NASA Johnson Space Center
Oral History Project
Edited Oral History Transcript
Judith
H. Allton
Interviewed by Jennifer Ross-Nazzal
Houston, Texas – 12 October 2017
The
questions in this transcript were asked during an oral history session.
Ms. Allton has edited and revised the answers. As a result, this transcript
does not exactly match the audio recording.
Ross-Nazzal:
Today is October 12, 2017. This interview with Judy Allton is being
conducted at the Johnson Space Center for the JSC Oral History Project.
The interviewer is Jennifer Ross-Nazzal, assisted by Sandra Johnson.
Thanks again for coming in this afternoon and walking across campus.
My car said it was 91 degrees when we walked back, so we appreciate
you coming over.
Today we were going to talk about the Genesis Discovery [Program]
mission. I was curious how you got involved with that mission.
Allton: It
was an opportunity for me to participate in a flight mission. As you
know, I’ve worked with the lunar samples for a long time, but
I didn’t participate in actually collecting those since I didn’t
come until ’74. This was an opportunity to see how you prepare
something to fly and how to make it work.
Also the planetary science community was very interested in determining
the precise solar composition. All the studies on the lunar rocks
and meteorites and other planetary bodies really needed to know the
elemental and isotopic composition of the starting material, the solar
nebula, thought to be captured in the Sun’s composition. There
were a lot of science folks who thought, “Wow, that’s
going to be critical information.”
I was asked to participate in Genesis by Eileen [K.] Stansbery, who
is currently JSC chief scientist. Eileen became the contamination
control officer for this mission, even though Genesis was managed
at [NASA] JPL [Jet Propulsion Laboratory, Pasadena, California]. The
spacecraft was built by Lockheed Martin [Corp.], but JPL built the
payload containing the solar wind collectors.
This, as the Discovery missions are, was a PI [principal investigator]-driven
mission. The principal investigator was Don [Donald S.] Burnett of
Caltech [California Institute of Technology, Pasadena, California],
who’s done a lot of work making laboratory measurements on lunar
and meteorite rock chemistry and isotopes. He had been very keen to
determine that key piece of information—the solar composition
as determined by direct measurement of solar matter. Previously, estimates
of solar composition were derived from meteorite analyses.
All of the people on the Genesis Science Team are precision chemists
in the lab, and persnickety, especially isotopers, who work in ultraclean
laboratories. They have a reputation for washing down the lab walls
and suiting up in cleanroom garments to keep the room clean. I came
from that background, because my background is chemistry and isotope
geology, and I worked in the Lunar Lab, which we keep in pristine
shape. In the Lunar Lab, we care about the chemical composition of
the paint on the wall, the floor, etc., because certain trace atoms
can interfere with the age dating for Moon rocks.
So I had the mindset, I think, of being a persnickety chemist, and
Don Burnett was an amiable guy. I respected his work a lot, Eileen’s
also. He picked Eileen to be contamination control officer, and that
is what made this Discovery mission, I think, unique in a lot of respects,
even though the mission was managed by JPL. Genesis was unique by
funding sample curation and allocation included in the proposal, and
unique in performing the cleanest payload assembly in ISO [International
Organizations for Standardization] 4 (Class 10) environment. That
Don and the science team expressed confidence in the curation expertise
and long experience by JSC Astromaterials curation was indeed a compliment!
Those Discovery missions were smaller than flagship missions. Right
now I’ve been peripherally involved in some of the Mars 2020
meetings, and that program involves a lot of people. The management
structure is quite large, but Discovery mission management was small,
with closer professional relationships and respect among team members.
By all accounts Don Burnett worked very well with the JPL management,
had some input into who was going to be on the JPL engineering team,
and, between him and the JPL managers they chose excellent team members.
It worked out very well. The engineers cared about the science, the
precise composition of the Sun, and did their very best to make it
work. Don is a real hands-on principal investigator, checking details.
Not all of the Discovery mission PIs were. Don would call up and ask
what we were doing. He would suit up and come into the lab. He visited
all the laboratories operated by the science team, which was comprised
of leading planetary scientists world-wide. It wasn’t a very—what
do you call when you—?
Ross-Nazzal:
Hierarchical?
Allton: Right.
Anybody could talk to anyone else on a first name basis. Everybody
who had hands-on access to the hardware to be used for collecting
these samples pretty much understood what science results were going
to come out of the mission, and that they had to be very careful about
contamination control. It was a team built on mutual respect.
Ross-Nazzal:
You mentioned it was unique because it was a smaller group. Do you
recall about how many folks were participating in this mission?
Allton: If
I think back to the telephone list we used, there were about 250 people
across groups at JPL, LMA [Lockheed Martin Astronautics], LANL [Los
Alamos National Laboratory, New Mexico], JSC, UTTR [Utah Test and
Training Range], KSC [Kennedy Space Center, Florida], and, of course,
the science team members from various universities. The largest number
of people were at JPL and LMA. JPL managed the mission, mission design,
navigation, and payload design and fabrication. LMA built the spacecraft
and sample return capsule (SRC), and controlled the mission during
flight from their control room in Denver. Los Alamos people built
and calibrated the concentrator, an active collector that concentrated
ions of the principal science goals—O, N, C.
People at KSC were involved with launch, and people at UTTR were extremely
helpful during recovery, especially after the parachute deploy failure
and resulting hard landing. I should talk later how the UTTR people
furnished all kinds of help in salvaging the payload, they are a real
“can do” outfit. Karen McNamara was the JSC curation point-of-contact
working with UTTR folks to prepare for recovery in 2004.
Burnett and his science team, about 30 people, and JSC contamination
control team, about 10 people, were invested in the mission from beginning
to end. At time of Genesis launch in 2001, Burnett had been working
on Genesis and its first-attempt proposal called Suess-Urey for about
20 years. [The Suess-Urey mission was named after two prominent scientists
in the field of cosmochemistry—Drs. Hans E. Suess and Harold
C. Urey]. The original science team members defined the collector
materials in the 1990s. I also count, from people I worked with directly,
about 15 payload people from JPL, 5-10 people from LANL, and 10-15
recovery people from LMA as being involved from mission design through
hardware fabrication, cleaning, assembly, flight operations, recovery
and allocation of samples to investigators. Having these long-term
relationships was very useful during the sample analysis period, which
still continues today, because I often consulted the payload and spacecraft
people concerning materials which might be contamination sources on
the surfaces of the collectors. This is a unique strong point of Genesis
planning and teamwork.
Materials scientist A. J. G. (Amy) Jurewicz is an example of someone
involved long-term with Genesis. She was the Genesis project scientist
at JPL pre-flight and most knowledgeable about the collector materials.
She continues to be the “go to” person as we document
how the collected materials were subtly changed by the space radiation
environment.
We at JSC were mostly concerned with cleaning and assembling the payload
in [Federal Standard 209E] Class 10 conditions. Today it would be
ISO Class 4. It’s very clean. We suited up entirely, and in
those days we had Teflon-coated suits, with helmets. Everything exhausted,
that you breathed out or that came off your body, went through a HEPA
[high efficiency particulate air]-filter on the back. It was like
a lightweight spacesuit, but it wasn’t a pressure suit. It was
merely to keep people from shedding into the lab.
We built the lab here at JSC because we had extensive experience in
cleaning hardware associated with science samples. So the JPL payload
engineers arrived at JSC with their payload. We and they took it apart.
