Problems
Problem statements
22 problems, set by the speakers in the SciHi sessions. Your team picks one by 18 October. Each speaker's problems sit in a row: swipe, or use the arrows, to see them all.
Any board, or simulationBoth are judged the same way.
Two usesName a use in space and a use on Earth.
Must build, then go further"What you must build" is the minimum. "Go further" is extra.
Low voltage onlyBattery or USB power. Never mains electricity.
SESSION · 6 SEPTEMBER
Dr. T. Madan Raghavan
University of Houston, Texas, USA
1 problem
PS-01
Life at the edge
Find a way to tell whether something is alive, even when life is very hard to spot.
“How can we detect life when it is hiding at the limits of survival? You may design an experiment, a sensor or device, a new way of imaging, a computer method, or a mix of these.”
In space
If life exists on Mars, or under the ice of Jupiter's moon Europa, it will be tiny, slow and rare. In 1976 the Viking landers tested Martian soil for signs of life.
On Earth
Tiny living things survive in hot springs, salt pans and Ladakh's cold desert. The same methods help check whether soil and water are healthy.
Ideas to start
- Seal a sample in a jar and measure the gas or moisture it gives off.
- Build a simple microscope with a camera, and write code that spots things moving on their own. Pond water and moss are good places to look.
What you must build
- Test a living sample: baker's yeast.
- Test a control: the same yeast after boiling it.
- Show that your method can tell the two apart.
Go further
Try a harsh sample, very salty, cold or dry. Find the weakest sign of life your method can still detect.
SafetyUse only yeast, soil, pond water or moss. Do not grow unknown microbes. Work with a teacher nearby.
SESSION · 6 SEPTEMBER
Mrs. Garima Nanda and Mr. Sumat Nanda
Plantables, Agra
3 problems
PS-02
Waste into material
Turn waste into a useful new material, and prove that it works.
In space
Astronauts cannot order new supplies, so they must reuse what they already have. The space station has tested turning old plastic into material for a 3D printer.
On Earth
Farmers burn crop stubble, and plastic piles up in landfills.
What you must build
- Pick one local waste: crop stubble, paper, coconut husk or plastic bags.
- Make test samples of your new material.
- Build a sensor setup that tests two things, such as strength, how much water it soaks up, or how well it keeps heat in.
- Compare it with the material it would replace.
Go further
Measure the energy and water needed to make it, and show what happens to it when it is thrown away.
PS-03
Sort it at source
Build a bin that sorts mixed waste by itself.
In space
On a long mission every scrap is useful, so everything must be sorted.
On Earth
Waste can only be recycled if it is sorted first, at home and at school.
What you must build
- Sort at least three types of waste.
- Use sensors, such as colour, metal, weight or wetness.
- Test it with 50 items and count how many land in the right bin.
Go further
Add a camera and an AI model running on the board, so it can learn new kinds of waste.
PS-04
Back to soil
Prove that a material really rots away, then make it happen faster.
In space
A base on the Moon or Mars could turn food and plant scraps into soil for growing food.
On Earth
Composting keeps waste out of landfills and makes soil richer.
What you must build
- Build a compost monitor that records temperature and moisture.
- Run it for at least two weeks.
- Compare a biodegradable sample with a piece of plastic, using photos and weight.
Go further
Control the moisture or air automatically, and measure how much faster it breaks down.
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SESSION · 12 SEPTEMBER
Dr. M. Jayakumar
Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram
5 problems
★Special prize for the best solution built on the Arduino® UNO Q
PS-05
Crew activity monitor
A wearable that knows whether you are resting, walking, exercising or falling.
In space
Astronauts must exercise every day in space, and the crew needs to know if someone is unwell.
On Earth
It can alert a family when an elderly person falls, and help athletes train.
What you must build
- Record your own movement data.
- Teach an AI model to recognise at least four activities.
- Run the model on the device itself.
- Test it on people who were not in your training data, and report how often it is right.
Go further
Detect a fall and send an alert within a few seconds.
PS-06
Where am I without GPS?
