How to Watch NASA’s ‘Kinder, Gentler’ Megarocket Tanking Test

After changing defective seals that resulted within the second scrubbed SLS launch try on September 3, NASA is able to proceed with a full-scale cryogenic tanking check of its megarocket on Wednesday, which you’ll be able to watch stay proper right here.

The tanking check begins vibrant and early on Wednesday, September 21, with the launch director anticipated to get the ball rolling at round 7:00 a.m. (all instances Eastern). Should the whole lot go easily, the check will conclude at round 3:00 p.m. NASA’s stay protection of the check is scheduled to start out at 7:15 a.m., which you’ll be able to watch at NASA TV, NASA’s YouTube channel, or on the feed supplied under. A short interruption of the tanking check will happen at 9:00 a.m., as NASA TV is planning to modify protection to the Soyuz MS-22 crewed launch to the International Space Station.

This check is in preparation for Artemis 1, an uncrewed Moon-orbiting mission to show the brand new Space Launch System rocket and NASA’s Orion crew spacecraft. A profitable check on Wednesday may set the stage for an SLS launch try on September 27, with NASA focusing on a launch window that opens at 11:37 a.m. and ends 70 minutes later. Failing that, NASA may strive once more on October 2.

Importantly, NASA has not but obtained flight permission from the Eastern Range, a department of the Space Force that oversees launches from Kennedy Space Center. Should the Range not grant the requested waiver, NASA must transport SLS from its present place on Launch Pad 39B to the close by Vehicle Assembly Building. There, engineers would examine and reset batteries related to the rocket’s launch abort system—the main target of the Range’s concern.

NASA is asking it a cryogenic demonstration check, however let’s name it for what it primarily is—the seventh moist gown rehearsal of SLS (the earlier six being the 4 formal moist gown rehearsals and the 2 failed launch makes an attempt). NASA officers are steadfastly refusing to name it a moist gown, saying groups gained’t go into the terminal depend part of the launch countdown, nor will they energy the Orion spacecraft or the aspect boosters. That stated, the groups will try to completely load propellants into each the core stage and higher stage tanks, and likewise cool the rocket’s 4 RS-25 engines all the way down to their required ultra-cold temperatures. Certainly smells like a moist gown rehearsal to me.

So, for this distinctly not-a-wet-dress, the teams will attempt a “kinder, gentler” propellent loading process, as Jeremy Parsons, deputy manager of NASA’s Exploration Ground Systems (EGS) Program, told reporters during a Monday media call. Through this tempered approach, ground teams will attempt to minimize pressure and temperature spikes, which they’ll do by slowly increasing the pressure within the liquid hydrogen tank, Parsons explained. This tanking strategy should slowly bring components down to ultra-cold temperatures and mitigate chances of thermal shock, and it shouldn’t add more than 30 minutes to the tanking process, he said.

Fingers crossed, this approach will prevent the kind of hydrogen leak that caused the second scrub in early September (the first scrub, on August 29, was the result of a faulty sensor that gave erroneous engine temperature readings). Following the second scrub, engineers replaced two seals on the rocket’s quick disconnect, an interface that connects the liquid hydrogen fuel line to the rocket’s core stage. The engineers performed the required fixes while the rocket stood on the Florida launch pad. Tom Whitmeyer, deputy associate administrator for common exploration systems development at NASA, said the primary objective of Wednesday’s test is to “look at the two new seals.”

Analysis of the 8-inch seal showed a potential indentation mark that could have resulted in the hydrogen leak, but as Artemis mission manager Mike Sarafin told reporters, no foreign object debris (FOD) was recovered. The indentation was tiny—under 0.01 inches—which “doesn’t sound like a lot,” Sarafin said, but hydrogen is the “smallest particle on the atomic chart.” As a propellant, pressurized hydrogen has a propensity to leak, but it’s valued for its power and efficiency.

Parsons clarified that the true cause of the indentation is not known, citing thermal or pressure shock as other possible causes. And indeed, an inadvertent command briefly raised the pressure within the system during the second launch attempt. The team is currently working through its fault tree in an attempt to source the problem, but Parsons said he has “no technical concerns” going into Wednesday’s test, and that the “kinder, gentler” tanking approach should prevent further hydrogen leaks. His biggest concern right now is the weather, but with a 15% chance of problematic lightning on Wednesday, the test is looking good to proceed as planned, Parsons said.

As for the potential launch on September 27, that’s still in the hands of the Eastern Range. John Blevins, SLS chief engineer, said NASA’s launch dates are pending and for planning purposes, and that “we are internally marching ahead” as some of preparatory activities “require longer lead times than what we’ve got available.” The goal is to have the teams ready once the Range’s decision comes, he added. Blevins said he’s “impressed” with the questions being asked by Space Force and that it’s “up to us to provide the information they’re asking for.” NASA is still having technical discussions with the Range, but the space agency is “being respectful” of the process, Blevins said. Space Force is aware of the cryogenic tanking test, according to Sarafin, and NASA will perform the demonstration “whether we fly or not” on September 27.

A successful launch of SLS would kickstart the Artemis era and our return to the Moon. NASA and its international partners are planning a series of missions over the coming years to build a sustainable human presence both on and around the Moon. Artemis is also serving as a precursor program for eventual crewed missions to Mars.

More: What to Expect from NASA’s DART Mission to Deflect an Asteroid.