From the archives: NASA launches Hubble Telescope in 1990

Key Concepts

Hubble Space Telescope: A space-based observatory designed to study the age, size, and fate of the universe, and to refine the Big Bang theory.
Space Telescope Science Institute (STScI): A $200 million, five-story facility at Johns Hopkins University dedicated to receiving and processing data from Hubble.
Launch Sequence: The automated countdown process, including critical milestones like "Main Engine Start," "Roll Program," and "Solid Rocket Booster (SRB) separation."
T-minus 31-second Hold: A technical delay caused by a valve failure in the oxygen fill and drain tank, which was successfully resolved to allow for launch.
Big Bang Theory: The cosmological model describing the origin of the universe approximately 15 billion years ago.

Mission Overview and Objectives

The primary objective of the Space Shuttle Discovery mission is the deployment of the Hubble Space Telescope. Scientists view Hubble as a "time machine" capable of providing a revolutionary perspective on the cosmos. Over its projected 15-year lifespan, the telescope is expected to:

Provide data to answer fundamental questions regarding the universe's age and size.
Refine the Big Bang theory.
Justify the significant financial investment and long development timeline (conceived in the 1940s, seven years behind schedule, and over budget).

Technical Challenges and Launch Procedures

The launch process faced significant scrutiny due to previous delays. Astronaut Steve Holly, for instance, set a record for the most launch attempts (11) across his missions.

The T-minus 31-second Hold:

The Issue: During the final countdown, the clock stopped at 31 seconds due to a system failure.
The Cause: A valve in the oxygen fill and drain tank failed to verify as "closed." This mirrored a similar valve-related issue that caused a hold two weeks prior.
Resolution: NASA engineers identified the specific valve, resolved the status, and successfully recycled the countdown clock.

Launch Milestones:

Main Engine Start: Initiated after the hold was cleared.
Roll Program: A maneuver performed shortly after liftoff to orient the shuttle into the correct launch plane.
Throttle Up: A critical phase where engines are throttled back up; this is a point of high tension for the crew.
SRB Separation: Occurring at approximately 2 minutes and 5 seconds into the flight, this is considered a major event where the solid rocket boosters are jettisoned.

Data Management and Future Expectations

To handle the massive influx of data expected from the telescope, the Space Telescope Science Institute was established.

Data Timeline: The first "checkout" images, featuring a star cluster, are expected within seven days of deployment. The primary stream of scientific data is anticipated to begin arriving in approximately eight months.
Scientific Context: This mission is part of a broader "second golden age of space science," joining other active missions such as the Magellan probe (Venus), Galileo (Jupiter), and the Neptune mission.

Notable Statements

On the nature of the mission: "Hubble is the centerpiece of a series of scientific missions that are expected to change our concepts of the universe."
On the psychological toll of launch: Astronauts have noted that "anyone who does not admit to being scared during these first two minutes of a shuttle ride is just not telling the truth."
On the resilience of the program: Despite being seven years behind schedule and significantly over budget, astronomers maintained that the delays were acceptable because "the universe will still be there."

Synthesis

The successful launch of Discovery marks a pivotal moment in astronomical history. Despite technical hurdles—specifically the recurring issue of valve failures—the mission proceeded to deploy the Hubble Space Telescope. This instrument represents a massive leap in human capability, designed to transform our understanding of the universe's origins and evolution. The mission serves as a testament to the persistence of the space program, transitioning from a history of delays to the active pursuit of deep-space discovery.