Engineering topics

Warren, J. L.

Publications and source records attributed to Warren, J. L..

11 records

NASA NTRS2012

Developing the New Hayabusa Curation Facility at Johnson Space Center

On 25 November 2005 the Japan Aerospace Exploration Agency (JAXA) Hayabusa spacecraft made contact with the asteroid 25143 Itokawa and collected a small amount of regolith dust from Muses Sea region of smooth terrain [1]. Even though optimal sample collection did not occur, the spacecraft returned to Earth with more than 10,000 grains ranging in the size from 30-180 microns [2]. These grains represent the only collection of pristine material returned from an asteroid by a spacecraft. As part of the joint agreement between JAXA and NASA for the mission, 10% of the Hayabusa grains will be transferred to NASA for parallel curation and allocation, the first 15 of which arrived in December 2011. In order to properly receive and process these samples, a new curation facility was developed at Johnson Space Center (JSC).

De Gregorio, B. T.↗

NASA NTRS2007

STARDUST Curation and Science at JSC

Dust particles released from comet 81P/Wild-2 were captured in silica aerogel on-board the STARDUST spacecraft and returned to Earth on January 15, 2006. STARDUST recovered thousands of particles ranging in size from 1 to 100 micrometers. During the six month Preliminary Examination period an international consortium of 180 scientists investigated their mineralogy/petrology, organic/inorganic chemistry, optical properties and isotopic compositions. Stardust samples are now available for research by the entire research community.

Nakamura-Messenger, K.↗

NASA NTRS2007

Clean Assembly of Genesis Collector Canister for Flight: Lessons for Planetary Sample Return

Measurement of solar composition in the Genesis collectors requires not only high sensitivity but very low blanks; thus, very strict collector contamination minimization was required beginning with mission planning and continuing through hardware design, fabrication, assembly and testing. Genesis started with clean collectors and kept them clean inside of a canister. The mounting hardware and container for the clean collectors were designed to be cleanable, with access to all surfaces for cleaning. Major structural components were made of aluminum and cleaned with megasonically energized ultrapure water (UPW). The UPW purity was >18 M resistivity. Although aluminum is relatively difficult to clean, the Genesis protocol achieved level 25 and level 50 cleanliness on large structural parts; however, the experience suggests that surface treatments may be helpful on future missions. All cleaning was performed in an ISO Class 4 (Class 10) cleanroom immediately adjacent to an ISO Class 4 assembly room; thus, no plastic packaging was required for transport. Persons assembling the canister were totally enclosed in cleanroom suits with face shield and HEPA filter exhaust from suit. Interior canister materials, including fasteners, were installed, untouched by gloves, using tweezers and other stainless steel tools. Sealants/lubricants were not exposed inside the canister, but vented to the exterior and applied in extremely small amounts using special tools. The canister was closed in ISO Class 4, not to be opened until on station at Earth-Sun L1. Throughout the cleaning and assembly, coupons of reference materials that were cleaned at the same time as the flight hardware were archived for future reference and blanks. Likewise reference collectors were archived. Post-mission analysis of collectors has made use of these archived reference materials.

Allton, J. H.↗

NASA NTRS2007

Stardust Curation at Johnson Space Center: Photo Documentation and Sample Processing of Submicron Dust Samples from Comet Wild 2 for Meteoritics Science Community

Dust particles released from comet 81P/Wild-2 were captured in silica aerogel on-board the STARDUST spacecraft and successfully returned to the Earth on January 15, 2006. STARDUST recovered thousands of particles ranging in size from 1 to 100 micrometers. The analysis of these samples is complicated by the small total mass collected ( < 1mg), its entrainment in the aerogel collection medium, and the fact that the cometary dust is comprised of submicrometer minerals and carbonaceous material. During the six month Preliminary Examination period, 75 tracks were extracted from the aerogel cells , but only 25 cometary residues were comprehensively studied by an international consortium of 180 scientists who investigated their mineralogy/petrology, organic/inorganic chemistry, optical properties and isotopic compositions. These detailed studies were made possible by sophisticated sample preparation methods developed for the STARDUST mission and by recent major advances in the sensitivity and spatial resolution of analytical instruments.

Nakamura-Messenger, K.↗

NASA NTRS2006

Genesis Spacecraft Science Canister Preliminary Inspection and Cleaning

The Genesis science canister is an aluminum cylinder (75 cm diameter and 35 cm tall) hinged at the mid-line for opening. This canister was cleaned and assembled in an ISO level 4 (Class 10) clean room at Johnson Space Center (JSC) prior to launch. The clean solar collectors were installed and the canister closed in the cleanroom to preserve collector cleanliness. The canister remained closed until opened on station at Earth-Sun L1 for solar wind collection. At the conclusion of collection, the canister was again closed to preserve collector cleanliness during Earth return and re-entry. Upon impacting the dry Utah lakebed at 300 kph the science canister integrity was breached. The canister was returned to JSC. The canister shell was briefly examined, imaged, gently cleaned of dust and packaged for storage in anticipation of future detailed examination. The condition of the science canister shell noted during this brief examination is presented here. The canister interior components were packaged and stored without imaging due to time constraints.

