over Mars at just the same time as the flight plan calls for the events to happen. For almost a year I've been using the wonderful NASA/Georgia Tech animation. It's hard to believe that it's now happening -- for real -- on Mars.

Back at JPL -- SUCCESS! The DSN captures a radio signal that Pathfinder has safely met the surface. In the press room managers and reporters alike cheer. It's a national holiday for most of Americans, but for JPL, Pathfinder's arrival is celebration enough. The red rockets over Mars are the pyrotechnics which have obviously worked to bring this ambitious spacecraft to the surface. Fireworks on the Red Planet! Now, a wait till 2:07 p.m., Pacific until the first real data are expected.