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Install and activate

From the installer to an open workspace: install, activate, and find your way around.

Install

KnownX MPT runs on 64-bit Windows 10 or 11. Nothing else needs to be installed first. See System requirements.

Get the current version from the download page. There are two ways to install it:

• Installer. Run KnownX-MPT-<version>-win64-setup.exe. It installs to Program Files\KnownX MPT and adds a Start menu entry.
• Portable. Unzip KnownX-MPT-<version>-win64-portable.zip to any folder and run KnownX.exe.

Activate

The first time KnownX MPT starts it asks for your licence key. The key looks like KNX-XXXXX-XXXXX-XXXXX-XXXXX and was emailed to you.

1. Enter the key.
2. Choose Activate.

Activation uses one of your licence’s seats for this computer. After that, KnownX MPT confirms its licence by itself each time it starts. Without a connection it keeps working for up to a week.

The Mission Launcher

KnownX MPT opens on the Mission Launcher.

The workspace

Launching a scenario opens the workspace: the 3D view in the middle, the System Bar across the top, and tool windows around it. Open or close windows from the Windows menu in the System Bar.

The System Bar shows a status badge for each physics model: VAL for validated, DEV for implemented. See Capabilities and status.

Controls

Next

Continue with the first tutorial, Fly your first orbit.

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System requirements

What a computer needs to run KnownX MPT.

Without an internet connection

A computer that is never connected can run KnownX MPT with an offline licence file, which works until the end of the period paid for. See Install and activate. The Mission Companion needs a connection.

Other platforms

KnownX MPT is available for Windows. Linux and macOS versions are planned.

Graphics drivers

If the 3D view does not appear or shows visual faults, update the graphics driver from the card manufacturer before contacting support.

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Fly your first orbit

Launch a ready-made scenario and see the physics models at work. About ten minutes.

Before you start

KnownX MPT is installed and activated. See Install and activate.

Steps

1. In the Mission Launcher, choose the earth-orbit template and launch it. It places a spacecraft in a 600 km circular orbit inclined at 51.6°, with J2 and drag switched on.
2. Press P to start time, then = a few times to speed it up.
3. In the Universe Explorer, select the spacecraft. Its altitude and velocity appear in the Inspector.
4. Press J to switch the zonal terms off. The run restarts from the same initial state. Let it run, then press J again and compare: with the terms on, the orbital plane turns slowly; with them off, it stays fixed.
5. In the Inspector, switch Atmosphere off and on to see the effect of drag. The Aerodynamics section shows the drag force as it acts.
6. Press T to light the engine for a few seconds, then V to show the new predicted path on the Trajectory Map.

What you used

• Gravity and Atmospheric drag
• Trajectory prediction

Next

Plan an avoidance burn.

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Plan an avoidance burn

Two spacecraft are on crossing orbits. Script a burn and watch the closest approach open. About ten minutes.

Steps

1. In the Mission Launcher, launch the conjunction-demo template. Two vehicles are on crossing 600 km orbits.
2. Look at the Trajectory Map. It reports the closest approach, for example a miss distance of about 6 km, with the time and the relative speed.
3. Open Mission Sequence and choose + Add Step.
4. Set the step to start at T+90 s with a duration of 45 s.
5. Tick Set attitude and choose Prograde, tick Set engine and choose Engine on, tick Set throttle and set 100%.
6. Choose Save Step.
7. Read the closest approach again. It updates as soon as the step is saved, because the assessment replays your plan. The miss distance opens from about 6 km to about 240 km.
8. Press P to fly it, and watch the burn run on the Mission Timeline.

Try it with the Mission Companion

Reset the run with F, open the Mission Companion panel and ask it to plan a burn that increases the miss distance. It prepares the step as a card. Compare its proposal with the one you built, then accept or dismiss it.

What you used

• Mission sequences
• Conjunction assessment
• Mission Companion

Next

Check against a real satellite.

