Space Grade 7

Module 1: Rockets 


Pre Class Activity (do by your own)

Q2. How do rockets work 


 
Class Notes 

How Rockets Work

• Rockets move using Newton’s Third Law: when hot gases are pushed down, the rocket moves up.

• This is called rocket propulsion.

• Fuel and oxidizer burn in the engine, making gases that shoot out at high speed.

• Types of fuels:

  • Solid fuel → simple, powerful, can’t be stopped.

  • Liquid fuel → controllable, used for big rockets.

  • Cryogenic fuel (very cold liquid hydrogen + oxygen) → gives very high power.

👉 ISRO uses PSLV (workhorse), GSLV (for heavy satellites), and LVM-3 (heaviest rocket for moon and human missions).

Theory Module 2: Rocket Transportation and Launch

Pre-Class Analysis Questions (for discussion)

1. How do you think such a huge rocket is moved from the factory to the launch site?

2. Can we transport a rocket in a normal truck like other goods? Why or why not?

3. Why do you think water transport (ships/barges) might be useful for rockets?

4. Have you seen trains carrying long objects like pipes or containers? Could the same method work for rockets?

5. What problems might scientists face while moving a giant rocket on roads?

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Class Notes

Question: What are the various methods used to transport rockets from their assembly site to launch pad?
Answer: Crawler-Transporters – giant tracked vehicles used by NASA to move rockets.
Rail Transporters – special trains used for rockets like Soyuz.
Road Transporters – specialized trucks for moving rockets.
Barges/Ships – used for transporting rocket stages and boosters over water.

Q2. How do India’s major launch vehicles — PSLV, GSLV, and LVM-3 — differ in their design, payload capacity, and applications, and why are they considered crucial for ISRO’s space missions?

Ans. India’s space program relies on a family of launch vehicles designed for different purposes, each playing a key role in expanding the country’s space capabilities.

1. PSLV (Polar Satellite Launch Vehicle)
Purpose / Usage: Primarily used to launch Earth observation, navigation, and smaller satellites into polar orbits and sun-synchronous orbits.
Nickname – “Workhorse of ISRO”:
Reliable: Over 50 successful missions.
Versatile: Can launch multiple satellites in a single mission (e.g., record-setting launch of 104 satellites in 2017).
Affordable: Lower launch costs compared to many global rockets.
Payload Capacity: About 1.7 tons to LEO (Low Earth Orbit), ~1.4 tons to polar orbits.

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2. GSLV (Geosynchronous Satellite Launch Vehicle)
Purpose / Usage: Designed to carry heavier communication and weather satellites into geostationary transfer orbits (GTO) at ~36,000 km altitude.
Key Difference from PSLV:
Uses a cryogenic upper stage (liquid hydrogen + oxygen), enabling heavier payloads.
Can lift ~2–2.5 tons to GTO, much more than PSLV.
Significance: Helped India achieve self-reliance in launching communication satellites without relying on foreign launchers.

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3. LVM-3 (Launch Vehicle Mark-3 / GSLV Mk-III)
Nickname: India’s “heaviest rocket”.
Payload Capacity:

Up to 4 tons to GTO.

Up to 8 tons to LEO.

Why “Heaviest”:
At 640 tons, it is ISRO’s most massive rocket, with the highest lifting power.
Uses two large solid boosters, a liquid core stage, and a cryogenic upper stage.
Key Missions:
Chandrayaan-2 (2019) — lunar orbiter and lander mission.
OneWeb satellites (2022–23) — commercial internet satellite launches.
Gaganyaan (planned) — India’s first human spaceflight mission.

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🚀 4. Other Vehicles in ISRO’s Family
SLV (Satellite Launch Vehicle) – India’s first launch vehicle (1980s), small payloads (~40 kg).
ASLV (Augmented SLV) – an experimental upgrade, used in early 1990s.
RLV-TD (Reusable Launch Vehicle - Tech Demo) – prototype for future reusable spaceplanes (still in testing).

SSLV (Small Satellite Launch Vehicle) – new, lightweight rocket for quick, low-cost launches of small satellites (<500 kg).

Module: Rocketrix

Theory Module: Rocket Aerodynamics and Control.

Pre-Class Questions

1. What do you know about aerodynamics?

2. Why do you think rockets need fins at the back?
   

Class Notes

Q. Which rocket is the most stable?

• The rocket is most stable when the Center of Gravity (CG) is in the front and the Center of Pressure (CP) is at the back.

Q. Why does the position of CG and CP affect the rocket’s stability?

• Think of CG as the balance point of the rocket (like the point where it balances on your finger).

• Think of CP as the point where air pushes the rocket.

• If CG is in front and CP is at the back, the rocket flies straight like an arrow.

• If CP comes in front of CG, the rocket wobbles or tumbles in the air.
  

Rocket Launching Game