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Larry Friesen, acting MDTC Secretary
The Artemis Society Mission Design Technical Committee (MDTC) held its first in-person meeting Dec. 12, 1995. Jim Sewell was designated the committee chairman. Larry Friesen became de facto secretary (not officially appointed). We met about once a month thereafter until Nov., 1996. Jim Sewell was unable to continue as Chairman, and MDTC is currently looking for a replacement.
The following summary is only roughly chronological. The committee defined its own function as designing operations, not hardware. The design of operations may levy requirements on hardware, but hardware is not the our primary concern.
It was further decided that the scope of our mission should extend through the first human crew to reach the lunar surface and return to Earth alive and well. This includes all preparatory flights, including unmanned flights, up to that point.
We agreed that the first mission ought to leave certain items in off-Earth locations for future use, including a lunar transfer vehicle (LTV) in low Earth orbit (LEO), a habitat on the lunar surface, a lunar ascent stage (probably in LEO), and possibly a robot vehicle on the lunar surface to pack lunar soil around the habitat.
The committee also understood that although it was responsible only for operations through the successful completion of the first human flight, it should plan those operations with an eye toward later human activities on the Moon, and at the very least, should not design the first mission in a way that'd make subsequent activities more difficult.
We decided that the committee does not have the function of maintaining the Artemis Project's technical data base, although it must certainly have access to that data base. Data base maintenance was seen to belong more logically to some other Artemis Project Technical Committee.
We identified a series of basic steps that must be taken to get a crew launched and sent to the Moon (this identification continued through the 2nd meeting). This list identifies activities that must be done to get the mission accomplished, not actions that we ourselves must perform. These steps are:
1. Select a lunar landing site, or a reasonable set of options from which a final selection can be made.The second meeting of the committee included a meeting with Lou Ramon, Director of Mission Development for the Artemis Project. We decided that the Mission Design Technical Committee should report to, and support him, or any successor who should hold that position. Vehicle sketches, weight breakdown, and timelines for Artemis Reference Mission were provided by Greg Bennett, passed out at 2nd meeting. Timeline chart included initial Delta-V calculations for reference mission launches, landing, and maneuvers.2. Decide what equipment, if any, needs to be sent to the landing site before humans arrive, what equipment needs to remain at the landing site after the first crew is gone, and whether any assets are needed in lunar orbit before, during, or after the first human flight.
3. GET precursor equipment to lunar orbit and/or the lunar landing site.
4. Decide what is to be brought back from the Moon in addition to the crew, such as: mission equipment, lunar samples, photos/video, souvenir items brought from Earth and returned (stamps, toys, etc.), and/or biosamples from the crew or any other organisms that might be brought on the trip.
5. Set requirements for lunar habitat: e.g. crew size, gender mix, stay times, etc.
6. Consider vehicle, rendezvous, and flight path options.
7. Decide how much autonomy vs. how much ground support is desirable for the mission.
8. Define selection criteria and training requirements for both the flight crew and support personnel on the ground.
9. Define what post-mission operations the initial mission organization needs to be responsible for, such as lunar sample curation and storage.
10. Design the lunar mission and select a launch system. These two activities are interdependent and need to be considered together.
11. Construct the lunar mission vehicle.
12. Select the flight crew.
13. Train the flight and ground crews.
14. Define the mission plan and timeline (closely related to step 13).
15. Launch the vehicle and crew to LEO.
16. Assemble the vehicle in LEO if it is not launched in one piece.
17. Trans-Lunar Injection (TLI) [the maneuver that sends the spacecraft out of LEO toward the Moon].
18. Insertion into low lunar orbit (LLO), a Lagrange point orbit, or direct lunar descent, depending on what mission plan is developed.
19. Lunar landing (if step 18 was insertion into LLO or a Lagrange point orbit).
20. Lunar surface operations.
21. Lunar ascent.
22. Rendezvous with orbital vehicle (unless step 18 was direct lunar descent).
23. Return to LEO.
24. Land on Earth.
25. Postflight crew and hardware operations, including medical attention for the crew if needed.
The Technical Library at Johnson Space Center was checked to find out if the lunar landing site criteria used for the Apollo project were readily available. Quite a bit of information was located on microfiche which, by title appears to pertain to Apollo landing site criteria. However, the microfiche has not as yet been examined.
We brainstormed to define skills/knowledge that need to be represented on the MDTC. Those identified were (in random order):
1. Orbital mechanics.The committee decided that lunar surface habitat requirements cannot be determined until crew size, mix, stay time, and activities are defined. What can be determined in advance of that are life support requirements per person per unit time.2. Rocketry and spacecraft design.
