PROBA-1 - Earth Online

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New cross-calibration readies PROBA-1 data for climate research

While PROBA-1 has already exceeded expectations by suppling over 21 years of Earth observation hyperspectral data, recent cross-calibration activities are aiming to ensure the data will robustly serve long time-series research, even when the satellite ends operation.

International collaboration: Summarising ESA’s Third Party Missions

ESA’s Third Party Missions programme consists of more than 50 missions from around the world. Learn more about the Third Party Missions in this video.

A summary of ESA Third Party Mission collections

A new summary is available, showcasing the ESA archives for Third Party Mission collections.

Space helps monitor Earth’s changing biosphere

Earth’s biosphere is continually changing. Through its pioneering Earth observation missions, ESA is making critical contributions to monitor these changes and their impacts on Earth’s water and carbon cycles.

PROBA-1 - From technology demonstration to long-term Earth observation

Learn about ESA's PROBA-1 (Project for On-Board Autonomy) mission in our new infographic.

About PROBA-1

The Project for On-Board Autonomy-1 (PROBA-1) was originally a technology demonstration mission of the European Space Agency, started in mid-1998 and funded within the frame of ESA's General Support Technology Programme.

Intended as a one-year mission, this small satellite - less than 1 cubic metre in size - has provided data since its launch on 22 October 2001 and is still operational today, although data from its primary sensor CHRIS was suspended in December 2022.

Orbit	LEO Sun-synchronous
Orbital Parameters	681x561 km
Swath Width	14 km
Orbit Height	615 km
Orbital Plane Inclination	97.9 degrees
Orbital Period	96.97 minutes
Repeat Cycle	Approx. 7 days

PROBA-1

PROBA-1 rolls in its orbit to take images: the satellite's platform and payload work as one: spinning reaction wheels guided by a star tracker roll it up to 25º side to side and ±55º/±36º along its path. This helps PROBA-1 to compensate for its 7.5 km/s speed, like a photographer panning to snap a moving target. So each target can be seen on up to five different angles (-55º, -36º, nadir view, +36º and +55º).

PROBA-1 Objectives

The objectives of PROBA-1 are:

In-orbit demonstration and evaluation of new hardware and software spacecraft technologies
In-orbit demonstration and evaluation of onboard operational autonomy
In-orbit trial and demonstration of Earth observation and space environment instruments.

PROBA-1 Instruments

The **Compact High Resolution Imaging Spectrometer (CHRIS)** is the prime PROBA-1 instrument, used to explore the capabilities of imaging spectrometers on agile small satellite platforms.
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The **High Resolution Camera (HRC)** is a black and white camera with a miniaturised telescope, studying Earth, it also returns data on its own immediate environment.
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PROBA-1 INSTRUMENTS

PROBA-1 DATA

PROBA-1 TOOLS