Quick Facts: Collisions Into Dust Experiment (COLLIDE)


Collide-2 performed six independent impacts of small quartz spheres into fine quartz sand. The impacts were videotaped by two small camcorders, allowing the CU team to analyze the amount, direction and speed of dust ejected from the target trays by each impactor. (Courtesy LASP)

Mission Introduction

The Collisions Into Dust Experiment (COLLIDE) studied the gentle collisions that occur between particles in planetary rings and in the early stages of planet formation. The weightless environment of the space shuttle allowed for collisions into dust at very low speeds to help understand how planetary rings evolve and how the planets themselves formed. The COLLIDE experiment was designed and built by engineering students at the University of Colorado. Six impact experiments were recorded on videotape for analysis after the experiment returned to Earth.

COLLIDE-2 was an investigation into planetary dust rings. A follow on to COLLIDE-1, which flew on STS-90, COLLIDE-2 performed low-velocity (~1cm/sec) impact experiments into simulated dusty regoliths in microgravity. These impacts simulate the conditions in planetary rings and early protoplanetary disks. The experiment gave scientists a look at the dynamics, origin and evolution of planetary ring systems. Rings are collisionally evolved systems. Collisions sculpt the ring, leading to spreading, transfer of annular momentum, release of dust particles and damping of waves and wakes. The rate of evolution depends on dissipation of energy in collisions. COLLIDE-2 results also can be applied to the lifecycles of planetary dust rings.

The purpose of COLLIDE-2 was to better understand the release of dust from the surfaces of small particles in planetary rings and protoplanetary disks, by spring launching Teflon spheres into trays of powdered basaltic rock. The experiment performed six impacts of small spheres into trays of lunar regolith at velocities from 1 centimeter/second to 100 centimeters/second. The ejecta from these impacts were measured with video camcorders for quantity, launch angle, and velocity distribution.

Experimental Objectives:

  1. Measure the impact velocities and resulting rebound velocities to high precision (within 1 percent).
  2. Identify the transition regime form low-velocity collisions where no mass is ejected to conditions where craters are formed and mass is ejected as a result of the impact.
  3. Determine the mass and velocity distribution of the ejected material as a function of impact parameters.
  4. Determine the dependence of coefficient of restitution (a measurement of how well the projectile “sticks” to the target material) on impact velocities for velocities ranging between 1 and 100 cm/sec.



Shown here is a still frame from IBS #1, taken 0.3 seconds after impact. The target surface is horizontal at the bottom and the projectile motion was vertical from the top. An image of the projectile on the target surface is visible in the mirror above. (Courtesy LASP)

LASP Roles

LASP provided:

  • Six Impactor Box Systems (IBS)
  • Engineering students at the University of Colorado designed and built the COLLIDE-2 experiment with the help of LASP engineering professionals
  • Scientific analysis on the COLLIDE-2 data
  • Principal Investigator, Joshua Colwell

LASP Instrument

The IBS is the central piece of equipment in the COLLIDE experiment. It holds the experiment dust (lunar simulant) behind its sliding door until the space shuttle has reached orbit. Once on orbit, the door in the IBS slides open, revealing the dust that floats in space. The launcher system then ejects a teflon projectile into the floating dust, which creates an impact that is filmed by the camera on the opposite end of the GASCAN. Each IBS has nearly 60 parts made from various materials including aluminum, teflon, delrin, and polycarbonate.

Quick Facts

Launch date: April 17, 1998 and December 5, 2001
Launch location: Kennedy Space Center, Cape Canaveral, Florida
Launch vehicle: Space Shuttle Columbia mission STS-90 and Space Shuttle Endeavor mission STS-108
Mission target: Earth orbit
Mission duration: Six experiments of approximately 3 minutes each
Other organizations involved:

  • NASA’s Glenn Research Center