science

Martin X-23 PRIME

Martin X-23 PRIME is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Martin X-23 PRIME rather than just read about it. In short: The Martin X-23A PRIME (Precision Reentry Including Maneuvering reEntry) (SV-5D) is a small lifting-body re-entry vehicle tested by the United States Air Force in the mid-1960s. Unlike ASSET, primarily used for structural and heating research, the X-23A PRIME was developed to study the effects of maneuvering during re-entry of Earth's atmosphere, including cross-range maneuvers up to 617 nmi (710 mi; 1,143 km) from…

Key takeaways

Martin X-23 PRIME belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Martin X-23 PRIME to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Martin X-23 PRIME from memory before moving on to harder problems.

Reference excerpt

The Martin X-23A PRIME (Precision Reentry Including Maneuvering reEntry) (SV-5D) is a small lifting-body re-entry vehicle tested by the United States Air Force in the mid-1960s. Unlike ASSET, primarily used for structural and heating research, the X-23A PRIME was developed to study the effects of maneuvering during re-entry of Earth's atmosphere, including cross-range maneuvers up to 617 nmi (710 mi; 1,143 km) from the ballistic track.

Design Each X-23A was constructed from titanium, beryllium, stainless steel, and aluminum. The craft consisted of two sections—the aft main structure and a removable forward "glove section". The structure was completely covered with a Martin-developed ablative heat shield 0.75 to 2.75 in (19 to 70 mm) thick, and the nose cap was constructed of carbon phenolic material. Aerodynamic control was provided by a pair of 12 in × 12 in (305 mm × 305 mm) lower flaps, and fixed upper flaps and rudders. A nitrogen-gas reaction control system was used outside the atmosphere. At Mach 2 a drogue ballute deployed and slowed the vehicle's descent. As it deployed, its cable sliced the upper structure of the main equipment bay, allowing a 47 ft (14 m) recovery chute to deploy. It would then be recovered in midair by a specially-equipped JC-130B Hercules aircraft.

Flight testing The first PRIME vehicle was launched from Vandenberg AFB on 21 December 1966 atop an Atlas SLV-3 launch vehicle. This mission simulated a low Earth orbit reentry with a zero cross-range. The ballute deployed at 99,850 ft (30,434 m), though the recovery parachute failed to completely deploy. The vehicle crashed into the Pacific Ocean. The second vehicle was launched on 5 March 1967. This flight simulated a 654-mile (1053-kilometre) cross-range reentry, and banking at hypersonic speeds. The recovery parachute deployed properly and was located by two of the deployed recovery aircraft. During an inspection fly-by of the descending parachute system it was seen that reefing cutters had failed to actuate. These cutters are on the harness suspending the vehicle from the parachute to ensure stability of the vehicle behind the JC-130B recovery aircraft during reel-in, and permit safely boarding the vehicle. As a result, the parachute and vehicle were allowed to descend to the sea. Subsequently, the vehicle separated from its flotation "balloon" in the rough seas and, with the parachute, sank before a nearby ship could arrive to retrieve it from the ocean. The final PRIME mission was flown on 19 April 1967, and simulated re-entry from low Earth orbit with a 617 nmi (710 mi; 1,143 km) cross-range. This time, all systems performed perfectly, and the X-23A was successfully recovered. An inspection by a USAF-Martin team reported the craft "ready to fly again", although no later missions were carried out. The third X-23A is now on display at the National Museum of the United States Air Force at Wright-Patterson Air Force Base in Ohio.

Specifications (X-23A) Data from The X-planes : X-1 to X-29General characteristics Length: 6 ft 8 in (2.03 m) Wingspan: 3 ft 10 in (1.17 m) Height: 2 ft 10 in (0.86 m) Gross weight: 894 lb (406 kg) Powerplant: × Nitrogen gas reaction control thrusters Performance

Maximum speed: 14,388 kn (16,557 mph, 26,647 km/h) Maximum speed: Mach 25 Hypersonic L/D Ratio: 1:1

Illustrations

Worked examples

Example 1 — a first encounter with Martin X-23 PRIME

Start with the simplest possible case. Write down what Martin X-23 PRIME 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 Martin X-23 PRIME 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 Martin X-23 PRIME 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 Martin X-23 PRIME

In research: Martin X-23 PRIME 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 Martin X-23 PRIME 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: Martin X-23 PRIME is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1960s United States experimental aircraft, Aircraft first flown in 1966, American spacecraft, so understanding it makes those chapters shorter.
In everyday life: Look for Martin X-23 PRIME 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.

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How to study Martin X-23 PRIME in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Martin X-23 PRIME 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 Martin X-23 PRIME out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Martin X-23 PRIME in simple terms?

Why does Martin X-23 PRIME 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 Martin X-23 PRIME?

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 Martin X-23 PRIME.