This story was updated at 11:49 a.m. ET.
CAPE CANAVERAL, Fla. ? The space shuttle Discovery is leaking again, delaying its planned launch by at least one day ? to Nov. 2 ? as engineers scramble to fix the spacecraft in time for its last space voyage, NASA officials said.
"Last night when we were doing our tank [pressurization] to flight mode, we did have a couple leaks that occurred," NASA test director Jeff Spaulding told reporters this morning (Oct. 29). "We tried to repair them overnight but weren't completely successful in doing so."
Discovery was slated to launch on its final mission on Nov. 1, but two leaks in one of its twin aft-mounted engine pods forced the delay. The leaks are in helium and nitrogen seals used to pressurize fuel line plumbing in one of Discovery's orbital maneuvering system pods.
They are unrelated to a fuel leak on Discovery that NASA repaired last week, Spaulding said.
The leaks must be fixed before the shuttle can launch, which forced NASA officials to delay the start of Discovery's countdown, and subsequently the launch date as well. This means that Discovery's earliest chance to launch is now Tuesday, Nov. 2 at 4:17 p.m. EDT (2017 GMT). [Video: Legacy of Shuttle Discovery]
Spaulding remained confident that the repairs could be done effectively and efficiently, saying that the agency's engineering teams have had previous experience fixing these types of leaks.
"The repairs, removal and replacement aren't very complicated, and we've done it in the past," Spaulding said. "It's fairly common ? a well-known process."
Discovery is scheduled to launch on an 11-day mission to the International Space Station to deliver a new storage module and a humanoid robot called Robonaut 2.
The mission will be Discovery's 39th and last trip to space before it is retired from service. Discovery is NASA's oldest flying shuttle and has flown the most missions of any orbiter in the space agency's fleet.
NASA is ending its space shuttle program and retiring its orbiter fleet ? Discovery, Atlantis and Endeavour ? next year to make way for a new plan aimed at sending astronauts to visit an asteroid and Mars.
Discovery's upcoming flight will be NASA's 133rd shuttle mission since the orbiters first began flying in April 1981.
- Video ? Space Shuttle Discovery: A Retrospective, Part 2, Part 3
- GRAPHIC: Meet Robonaut 2: NASA's Space Droid, Robonaut 2 Photo GalleryWant to See Space Shuttle Discovery's Last Hurrah? Here's How
Follow SPACE.com Staff Writer Denise Chow on Twitter @denisechow as she covers Discovery's final space voyage from Cape Canaveral, Fla. Click here for mission updates, new stories and a link to NASA's live webcast coverage.