Monday, August 29, 2011

Wanted - New small satellite launch vehicles

Tuesday, August 16, 2011

Japan plans more amazing microsatellites - Part 2

Professor Kazuya Yoshida is in charge of the Space Robotics Laboratory
at Tohoku University's Department of Aerospace
Engineering. He and
Professor Yukihiro Takahashi of Hokkaido University's Department of
Cosmosciences began working
together almost a decade ago on the development
of microsatellites for science missions. Prof. Takahashi played a major role in
selecting scientific missions and served as science mission coordinator for the
"RISING" series of microsatellites, among other things, while he was at
Tohoku University, too. These two partners formed a team from the Graduate
School of Engineering and the Graduate School of Science.

The "RISING" (Sprite-Sat) microsatellite was successfully launched into a
670 km high, sun-synchronous orbit in January, 2009. It went up as a piggyback
payload aboard a Japanese H-IIA launch vehicle. RISING is about 50 x 50 x 50 cm,
and weighs about 45 kg.

 "RISING" is derived from RAIJIN, the god of thunder and lightning in
Japanese mythology, for reasons that will become obvious in a moment.

 "The goal of this satellite is to establish key
technologies for a
university-based, 50kg-class of micro-satellites and to conduct
scientific observation of 'sprites' which are a type of Transient
Luminous Event (TLE) observed in the middle atmosphere. TLE's were
first discovered in 1989, and they typically occur at an altitude of
40 km to 90 km," said Prof. Yoshida. "It is considered that large scale
thunderstorms are capable of producing such luminous events over the
clouds, but a true mechanism is still under the veil."

Prof. Takahashi added that in order to clarify the mechanism of TLEs,
observing horizontal structures of TLEs is considered to be essential. 

"RISING and RISING-2 carry two cameras with different filters to
capture the TLEs in the direction of their nadirs. Other satellite
projects are proceeding which use the same type of imagers such as
ESA, and FORMOSAT-5 in Taiwan. Also, our
Japanese team has just completed the fabrication of the Global
Lightning and SprIte Measurements (GLIMS / JEM-EF or GLIMS / ISS)
experiment which will be installed soon on the Japanese Experiment
Module - Exposed Facility attached to the International Space Station,"
said Prof. Takahashi.

 GLIMS is scheduled to be launched this winter.

One of the major advantages of microsatellites in general is their
relatively quick turnaround time or development to launch cycle. 

"RISING was the first microsatellite to be launched (for the purpose
described above). Even GLIMS, whose development is based entirely on
the heritage of RISING, emerged earlier than the other missions," said
Prof. Takahashi.


Prof. Yoshida emphasizes that while RISING has experienced a crippling
blow as a result of a failed power control system, the engineering
verification of the key technologies for future microsatellites was
otherwise almost a complete success.

"The spacecraft is alive and in orbit now, but more than 930 days after
the launch, no scientific observations have been conducted yet due to
the problem caused by the power failure," said Prof. Yoshida.

RISING-2 is the exact same size and weight as RISING. Fabrication and
evaluation tests of the engineering model, and verification of the
flight model were finished by May. Evaluation tests and updating of
on-board software are continuing. There is no firm launch date.

RISING-2 features a telescope that is 10cm in diameter and has a 1m
focal length, and it take images with 5m resolution. It can generate
multi-spectrum images using a liquid crystal tunable filter as well as
Red-Green-Blue color photos.

"The primary mission is the observation of cumulonimbus clouds in
visible, near infrared. Also, TLEs in the upper atmosphere such as
sprite are observed using complimentary metal oxide semiconductor -
based sensors," said Prof. Yoshida.

Why would someone study thunderstorms and cumulonimbus clouds - hence
the RAIJIN connection?

"The development mechanism is very difficult to observe and gaining
more knowledge about these clouds, given their important role as
significant carriers of water vapor which is the dominant greenhouse
gas, is vital to increasing our understanding of the dynamics of
climate change," said Prof. Takahashi. "This detailed observation
may be only made possible via a microsatellite that can be operated on
demand by a scientist."

