HackHarvard 2026 · SpaceXAI challenge
Teardown
Bringing rocket science down to Earth.
Neel Bansal · Anders Haroldson
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
The problem
Kids watch rockets launch. They never get to fly one.
The facts are public, but they are scattered, and a webcast only lets you watch.
So kids never feel how one lean changes where a rocket ends up.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
Spec sheet
Height 70 m · 9 × 845 kN
Webcast
T+00:02:31 · MECO
Launch database
Sentinel-6 · 21 Nov 2020
The team
Neel and Anders + Cursor and Grok
The two of us built every part of it together, side by side.
We used Cursor and Grok as hard as we could. That is our real usage.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
Neel Bansal + Anders Haroldson
Built together, start to finish.
Cursor + Grok
Used as far as they would go.
Hardware for Good
Your phone is the rocket
We planned to solder our own sensor board, but Micro Center and the other stores nearby didn’t have the parts. Every phone already has them.
So a phone slides into a cardboard rocket and becomes its motion sensor, its speaker and its rumble. It runs in a web page, so there is no app to install.
We checked with the HackHarvard co-director: the phone’s accelerometer and speaker count as hardware for this track.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
| Move | What the sensor must see | Does |
|---|---|---|
| Lift | ≥ 2.5 m/s² up the nose for 180 ms | Launch |
| Lean | calibrated tilt past a 2° dead zone, ≤ 12°/s | Steer |
| Push | ≥ 3 m/s² along the nose | Engine power |
| Flick | ≥ 12 m/s² sideways for 40 to 220 ms | Drop stage 1 |
| Nose down | past 150° for 2 s | Abort |
| Silence | no frame for 2 s | Pause |
Live demo
One run, start to finish
Explode the rocket and push engine power. The cardboard rocket in your hands roars and shakes.
Calibrate, launch, lean to steer. At 8× the Earth curves away in under a minute.
Reach orbit, or crash. Either way Grok Imagine draws a postcard of your flight to download.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
- Take it apart
- Fly it
- Keep the postcard
Under the hood
One store, three ways in
The phone, the mouse and Grok all drive one store, so Grok uses the same actions as the buttons.
Real orbital physics, 60 steps a second. 1,116 unit tests, plus a flight test with a simulated phone.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
- Phone rocket
- Mouse · touch · keys
- Grok agent
- 3D Falcon 9
- Flight physics + NASA Earth
- Cards · readouts · CO₂
SpaceXAI challenge
Built for this track
The running app meets every requirement, and you just saw each one in the demo.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
| ✓ Real space data | Falcon 9 specs from spacex.com, Sentinel-6 published milestones, NASA Earth imagery, a sourced emissions file |
|---|---|
| ✓ Grok Voice or Imagine | Both: Grok Voice narrates every part and talks live, Imagine draws a postcard of every flight, plus function calling |
| ✓ Built with Cursor | Built in Cursor, plans in docs/plans/, using Grok Bot |
| ✓ Hardware for Good | A phone in a cardboard rocket: accelerometer, gyro, speaker, vibration. Confirmed with the co-director |
Appendix · Demo backup · Explore and Grok
Take it apart
Slide Explode and the Falcon 9 splits into its 10 real parts. Tap one for a card with real specs and a source link.
Push Engine power and nine Merlin plumes grow. The phone inside the cardboard rocket roars and vibrates with them, so a kid feels every burn in the rocket they are holding.
Press Start tour and Grok Voice flies to each part and explains it out loud, at Kid, Curious or Engineer level. Press Voice to talk back live.
Or type or tap a question chip: Grok selects parts, explodes the rocket and flies the camera with the same actions the buttons use.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
Appendix · Demo backup · Your mission
Fly it to orbit
You steer and set engine power. Real physics does the rest, and the game never hands you a win.
Go straight up and you fall back. Turn too hard and you hit the ground. Kids work out what orbit is by getting it wrong a few times.
Orbit or crash, Grok Imagine draws a postcard of your flight, with your numbers on it, to download and keep.
Made by Neel Bansal and Anders HaroldsonStudent project. Not affiliated with SpaceX or xAI.Model: “Falcon 9 - SpaceX” by Stanley Creative, CC BY 4.0. Model page
