|This article is the subject of an educational assignment supported by Wikipedia Ambassadors through the India Education Program.|
|This article is of interest to the following WikiProjects:|
The statement that spacecraft design will undergo significant development in the 21st century is either so generic it doesn't mean anything, or misleading. In fact, spacecraft technology has pretty much stagnated since the last 30 years. Only two areas can be claimed as having made real progress: Propulsion, with the advent of electric propulsion, and communications, with digital communications and general space data production capacity following suit to the terrestrial evolutions. I thus proposed some changes. --Wouarnud 22:20, 16 August 2005 (UTC) (arnaud)
"An important difference though is that spacecraft operate part or all of their life in vacuum and interplanetary space environment."
On-board Computer systems
Computer Subsystem is far from being based purely on terrestrial technologies, for example there is use of:
- Radiation hardened processors which usually have latch-up prevention mechanisms and have reduced SEU (single event upset)] probability. See RAD750 for an example.
- RAM and Solid-State Recorders having built-in error error detection and correction (EDAC) mechanisms (to deal with bit-flips due to SEU)
Software may be said to be similar to terrestrial applications, but unlike most terrestrial software, it must be extremely autonomous & reliable, thus using many techniques to achieve this goal, such as:
- Hot Redundancy
- Dedicated Watch-dog mechanisms (to switch/reset computers)
- Must usually handle successfully single hardware malfunction and be able to recover autonomously, usually through entering emergency modes in witch the spacecraft attempts to switch hardware, change attitude, etc.
Which makes it more like avionics systems in airplanes than terrestrial applications.
Space Shuttle centric content
The Space Shuttle centric stuff should in my opinion be removed or perhaps moved to the Space Shuttle article. In the latter case it would need cleanup first. Martijn Meijering (talk) 20:59, 17 October 2011 (UTC)