More specifically, this telescope images at any wavelength in
the 650-1050 nanometer range using a liquid crystal filter for the
first time. This enables its operators to measure the absorption line
of water vapor around a thundercloud, which is a result of updrafts
which are essential to thunderstorm activity.

"This telescope can be useful for many other important purposes
including the estimation of carbon fix, and observation of planetary
phenomenon such as
cloud heights and cloud structures on Jupiter, for
example," said Prof. Takahashi.

RISING-2's power control system, which caused such a problem on the
previous satellite, has been much improved to ensure the system's

 "A new 3-axis attitude sensing and control system, including sun
sensors, star trackers, reaction wheels and an on-board computer
dedicated to attitude control, was also developed. This one differs
from the original installed on RISING which relied on passive
gravity-gradient plus active damping control" said Prof Yoshida.

The Rapid International Scientific Experiment Satellite (RISESAT) will
be this team's third 50 kg-class demonstration microsatellite, and it
counted as one of the 5 satellites that will be developed under the
"New-Paradigm of Space Development and Utilization by Nano-Satellite"
program led by Prof. Nakasuka at the University of Tokyo with
support from the Cabinet Office, Government of Japan.

(See the discussion of the"Hodoyoshi" program in Part 1 where RISESAT
was identified as "Hodoyoshi-2")

RISESAT will carry 8 scientific instruments with a total mass of 10 kg
- the preliminary design review was completed recently - developed by
the following countries: Sweden, Czech Republic, Hungary,
Taiwan(China), Vietnam, USA and Germany. These were selected from 17
candidates who responded to the RISESAT open call. The instruments
include a High Precision Telescope, a 3D Magnetometer, a 3D Cosmic
Radiation Sensor, and a Meteor Detector.

The onboard telescope is a successor to the RISING-2 telescope. A
Japanese science team will
support ongoing development, operation and
analysis activities. The main objectives are astronomical  observation
and forestry surveillance in collaboration with the requisite
Taiwanese, Vietnamese and Japanese agencies.

The team's 10 x 10 x 20 cm Cube-Sat called RAIKO weighing 2 kg will be
deployed from the International Space Station next year. RAIKO means a
drum that is carried by RAIJIN. This project is a collaboration with
Wakayama University and the University of Tokyo.

"The mission is a technology demonstration which will verify some
components that will be useful for future micro and nano satellites,"
said Prof. Yoshida.

"Microsatellites in the 50 kg range with dimensions roughly 50 x 50 x
50 cm have a great potential for significant scientific observation and
remote-sensing missions, while Cube-Sats are mostly useful for
technology demonstration and education."

"Today, the commercial and government markets for small satellites in
the 100 kg to 300 kg category are growing rapidly, and in this domain,
some pioneering companies, such as UK-based SSTL, are already
successful," said Prof. Yoshida. "Japan has a chance to be successful
in the markets involving much smaller satellites with a 50 kg maximum
weight. This market is not yet well established commercially."

Japan has always excelled at anything involving miniaturization and
Japan's list of creative breakthroughs in this regard is long indeed.
If it can be made lighter, smaller, and more economically-efficient,
Japan can figure out how to do it. Japan's formidable and agile
knowledge-intensive industrial base plays a fundamental role here.

"The Japanese government is very supportive of this concept and our 3
microsatellites - RISING, RISING-2 and RISESAT - are all funded by
government programs. Development costs range approximately between $USD
1.5 - 3.8 Million. Typical development time is 1.5 to 2 years," said
Prof. Yoshida.

He is excited that these 3 microsatellites are contributing to
breakthroughs in scientific and remote sensing types of applications
such as climate and disaster
monitoring as well as the comprehensive
investigation of carbon circulation mechanisms beginning with the
observation of TLEs, cumulonimbus clouds and thunderstorms.

When exactly will the launches of RISING-2 and RISESAT take place?