3. Mission planning. Includes at least 3 subtopics:
a. Systems engineering.
b. Program engineering.
c. Timelining and sequencing.
4. Logistics.
5. Data hunting and archiving (aka Library skills).
6. Use of Internet and World Wide Web.
7. Computer data base design and management.
8. Technical liaison to other Artemis technical committees, including:
a. Delegation of subtasks to other technical committees.
b. Persuading the other committees to do the delegated tasks.
9. Life support requirements.
10. Software engineering.
11. Publicity and artistic appeal.
12. Secretarial skills.
We proposed that any lunar base will need communication gear, some level of computing power, and some form of temperature control, although the types and amounts of these are yet to be defined.
Committee members helped with planning and preparation for the Artemis '96 Conference, because they were among the more active members of the Houston Artemis chapter. We sought out papers on uses of lunar materials for a wide variety of functions. And we found data about several methods for generating oxygen on the Moon, from lunar resources.
One member prepared outlines for proposed lunar mission profiles for Artemis Project missions 1 through 15, meant not as "last words" but as aids to planning. These were discussed in view of what items each mission would bring to the Moon. "Safari" type tourism could start as early as Mission 7 in this sequence. This would be a very expensive and very much "roughing it" type of expedition such as a rich 19th century Englishman could have financed to visit Africa. This set of missions was subsequently expanded to include support and supply missions.
We also discussed how lunar flights might mesh with any orbital infrastructure that might be located in LEO, LLO, and/or the Earth-Moon L1 Lagrange point, deciding that it will be important to consider what types of orbital infrastructure could best support long term lunar operations, and in what orbit or orbits that structure would best be located.
One member performed an independent check of the delta-velocities being used for the Artemis Reference Mission, and reported finding a possible omission of a delta-V for capturing the Lunar Transfer Vehicle (LTV) into lunar orbit. He also noted that there would be a 530 meters/second plane change delta-V penalty for a Reference Mission spending 10 days on the lunar surface at 22 degrees north lunar latitude. Such plane change delta-velocities can be avoided if the LTV is placed in lunar polar orbit and the lunar surface stay time for the crew is 13.7 days (1/2 of a lunar sidereal period) or an integer multiple thereof. Greg Bennett reported correcting errors found in the Reference Mission delta-V's in the Artemis on-line file.
The issue was raised of revisiting the Artemis Reference Mission with the following consideration: The committee needs to identify any pieces of equipment the Artemis Reference Mission expects will be supplied by parties outside the Artemis Project and determine for each whether it is essential for the Reference Mission. For each such essential piece of equipment, it is necessary to have a plan in place for the Artemis project to supply that piece for itself if no outside party does so after all.
The first example named was the rover or dozer that will cover the habitat with regolith. The habitat must be covered, even though the Reference Mission statement (as of 10/1996) does not envision the Artemis Project itself supplying the rover/dozer.
We noted that the Artemis Project must understand what the requirement for LTV reusability implies for LTV refueling capacity, rendezvous and docking capabilities, hardened electronics with redundancies (against radiation damage), and its ability to operate unmanned. Unmanned LTV operation has two aspects: vehicle autonomy, and ability to be controlled from the ground.
The question was also raised as to whether the LTV will need an on-orbit tender, and if so, what capabilities the tender must have. If the LTV does not have an on-orbit tender, it will need certain capabilities and hardware - and therefore weight - it would otherwise not need. For example, without an orbital tender, the LTV will need some robot manipulating capability, similar to a Shuttle robot arm, to move and handle vehicle components and hardware items, to assemble the "stacks" for the second and later flights to the Moon.
If a tender is used, it would eventually become a construction shack and transfer node for missions to the Moon. It could later grow into a full fledged space station whose primary focus is lunar transportation support. The tender is another example of a piece of equipment that could be supplied by organizations not directly connected with the Artemis Project, because its services could be useful for a variety of customers.
We noted a number of lunar surface robotic capabilities the Artemis Project will need, such as:
1. Pre-mission survey of the proposed landing site.2. A good quality camera in place at or near the landing site before the first manned mission, able to acquire the incoming spacecraft autonomously and track it all the way to landing. It is desirable for the lander spacecraft to be able to use the camera site as a beacon.
3. Dirtmoving and/or bulldozing.
Not all of these capabilities need to be incorporated into the same robot. They could be combined, or divided among several. All lunar surface robots, however, will have to be robust to temperature changes and to solar and galactic cosmic radiation. <LF/MDTC>