A robot or cart that keeps track of where it is, using only its own sensors.
In space
There is no GPS on the Moon or Mars. Rovers work out where they are by counting wheel turns and measuring how they turn.
On Earth
GPS does not work in tunnels, mines, big buildings or disaster zones.
What you must build
- Work out position from motion sensors and wheel or step counts.
- Drive a known path, such as a 2 metre square.
- Measure how far from the finish point it ends up.
Go further
Small errors add up over time. This is called drift. Use a camera or AI to correct it. The smaller your error, the better.
PS-07
Say the word
A device that waits quietly and wakes up only when it hears your special word.
In space
Astronauts in thick gloves can control equipment without pressing buttons.
On Earth
A voice switch for someone who cannot use their hands, or voice control where there is no internet.
What you must build
- Choose your own wake word, not one used by an existing voice assistant.
- Detect it on the device itself.
- Make it do one useful thing when it hears the word.
- Say the word 50 times and count how often it wakes. Count false alarms over one hour.
Go further
After it wakes, send the next few seconds of speech to another computer. Measure the delay, and the power it uses while waiting.
PrivacyNever save other people's voices without asking them first.
PS-08
Lock on
A camera that finds a light and keeps pointing at it as the light moves.
In space
Satellites that talk using beams of light must keep pointing exactly at each other.
On Earth
Solar panels that follow the sun, antennas and telescopes.
What you must build
- Build a mount with two motors that turns left-right and up-down.
- Track a bright LED as it moves across a room.
- Measure how far from the centre of the picture the light stays.
Go further
Predict where the light is going so you can keep up with fast movement, and find it again after it is hidden for a moment.
SafetyUse LEDs or a torch. Never use a laser pointer.
PS-09
Catch the fault early
Watch how a machine shakes and heats up, and warn before it breaks.
In space
Every part for a spacecraft is tested for hours on the ground to catch the weak ones.
On Earth
Farm pumps, fans and workshop motors, where a breakdown costs days of work.
What you must build
- Record how a small DC motor or fan normally behaves: its shaking, temperature or current.
- Add a fault, such as tape on a fan blade or a blocked air vent.
- Detect the fault automatically, with few false alarms.
Go further
Tell different faults apart, with the AI running on the device.
1 of 5
SESSION · 27 SEPTEMBER
Dr. Samyak Munot
Indian Youth Nuclear Society (IYNS)
“Radiation: Friend or Foe”
1 problem
PS-10
Shield the crew
Measure natural radiation, then find out which everyday materials block it best.
In space
Radiation is one of the biggest dangers on a trip to Mars, and spacecraft must carry shielding without adding too much weight.
On Earth
Radiation is all around us at low levels. Measuring it correctly replaces fear with facts.
What you must build
- Build a radiation counter with a Geiger counter tube or module and a microcontroller, logging counts per minute.
- Survey at least five everyday sources, such as bananas, potash fertiliser, granite and the open air. Count each for at least 10 minutes.
- Test shielding: put water, books, bricks and other materials between a bag of potash fertiliser and your counter. Rank them by how much they block for their weight.
Go further
Write a short case study on one small-scale use of nuclear technology, such as replacing diesel generators in remote places or improving crops. Explain the benefits and the risks in plain words.
SafetyUse only natural sources like these. Never open smoke detectors or handle any other radioactive material.
SESSION · 27 SEPTEMBER
Dr. Sonali Bhatnagar
DEI, Agra
“The Techno Search for Life”
4 problems
PS-11
Clock the space station
Measure the speed of the International Space Station yourself, from your own rooftop.
In space
Every orbit is a balance between speed and gravity, and mission teams calculate it for every satellite.
On Earth
The same calculation tells us when a satellite will pass over a farm, a flood or a disaster zone.
What you must build
- Calculate the speed of the ISS from its height and Earth's gravity, showing every step.
- Watch a visible ISS pass. Time it with a device you build, such as a sighting tube with a button, or measure its streak in a long exposure photo.
- Work out its speed from your own observation, compare it with your calculation, and explain the difference.
