Scenario 11 - LEOP: Launch Day
Shift Turnover Notes
Section titled “Shift Turnover Notes”Date: Monday 22 March, 0850 Local (Galway runs UTC in March) Station: GW-01 Galway, Ireland - NATS Europe (first commercial station on the SAR-3 ground track) Operator on Duty: You, solo LEOP Lead: Anneke Visser, MERIDIAN Constellation Operations (Rotterdam; LEOP room open, whole team on the floor)
Launch went at 06:50 and the upper stage released MERIDIAN-SAR-3 at 07:26. No ground station has heard from her. Rotterdam’s LEOP card is on the console and it is the only document this shift runs on. Per the flight rules the BUC is muted and the amplifier is disabled; they stay that way.
SAR-1 and SAR-2 are on the board later in the morning and are not tasked. This morning the station has one job, and it is a bird nobody has ever pointed at.
- Turnover note, 0845
LEOP Card MER-LEOP-SAR3-001
Section titled “LEOP Card MER-LEOP-SAR3-001”Cover note (A. Visser, 08:40):
Separation confirmed 07:26 UTC. Everything on this card comes from the launch provider’s injection estimate, which they quote with a 20 s one-sigma along-track uncertainty. I am solving the first ranging arc now and will push refined elements to your console the moment it closes; expect them shortly after you open this card.
Flight rules for the pass: readiness review, refined elements loaded, beacon, state of health. Nothing goes up. The uplink stays cold whatever the link looks like. Log every line in the LEOP log as you go; the room reads it live.
Spacecraft
Section titled “Spacecraft”| Item | Value |
|---|---|
| Spacecraft | MERIDIAN-SAR-3 |
| NORAD / COSPAR | 61703 / 2027-031A |
| Separation | 07:26 UTC, 84 min before shift start |
| Orbit | Sun-synchronous, ~360 km, 97.6° inclination, new plane |
| Contacts to date | None |
Element Sets
Section titled “Element Sets”| Set | Source | Predicted AOS | Max Elevation | LOS |
|---|---|---|---|---|
| Injection estimate (loaded at shift start) | Launch provider; 20 s 1-sigma along-track | 09:08:30 (az 142°) | 30.3° at 09:13:16 (719 km) | 09:18:02 (az 354°) |
| Refined (first ranging arc) | Rotterdam; arrives on the console after the card is opened | 09:08:59 (az 143°) | 31.6° at 09:13:44 (696 km) | 09:18:33 (az 353°) |
The two sets differ by about 30 s along-track and 0.3° in RAAN. Northbound pass, 9.6 minutes. Her second Galway pass is at 10:40:49 (17.8°) and is not on this card.
Which matters more, the age of a set or its origin? Origin. The injection set is a fit to no observations; it is what the rocket said it did. The refined set is fitted to ranging. Age grows the along-track error of whichever set you hold, which is why the refined set is replaced again after this pass.
Ephemeris Panel (Pass Schedule tab)
Section titled “Ephemeris Panel (Pass Schedule tab)”| Display | Meaning |
|---|---|
| STALE | The refined set has reached the console and the loaded SAR-3 elements pre-date it |
| Load Updated Ephemeris | Replaces the injection estimate; predictions and program-track update immediately |
| UPDATED | Refined elements loaded; pointing solution is Rotterdam’s, not the launch provider’s |
Flight Rules, This Pass
Section titled “Flight Rules, This Pass”| Rule | Value |
|---|---|
| Commanding | None. No command is sent until SOH is on record and the station has demonstrated tracking |
| Uplink chain | TX modem off air, BUC muted, HPA disabled, throughout; all powered and on reference. Cold is a defined state, not an absence |
| Sequence | Sweep and TRR, then elements, then beacon, then SOH line by line, then close-out and handover |
| Record | LEOP log, sections Readiness, State of Health, Close-out |
SAR-3 Frequency Plan
Section titled “SAR-3 Frequency Plan”LNB high-side: IF = LO − RF (13,100 MHz). BUC low-side: RF = IF + LO (12,600 MHz). SAR-3 does not share SAR-1’s numbers, and the station boots on SAR-1’s numbers.
| Signal | RF (MHz) | IF (MHz) | Format | This pass |
|---|---|---|---|---|
| SAR-3 telemetry beacon | 11,785 | 1,315 | CW, 0 dBm | Acquire, lock, read the level |
| SAR-3 imagery downlink | 11,760 | 1,340 | QPSK 3/4, 36 MHz, 28 dBm | Not decoded; the payload is not powered until commissioning |
| SAR-3 TT&C uplink | 14,065 | 1,465 | QPSK 3/4, 36 MHz | Cold |
| SAR-3 transponded downlink | 11,810 | 1,290 | Not used | |
| SAR-1 telemetry beacon (for contrast) | 11,711 | 1,389 | CW | What the ACU is set to now |
The beacon on the analyzer
Section titled “The beacon on the analyzer”Downlink Doppler runs to about ±270 kHz across the pass. With the high-side LO the IF spectrum is inverted: an approaching bird (RF shifted up) lands below 1,315 at IF, and the tone slides upward as the range rate falls toward culmination, through 1,315 at the top, and on above it as she recedes. A tone on the wrong side sliding the wrong way is not your bird.
| Setting | Search | After the find |
|---|---|---|
| Centre | 1,315 MHz | 1,315 MHz |
| Span | 2 MHz (the whole Doppler walk on screen, tone clear of the floor) | 2 MHz |
| RBW | Auto | 10 kHz (the CW line is a line; read the slide) |
At the station’s 60 MHz / 1 MHz RBW default a CW tone is one pixel above a 1 MHz noise bin, and 1,315 is not on the screen at all. Span decides what you can see; RBW decides how well.
