Arcadia Base, Mars. A dust storm, an airlock with a warning and a message that arrived too soon.
At 14:07, the communications screen at Arcadia Base lit up with a message from Earth: “AUTHORISED. OPEN AIRLOCK B.” Rocío Vidal, the engineer on duty, let out the breath she had been holding and leapt to her feet. “At last,” she said. “I’m going to open it.”
Outside, the dust storm had turned the afternoon into a reddish night. Somewhere in that darkness, the rover was heading back to the base with Dr Marta Ibarra, Kai’s mother, on board, and only one hour of reserve oxygen. It could come in through either of the base’s two airlocks: A, on the north side, or B, on the south side, the closer one to its route.
But airlock B had been showing a possible-leak warning all morning. The base rules were clear: with a leak warning, that airlock must not be opened without permission from mission control, back on Earth. That was why, at 14:02, Rocío had sent the question: “Leak warning on airlock B. Can we open it to let the rover in?”
Kai, who was fourteen and had been glued to the screen all afternoon, looked at the whiteboard on the wall. There, as every day, someone had written in marker the figure that mattered most for talking to home: “Signal delay today: 12 minutes.” That was how long a message took to travel, at the speed of light, from Mars to Earth. And the same to come back.
Kai looked at the clock. He looked at the whiteboard again. Then he planted himself in front of the door to the south corridor.
“Rocío, wait. That message isn’t the answer to your question.” In the corner of the screen, the rover’s signal was blinking: it would reach the base in ten minutes. By the north side, in fifteen.
Activities
1 Detective Inference
What was the message that arrived at 14:07, really? Tick the correct hypothesis.
- a) Mission control’s answer to the question Rocío had sent to Earth at 14:02.
- ✓b) A message that had left Earth before Rocío asked, and that had nothing to do with the leak warning.
- c) A prank by someone on the base, who wanted to rush Rocío into opening the airlock.
- d) A message from Dr Ibarra in the rover, who needed to get in through airlock B as soon as possible.
Which clue proves it? Copy or summarise the clue from the text that proves it.
Correct hypothesis: b). Exactly: it left Earth at 13:55, seven minutes before the question.
Key clue: “The question went out at 14:02; with 12 minutes there and 12 back, the answer couldn’t arrive before 14:26.” That’s Kai’s sum: the message arrived nineteen minutes earlier than possible, so it couldn’t be the answer.
2 The Loom Order of events
Put the events in the order they happened, including the one that isn’t told but can be worked out. Write the order number (1, 2, 3…) in each box.
- 3 Rocío sends her question to mission control.
- 4 The message “AUTHORISED. OPEN AIRLOCK B” arrives.
- 5 Kai plants himself in front of the door to the south corridor.
- 2 The message that will arrive at 14:07 leaves Earth.
- 1 Airlock B starts showing a possible-leak warning.
Correct order:
- Airlock B starts showing a possible-leak warning.
- The message that will arrive at 14:07 leaves Earth.
- Rocío sends her question to mission control.
- The message “AUTHORISED. OPEN AIRLOCK B” arrives.
- Kai plants himself in front of the door to the south corridor.
The leak warning had been on “all morning”. If the message arrived at 14:07 and the signal takes 12 minutes, it left Earth at 13:55: before Rocío sent her question at 14:02. Then the message arrived and, finally, Kai did the sum and stopped her.
3 The Missing Page Coherence
Which continuation fits everything we know? Tick only one option.
- ✓a) Rocío tells Dr Ibarra to come in through airlock A. At 14:26 the real answer from Earth arrives: “Do not open B. Use A.”
- b) At 14:10 the real answer from Earth finally arrives: “Do not open B. Use A.” Rocío warns Dr Ibarra straight away.
- c) Rocío asks the doctor to come in through airlock C, on the east side, which has no leak warning and is only two minutes away.
- d) Rocío video-calls Earth and the mission chief replies instantly that she must not open airlock B under any circumstances.
Answer: a). It fits: 14:02 plus 12 minutes there and 12 back makes 14:26, and the north side only took the rover five minutes longer.
- b) With 12 minutes there and 12 back, no answer could arrive before 14:26.
- c) The base only has two airlocks: A, to the north, and B, to the south.
- d) With a 12-minute delay each way, an instant conversation is impossible.
4 Spot the Contradiction Literal reading
Three statements don’t fit the story. Put an X next to the 3 statements that don’t fit the text.
- a) Rocío sent her question to Earth at 14:02.The third paragraph says so.
- ✗b) Airlock B was on the north side of the base.B was on the south side; A was on the north.
- c) That day, the signal took twelve minutes to travel from Mars to Earth.It’s the figure on the whiteboard.
- ✗d) The rover had reserve oxygen for several days.It only had one hour of reserve oxygen.
- e) Kai was fourteen.The fourth paragraph says so.
- ✗f) Airlock B was the furthest from the rover’s route.It was the closest; by the north side it took five minutes longer.
5 The Gallery Visualisation
In the game you choose the illustration that answers this question: “Which illustration shows the control room just as the message arrives?”. Here, you draw it yourself, with every detail the text gives you.
What should appear: A dust storm beyond the porthole, the clock at seven minutes past two, and only Rocío and Kai in the room.
Reward drawings that include the details from the text, not artistic skill.
Ending
To read aloud once the answers have been checked.
Rocío froze, her hand on the lever. Then she did the sum out loud: the question had gone out at 14:02; it would take twelve minutes to reach Earth, and the answer another twelve to come back. Nothing could arrive before 14:26. The 14:07 message had left Earth at 13:55, before she had even asked.
It was an old authorisation, for a routine check of airlock B that had been scheduled the week before and that the storm had left stuck in the sending queue. It knew nothing about the leak warning.
Rocío warned Dr Ibarra, who took a detour and came in through airlock A at 14:22, with oxygen to spare. At 14:26 the real answer from Earth arrived: “DO NOT OPEN AIRLOCK B. USE A.” When the technicians checked B the next day, they found a broken seal. If it had been opened, the base would have lost air.
Suggested marking
Each activity is worth 2 points (10 in total). In 1, one point for the hypothesis and one for the clue. In 2, give one point if only a couple of events are swapped. In 4, half a point for each correct cross and minus half a point for each true statement crossed out.