Lesson 3 of 4 · Read a beacon as a measurement
Read a beacon as a measurement
6 minute lesson · 3 checks along the way
Your goal for this lessonInterpret a dated telemetry report, convert an illustrative sensor value and reason about reception opportunities.
In this lesson 3 sections · 3 checks
Read & understand
A beacon is the beginning of diagnosis
The BIRDS report describes Kyutech’s reception work during 8–10 August 2019 and subsequent analysis by the Egyptian team. Listed beacon fields include identity, battery voltage, operating mode, temperature and mission data. The report also describes responses to ground commands. These are historical observations, not a claim that either satellite is operating today.
Each field has a definition. A voltage number without units or scaling is ambiguous; a mode number needs the corresponding software’s lookup table. Even a correctly decoded packet describes one time and set of conditions. An old healthy sample cannot be silently relabeled as the current state.
Check 1 of 3
10 pointsUse the reading above. You can try again without losing points.
Read & understand
Convert a raw value with the right model
Suppose an invented sensor sends an integer count and its documented conversion is voltage equals count times 0.02 volts. Count 185 means 3.70 volts. If a later firmware version changes the scale to 0.01 volts per count, interpreting a packet with the old conversion would double the indicated voltage. These example scales are not NARSSCube’s telemetry format.
Retain both the raw packet and the decoder version so another analyst can reproduce the result. A checksum can help detect transmission corruption, but it cannot establish that a sensor is calibrated or that the wrong conversion was not selected. Data integrity, decoding and physical interpretation are separate checks.
Check 2 of 3
10 pointsUse the reading above. You can try again without losing points.
Read & understand
Silence can have several explanations
The historical report describes a beacon interval of six minutes. Use a fictional timeline to explore the consequence: a receiver has line of sight from minute 1 through minute 9, while transmissions occur at minutes 0, 6 and 12. Only the minute-6 transmission falls in that window. This does not guarantee reception: antenna orientation, signal strength, interference and receiver setup also matter.
A missed pass therefore calls for diagnosis before a declaration of spacecraft failure. Check the predicted window, receiver configuration and other stations’ dated observations. Conversely, a received beacon does not prove the camera delivered an image. Ask what function each observation actually tests.
Only one scheduled beacon falls in the window
Original teaching diagram. Invented timing exercise; no current NARSSCube listening schedule is implied.
Open full-size diagram in a new tab: Only one scheduled beacon falls in the windowCheck 3 of 3
10 pointsUse the reading above. You can try again without losing points.
Put it together
Your lesson progress
Each check connects to a part of the story. Complete all 3 to earn your 25-point lesson bonus.
Explore further · Optional
Go to the source
Explore the evidence behind this lesson. These optional readings and videos open in a new tab.
- Read: BIRDS project newsletter 43: NARSSCube-2 reception, pages 31–32Pages 31–32: participant report of NARSSCube-2 release on 7 August 2019 and first Kyutech reception on 8 August. Historical observations, not present health; some later secondary summaries give a different release date.
- Read: NASA: verifying a system against its requirementsGeneral verification methods used for original teaching examples; not documentation of NARSSCube’s undisclosed test procedures.