We cleaned the parts. They put it back together, but it was a well-integrated
process, a smooth interaction. The JPL folks came to Texas in August
and stayed here for months. Their processes were very different than
ours. For Eileen Stansbery and I, it was an interesting difference,
watching the meeting of cultures.
I can remember when the people from JPL showed up with a truck, with
their payload in it in hot weather here. They stepped out wearing
their Hawaiian shirts, Bermuda shorts, and sandals, and here we were
in our blue jeans. Jack [L. Warren] had a gimme [baseball] cap on.
It just looked like two cultures meeting each other.
They came from a place where they do big missions. They put spacecraft
together in enormous, multistory clean rooms that weren’t really
so clean by our standards. We asked them to work in a room that had
only an eight-foot ceiling height. Because the top of the room was
covered with ULPA [ultra low penetration air] filters, and the air
would go straight down through the floor and then back up the sidewall.
We had a laminar flow that would sweep particles down and away, but
the ceiling wasn’t very high.
They were pretty good sports, because we said, “Now all of you
have to work in this not-too-high ceiling room. You have to wear this
suit, which completely encloses your body. The head gear encloses
your face and allows vision through a plastic face shield, the suit
motor pulls all exhaled breath and particles shed from your body through
a small HEPA filter, and gloves and boots complete the enclosure.
When you install screws in the hardware, you can’t touch the
screws with the gloves, you have to use tweezers.” They were
either good actors or good sports, because they did it without grumbling.
They had new rules for us as well. JPL is very careful about controlling
electrostatic discharge during spacecraft assembly because it can
cause undetectable damage, so we had to take ESD [electrostatic discharge
control] training and become sensitive to ESD safe protocols.
In addition to assembling a payload in Class 10, we were cleaning
the hardware with ultrapure water (UPW). Measuring the carbon isotope
composition of the Sun was one of the science goals. We felt like
organic solvents would leave some organic residue, so the final cleaning
was just water that’s very, very pure – ultrapure water.
UPW has very high resistivity and acts a little bit like an acid,
a little bit like a base. It is “hungry” water and removes
many contaminants without leaving a residue. Our UPW production was
10 gallons per minute.
The JSC team cleaned the payload hardware in one cleanroom. There
were only about five of us that did all that work. We felt like the
A-Team [television series] or Skunk Works [Lockheed Martin Advanced
Development Programs]. We would work right into the night. We would
go out to the hardware store or other places and buy equipment needed
to make the lab work using our own money. We have one picture of people
scrubbing the threads on very tiny screws. Everyone is fully suited
up, and the “dishwashers” were 2 PhDs and a Master’s
level geochemists. Because everybody put in a lot of effort, it was
team-building work. That’s the JSC side. We would hand-off the
cleaned hardware to the JPL team in assembly cleanroom.
We started every day with a meeting to review actions. Eileen Stansbery
set that up. The JSC-JPL team just worked really well together, because
there weren’t very many of us. There were about four or five
of them, and there were about four or five of us. There were some
problems getting hardware cleaned and assembled but that got worked
out. That was getting ready for flight. I note here that the families
of everyone working this mission deserve credit for mission success
because of the long hours required. People who work flight missions
know this.
Finally, all was cleaned and assembled. Then the payload canister,
containing the 300 solar wind collectors, was closed for the final
time in this room. Everybody present and watching was enclosed in
Teflon fabric suits with faceplates. I thought, “The arrays
with the polished collectors are so beautiful. Wow, I wonder what
it will look like when we get it back.” Genesis was supposed
to be launched in 2000 but didn’t get launched till 2001. Genesis
re-entered Earth in September 2004. I was there in Utah for the return
September 8, 2004, at 10 a.m. Genesis had been parked in a halo orbit
at Earth-Sun L1 and was open to collect solar wind for about 27 months.
That was just barely enough time to gather enough solar atoms in these
collectors so people could make solar wind measurements above background
level. All of Genesis involved cutting-edge analytical challenges.
Ross-Nazzal:
I wanted to go back and ask a couple questions. You mentioned Eileen
Stansbery. She approached you with the possibility of working on the
team?
Allton: She
did. I was at an age where I thought I could do anything.
Ross-Nazzal:
How did you come up with that contamination control document? Just
being over at the old LRL [Lunar Receiving Laboratory] today was amazing.
I’m thinking about all the things that went into contamination
control. You have a much smaller space, but you obviously had to think
about all of those things. Can you talk about how you started, and
how that idea evolved?
Allton: For
contamination control procedures and processes?
Ross-Nazzal:
Yes.
Allton: Actually
started after the LRL. The rocks were moved out of the LRL, because
in general the geology people felt they couldn’t keep it clean
enough because of the materials and animals required by the hazard
detection people. Plus, the geologists wanted to keep the samples
under positive pressure nitrogen, which is what they did after quarantine
was no longer required. They designed the building that’s now
31N especially for the purpose of keeping the lunar rocks clean and
pristine, and it was done by a committee of about five planetary scientists.
Most of them were isotopers because they’re picky about keeping
labs clean, and all of them had built ultraclean laboratories. Two
of these lunar facility committee members are notable not only for
detailed attention to the new lunar facility back the 1970s, but also
for their long service to Genesis mission serving, until recent time,
on the oversight committee for allocations of Genesis samples: Dimitri
[A.] Papanastassiou and Laurence [E.] Nyquist.
The lunar facility committee worked closely with the engineering people
on Building 31 to screen the elemental content of the flooring, the
paint, and the wires that plug into the lights. For example, this
subcommittee required that the brass plaques identifying doors as
fire-rated doors be removed from the doors for contamination control
reasons; brass is composed of elements that interfere with science
results. It was very tightly managed. Everyone who worked there was
focused on not bringing certain elements into the lab where they could
inadvertently get in the samples. My chemistry background was helpful
in this respect.
While I worked in the Lunar Lab, one of the things I did was dissect
lunar cores. The drive tubes from the last three missions are the
main ones that I worked on. To get those out of the tube takes a lot
of equipment, which is assembled inside of a nitrogen-filled glovebox
inside of a cleanroom. We had detailed procedures because the assembly
had to be done in a precise sequence. Extrusion and dissection of
Apollo drive tube samples was a controlled and documented process
with attention to detail. We used the same thing approach to define
what we should do for Genesis, which had even more stringent contamination
requirements.
We put that laminar flow clean room on the first floor of the Lunar
Sample Building (Building 31N). We did not have enough money or time
to build a new lab for Genesis. But we chose the Lunar Sample Building
location because I figured—or maybe Jack and I did—that
that building would not blow away in a hurricane. As you know, the
lunar sample facility is very solidly built. The lunar samples are
up above what was the predicted extreme storm surge at that time.
For the Genesis Lab we chose a space on the first floor directly below
the Pristine Lunar Sample Lab, because the building was solid, and
it was built out of materials compatible with Genesis contamination
control requirements.
Ross-Nazzal:
You mentioned the Teflon suits that you wore and the faceplates. Was
that something that was on the market? Or was that something that
you had to look at and develop? Was there other hardware or tools
that you had to develop unique to that lab?
