Columbia subject headings:
Astronomy--Research--United States--Congresses.
Hubble Space Telescope (Spacecraft)--Congresses.
Orbiting astronomical observatories--Congresses.
Harvard subject headings:
Astronomy--Research--United States--Congresses.
Hubble Space Telescope (Spacecraft)--Congresses.
Orbiting astronomical observatories--Congresses
Princeton subject headings:
Astronomy--Research--United States--Congresses.
Orbiting astronomical observatories--Congresses.