astronomy

Relay program

Relay program is a astronomy 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 Relay program rather than just read about it. In short: The Relay program consisted of Relay 1 and Relay 2, two early American satellites in elliptical medium Earth orbit. Both were primarily experimental communications satellites funded by NASA and developed by RCA.

Key takeaways

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

Reference excerpt

The Relay program consisted of Relay 1 and Relay 2, two early American satellites in elliptical medium Earth orbit. Both were primarily experimental communications satellites funded by NASA and developed by RCA. As of December 2, 2016, both satellites were still in orbit. Relay 1 provided the first American television transmissions across the Pacific Ocean.

Relay 1

Relay 1 (COSPAR satellite ID: Relay 1 1962-Beta-Upsilon 1 (62BU1)) was launched atop a Delta B rocket (355/D-15) on December 13, 1962, from LC-17A at Cape Canaveral Air Force Station. Its payload included radiation experiments designed to map the Earth's radiation belts. The spin-stabilized satellite had an initial spin rate of 167.3 rpm and an initial spin axis orientation with a declination of -68.3 deg and a right ascension of -56 deg. Its orbital period was 185.09 minutes, with an apogee of 7500 km and a perigee of 1300 km. Shortly after launch, two basic problems evolved. One was the satellite's response to spurious commands, and the other was the leakage of a high-power regulator. This leakage caused the first two weeks of satellite operation to be useless. After this period, satellite operation returned to normal. The satellite carried one transmitter for tracking and one for telemetry. The telemetry system was PCM at 1152 bit/s. Each 128 words per telemetry frame (of one second duration) used 113 words for the particle experiment. Relay 1 was the first satellite to broadcast television from the United States to Japan. The first broadcast during orbit 2677 (1963-11-22, 2027:42-2048 (GMT), or 1:27 pm Dallas time) was to be a prerecorded address from the president of the United States to the Japanese people, but was instead the announcement of the John F. Kennedy assassination. On orbit 2678, this satellite carried a broadcast titled Record, Life of the Late John F. Kennedy, the first television program broadcast simultaneously in the U.S. and Japan. In later orbits, NBC transmitted coverage of the funeral procession from the White House to the cathedral. In the three days following the Kennedy assassination, Relay 1 handled a total of 11 spot broadcasts; eight to Europe and three to Japan. All the useful passes of the satellite were made available to permit immediate coverage of the tragic events. In August 1964, this satellite was used as the United States-Europe link for the broadcast of the 1964 Summer Olympics from Tokyo, after the signal was relayed to the United States via Syncom 3. This marked the first time that two satellites were used in tandem for a television broadcast. The leakage problem caused the spacecraft to revert to a low voltage state early in 1965. Sporadic transmission occurred until February 10, 1965, after which no usable scientific data was obtained.

Relay 2

Relay 2 (COSPAR satellite ID: Relay 2 1964-003A) was launched atop a Delta B rocket (373/D-23) on January 21, 1964, from LC-17B at Cape Canaveral Air Force Station. Apogee was 7600 and perigee 1870 km. It was physically similar to Relay 1. Design changes in this satellite improved its performance so response to spurious commands was essentially eliminated. NASA ceased operations with Relay 2 on September 26, 1965, with the repurposing of the Mojave Desert Ground Station, the only one in the world equipped to communicate with the satellite, for use with the Applications Technology Satellite program. The final broadcast was of Sen. B. Everett Jordon (D-N.C.) opening the week-long International Exposition of the American Textile Machinery Association in Exposition Hall in Atlantic City. One of the two onboard transponders operated normally until November 20, 1966. From that time until its failure on January 20, 1967, it required a longer time than normal to come on. The other transponder continued to operate until June 9, 1967, when it too failed to operate normally. On June 13, 2025, a brief radio signal was detected from Relay 2, which may have been an electrostatic discharge event or a cloud of charged plasma from a collision with a micrometeorite.

Illustrations

Worked examples

Example 1 — a first encounter with Relay program

Start with the simplest possible case. Write down what Relay program claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 Relay program 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 Relay program 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 Relay program

In research: Relay program appears in astronomy 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 Relay program 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: Relay program is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1962 in spaceflight, 1964 in spaceflight, Communications satellites, so understanding it makes those chapters shorter.
In everyday life: Look for Relay program 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Relay program in 20 minutes

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

Frequently asked questions

What is Relay program in simple terms?

Why does Relay program matter?

Because it connects several astronomy 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 Relay program?

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 Relay program.