astronomy

Suisei (spacecraft)

Suisei (spacecraft) 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 Suisei (spacecraft) rather than just read about it. In short: Suisei (すいせい; lit. "Comet"), originally known as Planet-A, was an uncrewed space probe developed by the Institute of Space and Astronautical Science (now part of the Japanese Aerospace Exploration Agency, or JAXA). It constituted a part of the Halley Armada together with Sakigake, the Soviet Vega probes, the ESA Giotto and the NASA International Cometary Explorer, to explore Halley's Comet during its 1986 sojourn th…

Key takeaways

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

Reference excerpt

Suisei (すいせい; lit. "Comet"), originally known as Planet-A, was an uncrewed space probe developed by the Institute of Space and Astronautical Science (now part of the Japanese Aerospace Exploration Agency, or JAXA). It constituted a part of the Halley Armada together with Sakigake, the Soviet Vega probes, the ESA Giotto and the NASA International Cometary Explorer, to explore Halley's Comet during its 1986 sojourn through the inner Solar System.

Spacecraft Suisei was identical in construction and shape to Sakigake, but carried a different payload: a CCD UV imaging system and a solar wind instrument. The main objective of the mission was to take UV images of the hydrogen corona for about 30 days before and after Comet Halley's descending crossing of the ecliptic plane. Solar wind parameters were measured for a much longer time period. The spacecraft was spin-stabilized at two different rates (5 and 0.2 rpm). Hydrazine thrusters were used for attitude and velocity control; star and Sun sensors were included for attitude control; and a mechanically despun off-set parabolic dish was used for long range communication.

Launch Suisei was launched on August 18, 1985, by M-3SII launch vehicle from Kagoshima Space Center on M-3SII-2 mission. It was sent on an intercept course with Comet Halley, after which it would remain in a heliocentric orbit for later use as long as it was viable.

Halley encounter Suisei began UV observations in November 1985, generating up to six images/day. The spacecraft encountered Comet Halley at 151,000 km on sunward side during March 8, 1986, suffering only two dust impacts which tilted the craft by 0.72 degrees. Suisei carried two instruments designed to study the growth and the decay of the cometary object's hydrogen corona, and the interaction of the solar wind with the cometary ionosphere. These observed a peak in Comet Halley's hydrogen emissions every 53 hours.

Earth flyby Fifteen burns of Suisei's 3 N motors during the period of April 5–10, 1987, yielded a 65 m/s velocity increase for a 60,000 km Earth gravity assist swingby on August 20, 1992, although the craft was then lost behind the Sun for the summer. The hydrazine fuel was depleted on February 22, 1991. Preliminary tracking indicated a 900,000-km flyby of Earth had been achieved

Other planned encounters ISAS had decided during 1987 to guide Suisei to a November 24, 1998, encounter with 21P/Giacobini–Zinner, but due to depletion of the hydrazine, this, as well as plans to fly within several million kilometers of Comet 55P/Tempel–Tuttle on February 28, 1998, were cancelled.

References

External links

Suisei Mission Profile by NASA's Solar System Exploration

Illustrations

Worked examples

Example 1 — a first encounter with Suisei (spacecraft)

Start with the simplest possible case. Write down what Suisei (spacecraft) 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 Suisei (spacecraft) 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 Suisei (spacecraft) 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 Suisei (spacecraft)

In research: Suisei (spacecraft) 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 Suisei (spacecraft) 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: Suisei (spacecraft) is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1985 in spaceflight, Derelict space probes, Earth flybys, so understanding it makes those chapters shorter.
In everyday life: Look for Suisei (spacecraft) 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Suisei (spacecraft)” →

Affiliate

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

How to study Suisei (spacecraft) in 20 minutes

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

Frequently asked questions

What is Suisei (spacecraft) in simple terms?

Why does Suisei (spacecraft) 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 Suisei (spacecraft)?

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 Suisei (spacecraft).