Hittle, J. D.↗

NASA NTRS2003

Leonid Dust Spheres Captured During the 2002 Storm?

An effort was made to collect dust from a known source, comet 55P/Tempel-Tuttle, in the form of Leonid meteor debris in the hours after the 2002 storm. No interplanetary dust particles (IDPs) have yet been recovered from a known source. We do not expect Leonid debris at 72 km/s to survive atmospheric entry as aggregates and our effort was predicated on the notion that mm-sized and larger meteoroids after extreme mass could survive as up to approximately 100 micron-sized silicate spheres. Two anticipated Leonid storms, rather than its annual shower activity, were the target of the last Leonid Multi-Aircraft Campaign during the Nov. 19, 2002 storm. Flying westwards from Spain to the US the mission covered both the 1767 and 1866 dust trails whereby early in the flight the aircraft flew several hours across the region exposed to the first storm peak that did not include the continental US of the second peak with 5,400 meteors.

Rietmeijer, Frans J. M.↗

NASA NTRS2003

Genesis Discovery Mission: Science Canister Processing at JSC

Genesis addresses questions about materials and processes involved in the origins of the solar system by providing precise knowledge of solar isotopic and elemental compositions. Solar wind ions are collected and returned to Earth for analyses. The spacecraft has two primary instruments to collect solar wind: a set of collector arrays each of which can deploy to sample different solar wind regimes, and a concentrator that is an electrostatic mirror to concentrate and focus low mass ions onto a 6 cm target. One of the key challenges to obtaining a good sample of solar wind, uncontaminated by terrestrial atoms, is to have clean collection surfaces in a clean sample canister and clean facilities to handle the samples for allocation and future reference. The Johnson Space Center (JSC) is responsible for contamination control for the mission, for ensuring the cleanliness of collection surfaces, and for providing a clean environment for handling of the samples. The level of cleanliness required is high; at the time of analysis (after sample return), the surface contamination by C, N, O must each be <10(exp 15) atoms/sq cm and for other elements the number of atoms/sq cm of each surface contaminant shall not exceed the estimated solar wind fluence of the species (varies by element between U at approx. 10(exp 4) atoms/sq cm to Fe, Si, Mg, and Ne at approx. 10(exp 12) atoms/sq cm).

Stansbery, E. K.↗

NASA NTRS2001

Genesis Discovery Mission: Science Canister Processing at JSC

This document includes a description of collector material installation and final cleaning of the Genesis Discovery Mission science canister at Johnson Space Center. Additional information is contained in the original extended abstract.

Stansbery, E. K.↗

NASA NTRS1989

The detection and observation of meteoroid and space debris impact features on the Solar Max satellite

The results of optical observations on the entire population of impact pits and holes discovered on nearly all of the returned parts of the Solar Maximum Mission satellite are described. Some statistically significant new results on impact dynamics are obtained as well as new number vs. size distributions for craters and holes ranging from 40 to 900 microns. The local spacecraft geometric shielding corrections are calculated and applied to the data. Some selected compositional results are presented which indicate that the Space Shuttle can be a source of impacting debris.

Warren, J. L.↗

NASA NTRS1985

Examination of returned solar-max surfaces for impacting orbital debris and meteoroids

Previous theoretical studies predicted that in certain regions of earth orbit, the man-made earth orbiting debris environment will soon exceed the interplanetary meteoroid environment for sizes smaller than 1 cm. The surfaces returned from the repaired Solar Max Mission (SMM) by STS 41-C on April 12, 1984, offered an excellent opportunity to examine both the debris and meteoroid environments. To date, approximately 0.7 sq. met. of the thermal insulation and 0.05 sq. met of the aluminum louvers have been mapped by optical microscope for crater diameters larger than 40 microns. Craters larger in diameter than about 100 microns found on the initial 75 micron thick Kapton first sheet on the MEB (Main Electronics Box) blanket are actually holes and constitute perforations through that blanket. The following populations have been found to date in impact sites on these blankets: (1) meteoritic material; (2) thermal paint particles; (3) aluminum droplets; and (4) waste particles.

Kessler, D. J.↗

NASA NTRS1983

El Chichon volcanic ash in the stratosphere - Particle abundances and size distributions after the 1982 eruption

Volcanic ash particles collected from the stratosphere after the March/April, 1982 explosive eruption of El Chichon volcano, Mexico, were mostly 2-40 micron vesicular shards of silicic volcanic glass that varied in abundance, at 16.8-19.2 km altitude, from 200 per cu m (30-49 deg N lat.) in May to 1.3 per cu m (45-75 deg N) in October. At the minimum, the ash cloud covered latitudes 10-60 deg N in July and 10 deg S-75 deg N in October. In May and July, ash particles were mostly free, individual shards (and clusters of shards) but, by October, were intimately associated with liquid droplets (presumably, sulfuric acid). In May 1982, the total stratospheric burden of ash was at least 240 tons (2.2 x 10 to the 8th g) although the total ash injected into the stratosphere by the eruption was probably 480-8400 tons.

Gooding, J. L.↗