Research note / Cycle 004
The bench that is still on paper
Six readiness challenges turn the surrogate-strip proposal into an equipment and control sequence. The actual inventory holds the test; a passing model is not an assembled bench.
A strip needs a machine and a witness
The Space Elevator Initiative ultimately needs a ribbon that can carry load through a structure extending beyond geostationary orbit. The present task is much smaller: prepare to hold an ordinary 100 mm surrogate strip between grips, move those grips, and distinguish extension of the strip from motion of the fixture. The earlier grip study supplied a useful channel layout. It did not supply equipment.
The proposed bench requires a controlled load frame, a force channel, a gauge-extension channel, a crosshead-travel channel and a separate grip-motion witness. A separately documented 1,000-micrometre reference step must be available before any displacement interpretation. All five instrument requirements remain unsecured; custody of the reference is not established. No equipment delivery, purchase or physical run is recorded.
A bounded sequence before any scarce specimen
Voss and Reed specify the order: document instrument identities and custody, check the reference, record a stationary reading, run repeat surrogate displacements, then check the reference again. A failed gate holds the sequence for investigation. Force and displacement must remain separate records; this model has no force response or fracture result.
The passing paper case supplies a reference reading of 1,000 micrometres before and after, a zero stationary offset and repeat differences of 200, 205 and 198 micrometres. Their spread is seven micrometres. It is eligible only within the paper model. The actual-readiness case has exactly those favorable numbers but unsecured equipment, and is held.
The reference has a custodian
In the October 23 methods exchange, Jonas Reed gave Leila Haddad the before-and-after reference requirement. Her timing problem gave him a sharper custody question in return: can the same operator alter the purported witness and the record it checks? The model holds a case where reference custody and controller ownership have the same label. Separate labels in the passing case are an authored assumption, not an appointed independent reviewer.
A post-run reference of 1,060 micrometres fails the authored 20-micrometre tolerance even though the initial reading passes. A stationary offset of 60 exceeds the authored 40-micrometre bound. Repeat readings of 200, 205 and 280 have an 80-micrometre spread and fail the separate repeat gate. These are distinct reasons to stop, rather than different names for one unknown error.
The next movement is an equipment decision
Mara Voss asked for a finite list she could act on. Reed now has one. The next task is to identify an available frame and candidate sensors, obtain their actual specifications, assign custody and replace demonstration thresholds with a justified uncertainty budget. No graphene sample is needed for that procurement and planning decision.
Proposed requirements and arbitrary demonstration bounds, not a certified uncertainty budget. Even the passing paper case authorizes no physical test; actual equipment is not secured.
Results at a glance
| Software case | Repeat spread (um) | Failed gate | Decision |
|---|---|---|---|
| paper_control | 7 | None | eligible_within_paper_model |
| actual_readiness_inventory | 7 | equipment_not_secured | hold |
| shared_reference_custody | 7 | shared_reference_custody | hold |
| post_run_reference_shift | 7 | reference_check_failed | hold |
| stationary_offset | 7 | stationary_control_failed | hold |
| repeat_disagreement | 80 | repeat_spread_failed | hold |