Imagine a major earthquake, flood, or wildfire strikes your region. Power lines are down, and cell towers are damaged. You have no internet, no way to call for help, and no way to receive emergency instructions. How do you know where to go or what to do? Today, we'll explore new "direct-to-cell" satellite technology that could solve this problem. We will work in teams to design an emergency alert system for a disaster scenario.
Hook: Where's Your "Dead Zone"?
Think-Pair-Share (5 minutes)
Think about your daily life in your city or town. Are there any places where your phone loses its signal completely? Maybe it's in a basement, an underground metro, or a remote park.
- Think (1 min): Silently, think of one or two "dead zones" where you can't get cell service.
- Pair (2 mins): Turn to a partner and share your locations. Why do you think these spots have poor coverage?
- Share (2 mins): A few students can share their ideas with the class.
Input: How Does "Text From the Sky" Work?
Several companies are developing technology to send texts, and even make calls, directly from satellites to regular smartphones. This means you wouldn't need a special satellite phone. If the normal cell network is down, your phone could connect to a satellite in space. Let's look at two leading systems.
Starlink Direct to Cell
Starlink, a project by SpaceX, is launching hundreds of satellites that act like cell towers in space. They have already started basic texting services in several countries and plan to offer voice and data services in 2025. This technology aims to eliminate mobile dead zones worldwide.
- Strengths: Huge satellite network, fast rollout.
- Limits: New technology, slow initial data speeds.
AST SpaceMobile
AST SpaceMobile is another major player. They successfully made the world's first space-based 5G video call using a standard smartphone. They are working with major mobile network operators like Vodafone to build a global network to provide full 4G/5G broadband from space.
- Strengths: High speed potential, strong partnerships.
- Limits: Fewer satellites currently, complex technology.
SpaceX and T-Mobile: Coverage Above & Beyond
This video explains how the satellite network connects to phones on the ground.
Video Transcript
I'm here in Seattle, Washington, because this is Ground Zero for the new space race. I'm talking about direct-to-cell technology, in other words, making calls to freaking space. Right now, if you want to make a call or text via satellite, you need to buy a dedicated satellite phone and a dedicated satellite phone plan, and that can get expensive really fast. Plus, you look like this. But in 2022, T-Mobile and SpaceX hatched a plan to make your phone work no matter where you are, no matter where you go. Basically, if you have a clear view of the sky, your phone just works. [ 00:30 ]
But as a man of science, I require proof, so I'm going to pick the most random, remote location I can find to see if this actually works where it actually matters. "Oh boy, this isn't close." "How are your navigation skills?" "Not great." "Fantastic." A few days ago, I went to SpaceX's Starlink factory where they actually make these satellites to find out how all this works. Cameras, unfortunately, are off-limits, so you stay here and I'll be right back. That was wild. [ 00:58 ]
While I was inside, here's what I learned. So basically, we need two things to make it all work: your phone and satellites, lots and lots of satellites. In fact, T-Mobile and Starlink are currently launching the largest satellite-to-cell constellation in the world. "That factory is set up for just efficiency and cranking these things out. It felt like an automotive factory. The speed and scale at which we're going to be able to deploy hundreds of satellites and eventually thousands is completely unprecedented by anyone else doing this. We're super uniquely positioned to be able to pull this off with T-Mobile. We throw down 248 beams per satellite, so this is like 48 cell phone towers." [ 01:31 ]
They're essentially taking hundreds of cell phone towers and then launching them hundreds of miles up to space where they'll be constantly zooming around the Earth at 17,000 mph, just waiting to get your text message to tell your dog groomer you're running 3 minutes late. Now let's go see if this works in the middle of nowhere. T-Mobile Starlink is going to be a game-changer for those going off the beaten path, and that beaten path is more than half a million square miles of the US with no on-the-ground cell coverage because of topography or other factors. [ 01:58 ]
This is, by the way, he's an actual network engineer from T-Mobile. "Are you nervous for the test, Ryan?" "Nope." "Confidence seems high." "Yeah, I wish you were this confident with navigating maps." "Sorry." "Sorry's not going to help a lot when we're stranded in the woods." "Kind of feel like I'm doing all the paddling." "Oh, land ho! It's a safey." "Ryan, is this remote enough for you?" [ 02:19 ]
