STS-48

Key takeaways

STS-48 belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect STS-48 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of STS-48 from memory before moving on to harder problems.

Reference excerpt

STS-48 was a Space Shuttle mission that launched on September 12, 1991, from Kennedy Space Center, Florida. The orbiter was Space Shuttle Discovery on her 13th flight. The primary payload was the Upper Atmosphere Research Satellite (UARS). The mission landed on September 18 at 12:38 a.m. EDT at Edwards Air Force Base on runway 22. The mission was completed in 81 revolutions of the Earth and traveled 3,530,369 km (2,193,670 mi). The 5 astronauts carried out a number of experiments and deployed several satellites. The total launch mass was 108,890 kg (240,060 lb) and the landing mass was 87,440 kg (192,770 lb).

Crew

Crew seat assignments

Mission highlights

Space Shuttle Discovery was launched into a 57.00° inclination orbit from the Kennedy Space Center (KSC) Launch Complex 39A at 7:11 p.m. EDT on September 12, 1991. Launch was delayed for 14 minutes at the T−5 minute mark due to a noise problem in the air-to-ground link. The noise cleared itself, and the countdown proceeded normally to launch. On the third day of the mission, the Upper Atmosphere Research Satellite (UARS) was deployed from Discovery's payload bay 650 km (400 mi; 350 nmi) above Earth to study human effects on the planet's atmosphere and its shielding ozone layer. The UARS mission objectives were to provide an increased understanding of the energy input into the upper atmosphere, global photochemistry of the upper atmosphere, dynamics of the upper atmosphere, the coupling among these processes, and the coupling between the upper and lower atmosphere. This provided data for a coordinated study of the structure, chemistry, energy balance, and physical action of the Earth's middle atmosphere – that slice of air between 16 km (9.9 mi; 8.6 nmi) and 97 km (60 mi; 52 nmi) above the Earth. The UARS was the first major flight element of NASA's Mission to Planet Earth, a multi-year global research program that would use ground-based, airborne, and space-based instruments to study the Earth as a complete environmental system. UARS had ten sensing and measuring devices: Cryogenic Limb Array Etalon Spectrometer (CLAES); Improved Stratospheric and Mesospheric Sounder (ISAMS); Microwave Limb Sounder (MLS); Halogen Occultation Experiment (HALOE); High Resolution Doppler Imager (HRDI); Wind Imaging Interferometer (WlNDII); Solar Ultraviolet Spectral Irradiance Monitor (SUSIM); Solar/Stellar Irradiance Comparison Experiment (SOLSTICE); Particle Environment Monitor (PEM) and Active Cavity Radiometer Irradiance Monitor (ACRIM II). UARS's initial 18-month mission was extended several times – it was finally retired after 14 years of service. Secondary payloads were: Ascent Particle Monitor (APM); Middeck 0-Gravity Dynamics Experiment (MODE); Shuttle Activation Monitor (SAM); Cosmic Ray Effects and Activation Monitor (CREAM); Physiological and Anatomical Rodent Experiment (PARE); Protein Crystal Growth (PCG II-2); Investigations into Polymer Membrane Processing (IPMP); and the Air Force Maui Optical Site (AMOS) experiment. The flight was the first to test an electronic still camera in space, a modified Nikon NASA F4. Images obtained during the flight were monochrome with 8 bits of digital information per pixel (256 gray levels) and stored on a removable hard disk. The images could be viewed and enhanced on board using a modified lap-top computer before being transmitted to the ground via the orbiter digital downlinks. STS-48 was the second post-Challenger mission to have Kennedy Space Center as the planned End-Of-Mission landing site, and the first mission to have a planned night landing at KSC. However, due to weather conditions at KSC in Florida, Discovery flew one extra orbit and landed at Edwards Air Force Base, California, at 3:38 a.m. EDT on September 18, 1991. The orbiter returned to KSC on September 26, 1991.

Ice particles

Video while in orbit on September 15, 1991, shows a flash of light and several objects that appear to be flying in an artificial or controlled fashion. NASA explained the objects as ice particles reacting to engine jets. Philip C. Plait discussed the issue in his book Bad Astronomy, agreeing with NASA. This topic was also discussed in an episode of UFO Hunters.

Wake-up calls NASA began a tradition of playing music to astronauts during the Project Gemini, and first used music to wake up a flight crew during Apollo 15. Each track is specially chosen, often by the astronauts' families, and usually has a special meaning to an individual member of the crew, or is applicable to their daily activities.

Illustrations

Worked examples

Example 1 — a first encounter with STS-48

Start with the simplest possible case. Write down what STS-48 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to STS-48 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about STS-48 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of STS-48

In research: STS-48 appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses STS-48 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: STS-48 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Edwards Air Force Base, Space Shuttle missions, Spacecraft launched in 1991, so understanding it makes those chapters shorter.
In everyday life: Look for STS-48 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study STS-48 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what STS-48 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain STS-48 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is STS-48 in simple terms?

STS-48 was a Space Shuttle mission that launched on September 12, 1991, from Kennedy Space Center, Florida. The orbiter was Space Shuttle Discovery on her 13th flight.

Why does STS-48 matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study STS-48?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on STS-48.