What does "siege" mean here?
And they did this big siege approach where they had thousands of porters and they brought big camps and afternoon tea and all this kind of stuff.Context:
20141223-Humans on Mars Soonish Says NASA Bigwig
Last week NASA hailed the launch of its new Orion capsule as the first step toward sending people to Mars. But is a manned mission to the Red Planet really doable?
“I liken it to the 1920s, ‘30s, ‘40s when it was believed that Everest might be impossible to climb.” John Grunsfeld, the former astronaut who now heads NASA’s Science Mission Directorate. We spoke at Cape Canaveral just before the Orion launch.
“Well, eventually it was climbed by Tenzing Norgay and Sir Edmund Hilary. And they did this big siege approach where they had thousands of porters and they brought big camps and afternoon tea and all this kind of stuff. And that was kind of the Apollo approach to going to the moon and back safely in a decade. We brought all resources to bear.
“But modern exploration on Earth—polar exploration, Antarctic, climbing, even climbing Mount Everest—people do it in a very light fashion using technology, they’re very creative and they take more risks in some cases. And I think that’s going to be our path to Mars, a much leaner path and one where we are able to use technology to enable the way, rather than a big siege approach.
“And so I think it’s very realistic. I think we could do it in the 2030’s, certainly by the 2040’s, with the national will and the interest. And I think it’s our science missions that are providing that drive.”