Boeing 601

The Boeing 601 (sometimes referred to as the BSS-601, and previously as the HS-601) is a communications satellite bus introduced in 1987 by Hughes Space and Communications Company. The more advanced 601HP derivative (for "high power") was introduced in 1995. Hughes, and the 601 platforms, were acquired by Boeing in 2000.

Design

Structure

The 601 bus is divided into two modules. The first module houses the propulsion system, batteries, and electronics for the bus, and bears launch vehicle loads. The second module contains shelves carrying the communications equipment, payload electronics, and heat pipes. Solar arrays, reflectors, and antenna feeds are mounted to the payload module.

Payload

The standard 601 platform supports up to 48 transponders and provides up to 4,800 watts of power. The 601HP supports up to 60 transponders and provides up to 10,000 watts.

Failures

A significant number of Boeing 601s have experienced failures in orbit, some resulting in complete failure of the satellite.

.bss

In computer programming, the name .bss or bss is used by many compilers and linkers for a part of the data segment containing statically-allocated variables represented solely by zero-valued bits initially (i.e., when execution begins). It is often referred to as the "bss section" or "bss segment".

Typically only the length of the bss section, but no data, is stored in the object file. The program loader allocates and initializes memory for the bss section when it loads the program. Operating systems may use a technique called zero-fill-on-demand to efficiently implement the bss segment (McKusick & Karels 1986). In embedded software, the bss segment is mapped into memory that is initialized to zero by the C run-time system before main() is entered.

On some computer architectures the application binary interface also supports an sbss segment for "small data". Typically, these data items can be accessed using shorter instructions that may only be able to access a certain range of addresses.

BSS

BSS may stand for:

Computing and Telecommunications

Entertainment

Media

Bang senseless

Bang senseless (bss) is a gene identified in Drosophila melanogaster that is known to yield seizure-like activity in mutant phenotypes.

Location

Bang senseless has been localized to 1-54, left of forked (f) and right of scalloped (sd).

Inducing seizure activity

Seizures can be induced by mechanical shock, electrical shock, or high-frequency visual stimuli such as strobe lights. Mechanical shock can be achieved by vortexing bang senseless mutants in a small vial for ~10 seconds on a VWR vortex set to its maximum setting.

Alleles

Aside from the wild-type allele, two mutant alleles have been identified: bss¹ & bss².

bss¹

The bss¹ mutants typically recover from seizure after 100–400 seconds.

bss²

Less is known about the bss² allele, but it is known that it is also a paralytic mutant (prone to seizure-like activity).

References