There are some things on this planet that are highly valuable, but extremely short-lived. Some isotopes used for medical diagnostics, for example, have a half-life of a few weeks. Last year one of the reactors that created them was shut down for a while, and there was a serious shortage of the isotopes. There wasn't even a way to stockpile them.
I propose filling a bunch of spaceships with these time-sensitive items. Then put the caravan of ships in orbit around the sun at a velocity that is relatively higher than Earth's orbit around the sun. Because of dilation, less time will pass for the ship than Earth, and thus items on board will be "preserved".