The Super Guppy

Watch

1. Have you heard of the Super Guppy?youtube.com/shorts/VzgMYgg4Fwc

Word of the day

Aeronautics (air-uh-NAW-tiks). The design, construction and operation of aircraft, and the scientific study of flight through the atmosphere.

• In Greek myth, the Argonauts sailed with Jason on the ship Argo. Their name means “crewman of the ship Argo.”
• An aerosol is a system of tiny particles dispersed in a gas, such as smoke, fog or mist.

Bonus word. Fuselage (from French fuselé, “spindle-shaped”) names the central structure of an airplane, where the wing, tail surfaces and engines attach.

Predict

1. NASA’s aircraft page lists the Super Guppy’s cargo bay as 25 feet wide, and the video says about 25 feet too. Before you open NASA’s guide, make a prediction and give your reasoning in one sentence. How wide, in feet, is the widest part you think the Super Guppy can carry?

   Hint. Picture the shape of the bay. How much space does a part need around its edges?

Read the paper

NASA Johnson Space Center Aircraft Operations Division, Super Guppy Transport User’s Guide, AOD 33973 Rev C, May 2023. The guide is free to read.

NASA’s Aircraft Operations Division in Houston flies the Super Guppy and wrote this guide for teams that want to ship hardware on the plane. Teams use the guide to check whether a part fits and to plan how the part gets loaded and protected. Read Section 5, Sections 6.2 and 6.4, Figure 14, Section 6.8 and Section 6.9. Figure 14 shows the cargo bay’s cross section. The round upper part has a radius of 144 inches, and its center sits 155 inches above the cargo floor. Below the circle, the bay narrows toward the floor. Section 6.4 requires at least 6 inches of clearance between cargo and the plane’s body, and NASA prefers 12 inches. Table 1 sets the allowable cabin load at 48,000 pounds, counting the payload, pallets and adapters. Fill in the table, using 12 inches to the foot.

1. Outcome 1, solving engineering problems The bay is widest across the circle with a 144-inch radius. NASA prefers that a part clear the plane’s body by 12 inches on each side. With 12 inches of clearance on each side, how wide a part can the Super Guppy take? Which parts in the table pass that width check? And which part passes on width but fails another limit in the guide?

   Hint. Double the radius, then subtract the clearance on both sides. For the last part, compare its weight with the 48,000-pound allowable cabin load in Table 1.

2. Outcome 6, analyzing and interpreting data Section 5 says that because of the bay’s unique cross section, many payloads are too wide to fit directly on top of the pallet. They’re raised “so that the widest part of the payload fits within the widest part of the cargo bay.” In Figure 14, the center of the round upper bay sits 155 inches above the cargo floor, and the bay narrows below the circle. Why do wide payloads like the 198-inch Orion heat shield ride on raised supports? About how high should the shield’s widest part sit? And what does Section 5 ask of the structures that raise payloads?

   Hint. Find where the bay is widest in Figure 14. Then read what Section 5 says those structures are sized to do.

3. Outcome 7, acquiring and applying new knowledge Section 6.8 lists the flight, landing and crash conditions that cargo and its supports must be designed to survive. Footnote 17 says NASA added four flight and landing cases after the Artemis I airlift of the Orion crew and service modules, when accelerometers on the cargo rails showed a sideways push during landing. What did the Artemis I sensor data teach NASA about protecting cargo in the Super Guppy? And why should a design rule change after a measured flight?

   Hint. What did the earlier flight and landing cases assume about sideways pushes?

4. Outcome 2, engineering design The Super Guppy’s cargo bay isn’t pressurized. Table 5 of the guide lists absolute air pressure of 14.70 psi at sea level and 6.75 psi at 20,000 feet, and missions typically plan for a top altitude of 18,000 feet. Sealed cargo must be analyzed for altitude pressure loads. Vented cargo needs vents sized for an emergency descent of 3,000 feet per minute, a pressure change of 1.55 psi per minute. A team is shipping a large, hollow spacecraft structure. Should the structure be sealed or vented? Write your recommendation in one paragraph that uses at least two numbers from the guide.

   Hint. Find the pressure difference across a sealed wall at 20,000 feet. Then think about what a vent has to handle during an emergency descent.

Exit ticket