STS-115

Key takeaways

STS-115 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect STS-115 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of STS-115 from memory before moving on to harder problems.

Reference excerpt

STS-115 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle Atlantis. It was the first assembly mission to the ISS after the Columbia disaster, following the two successful Return to Flight missions, STS-114 and STS-121. STS-115 launched from LC-39B at the Kennedy Space Center on September 9, 2006, at 11:14:55 EDT (15:14:55 UTC). The mission is also referred to as ISS-12A by the ISS program. The mission delivered the second port-side truss segment (ITS P3/P4), a pair of solar arrays (2A and 4A), and batteries. A total of three spacewalks were performed, during which the crew connected the systems on the installed trusses, prepared them for deployment, and did other maintenance work on the station. STS-115 was originally scheduled to launch in April 2003. The Columbia accident in February 2003 pushed the date back to August 27, 2006, which was again moved back for various reasons, including a threat from Tropical Storm Ernesto and the strongest lightning strike to ever hit an occupied shuttle launchpad.

Crew

Crew notes Canadian Space Agency astronaut MacLean became the first Canadian to operate Canadarm2 and its Mobile Base in space as he was handed a new set of solar arrays from Ferguson and Burbank controlling the original Canadian robotic arm, the Canadarm. MacLean performed a spacewalk, becoming only the second Canadian, after Chris Hadfield to do so. The mission patch worn on the clothing used by the astronauts of STS-115 was designed by Graham Huber, Peter Hui, and Gigi Lui, three students at York University in Toronto, Ontario, the same university that Steve MacLean attended. The students also designed Steve MacLean's personal patch for this mission.

Mission payloads The primary payload was the second left-side ITS P3/P4 Truss segment, a pair of solar arrays, and associated batteries.

Mission objectives Delivery and installation of two truss segments (P3 and P4) Delivery and deployment of two new solar arrays (4A and 2A) Perform three spacewalks to connect truss segments, remove restraints on solar arrays, and prepare the station for the next assembly mission by STS-116

Crew seat assignments

Mission background NASA managers decided to move the STS-115 launch date forward to August 27 to obtain better lighting conditions to photograph the external tank. This occurred before with STS-31 and STS-82. The launch window was co-ordinated with the Soyuz TMA-9 launch in mid-September, which delivered a new ISS crew and fresh supplies to the station. The Soyuz spacecraft operationally did not dock to the station while the Space Shuttle was there. The mission marks:

147th NASA crewed space flight. 116th space shuttle flight since STS-1. 27th flight of Atlantis. 91st post-Challenger mission. 3rd post-Columbia mission. 1st post-Columbia mission of Atlantis.

Mission timeline

Launch preparations

Atlantis was rolled out from the Orbiter Processing Facility to the Vehicle Assembly Building (VAB) on July 24, 2006. It was lowered onto the mobile launcher platform on July 26 and rolled out to Pad 39B in the early morning hours of August 2. The rollout was scheduled for July 31, but a storm in the vicinity of the Kennedy Space Center resulted in a delay of two days from fears of the orbiter being hit by lightning, which could cause immeasurable damage. On the weekend of August 5 to 6, 2006, engineers completed a "flight readiness" check of the shuttle's main engines, which were deemed ready for launch. The crew arrived at the Kennedy Space Center August 7, 2006, for four days of launch rehearsals, including a practice countdown August 10. Top NASA managers held a Flight Readiness Review (FRR) meeting August 15–16, 2006 to finalize the launch date. Foam loss from the external tank was a key issue at this meeting because on August 13, 2006, NASA announced there was an average amount of loss from the external tank of STS-121, the previous mission. Columbia's demise was due to a piece of foam, shed from its external tank, striking the shuttle's left wing during launch and causing a hole that was breached during re-entry.

The meeting also discussed problems with the bolts securing the shuttle's Ku-band antenna, which might not have been threaded correctly. The installation had been in place for several flights and hadn't experienced any problems. At the end of the two-day meeting, NASA managers had decided to proceed with the launch on August 27, 2006. However, on August 18, 2006, NASA decided to replace the antenna bolts with Atlantis still on the launch pad. NASA had no procedure to replace these on the pad, but the work was nonetheless completed by August 20, without affecting the planned launch date.

On August 25, 2006, a direct lightning strike, the most powerful recorded at Kennedy Space Center, hit the lightning rod atop the launch pad. As a result, on August 26 the Mission Management Team ordered the mission postponed for at least 24 hours to assess damage. On August 27, the decision was made to postpone the launch for another 24 hours, making the earliest possible launch date August 29, 2006, still unassured that there was no damage from the lightning strike and taking into account the possible threat from Hurricane Ernesto.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with STS-115

Start with the simplest possible case. Write down what STS-115 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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-115 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-115 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-115

In research: STS-115 appears in science 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-115 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-115 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Human spaceflights to the International Space Station, Space Shuttle missions, Spacecraft launched in 2006, so understanding it makes those chapters shorter.
In everyday life: Look for STS-115 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-115 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what STS-115 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-115 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is STS-115 in simple terms?

STS-115 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle Atlantis. It was the first assembly mission to the ISS after the Columbia disaster, following the two successful Return to Flight missions, STS-114 and STS-121.

Why does STS-115 matter?

Because it connects several science 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-115?

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-115.