Technicians at Kennedy Space Center in Florida, US, have begun hands-on repair work on the Artemis II rocket inside the Vehicle Assembly Building (VAB).
This comes after a helium flow problem forced the Artemis II rocket off the launch pad on February 25, delaying the planned launch in early March.
WHAT HAPPENED TO ARTEMIS II?
Once Nasa’s Artemis II Space Launch System (SLS) rocket and Orion spacecraft arrived at the VAB, technicians immediately began investigating why the flow of helium to the rocket’s upper stage was interrupted.
The fault was not detected during the test itself. Rather, it was spotted when engineers were returning the rocket to normal operations after a wet dress rehearsal that concluded on February 19.
Engineers have since zeroed in on two likely culprits: a seal on the tubing’s quick disconnect and a check valve on the other end of that same tubing.
The quick disconnect is a specialised joint that allows a hose to be attached to or removed rapidly from a rocket, while the check valve is a safety device that ensures fluid or gas flows in only one direction and cannot leak backward.
HOW IS ARTEMIS II BEING REPAIRED?
To carry out the repairs, teams are installing two sets of internal access platforms inside the launch vehicle stage adaptor.
They also must remove thermal blankets covering the area of interest on the rocket’s interim cryogenic propulsion system, or upper stage, which is the section that houses connections for multiple umbilicals, including tubing used to fill the upper stage with helium.
Helium is critical as it keeps the stage’s engine in the right environmental conditions and pressurises the propellant tanks for flight.
Beyond fixing the helium issue, teams will also install new batteries for the SLS upper stage, core stage, and solid rocket boosters, retest the flight termination system, and refresh avionics and control systems.
The Orion spacecraft’s launch abort system batteries will also be recharged, and engineers may refresh some stowed items inside the crew module.
WHEN WILL ARTEMIS II LAUNCH?
Pending the outcome of data reviews and repair efforts, the Artemis II Moon rocket is expected to roll back to Launch Pad 39B in time for launch in April.
The mission will carry Nasa astronauts Reid Wiseman, Victor Glover, and Christina Koch, along with Canadian Space Agency (CSA) astronaut Jeremy Hansen, on a free-return trajectory around the Moon.
Artemis II is the first crewed lunar mission since Apollo 17 in 1972.
The 10-day mission will also carry a payload called Avatar that will include devices that mimic individual astronaut organs to study the effects of radiation and microgravity on human health.
It is also the first crewed flight of the SLS rocket and Orion spacecraft, and serves as a vital precursor to Artemis III, which aims to land the first woman and first person of colour on the lunar surface in 2027.
