Ricochet is the best place on the internet to discuss the issues of the day, either through commenting on posts or writing your own for our active and dynamic community in a fully moderated environment. In addition, the Ricochet Audio Network offers over 50 original podcasts with new episodes released every day.
Building an Apollo Simulator
For two years, I’ve been working to program and build a complete Apollo space flight simulator to use in my physics classes. When I say “complete,” I mean not just a computer program that lets you fly, but a mock-up of the spacecraft control panels and the entire Mission Control, as well.
I’m a physicist, and I do a lot of computer programming in my research, so I started with writing a Python language program to handle the physics of space flight. The basic idea is that, given a starting position and speed, you add up the forces acting on the spacecraft (gravity, atmospheric drag, engines), and from that you get the acceleration. That gives you, in turn, the new position and speed. Step the clock forward a fraction of a second, and repeat. I have a lot of computer engineering students in my class, so it fit naturally with the lessons.
I was able to write the main program by myself, but I wanted more than just a few numbers dancing around my laptop screen, accurate though they may be. I needed a view out the window, switches to control the spacecraft, and terminals for the flight controllers down in “Houston” to watch the telemetry. The graphics and networking were something I’d never done before, so I hired one of my students to handle all of this.
The view from the astronauts’ seats.
For the spacecraft, I built a control panel out of whiteboard panel and borrowed toggle switches and lights from the Engineering Department for the most basic flight controls: abort, engine, parachutes, attitude, and stage separation. They gave me an Arduino microcontroller to connect them to the simulator (more programming for my student). My student set up graphics for the earth, moon, and stars, so the astronauts would have a view out the window, and he put in a display for the Apollo Guidance Computer. Finally, I printed out a full-sized poster of the actual Command Module control panel to give them more sense of being in and surrounded by the spacecraft.
Mission Control was easier, in a lot of ways. The flight controllers only need to look at telemetry—numbers and plots—no fancy graphics, but we had to figure out how to send all of that from my laptop, over the network, and get it to display, live.
The last component was the Mission Planning and Analysis Division, who works out the orbits and the plans for maneuvers, to get the crew out to the Moon and back. That meant a few more programs from me that would let the students design the orbit, and I had to test it out myself to make sure I could put the whole flight together.
Finally, I had to write up manuals and procedures for everybody. The astronauts needed to know how to handle maneuvers and reentry. The flight controllers had to know what problems to look for and when to call an abort.
I had originally planned to have it ready for next summer, on the 50th anniversary of the Apollo 11 moon landing. But I started to realize that it was coming together faster than I expected, so I pushed the date up and committed to having the class carry out a round-the-moon flight (a recreation of Apollo 8, without any landing) this semester. Last month, I finally had it ready to go, and we had a launch.
View of Mission Control
I split the class into two teams, Red and White, who would take separate shifts and assigned each of the students to a role I thought they were well fitted for. Astronauts and the Flight Dynamics Officer (FIDO) had pretty hefty duties, so those went to some of the best students. CAPCOM (capsule communicator, the only one to speak directly to the crew) went to the chattier students. Others were more flexible in the assignments. In the view here, Red CAPCOM is talking through a walkie-talkie app to the astronauts.
My Mission Control security badge
You might see green badges on the students’ shirts. I made a fair imitation of the original Mission Control badges using Powerpoint, typed their names on them with my manual typewriter, and laminated them.
So how did it go? Pretty well, considering it was our test flight. A real crowd turned up to watch us. We had two launches and two reentries. The first launch went smoothly, mostly because of the bug that kept me from creating the engine failure I was trying to slip them. The second time, I gave them one engine failure on the second stage. The Booster Systems Engineer caught it and said we could continue on the other four engines. Then I made a second one fail, and he correctly called an abort. This caused some excitement, and I could hear the astronauts (in the same room with us for practice runs) frantically hitting the abort switch.
The first reentry had a real—and unplanned—switch failure that made the crew skip out of the atmosphere, because they couldn’t roll the spacecraft into the correct orientation. The second reentry was very smooth. As they entered the radio blackout (I’ve made the simulation stop sending data to Mission Control as long as it lasts), we heard a phone buzz. It was a telemarketer calling up one of the astronauts! That relieved some tension in the room, as people started joking about it. I remarked how impressed I was that they’d gotten the call through the ionization blackout. Perhaps we should hire them to handle communications. Finally, the crew opened their parachutes and splashed down gently in the Pacific Ocean.
