On The Need for Lunar Lander Simulations: A Human Factors Perspective Robert S. McCann

1. On The Need for Lunar Lander Simulations: A Human Factors Perspective Robert S. McCann Human-Systems Integration Division NASA Ames Research Center Go For Lunar Landing Conference March 5 2008

2. Human Factors of Lunar Landing Simulations • Apollo: all landings near-side equatorial • LEM operations concept heavily dependent on real-time communications loop with the ground • Preliminary Altair Concept of Operations: • Anywhere, anytime landing capabilities • Includes polar and far-side targets • Strong possibility of autonomous descent and landing operations requirement

3. Trajectory Management Inner-loop Flight Control Systems Health Management Mission Decision Making Lunar Lander Descent and Landing Operations • What is the workload associated with the task? • What are the task related crew-vehicle interfaces?

4. Lessons Learned from Apollo 11 Operations: Workload • Apollo Operational Workload Assessment: “The most difficult part [of the entire mission] from my perspective, and the one that gave me the most pause, was the final descent to landing” “far and away the most complex part of the flight” “systems were very heavily loaded at that time” “the unknowns were rampant” “there were just a thousand things to worry about… It was hardest for the system and it was hardest for the crews to complete that part of the flight successfully” - Neil Armstrong, September 2001

5. Apollo 11 LEM Descent and Landing Operations • 102:38:26 Armstrong: (With the slightest touch of urgency) Program Alarm. • 102:38:30 Armstrong: (To Houston) It's a 1202. • 102:38:32 Aldrin: 1202. (Pause) • 102:38:42 Armstrong (on-board): (To Buzz) What is it? • (To Houston) Give us a reading on the 1202 Program Alarm. • 102:38:53 Duke: Roger. We got you...(With some urgency in his voice) “We're Go on that alarm.”

6. Systems Health Management Mission Decision Making Apollo 11 Operations • “I was very much in the dark when this came up.” - Buzz Aldrin • “Our most knowledgeable NASA software engineer advised Mission Control to inform the astronauts to push on. It was a gutsy call.” - Fred H. Martin, M.I.T. Instrumentation Laboratory

7. Mission Decision Making Apollo LEM Operations Second Malfunction: Descent and Landing Phase Trajectory Management Inner-loop Flight Control Systems Health Management

8. Lessons Learned from Apollo 11 Operations • 102:44:45Aldrin: 100 feet, 3 1/2 down, 9 forward. Five percent (fuel remaining). Quantity light. • Quantity light indicated that 5.6% of the original propellant load remained • Started a 94-second countdown to a 'Bingo' fuel call which meant ‘land in 20 seconds or abort’ • If you're 50 feet up at 'bingo fuel' with all of your horizontal rates nulled and are coming down to a good spot, you could certainly continue to land… At anything over 100 feet, you'd punch the abort button and say goodbye to the moon • Quantity light was based on erroneous sensor reading

9. Lessons Learned from Apollo 11 Operations • “As we got lower, the visibility continued to decrease. • The thing that was confusing to me was that it was hard to pick out what your lateral and downrange velocities were, because you were seeing a lot of moving dust that you had to look through to pick up the stationary rocks and base your translational velocity decisions on that. • I found that to be quite difficult. • As we approached the ground, I still had a left translational rate which made me reluctant to shut the engine off while I still had that rate. I was also reluctant to slow down my descent rate anymore than it was, or stop (the descent), because we were close to running out of fuel. We were hitting our abort limit." • - Neil Armstrong

10. Lessons Learned from Apollo 11 Operations • Workload with Apollo’s (or even shuttle’s) level of onboard decision-making and systems management support could very likely have overloaded the crew • Autonomous operational concept for descent/landing requires the development of various forms of onboard decision support tools: • Systems health management tools (e.g. Advanced Caution and Warning System) • Automated flight control tools • Automated mission management support tools

11. Lessons Learned from Apollo 11 Operations • Infusing automated support tools for autonomous descent and landing operations raises a host of operational concept definition issues, such as: • Determining the appropriate crew-machine functional allocation (level of automation) from the well-known levels of automation scales (e.g., Sheridan-Verplank) • Designing crew interfaces with automation to • A) enable crew to maintain situation awareness of automated actions and their causes • B) enable smooth reversion to manual control in the event of automation failure • Promoting effective crew resource management

12. Altair Ops Concepts Definition • These operational concept development issues create an urgent need to design, develop, test, and validate: • Decision support software • Autonomous operational concepts that involve the decision support software via human-in-the-loop simulation • Failure to do so in a timely manner raises considerable risk that autonomous descent and landing operations will fail constellation human-system integration requirements for operational error and crew workload