Allton: No,
those suits were on the market. The brand name was Dryden suits. I
say Teflon, you’re probably picturing something like a Teflon
bag and crinkly. It wasn’t that. It was actually—I think
it was a polyester fabric. It just had a Teflon coating on it. That
was used to cut down on particles being shed off the suit. I think
they may make something similar now. Just recently we started getting
rid of the old Dryden suits because those things have a certain shelf
life. After Genesis crashed, we just worked in regular full suits
with only eyes exposed, without the HEPA filter headgear. It didn’t
seem to be required after we had retrieved collectors off the desert
floor. Some new labs are looking at similar suits now. Those suits
are not as common.
We were riding the crest of the semiconductor industry innovation
when we put Genesis Lab together. They’re very conscious of
operating low-particle labs. People are very dirty, they shed about
7 pounds of skin and hair annually. Those suits were used in semiconductor
industry in ultraclean labs, back around 1998 when we were putting
the lab together.
The industry has moved on. Now there’s more robots and less
people, so the need for those suits is not what it once was. I don’t
know if we could find the same thing again. Similar suits have gone
into the medical-surgical arena. I’m not sure they’d be
exactly the same.
Ross-Nazzal:
You had talked about cleaning that container when JPL brought that
payload out. Were there some other cleaning solvents that you may
have used before that? How big of a container are we talking about?
How long did that whole process take?
Allton: The
payload itself was the shape of a tuna can, about 30 inches across,
about 18 inches high. It opened with a hinge, like a clam shell, and
it was constructed of bare aluminum. A lot of spacecraft designers
will finish off their aluminum parts with anodized finish, but anodized
finish is kind of porous and can trap a lot of contamination, so Genesis
did not use anodization surface treatment on the interior parts next
to the collectors. On the exterior, the cover top was painted white
for thermal management, and the bottom was anodized.
This was the first experiment that I know of—I think it was
the first payload ever assembled in an ISO Class 4 clean room. The
aluminum did not have an anodized finish on it, or any kind of finish.
We cleaned it with the water. I’m sure we created some aluminum
oxide on there, and in fact if you use too hot a water it would get
a little bit brown. We were careful with that. But we could get the
particle counts down really low to level 25, when you collect the
rinse water on those two big pieces.
We had an ultrapure water tank that was a little bigger than the tuna
can. It was taken down to its piece parts. The lid, with exterior
white paint, and the bottom, with exterior hard anodize, were not
submerged. For those we had a wand that would take the ultrapure water
and put megasonic energy in it, so you could hose down those two large
pieces, with very clean water that had been megasonically energized
and would lift particles off.
Ross-Nazzal:
What does that mean? I don’t understand what that means.
Allton: Many
labs submerge hardware to be cleaned in ultrasonic cleaners. The ultrasonic
energy loosens the particles so they can be washed away. Megasonic
is a higher energy level. The cleaning effects are slightly different
than ultrasonic. Our device provided a shower of megasonically energized
ultrapure water aimed at the object to be cleaned. It’s like
taking a shower versus taking a bath. In the bathtub you’re
sitting with the dirt, in the shower the dirt is washed down the drain.
There was that difference. By particle counts that we took, it worked
really well, getting these large, odd-shape pieces particle-free and
cleaned up.
Ross-Nazzal:
How long did that process take you?
Allton: Trying
to recall the dates. If we were to clean one piece, like the bottom
or the top, it would be a daylong thing: getting it in there, cleaning
it up. Then you had to take nitrogen jets and dry it. All of this
was in a fairly particle-free room. You’d set that out overnight.
It would be ready to assemble the next day.
Ross-Nazzal:
Did you say this was also manufactured in a clean room? So if it was,
what was the idea or the intent behind having to clean the equipment
again?
Allton: I
think payload parts were manufactured in a regular machine shop, perhaps
with care to keep it clean. Additionally parts arrived from JPL cleaned
and bagged, but their typical flight cleaning requirements were not
sufficient to meet the science requirements.
Ross-Nazzal:
Oh, it was. Okay.
Allton: We
did some precleaning on it, you know wiping. We actually used a little
bit of surfactant. In this case it was Joy [dishwashing liquid], two
drops of Joy in a whole pan of water, but that was just to get handling
debris off of it.
Ross-Nazzal:
There was concern about contamination. Is that why it had to be clean?
Were you concerned about bringing life here and sending it to the
Sun? I’m just curious about that.
Allton: We
weren’t concerned about biology. It’s just that small
particles of any kind, if they got onto the collector surfaces, would
make it harder to analyze the solar wind. Most of the solar wind collection
surfaces were highly polished. Most of them were silicon wafers. That
was a semiconductor product of the time. It’s another reason
Genesis happened at the right time to match the semiconductor industry.
They were making a lot of very pure silicon wafers and they knew how
to get them superclean.
We didn’t actually clean the polished wafers that we bought.
They came off a process line from the suppliers that produced the
cleanest wafers. Science team members analyzed several samples and
determined who provided the purest, cleanest wafers.
Those arrays, on which the mirror polished hexagonal-shaped wafers
were mounted, were objects of beauty! This was an interesting lesson
in the value of contamination control personnel having “eyes
on” the fabrication processes. The arrays were delicately and
precisely carved out with a process called electric discharge machining
(EDM), which is a wire that cuts the metal using high voltage and
is a relatively dirty process. Metal particles from the wire become
embedded in the cut piece. These process details are not always obvious
to the contamination control monitors, nor the science effects straightforward
to the engineers tasked with fabricating the hardware.
When cleaning the array frames at JSC, this problem was detected and
mitigated by resurfacing the array frames. Residues of copper and
zinc from the cutting process were detected by analysis of the cutting
coupons collected and archived during fabrication. This example illustrates
the value of acquiring and archiving reference and witness materials,
for which Genesis curation is recognized. For Genesis we archived
several kinds of reference materials: samples of all the materials
used in constructing the Class 10 lab. This includes paint, fireproofing,
flooring, caulk, and gaskets. Samples of spacecraft components: spare
fasteners cleaned for flight, bags, RTV [room temperature vulcanizing]
staking compound, lubricants, cutting oil, array frames including
the outfall pieces from the EDM, engineering model spares. Most important
reference materials were the non-flown collectors. These are critical
for background measurements for analyzing solar wind collectors. In
fact, over the years we have allocated 600 fragments of solar wind
collectors and over 300 reference collectors. All of these reference
materials are tracked in a database, just like Genesis-flown collectors.
We were careful about clean hardware adjacent to the solar wind collectors.
Micrometeorite impacts from interplanetary dust might hit the aluminum
frame and splatter frame material on the collectors. That’s
one reason we were so picky about everything that went into it.
Ross-Nazzal:
It sounds like it. You mentioned the suit. I’m just curious
because also when we were over at [Building] 37 mentioned how every
time somebody left that building they had to take a shower. Did you
have other requirements beyond donning a suit for going in there?
Allton: No,
we actually had people change out of their street clothes and put
on scrubs under those suits just to keep from dragging particles from
street clothes into the lab. Also that was cooler than most street
clothes. The suits didn’t breathe all that well. Our precautions
were for the purpose of keeping the interior of the suits clean and
personnel comfort. The LRL procedure was for the purpose of containment
of potential biohazards inside the LRL.
Ross-Nazzal:
I can imagine with Teflon on.
Allton: Because
the clean room—the air coming from the ceiling to the floor
travels at 100 linear feet per minute. So what does that make, 12
air changes a minute? That “vertical breeze” cools things
off a lot just because the air is moving. In the LRL the scrubs were
the lab outfit. They made people take off everything and put on laboratory-furnished
scrubs. They had to take off everything and shower out before they
could leave. They were just trying to make sure no one carried anything
hazardous out of the lab.
