Terran 1

Key takeaways

Terran 1 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Terran 1 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Terran 1 from memory before moving on to harder problems.

Reference excerpt

Terran 1 was an expendable two-stage small-lift launch vehicle developed by Relativity Space. Development began in 2017 and the rocket was retired in 2023. Most structures and components of the vehicle are manufactured with 3D printing processes. Terran 1's first and only launch took place March 23, 2023 from Cape Canaveral, but did not achieve orbit due to a failure of the second stage. Following the failed launch, Relativity retired the rocket in favor of developing the much larger, reusable Terran R vehicle.

Design Terran 1 consisted of two stages. The first stage is powered by nine Aeon 1 engines burning methane and oxygen propellants (methalox) in a gas-generator cycle, each producing 100 kN (23,000 lbf) of thrust. The second stage is powered by a single vacuum-optimized version of Aeon 1, known as AeonVac, producing 126 kN (28,300 lbf) of thrust in vacuum. Both stages are autogenously pressurized. The vehicle's (notional) payload fairing measures 6.8 m (22 ft) long and 3 m (9.8 ft) in diameter. Payload capacity was specified to be 1,250 kg (2,760 lb) to lower inclination low-Earth orbits and 900 kg (2,000 lb) to a Sun-synchronous orbit (SSO). In any case, the vehicle never carried payloads, its sole launch featured an inert nosecone in place of a functional clamshell fairing. The primary and secondary structures of Terran 1 were manufactured with Relativity's Stargate 3D printer, which welded structures together from aluminum alloy. 90% of Terran 1 by mass consisted of printed components; Relativity claimed that they could reduce the part count in the vehicle by 100 times compared to traditionally-manufactured rockets and manufacture an entire flight article from raw materials in 60 days. Relativity's in-development Terran R launch vehicle will utilize the same tooling used to manufacture Terran 1. Relativity advertised a price per launch for Terran 1 of US$10 million in 2019. The advertised price per launch had been increased to $12 million USD in 2021.

Proposed upgrades In February 2022, Relativity CEO Tim Ellis stated in an interview with Ars Technica the nine Aeon 1 engines on the first stage could be replaced with a single Aeon R engine with substantially higher thrust. The Aeon R engine is planned to be used on Relativity's much larger Terran R rocket. The upgrade was planned to debut on the fourth flight of Terran 1 before the program was cancelled.

Launch Relativity received a Federal Aviation Administration (FAA) launch license to conduct the first launch of Terran 1, not-earlier-than (NET) 8 March 2023 from Cape Canaveral Space Force Station's Launch Complex 16. Originally, another static fire was planned with the full rocket stack before first launch. Relativity believed it performed enough tests and instead attempted a launch. Terran 1's initial flight scheduled for 8 March 2023 was scrubbed due to "exceeding launch commit criteria limits for propellant thermal conditions on stage two". A second launch attempt on 11 March was also scrubbed. Set for 18:00 UTC (14:00 EDT), high upper-level winds prevented liftoff for over an hour. A second attempt at 19:35 UTC (15:35 EDT) was cancelled at T−70 seconds from a boat in the launch safety range. A third attempt at 19:42 UTC (15:42 EDT) was cancelled half a second before liftoff. The engines briefly lit up before shutting down from a "launch commit criteria violation". A final attempt occurred at 21:00 UTC (17:00 EDT). An issue with the automatic stage separation promptly closed the launch window. Another launch window for Terran 1's initial flight opened on March 23. After holding twice from a boat in the launch safety range, and high upper-level winds, the rocket lifted off at 03:25 UTC (23:25 EDT). Following a nominal liftoff and powered flight of the first stage, the second stage failed to ignite, leading to the loss of the mission. Preliminary investigations blamed the failure on a slower-than-expected valve opening as well as vapor ingestion into the liquid oxygen turbopump causing reduced performance. Although the launch did not orbit, Relativity acknowledged the successful performance of the vehicle's 3D printed structures under flight loads. Following the loss of the first mission, the company abandoned further plans for Terran 1, instead choosing to focus efforts on developing the much larger reusable Terran R vehicle. Existing payloads on Terran 1 will likely have to be remanifested to Terran R or other flights.

Launches

Worked examples

Example 1 — a first encounter with Terran 1

Start with the simplest possible case. Write down what Terran 1 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 Terran 1 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 Terran 1 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 Terran 1

In research: Terran 1 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 Terran 1 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: Terran 1 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Private space launch vehicles, Space launch vehicles of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for Terran 1 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 Terran 1 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Terran 1 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 Terran 1 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Terran 1 in simple terms?

Terran 1 was an expendable two-stage small-lift launch vehicle developed by Relativity Space. Development began in 2017 and the rocket was retired in 2023.

Why does Terran 1 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 Terran 1?

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 Terran 1.