Rotterdam wants the beacon level as a number near culmination, not “present”. A level against the link prediction is the transmitter’s health, and today’s number is the baseline every later pass is compared with. Expect the beacon comfortably above −65 dBm at the analyzer input up high.
Test Readiness Review (as a sweep)
Section titled “Test Readiness Review (as a sweep)”| Item | Reads on | Required for a first acquisition |
|---|---|---|
| Board | Dashboard | Only the RX AGC no-carrier warning (empty sky, not a fault); on a new spacecraft every anomaly is blamed on the bird first, and the board is how you prove it was not the station |
| Reference | GPS Timing | GPSDO locked, no holdover, on the log. A station reference error looks exactly like a spacecraft frequency error; the Doppler curve is SOH evidence only if the reference is on record |
| ACU beacon frequency | ACU | 11,785 MHz (SAR-3). Selecting SAR-3 as the program-track target copies it into the field; typing it does the same |
| Analyzer | RX Analysis | Centre 1,315 MHz, span 2 MHz |
| Uplink | TX Chain | HPA output disabled, BUC muted, modem off air, and confirmed so on the log |
| Element set | Pass Schedule | Injection set loaded and flagged provisional; refined set to replace it before AOS; the refined pass read back off the schedule |
Other Traffic (not tasked)
Section titled “Other Traffic (not tasked)”| Contact | AOS | Max Elevation | LOS |
|---|---|---|---|
| MERIDIAN-SAR-1 | 09:47:59 | 25.1° | 09:57:27 |
| MERIDIAN-SAR-2 | 10:06:01 | 25.1° | 10:15:22 |
GW-01 Equipment Status
Section titled “GW-01 Equipment Status”| Equipment | Status | Notes |
|---|---|---|
| 4 m Ku tracker | Powered, manual, parked az 5° / el 3° | ACU beacon field 11,711 MHz (SAR-1); AOS is at az 143° |
| LNB | 13,100 MHz LO, reference locked | Stable |
| GPSDO | Locked, 9 satellites | Disciplined; on the log before the pass |
| Spectrum analyzer | Centre 1,414 MHz, span 60 MHz, RBW 1 MHz | The SAR-3 beacon at 1,315 MHz is outside this span |
| RX modem 1 | 1,414 MHz / 36 MHz / QPSK 3/4 | SAR-1 imagery; not retuned, no decode this pass |
| TX modem 1 / BUC / HPA | 1,405 MHz, not transmitting / muted / disabled | Stays that way, and is confirmed so before and after the pass |
| Pass Schedule | SAR-3 on the injection estimate | Ephemeris panel flags STALE when the refined set arrives |
| LEOP log | Readiness, State of Health, Close-out | Blank |
First Acquisition Checklist
Section titled “First Acquisition Checklist”Readiness (08:50 – 09:08)
Section titled “Readiness (08:50 – 09:08)”- LEOP card read; the along-track uncertainty and the 0.45° beam understood together
- Dashboard: only the RX AGC no-carrier warning (noise only, empty sky); no faults
- GPS Timing: GPSDO locked, no holdover
- ACU beacon frequency 11,785 MHz; TRR line in the LEOP log
- Analyzer centre 1,315 MHz, span 2 MHz
- TX Chain: HPA disabled, BUC muted, modem off air
- Pass Schedule: SAR-3 flagged STALE, refined elements loaded, reads UPDATED
- Refined pass read: AOS 09:08:59 az 143°, 31.6° at 09:13:44, LOS 09:18:33
During the Pass (09:09 – 09:18)
Section titled “During the Pass (09:09 – 09:18)”- Program-track MERIDIAN-SAR-3 on the refined set; beacon on RX analysis at 1,315 MHz IF
- RBW to 10 kHz; Doppler sign read (below 1,315, sliding up = approaching)
- ACU beacon lock, logged (SOH 1)
- Beacon level near culmination, above −65 dBm, logged (SOH 2)
- SOH call, logged (SOH 3)
After LOS
Section titled “After LOS”- TX Chain: uplink confirmed cold throughout; close-out line
- Handover to Anneke: what she has, and why nothing was sent
End of Briefing
Section titled “End of Briefing”On a new spacecraft every first is evidence. The first beacon, the first lock, the first level, the first Doppler curve: each one either matches the model or it does not, and if something is sent before those are on record then a rejected command explains nothing.
Anneke has a room full of people waiting on three lines from Galway. Load the elements, find her, and give them the lines.
Good luck.