Ross-Nazzal:
Did you ever go visit any clean labs in Silicon Valley as you were
creating this lab? Or did you just read up on literature and decide,
“These are the things that we need to have as we’re constructing
this lab”?
Allton: We
attended—between Eileen, Jack, and I—several semiconductor
conferences. They provided clean room classes, suit classes, air shower
classes. We went to the trade shows. That’s where we got our
megasonic cleaner that we used and the cascade tanks. Most of those
things were not very expensive. Back in those days several semiconductor
trade shows were in Austin, so we could drive. It was very economical.
Ross-Nazzal:
So most everything was off the shelf. It wasn’t anything newly
created for JSC?
Allton: Most
of our equipment was off the shelf, and one Genesis contribution was
adapting ultrapure water for cleaning flight hardware and assembling
the payload in a Class 10 environment. After the crash, we made another
significant contribution by adapting a wafer spin cleaner and using
it to megasonically spin clean selected Genesis collector fragments.
That works well.
Ross-Nazzal:
How did you come up with that idea?
Allton: Using
the spin cleaner to clean contaminant particles from Genesis samples,
after the crash, was the idea of Michael [J.] Calaway. Using UPW to
clean hardware was driven by the need to discontinue using Freon 113
to clean lunar tools. We had an enormous Freon still that was, I don’t
know, six or eight feet high. Our metal parts that we cleaned for
tools and containers for use in the lunar cabinets would be cleaned
with Freon. Every once in a while we find a piece of hardware that
was cleaned with Freon years ago and still bagged. Of course we haven’t
used Freon in decades, but the Freon-cleaned pieces are exceptionally
clean.
When we had to move away from Freon, we moved to was ultrapure water.
Curation built an ultrapure water system. It’s a water plant.
It’s equivalent to Milli-Q water that people use in small quantities
in labs. The resistivity is high, over 18-megaohm. We had several
hundred feet of piping, supplying several labs, producing about eight
gallons a minute. We produce enough to flush lunar glove boxes, meteorite
glove boxes, clean hardware with UPW water heaters. We had that in
place already. Don Burnett, thinking he didn’t want to have
any organic residue left on the hardware, thought we could use UPW.
So we did. A note about the ultrapure water—UPW cannot be captured
in a container and used at another location. The UPW reacts with container
walls and soon is no longer ultrapure. Labs using UPW have to be attached
to the circulating loop.
Ross-Nazzal:
Were you briefing him on all of these developments as you were working
on the clean room and the contamination plan?
Allton: He
knew about the water, because we had switched over to cleaning lunar
tools that way. We picked a cleanliness level, and what we would need
to achieve that cleanliness level. Since it was similar to the semiconductor
industry, Don Burnett was agreeable, because they had already been
buying materials cleaned by the semiconductor industry for collectors
and analyzing them. They were satisfied that they were clean enough.
They were probably the cleanest anyone could get things in those days.
Ross-Nazzal:
How far out had you been working on this clean room? Was it before
they started building the spacecraft? Or was it as they were designing
and building?
Allton: Genesis
was initially proposed as Discovery Mission called Suess-Urey. Suess-Urey
Mission did not get selected that time, but our sister sample return
mission Stardust did. However, many elements of the solar wind mission
had been already developed. We’d already written the contamination
control plan, of which I was a major contributor. When another round
of Discovery competition opened, the basic elements of Suess-Urey
plus improvements were submitted under the name Genesis, something
that sounded more attractive, I guess. A lot of the Phase A work was
already done.
We had already thought about how to do this clean room, so when it
was selected late in 1997 it was a matter of getting the Center (JSC)
to support the facility, which Eileen Stansbery negotiated and is
most knowledgeable about those details. JSC provided engineering support
and funding for preparing an existing room in 31N into which a Class
10 cleanroom could be placed. The cost was very modest, since we were
just setting a clean room inside of an existing room.
Ross-Nazzal:
The whole mission wasn’t that expensive. I saw the cost. It’s
very modest, especially compared to a Space Shuttle flight.
Allton: Oh,
yes. But what made it really go was the four or five of us were just
all persnickety. We were after every detail. To prepare a clean room
for this mission and to permit good analyses at that low sensitivity
level, you have to watch all the details, and sometimes that’s
not really appreciated.
Ross-Nazzal:
I’m sure some people, maybe facility people, got a little frustrated
at times.
Allton: The
facility people back in ’98 and ’99, they were a pleasure
to work with. We explained what we were trying to do. We met with
hands-on workers every morning. We took particle counts in the laboratories
adjacent to where workers were preparing the room in which the Class
10 room would be placed. We’d say, “Okay, the particle
count was this yesterday.” So they knew we were measuring how
much mess they were creating. Actually the particle counts were quite
good, so that was encouraging. They were very careful. That worked
very well.
What the JSC site people did, they created a lovely shell. The shell
was coated with clean room paint, the flooring was cleanroom compatible,
the incipient fire detection system installed, and the air handler
ductwork was sealed to prevent shedding. It was beautiful and still
is today. An outside contractor with expertise in cleanroom construction
built the cleanroom inside of the shell room. The walls, raised floor,
and ceiling were assembled from pre-made struts and panels. The Genesis
cleanroom consisted of total ceiling coverage with ULPA fan filter
units. There were 55 FFUs [fan filter units] all hung from the bottom
deck of the Lunar Lab. This was a creative solution from the contractor
to save space and maximize room size.
We got a fairly large size room in a small space. They knew what they
were doing. Looking back, all that worked well, because we were meeting
with them every day, monitoring the material composition, and explaining
if we had concerns. I’m not sure you could do that on a larger
scale.
Ross-Nazzal:
How big is that room?
Allton: The
lower elevation room is something like 20 feet by 10 feet. The upper
room is 15 feet by 15 feet. There’s a corridor that connects
them on two levels. The original use for the rooms that became Genesis
Lab included a public viewing room and restrooms. These rooms were
dropped down two and a half feet lower to confine any water from the
restrooms and prevent the water from entering lab areas where samples
were handled. This was a wise original decision.
Ross-Nazzal:
That makes sense.
Allton: The
original Lunar Sample Building was well done.
Ross-Nazzal:
You mentioned JPL coming out here. Did you have the opportunity to
go out to JPL or Lockheed at any time?
Allton: I
did not go to JPL or LMA during mission development. One reason is
that I was extremely busy at JSC getting the cleanroom ready. Eileen
participated in meetings at JPL as the principal JSC representative.
I interacted more with JPL, Lockheed Martin, and UTTR in the interval
after launch and getting ready for recovery. What we were going to
do in Utah, and how to get ready for that. There was still more procedures
that needed to be written. How did we want to document the handling
environment at UTTR, witness plates, etc.? What was the process of
retrieving the payload and the sample return capsule?
Genesis sample return capsule was scheduled to re-enter at UTTR at
10 a.m., September 8, 2004. The recovery plan called for a mid-air
retrieval of the capsule. After the parachute was deployed, slowing
down the descent, the parachute was to be snagged using a hook towed
by a helicopter. The helicopter pilot was to snag the parachute, set
it gently on the ground to secure it, and then fly the SRC to a clean
room that we had set up nearby at UTTR. That cleanroom operated with
a few HEPA FFUs and did not have a raised floor, so it was not the
level of cleanliness in the JSC Genesis Lab. This cleanroom was placed
at UTTR in order to saw open the SRC and put a nitrogen purge on the
closed payload canister. Then the payload would go into a shipping
box connected to a nitrogen cylinder. It would be transported under
nitrogen purge all the way back to Houston, and only be opened when
again back in the JSC clean room.