"The number of flight opportunities provided by JAXA is very limited.
RISING-2 is now registered by JAXA as a candidate of future launch, but
no suitable launch options for our mission exist prior to 2013," said
Prof. Yoshida. "As for RISESAT, most likely we will use a commercial
launcher such as a Russian Denpr or an Indian PSLV. But to make it
happen we need to obtain the necessary
funds to cover the launch cost,
which is rising steadily these days."

Prof. Yoshida is glad that so many eager researchers from other
countries are now emerging. That said, an intensive search is underway
for partners - especially in SE Asia - for the University International
Formation Mission (UNIFORM) microsatellite project that Japan announced
last year.

Sweden's AAC Microtec provided the on-board avionics technology that
was installed on RISING. And AAC's space plug-and-play avionics
solution will be handling the interfacing of the multiple scientific
instruments aboard RISESAT, too.

Sunday, August 14, 2011

Japan plans more amazing microsatellites - Part 1

Japan has always been regarded as a leader in the field of small
satellite development and operations with considerable expertise in
so-called microsatellites, and even smaller nano-satellites in

Still, Japan held its first "Nano-Satellite
Symposium" only last June.


And important organizations which support related research such as the
"Next generation Space system Technology Research Association" (NESTRA)
and the University Space
Engineering Consortium (UNISEC) are virtually
brand new.



Earlier this month I submitted questions to 3 top Japanese experts
about the work they were undertaking and they were kind enough to
respond promptly.

Part 1 of this post focuses on the work of Professor Shinichi Nakasuka
who is with the Intelligent Space System Laboratory (ISSL) in the
Department of Aeronautics and Astronautics at the University of Tokyo.
He is considered to be a pioneer in microsat and space engineering who
has contributed enormously to development of autonomous / artificially
intelligent space systems. He is also a strong advocate for the
implementation of a shared global Ground Station Network (GSN) to
oversee micro/nanosatellite operations. This project involves
identifying and establishing required functions for the GSN as well as
creating well-defined interfaces and a common architecture.

For readers who do not routinely keep track of these small satellites, I
offer this guide.

Minisatellites weigh between 50 kg to 500 kg

Microsatellites weigh between 20 kg and 50 kg

Nanosatellites weigh between 1kg and 20 kg

Picosatellites weigh between .1 and 1 kg

CubeSats with 1 kg maximum mass can be classified as either large
pico-satellites or small nanosats.

The smallest satellites are so-called femtosatellites which have a mass
of less that 0.1 kg.

Do not be surprised if you find others defining microsatellites as
weighing between 10 kg and 100 kg while designating nanosats as
weighing between 1 kg and 10 kg.

"The Micro-Nano boundary is rather flexble. It depends on the people
involved" said Prof. Nakasuka.

His team at the ISSL built CubeSat XI satellites which were so small -
10x10 cm and 1 kg in total weight - that each was carried in a
briefcase to its launch site at the Plesetsk Cosmodrome in Russia in
2003 and again in 2005.

The pico-satellite known as PRISM - now in orbit- is equipped with a
multi-lens refracting optical system and is capable of
performing high
resolution imagery capture with approximately 30 meters of ground
resolution. PRISM's 80 cm (when extended) tube-like telescoping lens is
mounted on a very tiny spacecraft bus weighing just over 8kg.

Next to be launched from Brazil's Alcantara launch facility aboard
a Ukrainian Cyclone -4 rocket will be the Nano-Japan Astrometry Satellite
Mission for Infrared Exploration (Nano-JASMINE) which is a nano-
satellite built to carry out astrometry - determining the very precise
positions of stars. And that mission will be followed in late 2012 by
"Hodoyoshi-1" which is the first satellite in Japan's new nationwide
"Hodoyoshi" project (2010-2014) involving a broad-based emphasis on
practical outcomes for low-cost micro/nano-satellite development and

Prof. Nakasuka presented a paper in April at the Small Satellite for
Earth Observation Conference in Berlin which outlined what he expects
to take place as the program gets underway. He is
responsible for
setting this joint university - industry program in motion by the way.