All right, Ryan, let's run this test. Actually, before we run the test, I have a couple of questions for you. Why do we still have dead zones? This is 2024. The US is really large, and we're not allowed to build in national parks. And then there's sheer cliffs inside the states and mountaintops that make it hard to cover everywhere. So what is this going to mean if you're a T-Mobile customer? We're hoping to improve the customer experience and connect you with friends and family anywhere you are in the States, even on a lake in the middle of nowhere in Washington. Absolutely. [ 02:41 ]
All right, kind of nervous. This is my first text message to space. "Hey Dad, I'm sending you this message from space." I hit send. Now what? "Well, text me back." Oh, there's a response. "Cool, I've received it." "How was space?" That was amazing, but like, kind of underwhelming. It just feels like I sent a text message. "Yeah, that's kind of the point." [ 03:07 ]
So there you have it. T-Mobile Starlink is going to be a game-changer. Now, we're still a few months out before this will be widely available to everyone. And text messaging will be first, and then data and voice will come soon thereafter. So stay tuned because this is just the beginning. To be one of the first to experience the T-Mobile Starlink beta, go to t-mobile.com/satellites or use the link in the video description. All right, now we just got to get out of here, right? What the heck, I just got a notification. It's a new Mark Rober video that dropped. I am Mark Rober. I guess I'll just text someone to pick me up. [ 03:36 ]
Language Focus: Clear Instructions & Conditionals
In an emergency, communication must be simple and direct. We use imperatives to give instructions and conditionals to explain situations.
Imperatives (Commands)
Imperatives use the base form of the verb. They are used for direct orders, instructions, and warnings. They are essential for emergency alerts.
Evacuate the coastal areas immediately.
Stay inside and away from windows.
Do not use tap water until further notice.
Conditionals (If..., then...)
First conditionals are used to talk about the result of a possible future action. They are useful for explaining emergency plans. The structure is: If + present simple, ... will + base verb.
If you are in an evacuation zone, you will receive a text alert.
If the main power fails, backup generators will be activated.
If you need assistance, go to the nearest community center. (Note: You can use an imperative in the result clause.)
Design Sprint: Create a Disaster SMS Plan
Group Activity (30 minutes)
Work in small groups of 3-4. Your city wants to use a new direct-to-cell satellite service for emergency communications. Your task is to design the core messaging plan.
Step 1: Choose a Scenario (5 mins)
First, choose a realistic disaster scenario for your city or a city you know well.
- Earthquake
- Major Flood
- Wildfire
- Typhoon/Hurricane
- Power Outage
Step 2: Design the Core Messages (20 mins)
Now, create the following components for your SMS plan. Remember to use clear, simple language and imperatives. Messages must be very short (like a tweet).
- Opt-in Phrase: How will citizens sign up to receive these alerts? Create a simple keyword and number. (e.g., To receive emergency alerts, text JOIN to 70707.)
- Alert Templates (x3): Write three short SMS templates for your chosen scenario: an Evacuation Alert, a Shelter-in-Place Alert, and an "All-Clear" Alert.
- Last-Resort Check-in: If all communication is down for more than 24 hours, the system will send one final message to help emergency services find people who need help. What will it say? (e.g., This is a city-wide safety check. If you need urgent help, reply HELP. If you are safe, reply SAFE.)
Step 3: Prepare to Share (5 mins)
Review your plan. Is it clear? Is it simple? Is it effective? Choose one person from your group to present your plan in the next activity.
Drill: 60-Second Emergency Brief
Speaking Practice (10 minutes)
One person from each group will now act as an emergency official. You have 60 seconds to deliver a clear voice message to the public explaining your SMS alert system. This is not a real recording, just speaking practice.
Use this structure for your brief:
- Introduction: "This is an important message from the [Your City] Emergency Office."
- The Situation: Briefly state why this new system is needed.
- The Action (Opt-in): Tell people exactly what to do to sign up. Use imperatives.
- The Promise: Explain what will happen if there is an emergency.
- Closing: End with a short, reassuring message.
Exit: A Question of Privacy
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