Ross-Nazzal:
Didn’t quite work.
Allton: No
it did not. That’s not what happened.
Ross-Nazzal:
Did you all come up with that idea of that helicopter coming in and
making that grab?
Allton: The
Lockheed engineers had an interest and the right connections to work
out the mid-air retrieval. Bob Corwin was the LMA lead engineer for
the mid-air retrieval effort. He and some of the UTTR personnel had
been fascinated with snagging stuff coming back from space, and there
was military precedent for that with round parachutes. The parafoil,
or gliding parachute, invented in 1967, offered a much safer and more
reliable alternative. The right connection for Bob Corwin was Roy
A. Haggard, who invented the flyby intercept method for military application
in the early 1990s. Those two became good friends and evangelists
for mid-air retrieval for Genesis. By the time I was involved in the
UTTR portion of the recovery planning, the mid-air retrieval had been
demonstrated many times, and it did look easy, due to the great skill
of the pilots.
Cliff [Clifford T.] Fleming was a movie stunt pilot. He was a military
veteran from, I think, probably Vietnam. We did get to watch them
practice that. They never ever missed. It was so graceful; it was
like a ballet in the sky. You’d think a re-entering spacecraft
would be traveling a high velocity, so snagging that spacecraft parachute
with a hook is going to be very hard to do. However, when the parafoil
is deployed it slows down the capsule putting it into a big spiral,
going about 20 miles an hour. So the prime helicopter and the backup
helicopter both had several chances to make the snag, if missed. They
never did miss.
The doors to the helicopter were removed so the crew could operate
a winch from the “back seat.” Cliff would lean out the
window to get a good view of the target. He placed the hook just left
of the centerline to make the snag. That would keep the parachute
from flopping around. They practiced setting the SRC gently on the
ground. But before the SRC was set down, the backup helicopter would
first set out a clean tarp, to keep the SRC touching the dry lakebed.
This interim set down, close to the snag site, was for the purpose
of securing the SRC to the helicopter tow line. Then the SRC was towed
to the cleanroom entry area and lowered into a cradle. Cliff could
set the SRC down so gently in the practice runs. I just couldn’t
believe it.
I could look up and see the helicopter bouncing up and down [demonstrates],
but the payload, the SRC, would be hanging straight and level, carefully
and slowly lowered into the cradle. I do not know how they can do
that, it was amazing, and that’s what they practiced. Of course,
they didn’t get to do that, as it turned out.
Ross-Nazzal:
Were you also practicing simulations in terms of getting the payload,
taking it back, and putting it in the nitrogen purge? Were you doing
any of those things, or were you primarily focused on procedures?
Allton: I
was part of that rehearsal process. After the SRC was placed in the
cradle, the cradle was to be rolled into the high bay. The next step
was to have been sawing the latches open. This is one of those little
“oops” things. There was no other way to open the capsule
because they would have blown the hinge off to make a more aerodynamic
entry. The plan was to take a saw and saw the latches off the outer
capsule, the SRC.
My job was to run the vacuum cleaner with the filter so it could trap
all the particles from sawing. We all had little jobs like that to
rehearse. I think Eileen might have been a backup for the people prepared
to use a sniffer. This was to check that there were no toxic fumes
coming off of the SRC from reentry heating.
Then re-entry day arrived, September 8, 2004, 10 a.m. People at the
Utah Test and Training Range and at Hill Air Force Base [Utah] were
tracking the incoming capsule—they were actually calling out
the altitude and the vector to Cliff and his crew and the second helicopter
crew. They’d call out numbers of the altitude and the vector.
The rest of us were watching this on long-range video, but the pilots
weren’t. All they could do was hear the call out.
The altitude numbers seemed to be dropping too fast to Roy [A.] Haggard
who was in the cockpit with Cliff Fleming. Roy was uneasy. Then Range
Control Officer Luke Topper at Hill Air Force Base said, “Impact.”
Cliff couldn’t believe it. He asked Luke to repeat that.
Ross-Nazzal:
What was the mood like in the room watching the video at that point?
Allton: I
watched the re-entry sequence in the high bay of the building (Building
1112) at Dugway next to the cleanroom set up to receive the SRC. I
was watching with the crew from JSC, LMA, and JPL who were prepared
to open the SRC and, inside the cleanroom, put the nitrogen purge
on the sample canister. We watched the capsule tumble downward and
smack into the dry lakebed. Our heads turned toward the storage cabinets
where we had placed kits for collecting shards off the desert floor,
if the recovery did not go as planned. We were already looking at
the cabinets, wanting to get the collecting kits, and go to the crash
site to recover the collectors. These kits were buckets with pre-numbered
containers, mostly bags, gloves, tweezers for cleanly picking up shards,
but also included a camera, scale bar, and notebooks.
Ross-Nazzal:
So you had worked on those contingency plans just in case?
Allton: Yes,
I brought terrain maps in case we needed them, but the people at Hill
Air Force Base, they had their own maps too. I had written a documentation
plan, which contained a section on documenting samples collected under
this unhappy circumstance of scattered shards. Yes, we were ready
for that. I’m not sure all the managers were ready for us to
go out there. It took a while for that to settle out, and we workers
had to obtain permission to go to the site and start recovering material.
Ross-Nazzal:
Oh, really? Why was that the case, do you think?
Allton: I’m
not sure.
Ross-Nazzal:
I’m sure as a scientist you were ready to get out there.
Allton: We
knew what we wanted to do. I guess they wanted to double-check everything,
which I thought would have been done already. I am sure those discussions
were interesting.
Ross-Nazzal:
How did you go out and capture this material? Did you have to suit
up? Or you could just go out dressed as we are today?
Allton: We
were dressed very casually because it was hot, and we expected to
be working in the cleanroom covered with smocks, hats, gloves, and
shoe covers. The team that went to the crash site to recover the science
canister and contents consisted of personnel from LMA, who designed
the SRC, JPL, who designed the payload, and one person, Karen [N.]
McNamara, from JSC representing curation. The field people were the
people who knew the hardware best, and Karen served to instruct everyone
the best way to recover and document the samples. The field team was
in contact with Don Burnett and Genesis managers via radio to collaborate
on decisions regarding the salvage operation.
The field team rode to the crash site in vans. The UTTR road floats
on the mud, and the capsule landed not that far off the road. McNamara
had the collecting kits and instructed the field team members in how
to document the collector pieces gathered at the crash site. The Lockheed
people had to safe the pyros [pyrotechnics] that were not yet exploded.
These pyros should have deployed the parachute. LMA people had to
do sniffing tests for toxic gases and get a safety clearance.
The SRC capsule had hit the ground “edge on,” like a dinner
plate one third buried. Even though the lakebed was moist, and thus
soft, the buried part of the SRC shell was mostly turned to powder.