Go further
Build a pointer with two motors that predicts the next pass and follows the ISS across the sky.
PS-12
A home beyond Earth
Design a home where people could live on the Moon, Mars or another world, and build a working model of its life support.
In space
Any long mission needs air, water, the right temperature and power, with no supplies arriving.
On Earth
The same systems help shelters in deserts, cold mountains and disaster zones.
What you must build
- Draw your habitat design and explain how it handles air, water, temperature and power.
- Build a scale model that monitors at least two conditions inside it, such as temperature and humidity.
- Make it respond automatically when a condition goes out of range, for example by switching on a fan.
Go further
Add a power budget showing how solar panels and batteries would keep the habitat running through a long night.
PS-13
Build a small satellite
Design and test the key systems of a small student satellite, on the ground.
In space
Students around the world have built and launched tiny satellites called CubeSats.
On Earth
The same systems are used in weather stations, remote sensors and drones.
What you must build
- Build a model satellite no bigger than 10 cm on each side, or simulate one.
- Make at least two subsystems work: power (solar panel and battery), sensing (temperature or light), or communication (sending data wirelessly).
- Build a ground station screen that receives and shows the satellite's data.
Go further
Add attitude sensing, so the satellite knows which way it is pointing.
TipDr. Bhatnagar calls this one ambitious. Start by reading about satellites that school and college students have already built.
PS-14
Read your planet
Investigate an environmental or climate problem near you, using real data from satellites and your own sensors.
In space
Earth observation satellites watch forests, rivers, crops and cities every day.
On Earth
That data can show what is happening to your own district, if someone looks.
What you must build
- Pick one local issue, such as rising heat, a shrinking lake, poor air or crops under stress.
- Use freely available satellite data from at least three different years.
- Add your own ground measurements with a sensor, and compare them with the satellite data.
- Present what you found, and what could be done about it.
Go further
Build a sensor station that keeps collecting ground data, and show the changes on a map over time.
1 of 4
SESSION · 3 OCTOBER
Dr. Monika Aggarwal
Professor, CARE, IIT Delhi
“Signal Processing: A Perspective”
2 problems
PS-15
Many sensors, one answer
Combine readings from several sensors to understand something no single sensor can tell you.
In space
A spacecraft combines many sensors to know where it is and whether it is healthy.
On Earth
Predicting rain, measuring the air quality in your street, or keeping track of someone's health.
What you must build
- Choose one question: Will it rain soon? How bad is the air here? Is this person well?
- Combine at least three different sensors to answer it.
- Show with test results that the combined answer is better than any one sensor alone.
Go further
Train a small AI model on your combined data, and run it on the board.
PrivacyIf you collect body signals, use only your own team's data, with consent.
PS-16
Real or fake?
Build a tool that tells whether an image, audio clip or video is real or has been faked.
In space
Images from satellites and space missions must be trusted, so we need ways to check they have not been changed.
On Earth
Fake images and voices spread quickly and cause real harm.
What you must build
- Choose one type: images, audio or video.
- Collect real and fake examples from public datasets.
- Build a method that tells them apart, test it on examples it has never seen, and report how often it is right.
Go further
Show why your tool made each decision, so a person can understand it.
EthicsDo not make fakes of real people. Use public datasets only.
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SESSION · 3 OCTOBER
Dr. Mridul Kumar
Ben-Gurion University of the Negev, Israel
“Fingerprinting Matter”
1 problem
PS-17
Colours that catch a cheat
Use a colour sensor to find out whether food is adulterated or water is polluted, quickly and cheaply.
In space
Spacecraft read the colours of light from planets and stars to learn what they are made of.
On Earth
Adulterated milk, spices and oil harm health, and polluted water often looks normal.
What you must build
- Build a test rig with a microcontroller and a spectral colour sensor.
- Make pure samples and adulterated samples from safe household items, such as milk with added water, or turmeric with added starch.
- Write a program that processes the readings in small batches as they arrive, and gives a result quickly.
- Report how often your rig gets it right.
Go further
Work out how much adulterant is present, not just whether there is any.
