Phoning Home: Communicating from Mars

Summary

Curiosity's dramatic landing on Mars is filled with uncertainties and high stakes. As the rover descends, it faces communication challenges, with potential signal losses during antenna switches and Mars's rotation cutting off direct contact. NASA relies on two orbiters, Mars Odyssey and Mars Reconnaissance Orbiter, to relay signals, though both face maneuver risks and limited time windows. Engineers must wait hours, even days, for confirmation. The process is fraught with challenges, exemplifying the true meaning of 'rocket science' as patience and precision play pivotal roles in this high-risk mission.

Takeaways

• 😀 After seven minutes of entry, descent, and landing, the fate of Curiosity is uncertain and could take time to confirm.
• 😀 Curiosity must switch to a new antenna during its descent, and this could cause brief signal loss at each switch.
• 😀 The direct communications link with Earth only works during the first half of the rover's descent due to Mars spinning out of view.
• 😀 NASA's Mars Odyssey orbiter helps relay Curiosity's signal during the second half of the descent.
• 😀 Odyssey needs to perform a maneuver it's never attempted before to successfully capture Curiosity's signal.
• 😀 If Odyssey's maneuver fails, the rover will still be fine, but the team will have to wait longer for confirmation.
• 😀 Curiosity's landing may happen on a slope, which could hinder Odyssey from picking up the signal, requiring backup plans.
• 😀 The Mars Reconnaissance Orbiter serves as a backup to capture landing data and store it for later transmission to Earth.
• 😀 Time is a critical factor; Odyssey has a very limited window to capture Curiosity's signal—only a few minutes.
• 😀 Engineers must decode the landing data collected by the orbiter, which could take several hours before the rover’s fate is confirmed.

Q & A

What happens during the entry, descent, and landing of Curiosity?

During the seven-minute entry, descent, and landing of Curiosity, engineers and mission controllers are on edge, awaiting the rover’s fate. The process is complicated, and there is a chance that communications could be lost temporarily at certain stages.

Why could Curiosity lose communication with Earth during its descent?

Curiosity could lose communication during its descent because it must switch to a new antenna at each transformation. This transition may cause a temporary loss of the signal, but it won’t affect the rover itself.

Why does the rover’s communications only work during the first half of the descent?

The rover's communication only works during the first half of the descent because Mars is rotating. As the rover and its landing site disappear from view, the direct radio contact with Earth is lost, much like the sun setting.

How do NASA’s spacecraft help with communications during Curiosity’s descent?

NASA has two spacecraft orbiting Mars. For the second half of Curiosity’s descent, the Mars Odyssey orbiter picks up the rover's signal and sends it back to Earth, enabling continued communication after Curiosity goes out of direct line of sight.

What challenge does the Mars Odyssey orbiter face during the landing process?

The Mars Odyssey orbiter faces the challenge of rotating an hour before landing to pick up Curiosity's signal. This maneuver is unprecedented and not guaranteed to work, which could delay communication.

What would happen if the Mars Odyssey orbiter fails to rotate properly?

If the Mars Odyssey orbiter fails to rotate correctly, the rover will not be affected. However, the delay in communication means that it could take longer to know the rover’s status.

What other scenario could affect communication with Curiosity?

If Curiosity lands on a slope, the Mars Odyssey orbiter, which flies low, might not be able to pick up the rover's signal. This situation would further delay the communication process.

What is the time constraint for the Mars Odyssey orbiter to receive Curiosity’s signal?

The Mars Odyssey orbiter can only be in line of sight to receive Curiosity’s signal for a brief window, likely no more than five minutes, making the timing crucial for communication.

What role does the Mars Reconnaissance Orbiter play in the landing process?

The Mars Reconnaissance Orbiter acts as a backup for communication. It will fly overhead to capture data from Curiosity’s landing and store it onboard for later playback to Earth.

Why might it take several hours to hear from Curiosity after the landing?

After Curiosity’s landing, engineers must decode the data transmitted by the Mars Reconnaissance Orbiter, which takes several hours. Depending on the timing, it could be the middle of the night before the rover’s fate is revealed.