Study: Halcyon lander silent through two contact windows on asteroid 4418 Teodora

STEP 01

Start here

The Merovan Space Office says its relay spacecraft is healthy and is examining whether the lander has dropped into a safe mode. A faint signal logged at Port Alder has not been confirmed as coming from Halcyon.

In one paragraph

The Halcyon lander on asteroid 4418 Teodora has missed two scheduled communication windows; its last confirmed contact on Monday showed all systems nominal.13 The Merovan Space Office says the Wren relay spacecraft is healthy and is reviewing whether the lander entered a safe mode.3 A faint signal near Halcyon's beacon frequency was logged at Port Alder, below the level the office counts as a detection. Its origin is unconfirmed.4

STEP 02

Key terms

Learn these first and the rest of the story reads easily. Press a term to ask a follow-up question.

a.: A scheduled period when the lander and its relay are positioned to exchange signals.1
b.: A protective state a spacecraft can enter after a fault, switching off non-essential systems and transmitting only a simple, low-rate beacon.3
c.: A craft that passes messages between a lander and Earth. For Halcyon, this is Wren.3
d.: How much stronger a received signal is than the surrounding noise. The office counts 3 dB or more as a detection.4

STEP 03

Who is involved

Mission director, Halcyon
Said the team was not assuming the worst after the first missed window.2
Flight operations lead, Merovan Space Office
Confirmed the Wren relay spacecraft is healthy.3
Organisation
Operator of the Halcyon lander and the Wren relay spacecraft.13

STEP 04

Where

Fictional atlas for the demo, drawn by Ford Colter.

Small asteroid where Halcyon landed; it turns once every 6.1 hours.25
Merovan capital and site of the deep-space dish whose logs show the faint signal.4

STEP 05

How we got here

Background, from the study guide

2024
Launch
Halcyon and the Wren relay spacecraft leave for asteroid 4418 Teodora.
October 2026
Landing
Halcyon settles on the surface of Teodora.
2 November 2026
Last contact
Halcyon reports all systems nominal.
3 to 4 November 2026
Two windows missed
No telemetry is received in two scheduled windows; a faint, unconfirmed signal is logged at Port Alder.

This story, update by update

2 Nov, 22:15
Last confirmed contact with Halcyon; all systems nominal.1
3 Nov, 06:15
First scheduled window passes with no telemetry.1
3 Nov, 14:35
Mission director says the team is not assuming the worst.2
4 Nov, 02:15
Second window passes without contact; safe mode under review.3
4 Nov, 07:15
Orbit Ledger reports a faint signal in Port Alder dish logs.4

STEP 06

Agreed and disputed

Of 6 key facts: 4 official statement, 2 reported.

How to read the faint signal

Merovan Space Office (detection rule, as reported by Orbit Ledger): A signal below 3 dB above background is not treated as a detection.4
Orbit Ledger (reporting dish logs): The dish logged a signal of about 2.1 dB near Halcyon's beacon frequency during the second window.4

STEP 07

Open questions

Why the lander has gone quiet. The office has raised safe mode as one possibility; specialist reporting notes that tilt or shadow can also cut power and line of sight. No cause has been confirmed.35
Whether the faint signal at Port Alder came from Halcyon or was background noise. The office has not commented on it.4
When the next contact attempt is scheduled and how many attempts are planned. The office's updates do not give a schedule.23
What the lander was doing at the time of its last contact. The published updates report its status as nominal but do not describe its activity.1

Check your understanding

STEP 08

Go deeper

Study guides

Deep-space missions
How spacecraft far from home stay in touch, what happens when they go quiet, and how to read a mission operator's updates.
Back to the briefing

Read the original reporting

Halcyon status update: no signal in scheduled windowMerovan Space Office
Second window passes without contact; safe mode under reviewMerovan Space Office