# Interstage Adapter Satellite

> instrumented transfer booster used to propel the Clementine spacecraft to the Moon

**Wikidata**: [Q112958719](https://www.wikidata.org/wiki/Q112958719)  
**Source**: https://4ort.xyz/entity/interstage-adapter-satellite

## Summary
The Interstage Adapter Satellite (ISAS) was an instrumented transfer booster used to propel the Clementine spacecraft to the Moon. Developed by the United States Naval Research Laboratory and Thiokol, it served as both a space tug and a technology demonstration spacecraft, playing a critical role in NASA's Deep Space Program Science Experiment (DSPSE).

## Key Facts
- **Classifications**: Space tug and technology demonstration spacecraft
- **Manufacturers**: United States Naval Research Laboratory and Thiokol
- **Launch Date**: January 25, 1994, at 16:34 UTC
- **Launch Vehicle**: Titan 23G (serial number 23G-11)
- **Launch Site**: Vandenberg Space Launch Complex 4 West
- **Operator**: Ballistic Missile Defense Organization
- **Power Source**: Star 37 engine
- **Orbital Decay**: June 8, 1994
- **Aliases**: Clementine Interstage Adapter Satellite, Clementine ISAS, DSPSE-ISA, STAR 37FM AKM
- **COSPAR ID**: 1994-004C
- **NSSDCA ID**: 1994-004C

## FAQs
### Q: What was the purpose of the Interstage Adapter Satellite?
A: The ISAS was designed to transfer the Clementine spacecraft from Earth orbit to a trajectory toward the Moon, serving as both a propulsion stage and a technology demonstrator.

### Q: Who built the Interstage Adapter Satellite?
A: The ISAS was developed by the United States Naval Research Laboratory in collaboration with Thiokol, with the Ballistic Missile Defense Organization operating it.

### Q: How did the Interstage Adapter Satellite contribute to the Clementine mission?
A: The ISAS provided the necessary propulsion to adjust Clementine's trajectory, enabling it to reach lunar orbit and conduct its scientific objectives.

### Q: What happened to the Interstage Adapter Satellite after its mission?
A: The ISAS reentered Earth's atmosphere and decayed from orbit on June 8, 1994, completing its role in the Clementine mission.

### Q: What was the significance of the Star 37 engine in the ISAS?
A: The Star 37 engine powered the ISAS, providing the thrust required to maneuver the spacecraft from Earth orbit to lunar trajectory.

## Why It Matters
The Interstage Adapter Satellite was a critical component of the Clementine mission, demonstrating the feasibility of using instrumented transfer boosters to propel spacecraft to the Moon. As a technology demonstration, it contributed to advancements in space tug design and interplanetary trajectory adjustments. Its successful deployment showcased the collaboration between military and civilian space programs, bridging the gap between defense and scientific exploration. The ISAS's role in Clementine's mission laid the groundwork for future lunar and deep-space missions, proving the effectiveness of modular spacecraft designs.

## Notable For
- **First Use of an Instrumented Transfer Booster**: The ISAS was the first spacecraft to use an instrumented interstage adapter for lunar trajectory correction.
- **Military-Civilian Collaboration**: Developed by the U.S. Naval Research Laboratory and Thiokol, it highlighted the intersection of defense and space exploration.
- **Technology Demonstrator**: Served as a testbed for propulsion systems and trajectory adjustment techniques in deep space.
- **Precise Trajectory Adjustment**: Enabled Clementine to achieve lunar orbit with high accuracy, crucial for its scientific objectives.
- **Short Operational Lifespan**: Completed its mission quickly, reentering Earth's atmosphere just five months after launch.

## Body
### Overview
The Interstage Adapter Satellite (ISAS) was a specialized spacecraft designed to transfer the Clementine probe from Earth orbit to a lunar trajectory. Developed by the United States Naval Research Laboratory (NRL) and Thiokol, it functioned as both a space tug and a technology demonstration vehicle.

### Development and Launch
- **Manufacturers**: The NRL and Thiokol collaborated on the ISAS, with the NRL overseeing the scientific instrumentation and Thiokol providing the propulsion system.
- **Launch Date**: The ISAS was launched on January 25, 1994, at 16:34 UTC from Vandenberg Space Launch Complex 4 West aboard a Titan 23G rocket (serial number 23G-11).
- **Operator**: The Ballistic Missile Defense Organization (BMDO) was responsible for the ISAS's operations during its mission.

### Mission Role
- **Propulsion**: The ISAS was powered by a Star 37 engine, which provided the necessary thrust to adjust Clementine's trajectory.
- **Trajectory Correction**: After separation from the Titan rocket's upper stage, the ISAS performed a series of maneuvers to place Clementine on a lunar transfer orbit.
- **Technology Demonstration**: The ISAS served as a test platform for deep-space propulsion and trajectory adjustment techniques.

### Mission Outcome
- **Lunar Transfer**: The ISAS successfully propelled Clementine toward the Moon, enabling the spacecraft to enter lunar orbit and conduct its scientific missions.
- **Orbital Decay**: The ISAS reentered Earth's atmosphere on June 8, 1994, completing its role in the Clementine mission.

### Legacy
The Interstage Adapter Satellite's role in the Clementine mission demonstrated the effectiveness of modular spacecraft designs and the potential for military technology to support civilian space exploration. Its brief but impactful mission contributed to advancements in space propulsion and trajectory correction, influencing future lunar and deep-space missions.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/isa.htm)
2. Jonathan's Space Report
3. [Source](https://www.n2yo.com/satellite/?s=22987)