Artemis II: Day Three
Past the halfway mark already
The Orion capsule Integrity has been sent on its course around the Moon, the ultimate objective of the mission lies another two days ahead, and for now it is all about mastering interplanetary flight in this spacecraft.
The life support system of the capsule ultimately responds to the presence of humans; for example, someone has to be breathing out carbon dioxide for the scrubbers to remove. So the crew can be thought of as part of the system themselves, and part of the process of testing it.
There had been complaints about both the temperature and humidity in the capsule being too low, both of which were resolved. The lower humidity in particular makes the performance of the carbon dioxide scrubbers worse. Somewhat more concerning, there was another anomaly with the on board toilet. In a worst case scenario the crew is able to relieve themselves into special bags, but fortunately the problem was fixed.
Aside from debugging issues with the life support systems, the crew exercised using a flywheel system to provide resistance, while mission control monitored any vibrations this caused in the spacecraft.
The Halfway Point
Integrity passed the halfway point to the Moon, in terms of distance, early today. At the time of writing it is even closer according to the most current tracking data:
The Moon has not yet entered this plot; it will appear tomorrow.
So far the trajectory is excellent; the trans-lunar injection burn was accurate enough that the error was only 0.8 metres/second, small enough that mission control decided to cancel today’s course correction.
The spacecraft slows as it gets further from Earth, so the closest approach will still not be for another three days. The crew are already preparing for this though, and spend some time testing how the spacecraft will be configured at the time of flyby, in terms of arrangement of cameras and orientation.
Space in Space
There was a conversation between Mission Specialist Christina Koch and mission control today about where to store some waste bags. The capsule is packed with supplies, and aside from the venting overboard of urine and excess CO2, all of the waste the crew produces must remain inside. So generally, waste has to be placed into the lockers that contained the supplies being used up.
As can be seen above, it is fairly cramped inside, but not that much by space capsule standards. The habitable volume of the spacecraft is about 9.3 cubic metres, shared between 4 astronauts. In comparison, an Apollo capsule had about 5.8 cubic metres shared between 3 astronauts. That means 2.2 cubic metres per crew in Orion compared to 1.9 cubic metres per crew in Apollo - the extra room being what allows facilities such as the dedicated toilet, exercise machine etc.
However, this is a lot less roomy than the Space Shuttle, which provided 8.9 cubic metres per crew, or as much as 14.7 cubic metres when flying with its Spacelab or Spacehab modules[1]. If Orion is going to be involved in deep space missions longer than this one, it will have to dock with something larger.
Yesterday I previewed some discussion of the broader Artemis plan; that will be in tomorrows update, as I ended up having more to discuss here than I thought.. If you haven’t already, please consider subscribing to follow along with the mission.
I worry about using a reentry path kludge to reduce stress on the heat shield. Haste makes dead astronauts.