The field team started taking the outer capsule apart. Those of us
near the cleanroom watched the fieldwork on long range video provided
by UTTR. The canister containing the collectors was itself breached,
it was broken. The bottom had been sheared off. After consultation
with PI Burnett and Curation Manager Eileen Stansbery by radio, it
was decided to roll the canister over onto a blue tarp, topside down
because the canister cover was still intact. This configuration captured
most of the collector fragments. It was overwrapped in a second tarp,
put aboard an Army Blackhawk helicopter, and flown back to the building
with the cleanroom. The big black helicopter was larger than Cliff’s
little red one. I was in the cleanroom area when the Blackhawk arrived
with tarp-wrapped canister, before sunset.
Ross-Nazzal:
How long did that process take?
Allton: The
field team had to wait a couple hours before they actually started
picking up collector pieces—and they were still on long-range
video, so we could watch them. The Army took out meals ready to eat
for them to eat and water. It was hot out there on the dry lakebed.
The Army folks knew what to do to help the recovery team. How long
did that take? I’m thinking it was late afternoon by the time
they got back to Building 1112, where the cleanroom was set up. The
tarp-wrapped canister was rolled in. Over the next few hours there
was some discussion as to whether the wrapped canister should be transported
back to Houston for extraction of the individual collector pieces
or whether to extract, photograph, and package the individual pieces
at UTTR.
The decision was the loose pieces would get more damaged in transport
unless they were stabilized. So that’s what we did. We obtained
tools for de-constructing the damaged canister so the collectors were
accessible. We already had with us containers for 6,000 specimens.
Our curation colleagues from Johnson Space Center arrived to document
and package fragments. All of them were skilled in cleanroom work
and handling astromaterial samples, so no on-the-job training was
needed!
That was September 8, 2004, when Genesis reentered and had a “hard
landing.” Always a public affairs term. October 3, which was
less than a month later, we flew everything back to Houston on the
Gulfstream III and had all the samples in a cleanroom receiving area
by afternoon. We spent that month in Utah picking fragments from the
damaged canister, photographing, logging the individual pieces, and
packaging collector pieces and hardware pieces. Some of the hardware
pieces of the outer capsule went to Lockheed Martin first for use
by the mishap investigation board. That was a separate activity, and
Karen McNamara was the curation representative to that board. All
the solar collectors and the payload canister came directly to JSC.
While we were in Utah, we photographed and packaged more than 10,000
pieces from the original 301. Some of those were jars of very tiny
fragments. Pick a number, it could be 15,000, 20,000. I think we really
got every collector fragment. The impact site ground was damp and
soft. The outer capsule was about 60 inches across. It hit edge on,
so the half portion that buried was destroyed, even though the impact
area was quite small, maybe 3 diameters of the capsule. Karen McNamara
and some of the Lockheed people went back a second day and actually
shoveled up 15 to 20 buckets of sand containing debris. So, I really
think we got nearly everything from the spacecraft. We went through
some of those buckets recently. We got rid of the mud.
Ross-Nazzal:
Did you find anything in the dirt?
Allton: Yes,
a lot of it was not too useful. Then there were some collector fragments
we pulled from the mud, which had been sitting in wet mud for 10 years
or so. So we salvaged some of that, but we did finally discard some
of the mud and crash debris that we had saved.
We do have samples of lakebed sediments that were taken right before
re-entry, which serves as reference material. We still have those.
People have asked for samples of the Utah dirt, because they’re
trying to distinguish between Utah dirt and solar wind. They have
a basis for making that distinction. We do have those kind of samples.
Curation-wise, we keep samples of reference materials, that would
be anything that might contaminate the collectors.
Ross-Nazzal:
What did you package everything in? Did you package it in plastic
or glass?
Allton: Pretty
much plastic. We did have some glass jars. We used a lot of plastic
vials, because that’s what’s used with some lunar samples
that have been returned. Our cleaning process for hardware at JSC
uses ultrapure water. Lots of plastic vials are cleaned to a high
level of cleanliness and packaged. Since we are able to produce a
lot of those, we sent several thousand vials to UTTR ahead of time.
We also could call our JSC colleagues and ask for additional supplies
to be sent to UTTR. The wonders of the government credit card! The
whole JSC team was very responsive. Everybody said, “What can
I do to help?” We’d call JSC and say, “We need this,
this, and this.” It would show up the next day in a FedEx [Corp.]
truck. At first I was wondering if FedEx delivered packages to the
Utah Test and Training Range which is relatively remote, and I found
out they do deliver there very promptly. We received clean packaging
supplies this way.
Same way with JPL. They needed different tools and hardware because
their job was disassembling the mangled mess of the science canister.
First thing they did, was drive to Home Depot [Inc.] in Salt Lake
City. One tool they purchased was a large bolt cutter. I too went
to Salt Lake City to the restaurant supply place and Sam’s Club
for things that we still needed more of like stainless steel tables.
The JPL engineers could call back to JPL and say, “I need X.”
Everybody was sending things we needed, delivered the very next day.
With a government credit card, a telephone, and FedEx, we got everything
that we needed.
A side note here on an image that remains in my mind. UTTR is isolated
and the nearest cell phone tower, at that time, was atop Deseret Peak
30 miles distant, for which we had line of sight from the parking
lot. Cell phones were not ubiquitous. To make those phone calls to
request supplies, one had to stand in the parking lot. At any given
time, 4-5 people would be in the parking lot with a phone to their
ear, spread out for privacy, and trying to write using a knee for
a table. Even the science team from around the world offered encouragement
and help. Many of them emailed, said, “We’re going to
do our best to make this analysis.” This encouragement was from
investigators who had invested 5 to 10 years preparing for this mission.
Ross-Nazzal:
Were you originally planning on taking the Gulfstream back with these
samples, or were you going to fly commercial?
Allton: Had
the crash not happened, the science canister was to be placed on nitrogen
purge and shipped in a large metal crate equipped with a nitrogen
cylinder. I think it was going to go by truck but maybe cargo plane.
By October 3rd we had all of the collector pieces and canister hardware
packed for transport in metal cases. The managers requested the Gulfstream
as a “gentle” transport to keep from further damaging
the collectors. Carol [M.] Schwarz and I were selected to escort those
samples, and of course we agreed! It was my first ride in the Gulfstream.
Ross-Nazzal:
How did you get the Gulfstream? That’s a unique opportunity.
Not everyone gets to fly on that plane.
Allton: It
was partly a perk for having stayed out there over a month and working
long hours.
Ross-Nazzal:
It’s just for Center leadership, isn’t it, pretty much,
the Gulfstream? At least it seems like it.
Allton: I
think we had an astronaut pilot.
Ross-Nazzal:
Oh, cool.
Allton: It
was cool.
Ross-Nazzal:
What was the reception like here when you finally came back? The Building
31 crew and then the Center as well. Do you remember?
Allton: I
remember we landed in a horrid rainstorm at Ellington [Airport, Houston,
Texas]. Then we just unloaded the plane, and it must have been vans.
I cannot remember that. It was a short trip from Ellington. We had
a clean room we had set up for space-exposed hardware, so that’s
where we put the boxes that we had unloaded from the Gulfstream at
Ellington. Then a portion of those were moved into Genesis Lab.
Lisa [A.] Fletcher (now Lisa Pace) had done an excellent job of logging
thousands of samples in Utah. We had prenumbered tags with all these
vials. We had a numbering system set up ahead of time for all this,
so we had all these numbers to put on clean vials and whatever we
put stuff in. All that was in a database, it was all logged in there
in Utah, so we could check it out when we got back.
