Orbiting Astronomical Observatory 2
NASA space observatory launched in 1968
The Orbiting Astronomical Observatory 2 (OAO-2, nicknamed Stargazer) was the first successful space telescope (first space telescope being OAO-1, which failed to operate once in orbit), launched on December 7, 1968. An Atlas-Centaur rocket launched it into a nearly circular 750-kilometre (470 mi) altitude Earth orbit. Data was collected in ultraviolet on many sources including comets, planets, and galaxies. It had two major instrument sets facing in opposite directions; the Smithsonian Astrophysical Observatory (SAO) and the Wisconsin Experiment Package (WEP). One discovery was large halos of hydrogen gas around comets, and it also observed Nova Serpentis, which was a nova discovered in 1970.
Celescope: Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory, also called Celescope, had four 12-inch (30 cm) Schwarzschild telescopes that fed into Uvicons. The Uvicon was an ultra-violet light detector based on the Westinghouse Vidicon. Ultraviolet light was converted into electrons which were in turn converted to a voltage as those electrons hit the detection area of the tube. There has been a Uvicon in the collection of the Smithsonian Institution since 1973.
Various filters, photocathodes, and electronics aided in collecting data in several ultraviolet light passbands.
The public source identifies “Orbiting Astronomical Observatory 2” as nASA space observatory launched in 1968. This brief keeps that definition visible, then builds a research path around Orbiting, Astronomical and Observatory.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Orbiting Astronomical Observatory 2”, the useful work is to connect “nASA space observatory launched in 1968” to the records capable of establishing context and consequence.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 24, 2026. The linked authority identifier is Q15261041. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1968, 1970 and 1973.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Orbiting Astronomical Observatory 2”, its source revision and the description used here.
- Expand the search: follow Orbiting Astronomical Observatory 2 primary sources, Orbiting Astronomical Observatory 2 archive and Orbiting research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Orbiting Astronomical Observatory 2”?
- What terminology or title could unlock a more precise catalogue search?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Orbiting Astronomical Observatory 2” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.