Apollo Spacecraft

*The information presented in this article is **true for my alternate history**, but either completely false, or only partly true for real life.*

The **Apollo Spacecraft** was an American manned spacecraft designed and built by North American Aviation (later North American Rockwell).

It was used to carry crew for a multitude of american space exploration programs, starting with the Apollo program.

It consisted of 2 parts:

### Command Module (CM):

The **pitch control motor** pushed the LES and CM toward the Atlantic Ocean and away from the LV during a low-altitude abort. Built by the Lockheed Propulsion Co. of Redlands, California, it was 22" long, 8.75" in diameter, weighed 49 lb (8.9 of which was propellant), and produced 2,420 lbT for 0.62 sec. The propellant was integrally cast as a 14-point internal burning star configuration. Total impulse was controlled by varying the propellant grain length.

Pitch control motor ignition was via an pellet-basket-type **igniter assembly** with two pyrotechnic igniter cartridges, each of which had a booster charge and Apollo standard hot-bridgewire initiator. Identical igniters were used in the launch escape and tower jettison motors.

The TE-M-380 **tower jettison motor** was used in all missions to jettison the LES. Built by the Thiokol Chemical Corp. of Elkton, Maryland, the jettison motor was 55.6" long, 26" in diameter, weighed 525 lb (205 of which was propellant, integrally cast in a 10-point double-web internal burning star configuration), and produced 31,500 lbT for 1.1 sec. The motor had two fixed nozzles, located 180° apart, that projected downward and outward, producing a thrust vector of about 4° that tipped the LES and pulled it free of the CM.

The **launch escape motor**, built by the Lockheed Propulsion Co. of Redlands, California, was 186" long, 26" in diameter, weighed 4,794 lb (3,162 of which was propellant, integrally cast in an 8-point internal-burning star configuration), and produced 138,300 lbT for 3.3 sec at sea level. This was enough impulse to carry the 13,000 lb CM about a mile from the LV. In order to provide a thrust vector angle of about 2.15° relative to the center of gravity excursion line, one of the two pitch-plane nozzle throat areas was about 5% larger than the yaw plane nozzles, while the other pitch-plane nozzle throat area was about 5% less than the yaw plane nozzles. The titanium motor skirt attached the motor stack to the tower.

The **launch escape tower** was a welded titanium tubing truss structure, about 10 feet long, 3 feet square at the top and 4 feet square at its base, and weighed about 500 lb. Its 2.5" and 3.5" titanium tubes were covered with Buna -N rubber insulation, which protected it from the rocket motor exhaust. The four tower legs fit into wells in the CM forward structure and were fastened with studs and frangible explosive nuts that facilitated LES/CM separation.

The **boost protective cover** was attached to the launch escape tower base. Impregnated fiberglass, honeycomb-cored laminated fiberglass, and cork layers comprised the boost protective cover's structure. It had 12" blowout ports for reaction control motors, vents, and an 8" diameter window that coincided with the CM hatch window. The cover protected the CM from LES rocket exhaust and also from atmospheric heating during launch. It was 11 feet tall, 13 feet in diameter, and weighed about 100 lb.

During successful launches, astronauts jettisoned the LES at a prescribed altitude, typically about 30 seconds after second-stage ignition.

### Service Module (SM):

A lot of different variants were developed during the years.

## Variants:

### Apollo Block III

Main propulsion swapped for a smaller LMDE-derived engine (non-throttleable).

### Apollo Block IV

Strenghtened CM, heavy interplanetary heatshield, 2 engines for redundancy. Used in Othrys program.

### Apollo Block V

Same as Block III, but docking port was swapped for an APAS-style.

### Apollo Block VI

Little is known, it was an abandoned study.

### Apollo Block VII

Initial version built for Coelus program's initial requirements.

### Apollo Block VIII

Redesigned version for Coelus program, flown twice.

### Apollo Block XI (Perseus)

Perseus (initially Apollo Block IX) was a major redesign of the spacecraft. The CM got bigger (4.4 meters). Uses updated, more modern RCS thrusters and electronics. Updated heatshield.

Used in Russo-American expedition to Neptune.