For the second time in a row, SpaceX wasforced to call offan attempt to launch its giant Super Heavy-Starship rocket on the program's 10th test flight, a milestone mission to demonstrate fixes and upgrades in the wake ofthree catastrophic failuresearlier this year. A launch attempt Sunday at SpaceX's sprawling Starbase facility on the Texas Gulf Coast was called off because of an oxygen leak in a ground system. Monday's scrub came with less than a minute to go because of an electrically charged anvil cloud near the launch pad that did not move out of the area in time. The companysays it will try for the third time Tuesday night. The hour-long launch window begins at 7:30 p.m. ET. Whenever it takes off, a successful flight would clear the way for a faster launch cadence as SpaceX gears up to test autonomous Starship-to-Starship propellant transfers next year, a requirement for a NASA moon landing as early as 2027 and for eventual flights to Mars. But the company will have to launch 10 to 20 Super Heavy-tankers to refuel a moon-bound Starship lander being built forNASA's Artemis program. Many observers doubt the system will be perfected in time for a 2027 landing and possibly not before the Chinese mount their own moon mission at the end of the decade. Speaking before the Monday launch attempt, SpaceX founder Elon Musk agreed that "there are thousands of engineering challenges that remain for both the ship and the booster." He put a special emphasis on perfecting orbital refueling. "No one has ever demonstrated [cryogenic] propellant transfer in orbit," he said. "This will be propellant transfer at very large scale. But with full reusability and propellant transfer, those are the key technologies needed for building a city on Mars. And I'm confident the SpaceX team will achieve these goals." In the near term, SpaceX's goal is to get the Super Heavy-Starship flying again after multiple back-to-back failures. The goals of the flight are to test the Super Heavy first stage under a variety of stressful flight conditions, deliberately shutting engines down during descent to splashdown in the Gulf to make sure it can handle real failures during an actual mission. Given the nature of the tests, SpaceX ruled out a dramatic return to the launch pad for a mid-air capture by giant mechanical arms on the support gantry. As for the Starship, the flight plan calls for sending the upper stage halfway around the world on a suborbital trajectory to a controlled reentry and splashdown in the Indian Ocean. Along the way, a variety of tests are planned, including the deployment of eight Starlink simulator satellites and an in-space restart of a methane-fueled Raptor engine. Modified heat shield tiles are in place to determine their ability to withstand extreme reentry temperatures. Multiple upgrades are also in place to minimize the chances of propellant leaks, fires and engine shutdowns like those that led to the loss of the last three Starships launched, none of which were able to complete their mission. Secretary of Transportation Sean Duffy, NASA's acting administrator, is optimistic SpaceX will work the bugs out in time for the agency's planned moon landing mission. "If you look at the company as a whole and past performance, they often times are behind, and then all of a sudden, they make these massive leaps forward," he said in an interview with CBS News. "I would be hard-pressed to say they're not going to meet the goals and the timelines." "Their leadership has said we feel very confident that we are going to be ready for the mission. And so I'll take them at their word," he said. CBS News interviewed multiple current and former NASA and contractor managers and engineers in recent weeks who unanimously agreed a moon landing in 2027 could not be safely carried out with the current architecture. And not one of them said they believed NASA could get there before the Chinese without a drastic change of course. "I think the folks you've talked to are accurate. We are not going to go ahead and get a crewed Starship to the moon by 2030, under any circumstances," a senior engineer who worked on the Artemis program said. "That doesn't mean they'll never get there. That doesn't mean the architecture couldn't work. But it's just too big of a technical leap to accomplish in the short time that we've got." But as Duffy pointed out, SpaceX has chalked up a remarkable record with its partially reusable Falcon family of rockets, launching them at an unmatched pace that allows the company to rapidly implement and test upgrades and fixes. As of Friday, SpaceX has launched 518 Falcon 9s and 11 triple-core Falcon Heavy rockets with just two in-flight failures. The company has successfully recovered first-stage boosters 490 times. Given its record, many fans give SpaceX the benefit of the doubt when it comes to the Super Heavy-Starship. But the giant rocket dwarfs the Falcon 9, and the requirements for a successful moon landing are well beyond those faced in a typical satellite launcher. "My concerns have to do with how complicated the mission architecture is, how many flights there are to send a single lander to the moon," said Douglas Cooke, a retired 38-year NASA veteran who now does consulting work for Boeing and other aerospace concerns. "Getting into the high numbers," he added, "reduces the probability of success." SpaceX did not respond to a request for comment. Welcome to New Orleans Maryland Gov. Wes Moore calls Trump D.C. 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