Search

The orbital motion of tethered satellites is a highly complex nonlinear problem. This investigation formulates a new method that significantly simplifies the dynamic analysis of tethered satellite systems. This is accomplished using the fundamental equation for constrained dynamic systems, which was formulated by Udwadia and Kalaba. As a result of this new method, a study of the periodicity of tethered satellite motion is conducted and an extension to formation flying satellites is made. With varying fixed tether lengths, the system motion seems to transition from periodic to quasi-periodic. The simplified method is also applied to the computation of the control force required for formation flight. DOI: 10.1061/(ASCE)0893-1321(2005)18:4(242) CE Database subject headings: Satellites; Motion; Nonlinear response.

Older people are often affected by impaired organ and bodily functions resulting in multimorbidity and polypharmacy, turning them into the main user group of many medicines. Very often, medicines have not specifically been developed for older people, causing practical medication problems for them like limited availability of easy to swallow formulations, easy to open packaging and dosing instructions for enteral administration. In 2020, the European Medicines Agency (EMA) published a reflection paper 'Pharmaceutical development of medicines for use in the older population', which discusses how the emerging needs of an ageing European population can be addressed by medicines regulation. The paper intends to help industry to better consider the needs of older people during pharmaceutical/clinical medicines development by summarising data on the most relevant topics, providing early suggestions on how to move forward and prompting expert discussions and studies into knowledge gaps. Topics include patient acceptability, (dis)advantages of an administration route, formulation, dosage form, packaging, dosing device and user instruction. While the paper is directed at older people and the pharmaceutical industry, the reflections are also relevant to younger patients with similar disease‐related needs and of value to other stakeholders parties, e.g., healthcare professionals, academics, patients and caregivers, as the paper makes clear what can be expected from industry and where collaborative work is needed. This commentary provides an overview of the different steps in the development of the reflection paper, discusses points considered most controversial and/or subject to (multidisciplinary) expert discussions and indicates their value for real world clinical practice. [ABSTRACT FROM AUTHOR]