astronomy

OMOTENASHI

OMOTENASHI 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 OMOTENASHI rather than just read about it. In short: OMOTENASHI (Outstanding MOon exploration TEchnologies demonstrated by NAno Semi-Hard Impactor) was a small spacecraft and semi-hard lander of the 6U CubeSat format intended to demonstrate low-cost technology to land and explore the lunar surface. The CubeSat was to take measurements of the radiation environment near the Moon as well as on the lunar surface.

Key takeaways

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

Reference excerpt

OMOTENASHI (Outstanding MOon exploration TEchnologies demonstrated by NAno Semi-Hard Impactor) was a small spacecraft and semi-hard lander of the 6U CubeSat format intended to demonstrate low-cost technology to land and explore the lunar surface. The CubeSat was to take measurements of the radiation environment near the Moon as well as on the lunar surface. Omotenashi is a Japanese word for "welcome" or "Hospitality". OMOTENASHI was one of ten CubeSats launched with the Artemis 1 mission into a heliocentric orbit in cislunar space on the maiden flight of the Space Launch System (SLS), that took place on 16 November 2022. After deployment from the Artemis I second stage, JAXA reported unstable communications with the spacecraft. On 21 November 2022, a Twitter message sent by JAXA reported that further attempts to communicate with the lander, which was scheduled to begin its landing sequences that day, had been ended.

Etymology The Japanese term omotenashi (お持て成し) means "hospitality".

Overview The OMOTENASHI mission was to land the smallest lunar lander up to then on the lunar surface to demonstrate the feasibility of the hardware for distributed synergistic exploration system with multi-point exploration. Once on the lunar surface, the OMOTENASHI lander was planned to observe the radiation environment of the lunar surface. The OMOTENASHI orbiter and lander were designed by the Japan Aerospace Exploration Agency (JAXA). It was a 6U CubeSat measuring 10 cm × 20 cm × 30 cm, and had a mass of 14 kg (31 lb). The principal investigator was Tatsuaki Hashimoto from JAXA. The spacecraft featured two body-fixed solar panels and lithium ion batteries. After measuring the radiation environment as it approached the Moon, OMOTENASHI's lander module was planned to perform a semi-hard landing on the lunar surface.

Flight JAXA announced that OMOTENASHI had successfully separated from the ICPS interstage around 90 minutes after launch. However, as of November 17, 2022, the spacecraft had yet to achieve Sun acquisition, and communication was unstable. JAXA continued operations to "stabilise attitude, secure power and establish communication," but after failing to restore operations, they abandoned recovery attempts on November 22. Reports indicate that the loss was due to failure of the solar cells to point toward the Sun. The next time they would be facing towards the Sun was March 2023. The team is considering recovery operations if they are able to reestablish contact with the spacecraft.

Payload The lander's scientific payload consisted of a radiation monitor and an accelerometer.

Propulsion and proposed landing OMOTENASHI was to use a cold gas thruster to enter a lunar-impact orbit, and a solid-rocket motor for the landing phase. The entry and landing phases would have been informed by the use of an X-band two-way Doppler radar. The orbiting module was planned to enter at a shallow flight-path angle of ≤7°, and to be ejected when the solid-rocket burn begins the deceleration manoeuvre. The rocket would have been ignited with a laser. After the deceleration rocket burn that was planned to last 15–20 seconds, OMOTENASHI's lander would have ejected the retrorocket, experiencing a free-fall of about 100 m. Just before impact, the lander was planned to deploy a single airbag about 50 cm in diameter to minimize the impact, estimated to be at 20–30 m/s.

See also The 10 CubeSats flying in the Artemis 1 mission Near-Earth Asteroid Scout by NASA was a solar sail spacecraft that was planned to encounter a near-Earth asteroid (mission failure) BioSentinel is an astrobiology mission LunIR by Lockheed Martin Space Lunar IceCube, by the Morehead State University CubeSat for Solar Particles (CuSP) Lunar Polar Hydrogen Mapper (LunaH-Map), designed by the Arizona State University EQUULEUS, submitted by JAXA and the University of Tokyo OMOTENASHI, submitted by JAXA, was a lunar lander (mission failure) ArgoMoon, designed by Argotec and coordinated by Italian Space Agency (ASI) Team Miles, by Fluid and Reason LLC, Tampa, Florida The 3 CubeSat missions removed from Artemis 1 Lunar Flashlight designed to map exposed water ice on the Moon Cislunar Explorers, Cornell University, Ithaca, New York Earth Escape Explorer (CU-E3), University of Colorado Boulder

References

External links (in Japanese) 月を目指す、わずか14kgの超小型探査機「OMOTENASHI」と「EQUULEUS」鳥嶋真也, 13 September 2017 NSSDCA page

Illustrations

Worked examples

Example 1 — a first encounter with OMOTENASHI

Start with the simplest possible case. Write down what OMOTENASHI 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 OMOTENASHI 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 OMOTENASHI 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 OMOTENASHI

In research: OMOTENASHI 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 OMOTENASHI 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: OMOTENASHI is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2022 in Japan, Artemis I secondary payloads, CubeSats, so understanding it makes those chapters shorter.
In everyday life: Look for OMOTENASHI 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 OMOTENASHI in 20 minutes

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

Frequently asked questions

What is OMOTENASHI in simple terms?

Why does OMOTENASHI 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 OMOTENASHI?

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 OMOTENASHI.