AS-104

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title: "AS-104" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["apollo-program", "spacecraft-launched-in-1965", "1965-in-the-united-states", "test-spaceflights", "spacecraft-launched-by-saturn-rockets", "saturn-i"] description: "1965 orbital test of a Apollo spacecraft" topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/AS-104" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary 1965 orbital test of a Apollo spacecraft ::

::data[format=table title="Infobox spaceflight"]

Field	Value
name	AS-104
image	Saturn SA8 launch.jpg
image_caption	Launch of Saturn AS-104
mission_type	Spacecraft aerodynamics;
micrometeoroid investigation
operator	NASA
COSPAR_ID	1965-039B
SATCAT	1385
mission_duration	8,810 days
orbits_completed	~79,790
distance_travelled	3282050195 km
spacecraft	Apollo BP-26
Pegasus 2
launch_mass	1451.5 kg
launch_date	UTC
launch_rocket	Saturn I SA-8
launch_site	Cape Kennedy LC-37B
decay_date
orbit_epoch	4 July 1965
orbit_reference	Geocentric
orbit_regime	Low Earth orbit
orbit_periapsis	511 km
orbit_apoapsis	739 km
orbit_inclination	31.7 degrees
orbit_period	97.2 minutes
apsis	gee
previous_mission	AS-103
next_mission	AS-105
programme	Apollo program
::

| name = AS-104 | image = Saturn SA8 launch.jpg | image_caption = Launch of Saturn AS-104 | insignia =

| mission_type = Spacecraft aerodynamics; micrometeoroid investigation | operator = NASA | COSPAR_ID = 1965-039B | SATCAT = 1385 | mission_duration = 8,810 days | orbits_completed = ~79,790 | distance_travelled = 3282050195 km

| spacecraft = Apollo BP-26 Pegasus 2 | manufacturer = | launch_mass = 1451.5 kg | landing_mass =

| launch_date = UTC | launch_rocket = Saturn I SA-8 | launch_site = Cape Kennedy LC-37B | decay_date =

| orbit_epoch = 4 July 1965 | orbit_reference = Geocentric | orbit_regime = Low Earth orbit | orbit_periapsis = 511 km | orbit_apoapsis = 739 km | orbit_inclination = 31.7 degrees | orbit_period = 97.2 minutes | apsis = gee

| previous_mission = AS-103 | next_mission = AS-105 | programme = Apollo program AS-104 was the fourth orbital test of a boilerplate Apollo spacecraft, and the second flight of the Pegasus micrometeoroid detection satellite. It was launched by SA-8, the ninth Saturn I carrier rocket.

Objectives

The primary mission objective was to demonstrate the launch vehicle's iterative guidance mode and to evaluate system accuracy. The launch trajectory was similar to that of mission AS-103.

The Saturn launch vehicle SA-8 and payload were similar to those of mission AS-103, except that a single reaction control engine assembly was mounted on the boilerplate service module (BP-26). The assembly was instrumented to acquire additional data on launch environment temperatures. This assembly also differed from the one on the AS-101 mission in that two of the four engines were of a prototype configuration instead of all engines being simulated.

Launch

This was the first nighttime launch in the Saturn I series. A built-in 35 minute hold was used to ensure that launch time coincided with the opening of the launch window.

AS-104 was launched from Cape Kennedy Launch Complex 37B at 2:35:01 a.m. EST (07:35:01 GMT) on May 25, 1965. The launch was normal and the payload was inserted into orbit approximately 10.6 minutes after lift-off. The total mass placed in orbit, including the spacecraft, Pegasus B, adapter, instrument unit, and S-IV stage, was 34,113 pounds (15,473 kg). The perigee and apogee were 314.0 and 464.1 miles (505 and 747 km), respectively; the orbital inclination was 31.78'. The 1397 kilogram (3080-pound) Pegasus 2 satellite was also carried to orbit by SA-8, being stowed inside the boilerplate's service module, and remaining attached to the S-IV stage.

The actual trajectory was close to the one predicted, and the spacecraft was separated 806 seconds after lift-off. Several minor malfunctions occurred in the S-I stage propulsion system; however, all mission objectives were achieved.

References

References

1. "Apollo Model 4".
2. McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page.
3. "Saturn Illustrated Chronology - Part 6 January 1965 through December 1965". NASA.
4. (May 17, 1965). "SA-8 operational trajectory".
5. Weichel, H. J.. (August 2, 1965). "SA-8 flight test data report". NASA.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::