Launch, Gravity & Orbit Basics
From Launch to Orbit
Follow launch to orbit: gravity pulls inward while high sideways speed makes the spacecraft keep “missing” Earth — that is orbit.
- Time estimate
- 20–25 min
- Complexity
- developing
- Maturity
- pilot ready
- Simulator readiness
- implemented
- Software available now
- Implemented as Launch-to-Orbit Free-Fall Visualizer — interactive activity on `/twin/learn/activities/orbit_from_launch_to_orbit`.
Student flow
1) Launch idea
2) Gravity arrow
3) Sideways velocity
Evidence and self-check are local-only. Copy/export or screenshot if you want to share.
Learning outcomes
Student explains orbit as continuous free fall: gravity plus sideways velocity, not “no gravity.”
- Explain the role of gravity in keeping a satellite in orbit.
- Describe why orbital speed must be high enough for a given altitude.
- Relate higher altitude to longer orbital period.
Concept primer
Follow launch to orbit: gravity pulls inward while high sideways speed makes the spacecraft keep “missing” Earth — that is orbit.
Open the Launch-to-Orbit Free-Fall Visualizer at `/twin/learn/activities/orbit_from_launch_to_orbit` — interactive 2D teaching model (not a certified propagator).
Draw Earth, gravity arrow toward center, velocity arrow along path, and a circular orbit sketch.
Interactive lab
Teaching-grade software activity slot — not a flight simulator or certified propagator.
Outcome: Near orbit
Explanation
Near-circular motion: at about factor 1.00 of the reference circular speed, the path stays above the surface for this run — orbit is continuous free fall: gravity pulls inward while velocity carries the spacecraft along the curve.
Local self-check
Assessment (practice only)
Use this as a self-check and discussion starter. It is local-only and not a grade.
Optional: attaches a local summary (completed / quick checks / checklist count).
Quick check
Multiple choice self-check
This is a local self-check to support discussion. It is not a grade.
Quick check: In orbit, which statement is most accurate?
Quick check: What is the role of sideways (tangential) velocity in orbit?
Discussion prompt
Short answer (local only)
Write notes for yourself or your group. Nothing is submitted.
Short answer (1–2 sentences): Explain orbit as continuous free fall without saying “no gravity.”
Checklist
Local checklist self-check
Use this to verify you covered key ideas. Nothing is submitted.
Checklist: Before you claim you understand “from launch to orbit”, can you say…
0 / 4 checked
Local summary
Assessment summary (practice only)
Completion
0 / 4 sections complete
Quick checks
0 / 2 correct
Shown only to support self-check.
Checklist
0 / 4 items checked
Reminder
Local-only practice summary. Not a grade and not submitted anywhere.
What this preview is / is not
Assessment engine v0 boundary note
- Student view (local practice): use this as a self-check and discussion starter.
- Local-only preview/practice: your answers are not submitted.
- No backend, no accounts, no roster, and no LMS integration.
- Not a grade. No credential or official scoring is implied.
- Teacher visibility into student answers is not implemented in MVPF8.
- Evidence runtime engine arrives in Phase 9 (not in this preview).
Capture
Evidence capture (local-only)
Capture what you did, what changed, what you observed, and how you explain it. This stays in your browser unless you copy/share it manually.
Selected inputs
- Speed factor: 1.00× (vs reference circular speed @ 400 km)
Generated outputs
- Path class: Near orbit
- Explanation: Near-circular motion: at about factor 1.00 of the reference circular speed, the path stays above the surface for this run — orbit is continuous free fall: gravity pulls inward while velocity carries the spacecraft along the curve.
Checklist
Evidence checklist
0/4 checked
Evidence artifact (local-only)
From Launch to Orbit
Captured: 2026-05-16T07:38:32.427Z · Level: middle_school · Track: launch_gravity_orbit
Summary
Copyable class summary
Copy a readable summary for class notes, or copy JSON for a structured record. Local-only: nothing is submitted.
Evidence artifact (v1) Activity: From Launch to Orbit Track: launch_gravity_orbit Learner level: middle_school Captured: 2026-05-16T07:38:32.427Z Mission brief: Use a simple 2D teaching model to explain orbit as continuous free fall: gravity pulls inward while sideways velocity carries the spacecraft forward. Selected inputs: - Speed factor: 1.00× (vs reference circular speed @ 400 km) Generated outputs: - Path class: Near orbit - Explanation: Near-circular motion: at about factor 1.00 of the reference circular speed, the path stays above the surface for this run — orbit is continuous free fall: gravity pulls inward while velocity carries the spacecraft along the curve. Checklist: - [ ] I can state that gravity pulls toward Earth’s center in orbit. - [ ] I can state that sideways velocity carries the spacecraft forward. - [ ] I can explain orbit as continuous free fall (not “no gravity”). - [ ] I used teaching-grade language (not a certified trajectory tool). Observations: (not provided) Reflection: (not provided) Model boundary note: Local-only teaching model. Not a certified propagator; not STK/GMAT. Evidence is not submitted anywhere and is not a grade. Policy reminder: - Local-only capture. Not submitted anywhere. Not a grade.
Evidence capture
Expected outputs learners should be able to show after the lab (Phase 9 evidence engine preview available).
- Speed factor selected in the visualizer
- Observed path class (falls back / near orbit / escape-like)
- Evidence summary copied with gravity-inward, velocity-sideways, free-fall checklist
Reflection
Throw a ball; imagine throwing harder until the curve matches Earth’s curvature (thought experiment).
Responses are not persisted in this preview unless a specific activity component adds storage later.
Assessment / quick check
Why doesn’t the satellite fall straight down to Earth even though gravity pulls it toward Earth?
Teacher notes
Use the ball thought experiment before any numbers; stress language precision (microgravity vs no gravity).
Teacher guide
From Launch to Orbit
Use this block as facilitation guidance. There is no roster, submission, or teacher visibility workflow in this phase — evidence is shared manually.
Facilitation moves
- Start with the ball thought experiment: “throw harder until you keep missing Earth.”
- Correct language: microgravity vs no gravity — orbit is free fall.
- Ask students to point to the velocity and gravity arrows and describe their roles.
Misconceptions to watch for
Orbit means there is no gravity.
Gravity is still strong in LEO. Orbit is continuous free fall with enough sideways velocity to keep missing Earth.
Boundary reminder: teaching-grade orbit models (not a certified propagator; not STK/GMAT) and local-only learning (no accounts, no submissions, not a grade).
Next activity
Suggested progression from the mission learning path. Links avoid missing activity routes.