Deepsix is a science fiction planetary survival novel by Jack McDevitt.

A couple of decades ago a science mission was sent to the planet Maleiva III. But after an attack by native avians that left a few people dead the Academy decided never to return to the planet. And during the escape one lander was left behind.

Now back to the present another science mission is sent to Maleiva III because a rogue gas giant is going to collide with it in about a month. Because of this impending doom Maleiva III is popularly known as Deepsix. But the science team's scanning satellites detect signs of a dead civilization, i.e. walls and buildings.

They didn't bring a lander though so the Academy diverts the nearest Academy ship with a lander, Wildside piloted by Priscilla "Hutch" Hutchins. She was doing a ferry run returning some people from an archaeological expedition back to Earth. And as fate has it one of her four passengers is Randall Nightingale, the leader of the first Maleiva III science expedition and since he survived all blame fell on him so now he's just an obscure old man who'd rather not get involved.

Skipping ahead. The story really starts when the Wildside lander is destroyed along with a lander from a cruise ship. That leaves Hutch, Nightingale, Gregory McAllister -- famous curmudgeon who was a passenger on the cruise ship and came down to see the ruins and get interviewed --, and two or three other survivors and expendable victims.

Now the survivors have three weeks to trek to the old lander from the first expedition so they can maybe take off. Meanwhile the science ship will try to cobble together a rescue plan that still depends on the survivors using a lander to at least get high off the ground.

And there's the mystery of the planet (which has dangerous native life). The ruins and artifacts indicate a small primitive race that still warred with each other. But there's evidence of a space elevator (including a remnant scaffold a thousand kilometers long orbiting the planet). Luckily the survivors will gather enough information to piece together what happened.

It's a good story and quite interesting. There are a lot of cameo characters but many are introduced with enough background and description to bring them alive. Like the nerdy physicist who comes up with a way to grab the survivor's lander, or the retired zero-g welder who really takes to teaching a few dozen volunteers how to do welding for the grabber.

Apparently this is the second novel in a series and at least the first three star Priscilla Hutchins.