Source: Space News
Wednesday 10 January 2024 19:10:03
SpaceX expects to conduct the third integrated test flight of its Starship vehicle in February as it works to demonstrate key technologies needed to land humans on the moon.
During a Jan. 9 media briefing about NASA’s Artemis lunar exploration effort, Jessica Jensen, vice president of customer operations and integration at SpaceX, said securing an updated Federal Aviation Administration launch license was the key factor driving the schedule for that test flight.
“From a hardware readiness perspective, we are targeting to be ready in January,” she said. The company performed static-fire tests of both the Super Heavy booster and Starship upper stage, or ship, intended for that launch in late December.
SpaceX, though, is still working on corrective actions identified from the second Starship test flight Nov. 18. On that flight the Super Heavy booster appeared to perform well, but exploded shortly after stage separation. The Starship upper stage triggered its flight termination system late in its burn.
SpaceX has released few details about what happened to both the booster and ship during that flight, and Jensen did not identify the corrective actions that SpaceX was undertaking. Closing out those actions, she said, was a condition for receiving an updated license. “We’re on track for that,” she said. “We’re expecting that license to come in February. So, it’s looking like Flight 3 will occur in February.”
She added that SpaceX was “working towards” a demonstration of propellant transfer capabilities on that flight through NASA’s Tipping Point technology program. In that test, SpaceX would transfer cryogenic propellant from a “header” tank within Starship to its main tank. That is designed to be a precursor to later tests of transferring propellant from one Starship to another in orbit.
Propellant transfer is a critical technology for the version of Starship that will be used for NASA’s Human Landing System program starting with the Artemis 3 mission, now scheduled for no earlier than September 2026. SpaceX plans to create a propellant depot in low Earth orbit, filled by a series of Starship “tanker” launches, that would then be used to fuel the lunar lander Starship for its trip to the moon.
The number of tanker launches needed for a Starship lunar lander mission has been a topic of controversy. Elon Musk, founder and chief executive of SpaceX, once stated that no more than eight, and perhaps as few as four, tanker launches would be needed. But at an advisory committee meeting in November, Lakiesha Hawkins, assistant deputy associate administrator for NASA’s Moon to Mars Program, said the number of tanker launches was in “the high teens.”
Asked about that issue at the briefing, both NASA and SpaceX initially declined to give a number. “So much of this is just going to have to come from flight tests,” said Amit Kshatriya, deputy associate administrator for NASA’s Moon to Mars Program. “Probably the reason why you’re hearing different numbers is because we have a lot of different modeling and analysis iterations that are going on.”
Jensen described an iterative process of flight and ground tests. “That will wind up determining how many missions we need,” she said.
NASA Administrator Bill Nelson then stepped in. “The question was, how many fuel transfers?”
“I will say it will roughly be ten-ish,” Jensen responded. “It could be lower, depending on how well the first flight tests go, or it could be a little bit higher.”
She downplayed the risks of SpaceX’s approach. “Propellant transfer in orbit sounds complex and scary, and it seems like this big nebulous thing,” she said. “But when you really break it down into the various pieces, we’ve actually achieved almost all of the complex parts already on our operational programs.”
Jensen noted that SpaceX has demonstrated rendezvous and docking through Dragon missions to the International Space Station, and rapid launch through its Falcon 9 and Falcon Heavy vehicles, which have launched hours apart from different pad and days apart from the same pad. “We’re going to leverage those capabilities that we’ve learned on to Starship.”
The key technology, she acknowledged, is the actual in-space transfer of cryogenic propellants, which has not yet been demonstrated in orbit. That is where the iteration and ground and space tests come in. She noted the company did not have a minimum number of flight tests currently planned for demonstrating propellant transfer.
“What’s been happening over the last few years is that we’ve been building the machine to build the machine,” she said, developing infrastructure required for high production and launch rates for Starship. That will enable the company to move quickly on flight tests, she argued.
“Even if it’s an extensive amount of missions, we have the capabilities and have already proven them through other vehicles,” she said. “We will be able to do what Artemis 3 needs.”