Pick up to 4 missions to compare side-by-side. State lives in the URL — share the link and the comparison loads exactly as you left it.
Six nations have placed lunar orbiters since 2007 — a 4× increase in 15 years.
| Attribute | |
|---|---|
| Agency | NASA |
| Status | Deorbited |
| Mission type | Orbiter |
| Launch date | 1998-01-06 |
| End date | 1999-07-31 |
| Orbit | 100 km circular polar orbit (lowered to 15-30 km for extended mission) |
| Mass | 158 kgas of [1]One of the smallest and lowest-cost ($63M) NASA lunar orbiters |
| Instruments | 5 instrumentsas of [1] |
| Key findings |
|
| Outcome | A low-cost ($63M) NASA Discovery mission that made one of the most important lunar discoveries of the late 20th century: strong evidence for water-ice at both poles. Deliberately impacted the lunar south pole at mission end; no detectable water plume was observed, but this was attributed to unfavorable geometry. |
All 11 lunar orbital missions with primary-source citations from NASA, ESA, JAXA, ISRO, CNSA, and NASA NSSDCA. Coverage spans Clementine (1994) through LRO (active 2026). Pure URL state — bookmark or share the link and the comparison reproduces exactly.