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Check against a real satellite

Import the published elements of a real satellite and compare KnownX with SGP4. About ten minutes.

Steps

1. In the Mission Launcher, open the Validation Center.
2. Choose Import TLE… and pick a file. Samples are in the data\tle folder next to the application: one for the ISS and a multi-year history for Zarya.
3. For a single element set, run Benchmark vs SGP4. KnownX and SGP4 propagate the same satellite for 72 hours. The radial, in-track and cross-track differences are tabulated and charted.
4. For an element history, run Forward Prediction. The history is first checked for manoeuvres. KnownX then predicts ahead and is scored against the later published elements.
5. Choose Export Report CSV to save the result.

Each report lists the conditions it applies to beside the numbers. Read them before quoting a result.

Reading the result

A difference that is mostly in-track and grows with time means the two propagations follow nearly the same path, slightly out of step. See the technical note on propagation accuracy for how to interpret these reports and for the results KNOWN has recorded.

What you used

• Validation Center

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Capabilities and status

What KnownX MPT does, and the standing of each capability.

How status is shown

Each capability has a status. The same status appears as a badge in the System Bar of the workspace.

Summary

Scope of this release

KnownX MPT is a planning and analysis tool. It is not intended as the sole basis for a safety-critical operational decision.

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Scenarios and data

Templates, building your own scenario, telemetry, and where files are kept.

Scenario templates

Building a scenario

Choose New scenario in the Mission Launcher to open the Scenario Composer. Add bodies and spacecraft, set orbits, and choose which models are active. A scenario can hold up to 8 bodies with full physics.

Saving and opening

Save a scenario with Save & Exit in the workspace, or from the Scenario Composer. Open it again with Open scenario in the launcher. A mission sequence is saved with its scenario.

Telemetry

The Plots window records and charts telemetry for the selected body.

1. Choose Record to start sampling.
2. Choose Stop when you have what you need.
3. Choose Export CSV and pick a location.

The recording holds position, velocity, speed, mass, altitude, drag, thrust, throttle and propellant.

Where files are saved

Uninstalling KnownX MPT leaves these folders in place.

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Gravity

Point-mass gravity from every body in the scenario, with the J2, J3 and J4 zonal terms for the Earth.

Status: point-mass gravity and J2 are Validated; J3 and J4 are Implemented.

Point-mass gravity

Every gravity source in the scenario attracts every body. No body is treated as the single fixed centre, so the same model serves an Earth orbit and the Earth and Moon system. For a source with gravitational parameter μ at distance r:

a = μ / r² · r̂

Zonal harmonics

The Earth is not a perfect sphere. Its flattening is described by the zonal harmonic terms, of which J2 is by far the largest. KnownX MPT models degrees 2, 3 and 4 about the body’s spin axis. With k the unit spin axis, ξ = r̂ · k, Rₑ the equatorial radius and Pₗ the Legendre polynomial of degree l, each degree adds:

aₗ = (μ Jₗ Rₑˡ / rˡ⁺²) · [ ((l+1) Pₗ(ξ) + ξ Pₗ′(ξ)) r̂ − Pₗ′(ξ) k ]

The main visible effect of J2 is a slow turning of the orbital plane (nodal regression) and of the orbit within its plane. J3 and J4 are several hundred times smaller.

Constants

In the application

• Press J to switch the Earth’s zonal terms on or off. The run restarts from the same initial state, so the two cases can be compared.
• The Inspector lists the models active for the selected body.

Scope

The spin axis and coefficients are fixed in time. Terms above degree 4, tesseral and sectoral terms, and the gravity of the Sun and Moon on spacecraft are not in this release.

Validation

J2 is checked against the analytic rate of nodal regression. See the technical note on propagation accuracy.

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Atmospheric drag

Drag against an atmosphere that rotates with its body, from launch through Low Earth Orbit.

Status: Implemented.

