Astronaut Jose Hernandez confirmed he’s interested in challenging Rep. Jeff Denham, R-Calif., again.

Hernandez, a Democrat, just isn’t sure when that will be: 2014 or 2016?

“Democrats tend to show up in lower numbers than Republicans in off-years. It’s one of the concerns I need to worry about,” he told Roll Call in a brief Friday afternoon telephone interview. “Is it more winnable in two years or four years?”

Earlier this month, Denham survived as the only targeted California Republican on the November ballot. Democrats defeated many of his California GOP colleagues; for example Rep.-elect Ami Bera toppled Rep. Dan Lungren in a 2010 rematch.

Now Hernandez, who lost by 5 points, hopes he might follow his friend Bera’s success. He plans to talk to him and senior Congressional leaders on a yet-to-be-scheduled trip to Washington.

But Hernandez cautioned that he hasn’t made a decision yet about running.

“I’m not saying I’m running, but I’m not saying I’m not running,” he said. “I’m keeping my options and exploring what would make sense to do.”