Conceptualization and demonstration of a novel
reliability concept -
“Reasonable Reliable Systems" or "Hodoyoshi" in Japanese - which is
suitable for micro/nano-satellites is one objective.

Here are 3 other goals -

- Research and development of all the required components for
micro/nano-satellites with
advanced technologies, aiming for best of
class performance per size.

- Reduction of development time via
innovative satellite development
processes and software tools including standardized interfaces and
ground test procedures.

- Creation of a self-sufficient and all-Japanese micro/nano-satellite
consortium - in effect a robust supply chain network - reinforced by
dedicated user
communities, and intensive human resource training, etc.

Pursuit of ultra-high reliability as required in conventional
governmental satellites is very important too.

"The “Hodoyoshi” concept evaluates cost-reliability relationships to
identify relevant and appropriate
design points which yield the highest degree of reliability per cost.
The incredible miniaturization of space components and systems now
underway separates small let alone tiny satellites from conventional
mid-sized or large satellites. Vastly different operating
characteristics come into play based on the satellite's size and the
power levels involved. More innovative subsystem design concepts are
needed, and this program encourages the development of an innovative
concept for each component via large scale, multi-player collaboration.

Hodoyoshi-1 will be used for remote sensing and earth observation,
introducing an innovative design concept for the satellite itself and a
new onboard optical sensor system. Hodoyoshi-1 will open anew chapter
in sensor design by nhancing the flexibility of sensors so that they
can address a wide range of applications and/or constraints. The
objective is to move away from overspecialized sensors that only fit
specific applications or function well under specific constraints.
Creating sensors that are optimized for reasonably high
performance in a much broader range of applications and constraints
only makes sense.

"Specifically, we aim to develop a 'flexible' sensor in terms of (1)
selectability of wavelength bands, (2)
adaptability to the required Ground Sample Distance (GSD), and (3)
optimal performance under a wide range of environmental temperatures,"
said Prof. Nakasuka.

This means that refractive optics will be in the spotlight because it
outperforms reflective optics in terms of its ability to capture a wide
field of view and do so on the basis of higher practical performance.
Refractive optics is simply more tolerant of several
types of misalignment of optical elements. In addition, lens elements
can be supported on both sides of the lens surfaces, although mirror
elements are often difficult to support in the same way due to
significant deformation of mirror surfaces.

The method of scanning in this instance involves staring via
two-dimensional CCDs as photodetectors on account of the much less
strict requirements
for a satellite’s attitude stability.

Prof. Nakasuka's discussion of the selectability of wavelength bands
and the functionality of the optics
will be omitted here. He does address the tendency of refractive optics
to defocus as the environmental temperature changes.

"In the proposed concept, we aim at overcoming this weakness by
designing athermal and apochromatic optics, whose focus position stays
extremely flat over a wide range of wavelength and temperature," said
Prof. Nakasuka. "To design athermal and apochromatic optics, first, we
have described the wavelength and the temperature dependences of
optical and structural parameters of glass materials as a mathematical model.

Second, we select glass materials with a specific power as a result of the optimization of the established model."

Prof. Nakasuka informed his audience in Berlin that the
optical design for the first sensor based on the proposed concept is
now in progress.

Hodoyoshi-2 will be a purely scientific satellite open to
researchers other nations. More than 12 proposals
have been submitted thus far from several countries.
Hodoyoshi-3, Hodoyoshi-4, and Hodoyoshi-5 will constitute a single
constellation of micro/nano-satellites An international "Mission Idea
Contest" has been recently conducted to identify appropriate and
attractive missions for this specific constellation.

In addition to seeing the Hodoyoshi project accomplish its goals,
Prof. Nakasuka looks forward to the future deployment of an earth
observation constellation consisting of more than 100 tiny satellites.

"A space science mission which requires very special technology is the
also most interesting," said Prof. Nakasuka. "More 'soft' entertainment
applications would be a new area and we expect to see some new ideas
emerging from outside of established space community."