Everybody had a great day, even though we didn’t wind up with enough time for the actual flight around the Moon. So I’m starting up a Spaceflight Club to give us more chance to practice the flights and carry out a full mission. I’m getting Engineering to machine a full-scale, realistic control panel. I’ll have all of the dials and switches of the real spacecraft, and it will be painted up to look like the original. By this coming summer, this is going to be pretty fantastic.
Published in Education
What an incredible project, @timh! I am so impressed, not only at what you accomplished (since I don’t much understand the technical stuff), but your dedication to the learning process, making it exciting and fun!
We watch the launches from Canaveral from our large kitchen window. (I was disappointed they postponed today’s, but it’s supposed to go off tomorrow.) I watch TV until the rocket flame appears outside my window. To me it’s all magical.
May I join your Spaceflight Club?
Way. Waaaaay cool. God speed Tim H. !
I know a gentleman who worked for the old Delco company in Santa Barbara, CA. He was involved in guidance systems and once showed me his NASA Apollo 13 mission handbook. Talk about cramming commands, telemetry, and nominal mission profile in one small, but bulky source.
Is it KSP-compatible?
No, it follows my & my student’s own custom pattern for the networking. But with Kerbal Space Program out there and especially the Project Apollo add-on to the Orbiter software, it might be nice to have some way of connecting them. The thing is that both Kerbal and Orbiter simulate the physics themselves, and most of my work has been in doing the physics, as well. So there’s duplicated effort there.
Orbiter is really impressive, and I’d like to try it myself, but it is Windows-only, and I have a Mac. Maybe run a virtual machine? I’ve seen where people have worked out control panels for the Apollo Guidance Computer to use with the Orbiter software, for example.
Some of the old Mission Control team members and Astronauts from Apollo are still around and kicking. Have you thought about letting them know of your project?
Outstanding teacher and project! Fantastic job and what a lesson!
That’s a great class project. Robert Zimmerman recently made an interesting comment on his blog.
Re Poindexter’s comment:
You might want to post a comment on http://www.collectspace.com Apollo era people post on this website.
Any time you’re around southern Ohio, please stop by, and I’ll show it to you.
I got up this morning, eager to watch four launches today, if only online, and I’ve been disappointed to have three scrubbed already. #4 isn’t looking good with the weather constraints, either.
I have been so happy with NASA’s Technical Reports Server. I have some of the Delco documents for the Apollo Guidance Computer (printed off all 400+ pp. of it!), in fact. Nearly everything I’ve needed to know, I’ve been able to find there.
Scans are great and useful, but for sheer historical feel, I’d love to get my hands on some original copies.
In the same vein, you could give extra credit to students who help you recreate the smells, sounds, and vibrations of the simulator and control room.
That’s a good idea. I’ve talked to Gene Kranz’s daughter via Twitter and told her about it. She worked under her father in the Shuttle era, and she gave me some tips on Mission Control, as well as the reference to a new book by one of the old guard. Sy Liebergot has been pretty active in explaining the history of Mission Control and how things worked in the past few years. Maybe I ought to contact them and let them know. I’ll wait ’til I’ve got the Mark II hardware done and it looks realistic in the Spring.
Oh—and a bunch of the old guys, including Kranz, have been down in Houston to help with the preservation and restoration of the original MCC room there to its Apollo-era condition. Three original flight controllers’ consoles had gone up on NASA surplus last month, and I was applying to try to get one for my college, but we didn’t win it. That would have been a fantastic display, though, wouldn’t it have?
Heh—I actually plan to put in speakers behind the astronauts and some solenoids to make the structure vibrate and “thump” whenever certain maneuvers are performed. Long term, I’d love to work up a 6-axis hydraulic system like real flight simulators, but…well, we’ll take care of the basics, first.
Extremely cool project. Your students are lucky to have you as their instructor for this class!
I am curious about how these actually work to give the correct illusions of motion…obviously, it is not physically possible to generate all the true G forces using a platform that can’t move very far, so physiological trickery must be involved.
