NASA Continues To Prepare For Artemis 1 & More
It has been around half a century since the last time humans stepped foot on the Moon. This is set to change in only a few years as NASA continues to prepare for the Artemis missions. Just a few days ago we watched Rocket Lab launch CAPSTONE into space headed to the Moon with the goal of learning more about Gateway’s future orbit.
In addition, after finishing the wet dress rehearsal of the Space Launch System, the agency is now moving on to the next steps in preparation for the first launch of the rocket. Since returning to the VAB, teams extended the access platforms surrounding the rocket and spacecraft to perform repairs and conduct final operations before returning to launch pad 39B for the Artemis I mission.
This launch will be one of the most significant in a long time as the results will have a big impact on the timeline and future of returning humans to the Moon. Not to mention the fact that Artemis hopes to not only put humans back on the surface but set up a more permanent human presence. Here I will go more in-depth into the recent progress, next steps, and what to expect in the coming months.
Recent Updates
Just a few days ago on July 7th, NASA tweeted saying, “New POV! Take a peek at the RS-25 engines gimballing during the latest wet dress rehearsal test. The engines on the Space Launch System will move during flight to steer the rocket and maintain a proper trajectory.” This tweet included a short video of the four engines gimballing. Only a few hours ago the agency tweeted again this time mentioning, “Since the SLS rocket and @NASA_Orion spacecraft arrived back at the VAB at @NASAKennedy on July 2nd, teams extended the access platforms to perform repairs and conduct final operations before returning to launch pad 39B for the #Artemis I mission.” More specifically, technicians are currently working to inspect, fix, and check out equipment associated with a seal on the quick disconnect of the tail service mast umbilical that was identified as the source of a hydrogen leak during the wet dress rehearsal test that ended June 20. During propellant loading operations on that day, launch controllers encountered a hydrogen leak in the quick disconnect that attaches an umbilical from the tail service mast on the mobile launcher to the rocket’s core stage. The team attempted to fix the leak by warming the quick disconnect and then chilling it back down to realign a seal, but their efforts did not fix the issue. Since then, engineers have disconnected the umbilical and are in the process of examining the area where they will replace two seals on the quick disconnect hardware. Working in tandem with those repairs, engineers also completed the last remaining engineering test that is part of the integrated testing operations in the VAB.
Teams also performed additional planned work on aspects of the rocket and spacecraft. Engineers swapped out a computer on the Interim Cryogenic Propulsion Stage called the Inertial Navigation and Control Assembly unit that was used during wet dress rehearsal activities with the one that will be used for flight and will test the unit next week. The newly installed flight unit includes freshly calibrated inertial navigation sensors and updated software to guide and navigate the upper stage during flight. Technicians also activated several batteries for the rocket elements, including for the solid rocket boosters and the ICPS. The batteries on the core stage will be activated in the coming weeks, and all the batteries will then be installed. The batteries provide power for the rocket elements during the final portion of the countdown on launch day and through the ascent. Engineers also charged the batteries for the secondary payloads located on the Orion stage adapter and will work to install payloads inside the Orion spacecraft in the coming weeks.
CAPSTONE’s Progress
In addition to the continued work on the Space Launch System, the agency has been working to ensure CAPSTONE works as intended and reaches the Moon. After a successful launch and deployment of the payload from Rocket Lab’s lunar photon, CAPSTONE began its solo journey to the Moon. However, the payload experienced communications issues following its deployment on July 4th. The spacecraft successfully deployed solar arrays, was stabilized, and began charging its onboard battery. CAPSTONE’s propulsion system was also readied for the spacecraft’s first maneuver. CAPSTONE made initial contact with the DSN ground station in Madrid, Spain, followed by a partial contact with the Goldstone ground station in California. From these contacts, mission operators were able to determine CAPSTONE’s approximate position and velocity in space. As a result of the communications issues, CAPSTONE’s first trajectory correction maneuver, originally scheduled for the morning of July 5, was delayed. This maneuver is the first in a series that are designed to make small corrections to increase the accuracy of the transfer orbit to the Moon, and the spacecraft remains on the overall intended ballistic lunar transfer while awaiting this trajectory correction. Thankfully, not long after the issues arose, NASA was able to reestablish communications.
While investigating the issue, the spacecraft operations team attempted to access diagnostic data on the spacecraft’s radio and sent an improperly formatted command that made the radio inoperable. The spacecraft fault detection system should have immediately rebooted the radio but did not because of a fault in the spacecraft flight software. CAPSTONE’s autonomous flight software system eventually cleared the fault and brought the spacecraft back into communication with the ground, allowing the team to implement recovery procedures and begin commanding the spacecraft again. While CAPSTONE was out of contact with Earth, the spacecraft autonomously maintained its orientation to keep its antenna pointed towards Earth and allow the solar panels to keep its battery charged. CAPSTONE also used its thrusters to perform a standard maneuver to dump excess momentum from its reaction wheels, which are internal wheels that help the spacecraft rotate and point itself. The mission operations team conducted CAPSTONE’s first trajectory correction maneuver at approximately 11:30 a.m. EDT on July 7th.
Most recently, CAPSTONE successfully completed its first trajectory correction maneuver, which started at 11:30 a.m. EDT Thursday. This is the first in a series of thruster burns over the next few months to more accurately target CAPSTONE’s transfer orbit to the Moon. The maneuver lasted just over 11 minutes and changed the spacecraft’s velocity by about 45 miles per hour (about 20 meters per second). CAPSTONE’s next trajectory correction maneuver is targeted for Saturday, July 9th. CAPSTONE is now about 289,000 miles from Earth, beyond the orbit of the Moon. CAPSTONE will loop back around and arrive at its lunar orbit, called a near rectilinear halo orbit, or NRHO, on November 13th. CAPSTONE will fly in the NRHO for at least six months to study the dynamics of the orbit, which is the same one intended for Gateway, a lunar space station for science and human exploration under Artemis.
After a four-month journey to its target destination, CAPSTONE will orbit this area around the Moon for at least six months to understand the characteristics of the orbit. Specifically, it will validate the power and propulsion requirements for maintaining its orbit as predicted by NASA’s models, reducing logistical uncertainties. It will also demonstrate the reliability of innovative spacecraft-to-spacecraft navigation solutions as well as communication capabilities with Earth. The NRHO provides the advantage of an unobstructed view of Earth in addition to coverage of the lunar South Pole. To test these new navigation capabilities, CAPSTONE has a second dedicated payload flight computer and radio that will perform calculations to determine where the CubeSat is in its orbital path. Circling the Moon since 2009, NASA’s Lunar Reconnaissance Orbiter (LRO) will serve as a reference point for CAPSTONE. The intention is for CAPSTONE to communicate directly with LRO and utilize the data obtained from this crosslink to measure how far it is from LRO and how fast the distance between the two changes, which in turn determines CAPSTONE’s position in space. This peer-to-peer information will be used to evaluate CAPSTONE’s autonomous navigation software. If successful, this software, referred to as the Cislunar Autonomous Positioning System (CAPS), will allow future spacecraft to determine their location without having to rely exclusively on tracking from Earth. This capability could enable future technology demonstrations to perform on their own without support from the ground and allow ground-based antennas to prioritize valuable science data over more routine operational tracking.
Conclusion
NASA has been very busy over the past few weeks with a bunch of projects revolving around future Artemis missions. We recently watched the agency return the Space Launch System to the VAB in addition to the launch of CAPSTONE. We will have to wait and see how it progresses and the impact it has on the space industry.