science

Impulse Space

Impulse Space 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 Impulse Space rather than just read about it. In short: Impulse Space is an American startup founded in 2021 developing in-space transportation technology and services for satellites that fly to Low Earth Orbit but then need to reach other orbits. The company was founded by Tom Mueller, employee No.1 at SpaceX and principal engineer of the Merlin and Draco rocket engines that power the Falcon 9 and Dragon spacecraft.

Key takeaways

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

Reference excerpt

Impulse Space is an American startup founded in 2021 developing in-space transportation technology and services for satellites that fly to Low Earth Orbit but then need to reach other orbits. The company was founded by Tom Mueller, employee No.1 at SpaceX and principal engineer of the Merlin and Draco rocket engines that power the Falcon 9 and Dragon spacecraft.

Orbital Transfer Vehicles Impulse Space designs and manufactures orbital transfer vehicles, to move satellites and payloads throughout space. As of 2026, they have been added to the list of National Security Launch Program providers for the United States Space Force.

Mira The size of a dishwasher, a Mira orbital transfer vehicle weighs approximately 300 kg (660 lb) when loaded with propellant. It uses Saiph bipropellant thrusters which have a specific impulse (Isp) of 290 s. It can impart a delta-v of from 500 m/s with 300 kg payload to 900 m/s with 100 kg payload. In November 2023 the first Mira flight was launched as part the SpaceX Transporter-9 mission. A second Mira spacecraft was launched as party of the Transporter-12 mission on 15 January 2025. Orbit Fab, in a mission funded by the Defense Innovation Unit (DIU), has contracted Impulse on a GEO in-space refueling mission using Mira.

Helios On January 17, 2024, Impulse announced their new high-energy kick stage, Helios. It is intended to propel up to 4 tons launched on a Falcon 9 and 5 tons on Relativity's Terran R vehicle from LEO directly into geostationary orbit. With a diameter of just under 3.5 meters, Helios is sized to fit within a Falcon 9 fairing. A Deneb engine providing 67 kN (15,000 lbf) of thrust will burn up to 14,000 kg (31,000 lb) of liquid oxygen and liquid methane propellant. On September 16, 2024, Impulse indicated the first flight of Helios was scheduled for 2026. In May 2025, Impulse signed a multi-launch agreement with communications satellite operator, SES to use Helios to lift four-ton SES satellites launched to LEO into geostationary orbit, with the first mission in 2027.

Mars Lander In July 2022, Impulse Space announced a joint mission with Relativity Space to land on Mars. Impulse is responsible for building the lander itself, the cruise stage and the entry capsule. Relativity would launch the spacecraft on its Terran R, which is currently under development. The mission has since moved to a 2026 launch date.

Rocket engines Since the founding of Impulse in 2021, the company has developed several rocket engines — Saiph, Rigel, and Deneb — for use in spacecraft.

Saiph On May 10, 2023, an Impulse Space press release announced the successful qualification of their 5 lbf (22 N) Saiph thruster. Using the propellants of nitrous oxide and ethane, the thruster achieved a burn duration of 12 continuous minutes and 50,000 pulses over the 17 day qualification period. Saiph thruster uses spark ignition. The company incorporated eight Saiph thrusters into their Mira spacecraft, which launched to space September 2023 on the SpaceX Transporter-9 mission. The company announced their successful firings of all eight thrusters in a November 2023 mission update. Vast, a privately funded commercial space station company, procured Impulse's Saiph thrusters and propulsion hardware for its Haven-1 mission. In May 2023, Vast unveiled its Haven-1 station and announced that SpaceX would launch the spacecraft and provide taxi services to the future habitat.

Rigel Rigel was the company's first rocket engine, designed for use on Impulse's Mars Lander vehicle. The engine has undergone extensive testing from the company's Mojave Air and Space Port facilities.

Deneb Deneb is a 15,000 lbf (67 kN) staged combustion cycle engine that uses liquid oxygen (LOX) and methane as propellants. It is being developed as the main engine of Impulse's Helios vehicle and would burn 14,000 kg of propellant across each mission.

Corporate affairs

Investors Impulse Space investors include Founders Fund, Lux Capital, Airbus Ventures, Space Capital, RTX Ventures and Venture Capitalist Dovi Frances.

Board of Directors

Facilities Impulse Space operates from three American locations. Its corporate headquarters operate from a 60,000-square-foot facility in Redondo Beach, California. In February 2023, the company opened an office in Boulder, Colorado. Rocket engine tests are conducted at the Mojave Air and Space Port.

References

Worked examples

Example 1 — a first encounter with Impulse Space

Start with the simplest possible case. Write down what Impulse Space 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 Impulse Space 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 Impulse Space 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 Impulse Space

In research: Impulse Space 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 Impulse Space 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: Impulse Space is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2021 establishments in California, Aerospace companies of the United States, American companies established in 2021, so understanding it makes those chapters shorter.
In everyday life: Look for Impulse Space 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 Impulse Space in 20 minutes

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

Frequently asked questions

What is Impulse Space in simple terms?

Why does Impulse Space 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 Impulse Space?

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 Impulse Space.