SafetyNever taste any sample. Do not use toxic dyes or chemicals.
SESSION · 10 OCTOBER
Mr. T. Preetam C. Anand
CTO, C2i Semiconductors Pvt. Ltd., Bengaluru
“How Semiconductors Work”
3 problems
Mr. Anand asks teams to build these from individual components, not from ready-made kits.
PS-18
Light after sunset
A solar desk light that charges during the day and lights a study table at night.
In space
Satellites run on solar panels and batteries, and must survive every trip through Earth's shadow.
On Earth
Millions of students study in places where electricity is unreliable.
What you must build
- Use a solar panel, a charging circuit, a small lithium-ion battery and white LEDs.
- Make the light switch on in the dark, and measure how many hours it runs.
- Measure the energy collected during the day and the energy used at night.
Go further
Show the battery level, and dim the light automatically to make it last longer.
SafetyUse a protected lithium-ion cell and a proper charger module. Work with a teacher nearby.
PS-19
Turn the speed
Control the speed of a small motor with a knob, like the fan regulator at home.
In space
Satellites turn by spinning wheels inside them at carefully controlled speeds.
On Earth
Fans, pumps and tools use far less power when they run only as fast as needed.
What you must build
- Control a small DC motor or fan with a microcontroller, a knob and a motor driver.
- Make the speed change smoothly from slow to fast.
- Measure the power it uses at three different speeds.
Go further
Keep the speed steady automatically, even when the load on the motor changes.
PS-20
Lights out, automatically
A light that turns on only when someone is there and it is dark, and proves how much energy it saves.
In space
On a spacecraft every watt counts, so nothing runs unless it is needed.
On Earth
Lights left on in empty or sunlit rooms waste a large share of a school's electricity.
What you must build
- Switch a lamp with a presence sensor, a light sensor, a microcontroller and a relay.
- Turn the lamp on only when the room is occupied and too dark.
- Add a manual switch, so a person can always turn the light on.
- Over at least three days, log how long a normal switch would have kept the lamp on, and how long yours did. Report the energy saved.
Go further
Dim the light gradually, depending on how much daylight there is.
SafetySwitch a low voltage DC lamp or LED strip only. Never connect anything to mains electricity.
1 of 3
SESSION · 11 OCTOBER
Dr. Arun Pratap Sikarwar
Associate Professor, DESM, NCERT, New Delhi
“Science in Space, Care of Mother Earth”
1 problem
PS-21
Build it here
Build a low-cost scientific instrument in India that is usually imported, and prove it is accurate.
In space
India's space missions become cheaper and more independent with every instrument we build ourselves.
On Earth
Imported instruments are often too expensive for schools, farms and small weather stations.
What you must build
- Choose one instrument, for example a wind speed meter, a sunlight meter, a soil moisture probe or a rain gauge.
- Build your own version from parts you can buy locally.
- Calibrate it against a trusted reference at five or more levels, and draw the calibration curve.
- Show it gives the same reading when you repeat a measurement, and compare its cost with the imported version.
Go further
Make it run outdoors for a week and send its readings wirelessly.
SESSION · 11 OCTOBER
Ms. Portia Putatunda
Planet Spiti Foundation, Spiti
“Growing Food with Almost No Water”
1 problem
PS-22
More food, less water
Grow nutritious food with as little water as possible, without harming the plants.
In space
Astronauts on long missions must grow food while using every drop of water carefully.
On Earth
Villages in dry and cold places, like Spiti, run short of water every year.
Questions to answer
- Can you reuse water safely?
- Can you make it affordable and energy-efficient?
- Could it work both in a space habitat and in a village short of water?
What you must build
- Build a small growing system using any method: hydroponics, soil, recycled water, or your own idea.
- Measure the water used and how the plants grow, over at least two weeks.
- Grow the same plants the normal way at the same time, and compare.
Go further
Answer all three of Ms. Putatunda's questions with measurements, not just ideas.
Choose by 18 October
Watch the session where your problem was set: the speaker
explains why it matters and where to start. You can begin building as
soon as your team has chosen.
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