Model

a = −½ ρ(h) A (C_pressure + C_skin) |v_rel| v_rel / m

A rotating atmosphere

The atmosphere turns with its body, so drag is computed from velocity relative to the air and not from inertial velocity:

v_rel = v_body − (v_source + ω_source × r)

This matters at launch, where the ground speed of the atmosphere is a large part of the vehicle’s inertial speed.

Density

Density follows a piecewise-exponential profile of 28 layers, from sea level (1.225 kg/m³) to 1,000 km. Each layer has its own base density and scale height, which keeps density realistic at orbital altitudes.

In the application

• The Aerodynamics section of the Inspector shows drag acceleration and force as they act.
• The drag coefficients and the reference area of a body can be edited there.
• Switch Atmosphere off and on to compare a run with and without drag.

Scope

The profile is static: it does not vary with solar or geomagnetic activity. Lift, winds and coefficients that depend on Mach number are not in this release. The model is intended for planning-level decay and launch studies, not re-entry analysis.

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Propulsion and attitude

Thrust from a throttled engine, the propellant it uses, and where the spacecraft points.

Status: Implemented.

Thrust and propellant

thrust = maximum thrust × throttle
mass flow = thrust / (Isp · g₀)

The mass of the spacecraft falls as propellant is used, so the same thrust produces more acceleration late in a burn. If the propellant runs out part-way through a step, thrust is reduced in proportion for that step.

Attitude

Attitude is commanded: the spacecraft turns at the rate asked of it. In a mission sequence an attitude target can be prograde, retrograde, normal, anti-normal, radial out, radial in, or a custom direction.

In the application

• W and S raise and lower the throttle; X cuts it.
• T toggles the engine; holding Space fires it while held.
• Arrow keys pitch and yaw; Q and E roll.
• The Inspector shows thrust, throttle and propellant remaining.

Scope

A vehicle has one engine with a fixed specific impulse. Staging, and attitude dynamics driven by torque and inertia, are not in this release.

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Integration, time and frames

How the equations of motion are stepped forward, and how time and frames are defined.

Integrators

Both integrators use the same force models, so a force cannot be present in one and missing from the other.

Time acceleration

The time rate can be doubled or halved with = and -. At high rates each frame is divided into smaller steps, and the rate backs off by itself if a step would become too large.

A run at a very high time rate uses a longer physics step. Use the Validation Center, not a fast-forwarded run, when the question is accuracy.

Time

Scenarios can be tied to a UTC epoch. When they are, the Earth’s rotation is set from Greenwich Mean Sidereal Time for that date, so the ground beneath the spacecraft is where it would really be.

Frames

Orbital states are held in an Earth-centred inertial frame. Results compared with SGP4 are expressed relative to the reference orbit as radial, in-track and cross-track components.

Units

Scenarios are defined in SI units: metres, kilograms, seconds, newtons. All calculation is in double precision.

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Mission sequences

Script what the spacecraft does and when: point, light the engine, set the throttle.

Status: Implemented.

What a step can do

A step starts at a mission time, measured from the start of the run, and can set any of the following, optionally for a set duration:

Adding a step

1. Open the Mission Sequence window.
2. Choose + Add Step.
3. Set the start time and, if needed, a duration.
4. Tick the settings the step should change and choose their values.
5. Choose Save Step.

Running a sequence

Steps run by themselves when the clock reaches them. The Mission Timeline shows each step as it goes.

A sequence is saved with its scenario.

Working with other tools

• Trajectory prediction and conjunction assessment replay the sequence, so they show where the plan leads.
• The Mission Companion can propose steps for you to review.

Scope

A sequence drives the scenario’s controlled spacecraft. KnownX MPT carries out the plan you give it; targeting an orbit and optimising a manoeuvre are not in this release.

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Trajectory prediction

See where the spacecraft is heading before it gets there.

Status: Implemented.

Modes

The prediction is computed on a copy of the scenario. It never changes the run itself.