Ross-Nazzal:
What did you start when you came back? Were you immediately cataloging
or curating?
Allton: I’m
going to digress here a little bit. If things had gone perfectly,
some of us would have had to fly back and stay up all night cleaning
more tools to get ready for examination and storage of samples, because
there was just too much to do.
The landing changed all that, so we didn’t have to do those
special examinations of complete hexagons. It gave us a little time
to think about it. We got samples into a dry nitrogen environment,
for the most part, and we already had a database set up, with our
numbering scheme, but now we had a little bit different data problem.
We had some things like that to work out.
We got the samples back here in the JSC lab in October. We wrote some
abstracts announcing the condition of the collection that were submitted
in January, so that was part of it. I think the one I did was based
a lot on notes we took in Utah. We were able to announce that we had
samples for scientists to request before the Lunar and Planetary Science
Conference [LPSC] in 2005.
Ross-Nazzal:
That quickly?
Allton: Yes.
Now some of the experiments were for certain PIs. One of them had
flown gold foil to look for nitrogen, another one flew a polished
aluminum piece to look at noble gases. So we subdivided those materials
in time for the abstracts that year. That’s what we would have
been doing in the November, December timeframe.
For instance, Alex [Alexander P.] Meshik came from Washington University
[St. Louis, Missouri] to JSC, and we cut the polished aluminum up.
He took some pieces back to his laboratory. We cut the gold foil—that
might have been a little bit later, the timing on that. But we did
announce it, I think, at the end of February and before LPSC of that
year. In April, the LANL concentrator team came to JSC and we finished
removing the concentrator target quadrants from the mounting. This
included the silicon carbide target in which the oxygen isotopes were
determined. In 2007, we sent that sample to Kevin [D.] McKeegan at
UCLA [University of California, Los Angeles], who did the analysis,
and presented preliminary results at LPSC in 2009.
Ross-Nazzal:
Tell me how you handle the samples. I’ve been in 31, and you
see the glove boxes and handling. Do you have something similar for
these samples, or are they just out on tables?
Allton: The
samples are stored in nitrogen-purged cabinets within the Class 10
cleanroom where we also work on the samples. When we image or subdivide
the samples, this work is done on stainless tables within the room.
The samples have been exposed to Earth atmosphere when the canister
broke open, but they’re stored under dry nitrogen. People are
fully suited up, and the tools that are used are cleaned with ultrapure
water.
We’ve developed the capability to take those pieces that have
fine debris on them and wash them with ultrapure water. We can wash
away the loose micron, submicron size particles, and that helps people
with their analyses. We don’t clean samples routinely, because
there is a worry that the water might change something.
The analyses so far—when they use beam instruments to measure
solar wind—seem to indicate that that cleaning with ultrapure
water does not do much damage, and it is more beneficial. But that
would be the call of the person who wants to make the analysis if
he would like us to clean them off with the water, so we can do that.
I guess one difference with Genesis—part of the science team
has helped try and figure out how to clean these things. We send samples
back and forth to people who might have a cleaning proposal for a
protocol to try. We do have numerous small pieces that can be used
for that purpose. It’s probably a good use of those pieces.
The oversight committee is aware of all this and keeps tabs on how
this is done.
For UPW cleaning of samples, picture the room: stainless steel table
and stainless steel tweezers. Samples are placed on a little vacuum
chuck and held under megasonically-energized UPW. The sample is spun
at 3,000 rpm [revolutions per minute] under the flowing water. It’s
a semiconductor device that we adapted for cleaning off these small
parts.
Ross-Nazzal:
How does that work so you don’t get rid of those small grains
of that solar wind?
Allton: The
atoms of the solar wind hit the collectors with such high energy they’re
implanted a little below the surface, say under 100 nanometers (nm).
The peak might be 40 nm deep or 20, which isn’t very much. Chemical
changes on the surface from cleaning might affect atoms at that shallow
depth, so care must be taken. Plus, dings or scratches from the crash
debris can be deeper than the solar wind.
We’re lucky in that a lot of the analytical techniques use an
ion beam to drill into the collector, knocking off solar atoms that
can be measured in a mass spec [spectrometer]. The area analyzed this
way is quite small, less than 100 microns wide. Therefore, the analyst
can pick a location on the fragment without scratches or gouges. Even
so there are problems if there’s contamination on the top surface.
The ion beam can garden the contaminant further into the surface.
Investigators found a clever way around this problem. The collector
fragment is glued face down (solar wind side down), and the ion beam
analysis is performed from the back side, thereby measuring the solar
wind before the contaminant is encountered. Investigators are getting
more successful at that. This example illustrates a very important
advantage of returning samples to Earth for analysis—many more
options for recovering from disaster, like crashes or malfunctions.
Ross-Nazzal:
How many of the samples have been used? Are there some like the Apollo
rocks that have been set aside and will remain pristine for generations
to come?
Allton: I’d
like to acknowledge that setting aside portions of Apollo samples
for future generations was a very wise thing to do. All of the astromaterial
collections do this, generally by choosing a portion to be set aside,
stored sealed under nitrogen, and a subset stored in a remote place.
A year or two after sample return, about 2006, representative samples
for each solar wind regime and each array collector material were
preserved in a vault in a remote location from JSC. For the samples
remaining as JSC, Genesis has a complicated sample retention plan
that allows the portions to be retained recalculated periodically,
based on the idea that these samples may have a shelf life, which
is unknown. The solar wind atoms are embedded in the crystal structure
of the collector. They could diffuse out with long periods of time.
Fifteen different materials were flown to collect solar wind. The
materials on the passive collector arrays, flown as hexagonal shapes
polished like mirrors—very beautiful—were mostly pure
silicon. Others were diamond on silicon, sapphire, aluminum on sapphire,
gold on sapphire, silicon on sapphire and germanium. These 300 hexagons
were distributed over 5 arrays. Two of these arrays collected solar
wind atoms for the entire exposure time of 27 months. We called those
samples bulk solar wind. The solar wind isn’t constant, but
changes character with time among 3 conditions, or regimes, as distinguished
by the Genesis spacecraft: interstream slow speed, high speed, or
coronal mass ejections (CME). The CMEs are sporadic burps of material.
Because of the suggestions, and perhaps insistence, to Don Burnett
by Marcia Neugebauer during the very early mission concept discussions,
the Genesis spacecraft was designed to capture separately these 3
regimes on individual arrays.
The separate arrays for each regime allows investigators to measure
differences in chemical and isotopic composition and fluence among
solar wind regimes. The deployment of the regime arrays was mutually
exclusive, and each regime collected solar wind for roughly one third
of the total exposure. Had Genesis not crashed, the identification
of the regime hexagon collectors would have been straightforward.
Because of the crash, what we recovered was a jumble of fragments
dislodged from the array frames. However, we can tell from which regime
for each fragment because of clever planning. Bulk solar wind collectors
are all 700 microns thick. Coronal mass ejections are 650 microns
thick, high speed 600, low speed 550. So we just take a little tiny
fragment and measure how thick it is, then we know which regime of
the solar wind. Eileen Stansbery and Andy Stone deserve credit for
implementing this mission saving idea.
