I’m breast-feeding my baby but have to make a transcontinental flight. What can I do? I can’t go that long without pumping.

Breast feeding. Can you take the baby with you? If not you can use a hand pump to express milk. And also take an electric pump with you.
? Taking Baby? With a few wardrobe modifications u can probably breast feed in the comfort of your seat during the flight. Capes & such will shield from view, those to squeamish to acknowledge the benefits. If babies not coming along, i'd pump & dump to maintain your flow.