Pioneer program in the context of Starship

A yo-yo de-spin mechanism is a device used to reduce the spin of satellites, typically soon after launch. It consists of two lengths of cable with weights on the ends. The cables are wrapped around the final stage and/or satellite, in the manner of a double yo-yo. When the weights are released, the spin of the rocket flings them away from the spin axis. This transfers enough angular momentum to the weights to reduce the spin of the satellite to the desired value. Subsequently, the weights are often released.

De-spin is needed since some final stages are spin-stabilized, and require fairly rapid rotation (now typically 30-60 rpm; some early missions, such as Pioneer, rotated at over 600 rpm) to remain stable during firing. (See, for example, the Star 48, a solid fuel rocket motor.) After firing, the satellite cannot be simply released, since such a spin rate is beyond the capability of the satellite's attitude control. Therefore, after rocket firing but before satellite release, the yo-yo weights are used to reduce the spin rates to something the satellite can cope with during detumbling in normal operation (often 2-5 RPM). Yo-yo de-spin systems are commonly used on sub-orbital sounding rocket flights, as the vehicles are spin stabilized through ascent and have minimal flight time for roll cancellation using the payload's attitude control system.

The Jupiter radius or Jovian radius (plural Jupiter radii or Jovian radii; denoted as R_J or, less commonly, R_Jup) has a value of 71,492 km (44,423 mi), or of 11.2 Earth radii (R_🜨) (one Earth radius, 6378 km, equals 0.08921 R_J). The Jupiter radius is a unit of length used in astronomy to describe the radii of large planets (especially gas giants) and certain exoplanets. It is also used in describing certain stars, in particular brown dwarfs.

The general shape of the planet Jupiter has been directly measured from radio occultations of passing spacecraft, starting with the Pioneer and Voyager missions. This method gives an overall margin of error of about ±5 km. Estimates of the radius at one bar pressure are then determined through extrapolation. The planet Jupiter has the approximate shape of an oblate spheroid, which is mainly set by the rate of rotation. This gives a difference of about 10% between its polar and equatorial radii. The polar radius has been determined with an accuracy of ±10 km (as of 1987). Density fluctuations within the planet can create variations in the equatorial radius of up to 30 km. The winds in Jupiter's outer atmosphere can vary the radius by up to 4 km.

Launch Complex 36 (LC-36) is a launch complex located at the Cape Canaveral Space Force Station in Florida. Located south of the Missile Row launch range, the complex originally consisted of two pads—designated LC-36A and LC-36B—to support the flights of Atlas launch vehicles equipped with a Centaur upper stage. From the 1960s to the 1980s, LC-36 was used by NASA and the United States Air Force to launch many payloads from the Atlas-Centaur and its derivatives, including the Pioneer, Surveyor, and Mariner probes. During the late 1980s, LC-36B was also used to launch the Atlas G, and General Dynamics (and later Lockheed Martin) modified the two pads to support the larger Atlas I, Atlas II, and Atlas III throughout the 1990s and early 2000s.

Following the Atlas program's relocation to Space Launch Complex 41 (SLC-41) in 2005, LC-36 stood vacant until Blue Origin acquired the lease in 2015 for use by their heavy-lift New Glenn rocket. The company made extensive modifications to the complex during this time, including demolishing 36A and 36B to build one large pad in place, as well as integrating the neighboring Launch Complex 11 (LC-11) into the facility. Following this large-scale renovation, the new era of LC-36 commenced with the maiden flight of New Glenn in January 2025.