Several years ago, I had to opportunity to ‘fly’ the Boeing 737 full-motion simulator belonging to Continental Airlines, back when that airline was still a thing. Very interesting experience.
Outstanding!
When I was in middle-school in the 80s, our science teacher was actually working on a very primitive shuttle simulation using the available school Apple IIe computers of the time, plus some radios and other doo-dads. It was a lot of fun for those students involved (a lower grade level than me at that time).
I also did Space Camp a couple years later, and again that was a lot of fun.
I’m glad to see that there are resources available today to put both of those experiences to shame.
Thanks, Trink!
You’ve got a limited range of motion, of course, so I think what it must do is to give an initial acceleration that starts your inner ear feeling the translation or rotation, but then it eases down to a stop and resets gently to the neutral position for the next maneuver. That’s my guess. I really want to read papers on how the 6-degree-of-freedom simulators calculate how much and how far to move for a given simulated motion.
If I get to the point of actually doing this, it’ll be some serious engineering compared to what I have now!
Wow, that must really have been something.
Hello, fellow Space Camp alumnus! I was there in August of 1986, the summer following the Challenger accident. That was the beginning of my freshman year of high school. When were you there?
I’ve been using my experience from Space Camp in designing this project, especially how I, as Simulation Director, try to get them to do problem solving with failures and errors in flight. I think once this is more visually impressive, I’ll try running a local space camp at the Planetarium on campus and doing this with high schoolers.
I was there the summer of ’88, just before the start of 7th grade, when they had just opened the Florida campus to supplement Huntsville. They didn’t even have the dorms ready, so we were all staying in a nearby motel with some serious mechanical defects, and eating at a local restaurant. Lots of things had a very ad-hoc feel to them, but it was a lot of fun. Plus it was all shortly before launches resumed.
Wow! I hope you get written up for teacher of the decade!!!!!!
Don’t you just hate it when your malfunctions malfunction and everything operates smoothly?
Exactly! A bug kept me from making an engine fail. Darn it, I was trying to make things not work!
Thanks, Skyler! I built it in a big part because I simply want to play with it, myself, but I am rather hoping that this keeps me looking indispensable to the administration. I’m tenured and full professor, but higher ed is a precarious business these days.
Actually, I hope you don’t get written up as teacher of the decade for this. I hope you get written up as teacher of the decade because objective, long-term evaluations show that your students have learned more stuff, more efficiently, than any others.
Wise thinking. Possibly related, I just posted the grades, and this year’s class was significantly better than I’ve seen in a long time. Could it be their excitement from the simulator project encouraged them to learn more? Better keep trying it and see if the pattern holds.
You do know we never really went to the moon — it was all done in Hollywood. Fake Science!
That’s the way it’s supposed to work, and it’s good to hear that it does.
For a number of years I used to help with a Saturday morning science program at our workplace. I usually usually teamed up with an entomologist colleague for two separate sessions, and we’d help each other out, collecting aquatic invertebrates from ponds and streams, sometimes taking the kids out collecting, and bring back buckets of material for kids to sort through in enamel trays and such, observe under dissecting scopes, and concentrate other, smaller organisms for observation under microscopes.
It was all busy and exciting for everyone, even for students who came back to the same activity for a 3rd or 4th year. There was always something new to see.
This was a program that we did together with students and parents. We discouraged the idea that this was something for which the parents would drop off the students in the morning and pick them up afterwards. It wasn’t always parents working with their own children, but we were all doing things together.
Once in a while a parent would say, “This is how science should be taught in school.” I didn’t stop to argue, but this was not how science should be taught in school. (I had once been an elementary science teacher, and liked to do activities like this back then, where I sometimes heard the same thing.) Hopefully, doing these kinds of activities on weekends (there was a lot more than aquatic invertebrates) helped the students learn at school, but it’s not a substitute for disciplined learning activities. This was fun and easy. Teaching and classwork is hard. Instead, I learned to look on what we did as an aid to learning, giving students knowledge and experience that can be touchstones for the learning they do in class. Except for perhaps a few exceptional people, it was not a substitute.
Actually, I proposed many years ago to a college who is an expert computer game developer, to do a PC game where you fly each of the space shots. I think it would have been cool. But what you’ve done way cooler. Good job. I’m jealous of you students. “Houston, we have no problems.”
To say the least!