He politely declined when asked to describe these things in greater

"I am sorry, but these special technologies are secret. We are
developing several new applications of microsatellite technology, and
the details and required technologies cannot be shared with your
readers at this time," replied Prof. Nakasuka. "What sort of
entertainment might be promising is also secret. Sorry about that. The
key point is that applications of microsat are very broad and we can
expect many new types of applications introduced by many new types of

He is eager to start testing new propulsion systems too.

"We are planning to use a small hydrogen peroxide (H2O2) propulsion
system, and we also plan to use an ion thruster which was specially
configured to be installed on a 50kg satellite" said Prof. Nakasuka.

JAXA appears to be meeting the demand for launch services required by
Japanese microsat researchers. Other launch options are available if
needed too.

"JAXA's H-IIA is providing launch services to accommodate a total of 9
micro/nano/pico satellites in Japan. The JEM module attached to the
International Space Station will be used to deploy 4 satellites next
summer," said Prof. Nakasuka. "But the number of slots are not enough
and we are negotiating in order to gain access to India's PLSV,
Russia's Dnepr and Rockot, and Ukraine's Cylone-4, to name a few."

Part 2 will examine cutting edge projects undertaken by a pair of top researchers, Prof. Kazuya Yoshida of Tohoku University and Prof. Yukihiro Takahashi of Hokkaido University.

Friday, August 12, 2011

Hypersonic Flight: HYFLEX deserves a closer look

The Falcon Hypersonic Technology Vehicle (HTV) team at the U.S. Department of
Defense must now prepare its formal analysis of the flight of the
Falcon HTV-2 on August 11. The loss of HTV-2 follows on the heels of
the HTV-1 failure last year and it will put quite a bit of pressure on
the team at a time when the U.S. is discussing enormous cutbacks
in defense spending including money for R&D.

Here is an excerpt from the DARPA release issued soon after the HTV-2 flight.

“Here’s what we know,” said Air Force Maj. Chris Schulz, DARPA HTV-2
program manager and PhD in aerospace engineering.  “We know how to
boost the aircraft to near space.  We know how to insert the aircraft
into atmospheric hypersonic flight.  We do not yet know how to achieve
the desired control during the aerodynamic phase of flight.  It’s
vexing; I’m confident there is a solution. We have to find it.”

“Prior to flight, the technical team completed the most sophisticated
simulations and extensive wind tunnel tests possible.  But these ground
tests have not yielded the necessary knowledge.  Filling the gaps in
our understanding of hypersonic flight in this demanding regime
requires that we be willing to fly,” said DARPA Director Regina Dugan.
“In the April 2010 test, we obtained four times the amount of data
previously available at these speeds.  Today more than 20 air, land,
sea and space data collection systems were operational.  We’ll learn.
We’ll try again. That’s what it takes.”

According to Schulz, three technical challenges exist within this HTV-2
flight regime.  They are categorized as aerodynamic; aerothermal; and
guidance, navigation and control.  And each phase of flight introduces
unique obstacles within these areas.
“To address these obstacles, DARPA has assembled a team of experts that
will analyze the flight data collected during today’s test flight,
expanding our technical understanding of this incredibly harsh flight
regime,” explained Schulz.  “As today’s flight indicates, high-Mach
flight in the atmosphere is virtually uncharted territory. ”

The first and only flight of Japan's Hypersonic Flight Experiment (HYFLEX)
happened in February 1996. Some readers might wonder why I elect to engage
in this exercise, injecting HYFLEX into the broader coverage of the HTV-2 testflight.
It is, they might argue, kind of like comparing apples to oranges.
I disagree because each of these experimental hypersonic flights -
albeit happening many years apart - involved hypersonic performance on
a sub-orbital trajectory.

A sustained air-launched hypersonic breakthrough has already been achieved
via the X-43 anyway. This is mentioned here as a matter of fact and not as a means
of triggering a broader discussion as to why the U.S. is so intent upon pursuing the
HTV solution in its quest for a "Prompt Global Strike" platform in the first place.

