Developing an environmentally friendly propulsion system using an advanced technology and materials
Bibliographic record
Abstract
Nowadays, satellites have a short lifespan due to the limited quantity of propellant that can be taken on board. On the other hand, some of the used propellants are not environmentally friendly, some of them being considered even poisonous, as hydrazine. This paper presents a new design concept for an environmentally friendly satellite propulsion system where an advanced technology and materials are used. This propulsion system is presently in a research-design-manufacturing stage at the Romanian Research and Development Institute for Gas Turbines - COMOTI. To reduce the necessary propellant quantity, in the case of cold gas propulsion systems working with gaseous N2, the periodical heating of gas using concentrated solar light was considered. When the correction of satellite attitude is necessary, the cold N2 is sent from the main tank in a small service tank placed in the focal point of a gold plated composite parabolic mirror. The mirror is permanently oriented with the concave (reflective) surface to the Sun. The sun rays parallel with the mirror’s symmetry plane are focused by the parabolic mirror on the service tank placed in its focal point (line). In this way the temperature of N2 from the service tank increases quickly with several degrees Celsius and the reaction force increases when the gas is expanded in the Laval nozzles. The parabolic mirror is made of carbon fiber composite, thus making the structure very light, (around 0.5 kg). The Laval nozzles have extremely thin walls (0.5 mm) being made using a technology of wall stiffening with Cerrobend alloy during machining.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".