Animation of the Orion spacecraft flying around the Moon. Credit: NASA.
During Artemis I, which is scheduled to launch on August 29, NASA plans to accomplish several major goals. These include demonstrating Orion spacecraft heat shield performance from lunar return speeds, demonstrating operations and facilities during all phases of the mission from launch countdown to recovery and recovery of the crew module for post-flight analysis.
However, as the first integrated flight of the Space Launch System rocket, the Orion spacecraft and ground exploration systems at NASA’s 21st Century Spaceport in Florida, engineers hope to accomplish a number of additional test goals to better understand how spacecraft work in space and prepare for future crewed missions.
Accomplishing additional objectives helps reduce the risk of missions with a human crew on board. This also provides additional data for engineers to assess trends in spacecraft performance or improve confidence in spacecraft capabilities. Some of the additional objectives planned for the Artemis I mission include:
Modal survey
In the European-built service module, Orion is equipped with 24 Reaction Control System (RCS) thrusters. These are small engines responsible for moving the spacecraft in different directions and making it rotate. The modal survey is a prescribed series of small RCS shots that will help engineers ensure the structural margin of Orion’s solar array wings during the mission. Flight controllers will command several small triggers on the motors to cause the arrays to flex. They will measure the impact of shots on the arrays and assess whether the inertial measurement units used for navigation are experiencing what they should. Until the modal survey is complete, large translational burns are limited to 40 seconds.
During Artemis I, the uncrewed Orion spacecraft will launch on the world’s most powerful rocket and travel thousands of miles beyond the Moon, farther than any human-built spacecraft has ever flown. Credit: NASA
Optical navigation camera certification
Orion has an advanced guidance, navigation and control (GN&C) system. This is responsible for always knowing where the spacecraft is in space, where it is pointing and where it is going. It mainly uses two star trackers. These sensitive cameras take images of the star field around Orion, the Moon, and Earth, and compare the images to the built-in star map. The optical navigation camera is a secondary camera that takes images of the Moon and Earth to help orient the spacecraft by observing the size and position of celestial bodies in the image. Several times during the mission, the optical navigation camera will be tested to certify it for use on future flights. Once certified, the camera can also help Orion return home autonomously if it loses communication with Earth.
Wi-Fi characterization of the solar array wing camera
Cameras placed on the tips of the solar array’s wings communicate with Orion’s camera controller via an onboard Wi-Fi network. Flight controllers will vary the positioning of the solar arrays to test Wi-Fi strength while the arrays are in different configurations. The test will allow engineers to optimize how quickly images taken by cameras at the ends of the arrays can be transmitted to on-board recorders.
Artemis I will be the first integrated flight test of NASA’s Deep Space Exploration System: the Orion spacecraft, the Space Launch System (SLS) rocket, and ground systems at the Kennedy Space Center in Cape Canaveral, Florida. The first in a series of increasingly complex missions, Artemis I will be an unmanned flight that will provide a foundation for human exploration of deep space and demonstrate our commitment and ability to extend human existence to Moon and beyond. During this flight, the uncrewed Orion spacecraft will launch on the world’s most powerful rocket and travel thousands of kilometers beyond the Moon, farther than any human-built spacecraft has ever flown, during a mission of ‘about three weeks. Credit: NASA
Crew Module/Service Module Surveys
Flight controllers will use cameras on the four wings of the solar array to take detailed photos of the crew module and service module twice during the mission to identify any micrometeoroid impacts or orbital debris. A survey conducted early in the mission will provide images shortly after the spacecraft has flown past the altitude where the space debris resides, and a second survey will be taken on the return leg several days before reentry.
Large File Delivery Protocol Uplink
Mission control engineers will link large data files to Orion to better understand how long it takes the spacecraft to receive important files. During the mission, the flight controllers use the deep space network to communicate and send data to the spacecraft, but pre-flight tests have not included the use of the network. The test will help inform engineers’ understanding of whether the spacecraft’s uplink and downlink capability is sufficient to support human qualification validation of end-to-end communication before Artemis II, the first flight with astronauts.