There is also no question that the entire HTV program involves more ambitious demonstrations including much longer flights and higher speeds than HYFLEX - Mach 20 vs Mach 15 - and yet HYFLEX flew over 700 miles in just over 3-1/2 minutes to its intended splashdown point.

The role of the two-stage J-1 booster in this HYFLEX deployment more
than 15 years ago in an attempt to bring the whole H-II Orbiting
Plane-Experimental (HOPE-X) concept one step closer to reality in this
instance was noteworthy in itself.

The dimensions of HYFLEX are often overlooked. It weighed just over
1000kg with a length of 4.4m along with a wingspan of 1.36m and a
height of just over 1m. This modest attempt by the then National Space
Development Agency of Japan (NASDA) along with the NAL and ISAS did
succeed. A malfunction of the flotation device for this spacecraft is
what sent HYFLEX to the bottom of the Pacific. Otherwise this
testflight was a remarkable event.

HYFLEX was all about demonstrating guidance and control technology -
something to keep in mind while DARPA ponders how it lost control of
both of its HTV's. Alteration of its flight trajectory using
aerodynamic forces took place in a relatively routine and predictable

Here in a nutshell is how the HYFLEX flight proceeded -

"The vehicle was launched from Tanegashima Space Center on a trajectory
with a maximum altitude of 110km. It was released from the launch
vehicle while traveling at a speed of approximately 3.9km/s and
performed a gliding right turn around Chichi-Jima Island in the
Ogasawara Islands group while flying at maximum Mach number of 15. It
finally splashed down in the Pacific using a parachute northeast of

See this report -

This same report highlighted the autonomous automatic flight control
system aboard HYFLEX.

"The vehicle's trajectory and attitude are regulated by guidance and
control laws programmed into an onboard computer, based on the
vehicle's attitude, position and velocity measured by an Inertial
Measurement Unit (IMU). Attitude control commands from the computer are
used to drive to the elevons and RCS. Guidance commands are computed
once per second, and control commands 20 times a second" the report
states. "Guidance that satisfies all flight limits, such as aerodynamic
heating rate and dynamic pressure, and depletes the kinetic energy
exactly at the destination, is performed on this plane. It can be seen
that guidance was performed properly in the experiment. Moreover,
HYFLEX demonstrated its ability to accurately reach a destination by
the fact that it splashed down only around 3km from the planned point."

Again this happened in early 1996. I intentionally bypass a discussion
here of the HYFLEX thermal protection system due to space limitations.
Any detailed discussion of flight data is also not included here for
the same reason. What exactly the Japanese and the French learned in 2003 after dropping a 500kg model of the Hope-X several times from balloons launched high over Sweden is unknown to me.

Wednesday, August 3, 2011

Japan elevates its space security agenda

From "DEFENSE OF JAPAN 2011" (Provisional Translation)

Part II The Basics of Japan’s Defense Policy and Build-up of Defense Capability
    Chapter 3 Toward a New Defense System

    1. Efforts for Development and Use of Space (excerpts)

    For Japan, a country which has an exclusively defense-oriented policy, the use of space, which does not
    belong to the national territory of any country and is not constrained by conditions such as surface
    topography, is extremely important for strengthening information gathering functions for detecting signs
    of various contingencies in advance, for strengthening warning and surveillance functions for use in sea
    and air zones in the neighborhood of Japan, and for ensuring means of communication in the international
    peace cooperation activities of the SDF.

    also -

    In the future, the Ministry of Defense intends to vigorously conduct examinations on specific measures, in
    coordination with related ministries, including the Cabinet Secretariat, based on the Basic Guidelines and
    the Basic Plan for Space Policy in order to promote new development and use of space in the security
    field. In FY2011, it will address projects such as 1) research for enhancement of C4ISR utilizing space, 2)
    enhance space-based communication capability, and 3) expanded use of imagery from commercial

    Section 5. New Efforts Based on Recent Trends