In the application

• Press V to show or hide the prediction.
• The predicted path is drawn in the 3D view and on the Trajectory Map, which can show the XZ, XY or YZ projection.
• If a mission sequence is scripted, the prediction follows it.

Scope

Predictions cover hours to days. They use the same force models as the run, with the standing given in Capabilities and status.

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Conjunction assessment

How close the planned path comes to another spacecraft, and when.

Status: Implemented.

What is reported

KnownX MPT propagates the whole scenario ahead over a 3-hour window and reports, against the nearest other vehicle:

The closest approach is marked on the Trajectory Map.

It follows your plan

If a mission sequence is scripted, the assessment replays it. Add or change a burn and the readout updates at once, which makes it straightforward to see what a planned manoeuvre does to the miss distance. The tutorial Plan an avoidance burn walks through this.

Scope

The assessment reports miss distance. Probability of collision needs uncertainty data for both objects and is not in this release. Planets and moons are excluded; contact with a surface is handled by the trajectory prediction.

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Mission Companion

An AI assistant in a panel beside the simulation. It works from the mission you have open, answers questions, and prepares changes for you to review.

Status: Implemented.

The panel

The Mission Companion panel has three parts.

What it reads

With each message, the Companion is given what the workspace shows at that moment:

• The objects in the scenario, with mass and speed.
• The controlled spacecraft: throttle, propellant remaining, dry mass, specific impulse and maximum thrust.
• The force models that are active.
• The mission sequence and the status of each step.
• The predicted trajectory and any closest approach.
• The validation status of the run.

What you can ask

• Questions about this mission: “How much propellant is left after step 2?”
• Questions about the simulation: “Why is the orbital plane drifting?”
• General orbital mechanics.
• Requests for a change: “Plan a 30-second prograde burn at T+120.”

What it can propose

Values outside the range an action accepts are refused before you see them.

Reviewing a proposal

1. The Companion replies in words and adds one or more cards under Proposed action.
2. Read the card. A plan of several steps is presented as one proposal.
3. Apply it, or dismiss it.

Nothing changes until you apply a card. Before proposing a burn, the Companion checks it against the propellant, mass and thrust the spacecraft has. If a request cannot be met, it says so and says what would be needed.

Validation status

The Companion reports the validation status of a run as the workspace shows it. For questions of accuracy it points to the Validation Center.

Connection and data

The Companion needs an internet connection and an activated licence. When you send a message, the message, the conversation in that session and the mission context listed above are sent through KNOWN’s service to an AI model provider, which produces the reply. See the privacy policy.

Tips

• Choose Clear to start a fresh conversation.
• Be specific about times and durations. Mission times are measured from the start of the run.
• Ask for a whole plan at once (“climb, then circularise”) so it arrives as one proposal.

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Validation Center

Compare KnownX MPT with published data for real satellites, on element sets you choose.

Open the Validation Center from the Mission Launcher, or by clicking a status badge in the System Bar.

Import a TLE

Choose Import TLE… and pick a file. A file can hold one element set or a history of element sets for the same object. Lines that fail their checksum are rejected.

Benchmark vs SGP4

For a single element set.

KnownX and SGP4 each propagate the same satellite for 72 hours. The report gives the difference between them as radial, in-track and cross-track components, in a table and a chart.

Forward prediction

For a history of element sets.

1. The history is checked for manoeuvres, and epochs affected by one are excluded.
2. KnownX predicts forward from the oldest remaining element set.
3. The prediction is scored against each later element set at its own epoch. SGP4’s own extrapolation is scored the same way for comparison.

Export

Choose Export Report CSV to save any report. A forward prediction can also export the epochs it excluded.

Reports are saved to Documents\KnownX MPT\Validation Reports.

Reading a report

Each report states the conditions it applies to beside the numbers. SGP4 is an analytic model fitted to tracking data, so a report measures agreement between two models. The technical note on propagation accuracy explains how to interpret the figures and gives KNOWN’s recorded results.