> 31 May 2000

[Recent Past Launches (FY98 or after)]{.underline}

# Intense wind shears and instabilities near 100 km

Using rocket-borne TMA trails, intense wind velocities and shears have
been observed near 100 km altitude at mid-latitudes. This discovery
could only be made with rocket-borne probes and are believed to
represent a common (and still unexplained) feature of the Earth's
atmosphere.

Furthermore, the shears have been shown to be unstable to the
Kelvin-Helmholtz instability and thus resolve a decade-long puzzle of
the mysterious "quasi-periodic" (QP) echoes observed by a growing
international contingency of ionospheric radars. Near-simultaneous
launches of two NASA rockets from Wallops Island in the summer, 1999,
during the presence of intense QP radar echoes revealed wind shears and
km-scale electric field waves emanating from the wind shear region.
Combined with the radar data, the measurements clearly demonstrate the
causality associated with this phenomena.

Intense wind shears at 100 km (near the base of the thermosphere) have
heretofore been obscured from satellite measurements due to their very
sharp gradients with respect to altitude. It is believed that both the
intensity of the mid-latitude winds (far in excess of those predicted by
tides) and their accompanying shears represent fundamental new physics
of the Earth's atmosphere and may indeed be present in the atmospheres
of other planets as well.

## "Nano-sat" micro-magnetometers demonstrated at 1000 km

An array of nano-sat "micro-magnetometers" have been successfully
deployed from a sounding rocket which reached an apogee of approximately
1000 km. The hockey-puck sized payloads, built by JPL and the University
of New Hampshire, all successfully transmitted their data to the ground
receiver at Poker Flat, Alaska.

Launched during an active aurora, the simultaneous measurements provide
unprecedented data concerning field-aligned currents and their gradients
in a space plasma.

The experiment provides invaluable nano-sat prototype and tracking
experience for NASA's upcoming ST5 Nano-Sat Constellation in the outer
magnetosphere.

Particle (droplet) size distributions and electrical environment of
Noctilucent Clouds measured

NASA sounding rockets launched from Norway in the summer, 1999, gathered
definitive measurements of the particle size distributions within
noctilucent clouds for the first time. The cloud layers were observed
near 83 km. Additionally, the charged particle environment and
fluctuating electric fields were also measured coincident with
observations of intense backscatter radar echoes emanating from the
region.

Seeded by hydrated ions, charged aerosols, and dust, such layers are
created at the Earth's summer mesopause near 81-85 km where the
temperature is sufficiently low such that ice particles form, creating
noctilucent clouds, the highest clouds on Earth.

The experiments represent comprehensive measurements within Nature's
most accessible and predictable region of "dusty plasmas". In many ways
behaving as a new state of matter, such dusty plasmas are believed to
occur elsewhere in the solar system, for example on Mars, where violent
wind storms and the lower gravitational field may routinely mix charged
dust with the lower ionosphere on planetary scales.

First rocket measurements in the dark cusp reveal solar wind driving of
the dayside ionosphere.

NASA launched two sounding rockets from Spitzbergen, Norway into the
dark, dayside cusp in December 1997, a region that permits direct entry
of solar wind particles and fields into the Earth's ionosphere and upper
atmosphere.

Because the rocket payloads travel at very slow speeds and hence dwell
in one location, the solar wind forcing of the cusp ionosphere
electrodynamics was determined for the first time. The payloads also
gathered vertical profiles of the electric fields and particles in the
cusp ionosphere during both IMF Bz North and South conditions.

The permanent Spitzbergen rocket range was established by the Norwegian
Space Centre specifically to carry out investigations of the Earth's
cusps and polar upper atmosphere regions.

Canadian/US sounding rocket tests new electro-optical detection of
charged particles.

In a joint cooperative program between Canada and the United States, a
rocket was launched to 1000 km in the aurora from Poker Flat, Alaska, in
February, 2000, to image the low energy "core" plasma for the first
time. Whereas previous instruments may only image the high energy tail
of the particle distributions, the University of Calgary designed a
combined phosphorous screen/micro channel plate, 360 degree particle
detector to image core electrons in the 0-10 eV range and suprathermal
ions that include suprathermal heating up to 50 eV. The detector uses
fibre optic cables and a 1 meter boom to avoid adverse effects of
payload charging. The experiment will be flown again on a NASA payload
in FY02 and has been included on at least one proposed NASA SMEX
satellite.

**Sudden Atom Layers near 90 km probed with rocket probes.**

Ground-based optical data at mid-latitudes have revealed the startling
yet frequently recurring phenomena of abrupt sodium atom layers that
"suddenly" appear near 90 km altitude. In February, 1998, a NASA
sounding rocket successfully pierced such a layer using instruments at
the Arecibo Observatory in Puerto Rico to determine the launch
conditions. The in-situ data provide information on the sodium
concentrations and the various mechanisms believed to create the layers.

[Upcoming Launches (FY00 or after)]{.underline}

# Ionospheric effects above an active thunderstorm

A sounding rocket will be launched to measure electric fields and
related transient phenomena above an active thunderstorm from Wallops
Island. The experiment promises to reveal the amount of energy deposited
in the ionosphere as a function of altitude above the thunderstorm and
to determine the effects on the charged particle environment created by
the upwards-propagating electromagnetic energy. The data promise to
reveal ionospheric effects resulting from the discharges that may also
be at work in the upper atmospheres of planets such as Venus and
Jupiter.

# Dusty plasmas to be explored with an array of mini-payloads

A series of small "dart-like" payloads of only 7 cm (2.8 inches)
diameter will carry miniaturized instruments to altitudes of
approximately 100 km to explore dusty plasmas in the earth's mesophere.

High altitude rocket will explore the dayside aurora and its relation to
the cusp and boundary layer

A NASA sounding rocket will be launched into the dark, dayside cusp from
Spitzbergen, Norway (geographic latitude 79 degrees) in December, 2001,
to explore the causes of the dayside cusp aurora and to distinguish
between local processes inherent to the cusp acceleration region and
particles and fields that are injected in the cusp from the solar wind.
The payload will also gather measurements across the cusp-boundary layer
interface in order to explore the electrodynamics and resulting particle
acceleration that are associated with both open and closed magnetic
field lines. Because of the rocket's low vehicle speed and its vertical
motion up along the magnetic field direction, the payload will linger in
the cusp for \~10 minutes, thus investigating for the first time long
period pulsations and other unique characteristics of the dayside
aurora.

The payload includes instruments provided by institutions in Canada,
France, and Norway.