Dust Collector and Sample Return Capsule

Dust Collectors

Collection of cometary particle samples is accomplished simply by exposing blocks of aerogel to the sample flux during spaceflight.

Aerogel Collector

The dust collector media consists of blocks of 1 and 3 cm thick underdense, microporous silica aerogel mounted in modular aluminum cells. This is similar to what was used for previous exposures on Spacehab, Shuttle and MIR experiments. For the STARDUST mission, cells will be mounted on both sides of a two-sided, grid-shaped array that will deploy from the Sample Return Capsule (SRC). After exposure, the cells assembly will fold up to a compact configuration for stowage into the Earth return capsule.

One side of the modules will be used to collect samples during the comet encounter and the opposite side will be used for interstellar collection. The useful collecting area is 1000 cm2 for interstellar dust grains and 1000 cm2 for cometary dust. Graded density media will be used to give even lower density for the initial impact. These collectors are totally inert and only have to be exposed and then recovered.

The Sample Return Capsule is about a meter in diameter, and is shown here open like a clamshell with the dust collector grid deployed into the dust stream.

Sample Return Capsule (SRC)

The Sample Return Capsule consists of the sample canister, the aeroshield/basecover, navigation recovery aids, an event sequencer, and a small parachute system.

The SRC stores the samples of comet dust and interstellar dust in the sample canister. The SRC is released just prior to Earth encounter. The spacecraft sets up the proper flight trajectory and entry angle, and imparts a stabilizing spin to the Capsule upon release. Upon entering the Earth's atmosphere the SRC passively stabilizes as a result of its center of gravity location, spin rate and aerodynamic shape.

Earth Return Sequence

The Sample Return Capsule will perform a direct entry at Earth. After entry the SRC will continue to free-fall until approximately 3 km, at which point the parachute deployment sequence will initiate. The planned landing site is the Utah Test and Training Range (UTTR).

The reentry to landing accuracy has been analyzed and found to be sufficient to achieve a landing footprint of 84 km by 30 km. - well within the Utah Test and Training Range. A reinforced ring-slot descent chute will be deployed with the aid of a pilot chute. The descending capsule will have a UHF beacon and the parachute will be tracked by ground radar.

Following touchdown, the SRC will be recovered by helicopter or ground vehicles and transported to a staging area at UTTR for retrieval of the sample canister. The canister will then be transported to the planetary materials curatorial facility at Johnson Space Center.