During Artemis I, Orion will venture thousands of kilometers beyond the Moon during a roughly three-week mission. Credit: NASA
Thermal evaluation of the star tracker
Engineers hope to characterize the alignment between the star trackers that are part of the guidance, navigation and control system and Orion’s inertial measurement units, exposing different areas of the spacecraft to the Sun and activating the trackers. stars in different thermal states. The measurements will report the uncertainty in the navigation state due to thermal bending and expansion that ultimately affects the amount of propellant required for spacecraft maneuvers during manned missions.
Radiator flow control
Two radiator loops on the spacecraft’s European Service Module help expel heat generated by various systems throughout the flight. There are two modes for the radiators. During speed mode, the radiator pumps run at a constant speed to help limit vibration and is the primary mode used during Artemis I and during launch for all Artemis flights. The control mode allows better control of the radiator pumps and their flow, and will be used in manned missions when more refined control of the flow through the radiators is desired. This objective will test the control mode to provide additional data on how it performs in space.
Artistic impression of Orion on the Moon. Orion is NASA’s next spacecraft to send humans into space. It is designed to send astronauts further into space than ever before, beyond the Moon to the asteroids and even to Mars. When they return to Earth, the astronauts will enter our atmosphere at speeds in excess of 32,000 km/h, but the capsule will protect them and ensure a bumpy but safe landing. Credit: NASA/ESA/ATG Medialab
Solar Array Wing Feather
Depending on the angle of the wings of the Orion solar array during some thruster shots, the plume or exhaust gases from those shots could increase the temperature of the arrays. Through a series of small RCS shots, engineers will collect data to characterize the heating of the solar array wings.
Propulsive slosh
Liquid propellant stored in spacecraft tanks moves differently in space than it does on Earth due to the lack of gravity in space. Propeller motion, or slosh, in space is difficult to model on Earth, so engineers plan to collect data on propellant motion during various planned activities during the mission.
Search and Track (SAT) mode.
SAT mode is an algorithm intended to regain and maintain communications with Earth after the loss of Orion’s navigation status, a prolonged loss of communications with Earth, or after a temporary power loss that have Orion reboot the hardware. To test the algorithm, flight controllers will command the spacecraft to enter SAT mode and, after about 15 minutes, restore normal communications. Testing the SAT mode will give engineers confidence that it can be relied upon as the final option for resolving a loss of communications when a crew is on board.
This artist’s rendering shows an aerial view of the liftoff of NASA’s Space Launch System (SLS) rocket. This configuration of the Block 1 crew of the rocket that will send the first three Artemis missions to the Moon. Credit: NASA/MSFC
Aerothermal inlet
During the spacecraft’s entry through the Earth’s atmosphere, a prescribed series of 19 shots will be made of the reaction control system on the crew module to understand performance compared to projected data for the sequence Engineers are interested in collecting this data during high heating in the spacecraft where aerothermal effects are greatest.
Integrated Search and Rescue Satellite Assisted Tracking (SARSAT) functionality.
The SARSAT test will verify the connectivity between the beacons that will be used by the crew on future flights and the ground stations that will receive the signal. The beacons will be remotely activated and powered for about an hour after the splash and will also help engineers understand if the transmitted signal interferes with communications equipment used during recovery operations, including the three-way beacon Orion’s integrated band that transmits the precise location of the spacecraft after splashdown. .
Restarting the ammonia boiler
After Artemis I crashes, Orion’s ammonia boiler will shut down for several minutes and then restart to provide additional data on system capability. Ammonia boilers are used to help control the thermal aspects of the spacecraft to keep its avionics and power systems cool and to keep the interior of the crew module at a comfortable temperature for future crews. In some potential contingency landing scenarios for manned missions, crews may need to shut down the ammonia boiler to check for hazards outside the spacecraft, then turn it back on to provide additional cooling.
Engineers…