SPACE ENVIRONMENT: ATMOSPHERE


Atmosphere affects satellites residing at the Low-Earth Orbit in the following ways:

Drag

Drag is a force that causes a satellite to fall back to Earth faster, shortening its lifetime. At less than 600 km from the Earth's surface, drag varies depending on how the atmosphere expands or contracts due to variations in solar activity.

The impact of drag on the satellite also depends on the satellite's speed, size, shape and orientation. For instance, deployable panels can make the drag more prominent, leading to satellite's shorter lifetime.

Atomic Oxygen

Radiation and charged particles can cause O2 molecules to split apart in space, creating atomic oxygen, O. In this form, metal oxidation leading to corrosion or rusting becomes more intense. This can cause degradation of exposed areas and create issues with interconnects on solar arrays and on optical surfaces.

Space Environment

References:
Understanding Space: An Introduction to Astronautics, 2nd edition, Jerry Jon Sellers, McGraw Hill, USA 2004
Spacecraft Systems Engineering, 3rd edition
 

Comments

Post a Comment

Popular posts from this blog

PHL-MICROSAT PROGRAM, DIWATA-1 and DIWATA-2

Image
This blog will not be complete without mentioning the country's initial foray to space through the PHL-Microsat Program. The PHL-Microsat Program The PHL-Microsat Program is a R&D program supported by the Philippine's Department of Science and Technology (DOST). It started on 2015, with an aim to develop, launch and effectively utilize the country's first microsatellites, Diwata-1 and Diwata-2, and lay the foundation for a sustainable space science and technology ecosystem in the country. The program is composed of five component project with focus on: Project 1 - Development of the microsatellites Project 2 - Development and operations of the ground receiving station for Diwata-1 and Diwata-2 Project 3 - Data processing, archiving and distribution Project 4 - Calibration and validation of remote sensing instruments Project 5 - Development of remote sensing data products Diwata-1 Diwata-1 , the country's first microsatellite is a ...
Read more

AGILA-2: PH's SECOND SATELLITE

Just a year after acquiring Agila-1 , the Philippines acquired its second satellite, Agila-2. However, compared with Agila-1, Agila-2 is designed for a Philippine company and is not acquired while already in orbit. Agila-2 is a telecommunications satellite built by Space Systems/Loral (SS/L) for Mabuhay Satellite Corporation. It was launched to space from Xichang Satellite Launch Center via the Chang Zheng 3B rocket on August 19, 1997 (17:50 UTC) and was positioned at the 146°E longitude orbital slot. The mass varies from sources, but according to Gunter's Space, its launch mass is 3775 kg while its dry mass is 1800 kg (Wikipedia reports 2,820 kg launch mass). Agila-2 is claimed to be the most powerful telecommunications satellite in the entire Asia-Pacific region, and one of the most efficient in the industry. It carries 24 C-band, 24 Ku-band, and 6 extended C-band transponders, making it the satellite with the largest number of active transponders compared to any oth...
Read more

SATELLITE CLASS BY MASS

There are many ways to classify satellites. These categories can be by function , by type of orbit or by mass. We will discuss satellite's functions and orbit in our next articles but for now, we will focus on satellite's classification by mass. Satellite's mass has direct impact on its cost, its development cycle and its launcher. The larger the satellite, the bigger is the development cost. This is because larger satellites carries more equipment such as redundancy modules, propellant, and more solar panels. Also, since it has more components and the lifetime and reliability expectation is higher, design reviews and tests conducted are also more than smaller satellites. Finally, larger satellites occupy larger space in the rocket, entailing higher launch cost. The names of the categories by mass is not an official convention. We can still, however use it for generic purposes: Large satellite - 1000 kg Medium-sized satellite - 500 kg to 1000 kg Small satellites...
Read more