The concentrator’s target samples would be those that would
be most judiciously saved for people that can make the very best measurements
on it. There’s one piece of silicon carbide from which UCLA
determined the solar oxygen isotopes. Subsequently that same sample
piece was sent to Bernard Marty in France [Centre de Recherches Pétrographiques
et Géochimiques, Nancy Université], who measured the
nitrogen isotopes. Neon isotopes were measured by a Swiss team. Much
science was accomplished by sequentially sharing the sample among
several research teams. Each team made their own little ion beam holes,
resulting in a sample appearance with a many small square shallow
pits. Sharing is another alternative to subdividing samples.
Ross-Nazzal:
Who makes the decision on who gets the samples? Is there a committee?
You mentioned an oversight committee. Are you part of that team?
Allton: The
request for Genesis research samples comes to me as curator. I acknowledge
receipt of the request and pass it along to the Genesis subcommittee
of CAPTEM (Curation and Planning Team for Extraterrestrial Materials),
a sample science advisory committee for NASA. The Genesis subcommittee
is composed of active or emeritus Genesis scientists, and I provide
to them information about sample availability. They render a finding
about the scientific merit and recommendation about allocating sample,
which I forward to the program scientists at NASA Headquarters [Washington,
DC] for concurrence. As curator, I’m allowed to make a few direct
allocations of small samples for cleaning studies. That’s just
to speed things up. The overarching goal of this review process is
to assure good science use of samples and fair access among researchers.
The Genesis sample allocation process is less formal than the larger
collections like Apollo and Antarctic meteorites, because it involves
ongoing review via email or telecon, which includes conversational
exchanges between curator and requestor to clarify information. In
contrast, the larger collections have review committees that meet
face-to-face twice a year and catalogs of samples from which the investigator
requests a specific sample. A Genesis investigator typically requests
a specific material from a specific regime for which the curator searches
for sample candidates for discussion.
Ross-Nazzal:
What have we learned from Genesis? Have there been any big questions
answered?
Allton: Let
me start by saying that Genesis mission highest priority science goal
was determination of the oxygen isotopic composition of the Sun, and
that was achieved. The general science goal was to determine the precise
composition of the solar nebula—the gas and dust that coalesced
into the Sun and planets, with the Sun retaining more than 99% of
the original starting material. Until Genesis, the composition of
the solar nebula was measured by precision analyses of primitive,
first-formed minerals found in oldest meteorites and assuming this
was original composition of the solar nebula. Genesis people contended
that the best measurement of the starting material for the Sun and
planets would be obtained directly analyzing solar material in the
best laboratories on Earth; hence, the Genesis spacecraft set out
to capture solar material and return it to Earth. The oxygen isotopic
composition was surprising because it was not like the Earth’s,
lending support, along with Stardust cometary analysis, to a more
turbulent history in the early solar system.
Until now, people were concentrating on bulk solar wind analysis because
there’s more solar wind available to measure in these samples.
The newest thing is people looking at regime samples. It turns out
in 2003, at the end of October, they had a whopping series of coronal
mass ejections [CME] over a few days. In fact, the CME energy went
off scale from some of the other robotic spacecraft that detect these
things, causing some to go into “safe” mode. Genesis just
happened to have a coronal mass ejection array out which captured
this big, energetic burp of solar material. These energetic CMEs became
known as the Halloween storms, and Genesis has samples of this solar
material that can be measured in the laboratory.
I’m optimistic that somehow we’ll make more connections
with the heliophysicists because solar atoms captured in the different
Genesis regime samples should contribute to ideas about mechanisms
for how the Sun operates. That wasn’t really the primary purpose
of Genesis mission. Genesis was for planetary science. However, Genesis
data may also help solar physics people of this generation, like those
using Parker Solar Probe data, perhaps.
Marcia Neugebauer, heliophysicist at JPL and early Suess-Urey/Genesis
mission contributor, was the first person to use Mariner [Program]
data to make solar wind measurements. I think it was Marcia that convinced
Don Burnett that he needed to take the solar wind regimes as separate
samples. It didn’t seem to be that much of an add-on for design
of the mechanisms, because altogether Genesis had very simple mechanisms.
People worry about reliability of robotic missions, and this was a
fairly simple spacecraft. All those mechanisms worked well in flight.
Ross-Nazzal:
I had forgotten to ask you. Did you go out and see the launch at the
Cape [Canaveral, Florida]? Did you get a chance to see that?
Allton: I
went to the Cape to see it launch, but we didn’t launch that
day, or the next, and I came home. Eileen was the only one from our
team who stayed the rest of the week.
Ross-Nazzal:
That’s disappointing.
Allton: We
hustled to get Genesis out the door to Denver, so it could be integrated
onto the spacecraft in August of 2000. Then we had to sit and wait
a whole year, because there was a Mars launch of some kind that needed
that launch window.
Ross-Nazzal:
Hurry up and wait, I guess.
Allton: Hurry
up and wait.
Ross-Nazzal:
How many people are working in the lab these days?
Allton: There’s
two people that we call processors that work with the samples, and
they’re doing inventory as we speak.
Ross-Nazzal:
That sounds like fun. What do you think your biggest challenge is
working with the Genesis Program, from the time you started working
on the contamination control plan until today? Do you have any major
challenges?
Allton: I
have to say, I think we all had it lucky. The team worked well together.
When I look at other missions and other teams—Don Burnett is
the principal reason for this. He still holds a meeting every year
of the people who are interested in working on Genesis samples. Many
of the people that come are back from the original team. He refers
to the team as family. In recovering from the crash, he asked people
to collaborate who might normally be competing. They did. One, because
they respected Don, and two, they wanted to help salvage the mission
science. And I’m beginning to see that it’s unusual for
relationships to work that well.
The annual gathering of the science team family is about 40 researchers
today. In the 8-10 years after sample return, the team photos show
about 80 people. Don once estimated 100 scientists have participated
on the science team. There were strong bonds of friendship among the
engineers, scientists, and curators that outlasted the mission status
of Genesis.
On the 5th anniversary of sample return, about 20 people—many
were technicians who helped salvage the samples from the desert floor—made
a pilgrimage to UTTR to set a steel obelisk bearing the name “Genesis”
and “September 8, 2004” to mark the landing spot. Inside
the obelisk a time capsule was placed. The contents are mission documents
and procedures, including a video of mid-air retrieval practice. JPL
Genesis Project Manager Don Sweetnam personally commissioned the making
of the marker. Now retired, Don Sweetnam still follows the Genesis
science results.
Ross-Nazzal:
You attribute that to Don? Or were there other factors?
Allton: Mostly
to Don.
Ross-Nazzal:
Probably holds a special place in your heart then.
Allton: Yes.
Ross-Nazzal:
What do you think was your most significant contribution to the Genesis
Program?
Allton: I
guess overall I’m kind of a stickler for looking at the composition
of everything that goes into the lab and checking it. But I could
say they kind of hold me responsible for having them send 6,000 containers
to Utah, just in case.
Ross-Nazzal:
Were you a Girl Scout? That was good contingency planning on your
part.
Allton: Yes,
we ran that one out as much as we could ahead of time.
Ross-Nazzal:
I think that we have exhausted my questions. I wasn’t sure—might
there be something else that you want to talk about in relation to
Genesis?
Allton: No,
because we touched on the future, and I’m hoping that solar
physics people, that we can be of service to them. I don’t know
at what rate samples ought to be used up. I come from a background
of being extremely stingy with samples from lunar days, but I also
realize that these samples may not always be perfect.
Ross-Nazzal:
Yes, that’s important to know. Thank you so much for coming
over today, I really appreciate it.
[End
of interview]