The Future of Earth Observation: Why PAIS is Changing the Game for SmallSats

For decades, the rule of thumb for satellite imagery was simple: if you wanted better resolution, you needed a bigger, heavier, and much more expensive satellite. But a new technology from Remondo, called Partial Aperture Imaging System (PAIS), is rewriting that rulebook.

A recently released technical analysis compares Remondo’s PAIS technology against traditional “full-aperture” telescopes (the kind with solid mirrors). Here is a breakdown of how they stack up.

The Comparison: 0.4m and 1.0m Apertures

Let’s look at two specific sizes—a 0.4-meter aperture (deployed on high-end small satellites today) and a 1.0-meter aperture (historically reserved for massive, billion-dollar government satellites).

What Stays the Same?

Surprisingly, the angular resolution and Ground Sample Distance (GSD) are identical between PAIS and traditional telescopes of the same diameter.

• Physics is Physics: Both systems are governed by the same diffraction limit. At 450 km altitude, a 1.0 m aperture is diffraction-limited to approximately 30 cm ground resolved distance (GRD) – whether PAIS or traditional. .
• Image Processing: While PAIS requires computational reconstruction to create a usable image, both modern systems leverage on-board processing that takes less than three seconds.

Where PAIS Wins: Breaking the “Physical Wall”

While the resolution might be the same, the physical footprint is where PAIS pulls ahead.

1. Launch and Size (The “Rideshare” Advantage)

A traditional 1.0-meter solid mirror based telescope is heavy (over 800kg) and simply too big to fit into a single rideshare launch slot.

• PAIS: It uses a folding design that stows into a compact cylinder on the satellite bus, only using between 0.5 to 1 launch slot.
• The Result: You can launch a 1.0m PAIS system on a standard, low-cost rideshare rocket, whereas a traditional 1.0m telescope would require a dedicated mission or multiple slots on a rideshare mission, significantly increasing its launch cost. This can conservatively make the launch cost 10 to 30 times lower for PAIS.

2. Manufacturing and Speed

Making a large, monolithic (solid) mirror is one of the hardest tasks in optics, and given the current supply chain, manufacturing is currently running 18  to 36 months to polish a single 1.0m mirror.

• PAIS: It uses smaller mirror segments that can be produced in parallel.
• The Result: Lead times for PAIS mirror segments are typically only 3 to 4 months, hence removing the optical payload from your long lead procurement list.

3. Mechanical Tolerances

Traditional telescopes require “nanometer-level” precision for their mirror surfaces, which is incredibly difficult and expensive to achieve, especially given the rigors of launch. PAIS allows for millimeter-level positioning—a 100x relaxation in precision—because it uses an on orbit smart calibration subsystem to continuously keep the mirrors aligned. .

The Verdict

Traditional systems have a few “old school” advantages such as:

• Photon Collection: Because a traditional telescope has a solid mirror, it collects more light (photons) than the “ring” design of PAIS. PAIS makes up for this by taking slightly longer integration time over the target(~5-10ms).
• Heritage: Traditional telescopes have been flying for decades. Remondo’s PAIS is the new player, with two  LEO demonstration satellites scheduled for 2027.

PAIS is the clear winner for the modern era. At smaller sizes (0.4m), PAIS is superior because it is smaller and lighter, and much cheaper to manufacture and deploy at scale. However, at larger sizes (1.0m and up), PAIS is the only viable path forward for small satellites. A traditional 1.0m telescope is simply too big and expensive for a commercial smallsat mission. PAIS provides the “only path” to getting 16 cm resolution from a low-cost rideshare launch, making high-resolution Earth intelligence more affordable and accessible than ever before.